Extended Opacity Tables with Higher Temperature-Density-Frequency Resolution

Science.gov (United States)

Schillaci, Mark; Orban, Chris; Delahaye, Franck; Pinsonneault, Marc; Nahar, Sultana; Pradhan, Anil

2015-05-01

Theoretical models for plasma opacities underpin our understanding of radiation transport in many different astrophysical objects. These opacity models are also relevant to HEDP experiments such as ignition scale experiments on NIF. We present a significantly expanded set of opacity data from the widely utilized Opacity Project, and make these higher resolution data publicly available through OSU's portal with dropbox.com. This expanded data set is used to assess how accurate the interpolation of opacity data in temperature-density-frequency dimensions must be in order to adequately model the properties of most stellar types. These efforts are the beginning of a larger project to improve the theoretical opacity models in light of experimental results at the Sandia Z-pinch showing that the measured opacity of Iron disagrees strongly with all current models.

Relationship between wingbeat frequency and resonant frequency of the wing in insects

International Nuclear Information System (INIS)

Ha, Ngoc San; Truong, Quang Tri; Goo, Nam Seo; Park, Hoon Cheol

2013-01-01

In this study, we experimentally studied the relationship between wingbeat frequency and resonant frequency of 30 individuals of eight insect species from five orders: Odonata (Sympetrum flaveolum), Lepidoptera (Pieris rapae, Plusia gamma and Ochlodes), Hymenoptera (Xylocopa pubescens and Bombus rupestric), Hemiptera (Tibicen linnei) and Coleoptera (Allomyrina dichotoma). The wingbeat frequency of free-flying insects was measured using a high-speed camera while the natural frequency was determined using a laser displacement sensor along with a Bruel and Kjaer fast Fourier transform analyzer based on the base excitation method. The results showed that the wingbeat frequency was related to body mass (m) and forewing area (A f ), following the proportionality f ∼ m 1/2 /A f , while the natural frequency was significantly correlated with area density (f 0  ∼ m w /A f , m w is the wing mass). In addition, from the comparison of wingbeat frequency to natural frequency, the ratio between wingbeat frequency and natural frequency was found to be, in general, between 0.13 and 0.67 for the insects flapping at a lower wingbeat frequency (less than 100 Hz) and higher than 1.22 for the insects flapping at a higher wingbeat frequency (higher than 100 Hz). These results suggest that wingbeat frequency does not have a strong relation with resonance frequency: in other words, insects have not been evolved sufficiently to flap at their wings' structural resonant frequency. This contradicts the general conclusion of other reports-–that insects flap at their wings' resonant frequency to take advantage of passive deformation to save energy. (paper)

Constancy and Change in the Prevalence and Frequency of Offending When Based on Longitudinal Self-reports or Official Records: Comparisons by Gender, Race, and Crime Type

Science.gov (United States)

Farrington, David P.; Hipwell, Alison E.; Stepp, Stephanie D.; Pardini, Dustin; Ahonen, Lia

2015-01-01

Introduction The study examines age-crime prevalence and age-crime frequency curves based on longitudinal data from boys in the Pittsburgh Youth Study and girls in the Pittsburgh Girls Study. Results Results show that the prevalence of the age-crime curve for theft and violence (based on self-reports or police charges) followed the typical age-crime curve for males and slightly less distinctly for females, with the peak of offending occurring earlier for self-reports than for police charges. The decrease in police charges for violence and theft took place at an earlier age for females than males, but this was not distinct when self-reported delinquency was the criterion. The mean frequency of self-reported theft and violence followed the age-crime curve for males but not for females, who showed a mean frequency of offending which was more constant. In contrast, the mean frequency of police charges increased with age for males and females. Comparing African-American and Caucasian males and females shows a higher prevalence but not a higher mean frequency of self-reported offending. Conclusions The results are reviewed in the light of other studies, and the policy implications of the findings are discussed. PMID:27610337

Higher moments method for generalized Pareto distribution in flood frequency analysis

Science.gov (United States)

Zhou, C. R.; Chen, Y. F.; Huang, Q.; Gu, S. H.

2017-08-01

The generalized Pareto distribution (GPD) has proven to be the ideal distribution in fitting with the peak over threshold series in flood frequency analysis. Several moments-based estimators are applied to estimating the parameters of GPD. Higher linear moments (LH moments) and higher probability weighted moments (HPWM) are the linear combinations of Probability Weighted Moments (PWM). In this study, the relationship between them will be explored. A series of statistical experiments and a case study are used to compare their performances. The results show that if the same PWM are used in LH moments and HPWM methods, the parameter estimated by these two methods is unbiased. Particularly, when the same PWM are used, the PWM method (or the HPWM method when the order equals 0) shows identical results in parameter estimation with the linear Moments (L-Moments) method. Additionally, this phenomenon is significant when r ≥ 1 that the same order PWM are used in HPWM and LH moments method.

Higher Eating Frequency Does Not Decrease Appetite in Healthy Adults.

Science.gov (United States)

Perrigue, Martine M; Drewnowski, Adam; Wang, Ching-Yun; Neuhouser, Marian L

2016-01-01

Consumption of small, frequent meals is suggested as an effective approach to control appetite and food intake and might be a strategy for weight loss or healthy weight maintenance. Despite much speculation on the topic, scientific evidence is limited to support such a relation in the absence of changes to diet composition. We examined the effects of high compared with low eating frequency (EF) on self-reported appetite as a secondary outcome in a controlled trial. We conducted a randomized, crossover intervention trial in 12 participants (4 men, 8 women) who completed 2 isocaloric 3-wk intervention phases of low EF (3 eating occasions/d) compared with high EF (8 eating occasions/d). On the last morning of each study phase, participants completed a 4-h appetite testing session. During the appetite testing session, participants completing the low EF phase consumed a meal at 0800. Participants completing the high EF intervention consumed the same meal spread evenly over 2 eating occasions at 0800 and 1030. Standardized ratings of hunger, desire to eat, fullness, thirst, and nausea were completed every 30 min with the use of paper-and-pencil semianchored 100-mm visual analog scales. A composite appetite score was calculated as the mean of hunger, desire to eat, and the inverse of fullness (calculated as 100-fullness rating). Linear regression analysis compared ratings between low EF and high EF conditions. The mean composite appetite score was higher in the high EF condition for the total testing period (baseline through 1200) (P appetite. This trial was registered at clinicaltrials.gov as NCT02548026. © 2016 American Society for Nutrition.

Analysis of Higher Order Modes in Large Superconducting Radio Frequency Accelerating Structures

CERN Document Server

Galek, Tomasz; Brackebusch, Korinna; Van Rienen, Ursula

2015-01-01

Superconducting radio frequency cavities used for accelerating charged particle beams are commonly used in accelerator facilities around the world. The design and optimization of modern superconducting RF cavities requires intensive numerical simulations. Vast number of operational parameters must be calculated to ensure appropriate functioning of the accelerating structures. In this study, we primarily focus on estimation and behavior of higher order modes in superconducting RF cavities connected in chains. To calculate large RF models the state-space concatenation scheme, an efficient hybrid method, is employed.

The Influence of Higher Protein Intake and Greater Eating Frequency on Appetite Control in Overweight and Obese Men

Science.gov (United States)

Leidy, Heather J.; Armstrong, Cheryl L.H.; Tang, Minghua; Mattes, Richard D.; Campbell, Wayne W.

2014-01-01

The purpose of this study was to determine the effects of dietary protein intake and eating frequency on perceived appetite, satiety, and hormonal responses in overweight/obese men. Thirteen men (age 51 ± 4 years; BMI 31.3 ± 0.8 kg/m2) consumed eucaloric diets containing normal protein (79 ± 2 g protein/day; 14% of energy intake as protein) or higher protein (138 ± 3 g protein/day; 25% of energy intake as protein) equally divided among three eating occasions (3-EO; every 4 h) or six eating occasions (6-EO; every 2 h) on four separate days in randomized order. Hunger, fullness, plasma glucose, and hormonal responses were assessed throughout 11 h. No protein × eating frequency interactions were observed for any of the outcomes. Independent of eating frequency, higher protein led to greater daily fullness (P < 0.05) and peptide YY (PYY) concentrations (P < 0.05). In contrast, higher protein led to greater daily ghrelin concentrations (P < 0.05) vs. normal protein. Protein quantity did not influence daily hunger, glucose, or insulin concentrations. Independent of dietary protein, 6-EO led to lower daily fullness (P < 0.05) and PYY concentrations (P < 0.05). The 6-EO also led to lower glucose (P < 0.05) and insulin concentrations (P < 0.05) vs. 3-EO. Although the hunger-related perceived sensations and hormonal responses were conflicting, the fullness-related responses were consistently greater with higher protein intake but lower with increased eating frequency. Collectively, these data suggest that higher protein intake promotes satiety and challenge the concept that increasing the number of eating occasions enhances satiety in overweight and obese men. PMID:20339363

Vibro-Shock Dynamics Analysis of a Tandem Low Frequency Resonator—High Frequency Piezoelectric Energy Harvester

Directory of Open Access Journals (Sweden)

Darius Žižys

2017-04-01

Full Text Available Frequency up-conversion is a promising technique for energy harvesting in low frequency environments. In this approach, abundantly available environmental motion energy is absorbed by a Low Frequency Resonator (LFR which transfers it to a high frequency Piezoelectric Vibration Energy Harvester (PVEH via impact or magnetic coupling. As a result, a decaying alternating output signal is produced, that can later be collected using a battery or be transferred directly to the electric load. The paper reports an impact-coupled frequency up-converting tandem setup with different LFR to PVEH natural frequency ratios and varying contact point location along the length of the harvester. RMS power output of different frequency up-converting tandems with optimal resistive values was found from the transient analysis revealing a strong relation between power output and LFR-PVEH natural frequency ratio as well as impact point location. Simulations revealed that higher power output is obtained from a higher natural frequency ratio between LFR and PVEH, an increase of power output by one order of magnitude for a doubled natural frequency ratio and up to 150% difference in power output from different impact point locations. The theoretical results were experimentally verified.

Forest cover, socioeconomics, and reported flood frequency in developing countries

Science.gov (United States)

Ferreira, Susana; Ghimire, Ramesh

2012-08-01

In this paper, we analyze the determinants of the number of large floods reported since 1990. Using the same sample of countries as Bradshaw et al. (2007), and, like them, omitting socioeconomic characteristics from the analysis, we found that a reduction in natural forest cover is associated with an increase in the reported count of large floods. This result does not hold in any of three new analyses we perform. First, we expand the sample to include all the developing countries and all countries for which data were available but were omitted in their study. Second, and more importantly, since forest management is just one possible channel through which humans can influence reported flood frequency, we account for other important human-flood interactions. People are typically responsible for deforestation, but they are also responsible for other land use changes (e.g., urbanization), for floodplain and flood emergency management, and for reporting the floods. Thus, in our analysis we account for population, urban population growth, income, and corruption. Third, we exploit the panel nature of the data to control for unobserved country and time heterogeneity. We conclude that not only is the link between forest cover and reported flood frequency at the country level not robust, it also seems to be driven by sample selection and omitted variable bias. The human impact on the reported frequency of large floods at the country level is not through deforestation.

Board meeting frequency and corporate social responsibility (CSR reporting: Evidence from Malaysia

Directory of Open Access Journals (Sweden)

Nurulyasmin Binti Ju Ahmad

2017-05-01

Full Text Available This study aims at determining the effectiveness of board meeting frequency on Corporate Social Responsibility (CSR reporting by public listed companies on the Main Market of Bursa Malaysia. A CSR reporting index consisting of 51 items was developed based on six themes: General, Community, Environment, Human Resource, Marketplace and Other. A content analysis was used to determine the extent of CSR reporting. An Ordinary Least Square (OLS regression was employed in determining the association between board meeting frequency and CSR reporting. The finding of the study is that advising tendency (frequency of board meetings is not associated with CSR reporting. Overall this study strengthens the idea that advising tendency of the board is essential to companies in order to safeguard all stakeholders’ interests. Accordingly, regulators and policymakers should be more stringent in monitoring company’s conformance towards regulations. This study provides a new avenue of knowledge and contributes to the literature on the practices of the board of directors and corporate social responsibility reporting in the context of a semi-developed country

Frequency of reporting and predictive factors for anxiety and depression in patients with advanced cancer.

Science.gov (United States)

Salvo, N; Zeng, L; Zhang, L; Leung, M; Khan, L; Presutti, R; Nguyen, J; Holden, L; Culleton, S; Chow, E

2012-03-01

The prevalence of anxiety and depression in patients with advanced cancer has been reported to be on average 25% and to significantly affect patients' quality of life. Despite high prevalence rates, these disorders remain underdiagnosed and undertreated. The purpose of our study was to examine the self-report rates of anxiety and depression with the Edmonton Symptom Assessment System (ESAS) and to assess the predictive factors for these reports in cancer patients with metastatic disease. Consecutive patients who attended the Rapid Response Radiotherapy Program (RRRP) completed the ESAS as well as baseline demographic information. Ordinal logistic regression analysis was used to determine factors that significantly predicted anxiety and/or depression. Pearson χ(2) was used to test goodness-of-fit for categorical variables and established whether or not an observed frequency distribution differed from a predicted frequency distribution. A univariate analysis was conducted first and those variables with a P valueanalysis. A score test was used to test the proportional odds assumption. In total, 1439 patients seen in the RRRP between January 1999 and October 2009 completed ESAS questionnaires. Fifty-five per cent of patients reported at least mild symptoms of depression and 65% reported at least mild anxiety. In the univariate analysis, patients who were female, who had a lower performance status score, or primary lung cancer were more likely to report depressed and anxious feelings. Primary prostate cancer patients were significantly less likely to report depression and anxiety. Patients referred for spinal cord compression were significantly less depressed. The multivariate models showed that younger patients were significantly more anxious than older patients and females reported more anxiety than males. Patients who reported higher feelings of nausea, tiredness, drowsiness, dyspnoea, and worse appetite and overall well-being on the ESAS tool were more likely to

Differences between food group reports of low energy reporters and non-low energy reporters on a food frequency questionnaire

Science.gov (United States)

Millen, Amy E.; Tooze, Janet A.; Subar, Amy F.; Kahle, Lisa L.; Schatzkin, Arthur; Krebs-Smith, Susan M.

2013-01-01

Background Low-energy reporters (LERs) and non-LERs differ with respect to a number of characteristics, including self-reported intake of foods. Limited data exists investigating food intake differences with LERs identified using doubly labeled water (DLW). Objective In the Observing Protein and Energy Nutrition Study (September, 1999-March, 2000), differences were examined between food group reports of LERs and non-LERs on a food frequency questionnaire (FFQ) (n=440). Design LERs were identified using DLW. LERs' (n=220) and non-LERs' (n=220) reports of 43 food groups on the FFQ were examined in three ways: whether they reported consuming a food group (yes/no), how frequently they reported consuming it (times/day), and the reported portion size (small, medium, or large). Analyses were adjusted for total energy expenditure from DLW. Results LERs compared to non-LERs were less likely to report consumption for one food group among women (soft drinks/regular) and no food groups among men. Reported mean daily frequency of consumption was lower in LERs compared to non-LERs for 23 food groups among women and 24 food groups among men (18 food groups were similar in men and women). Additionally, reported mean portion sizes were smaller for LERs compared to non-LERs for 6 food groups among women and 5 food groups among men (3 food groups were similar in men and women). Results varied minimally by sex and body mass index (BMI). Conclusions LERs as compared to non-LERs were more likely to differ regarding their reported frequency of consumption of food groups than their reported consumption (yes/no) of the food groups or the food groups' reported portion sizes. Results did not vary greatly by sex or BMI. It still remains to be known whether improvement in questionnaire design or additional tools or methods would lead to a decrease in differential reporting due to LER status on an FFQ. PMID:19559136

Radio frequency superconductivity at CERN: a status report

International Nuclear Information System (INIS)

Arnolds-Mayer, G.; Benvenuti, C.; Bernard, P.

1988-01-01

Up to 1984 the efforts in superconducting (s.c.) cavity development at CERN were mainly concentrated on 500 MHz cavities, leading to the test of a 5-cell, 500 MHz cavity at PETRA. The results confirmed that the achievable accelerating fields do not decrease at lower frequencies as strongly as previously suspected. Therefore, it was decided in 1984 to concentrate efforts on 352 MHz cavities. This frequency choice is suggested by the fact that LEP will be equipped at the beginning with 128 Cu cavities at 352 MHz which will bring up energies to 55 GeV/beam [5]. There is an obvious interest to install at a later stage s.c. cavities with the same frequency and to use at maximum the existing installation of radio frequency (r.f.) power sources. With the installed r.f. power of 16 MW, LEP could be upgraded to ∼ 90 GeV by using s.c. cavities. This will require the construction, testing and installation of several hundred of s.c. cavities, therefore arguments of economy and reliability are of outstanding importance. The LEP program asks for many additional items and substantial work has gone into the development, construction and testing of cryostats, main couplers, Higher-Order Mode (HOM) couplers and frequency tuners. Besides the main line based on Nb-cavities another development has been pursued and that is the deposition of a thin niobium layer on copper cavities. Results look very promising but more efforts will be needed to reach the same level of know-how as for Nb cavities. 34 references, 7 figures, 2 tables

Higher Eating Frequency Does Not Decrease Appetite in Healthy Adults12

Science.gov (United States)

Perrigue, Martine M; Drewnowski, Adam; Wang, Ching-Yun; Neuhouser, Marian L

2016-01-01

Background: Consumption of small, frequent meals is suggested as an effective approach to control appetite and food intake and might be a strategy for weight loss or healthy weight maintenance. Despite much speculation on the topic, scientific evidence is limited to support such a relation in the absence of changes to diet composition. Objective: We examined the effects of high compared with low eating frequency (EF) on self-reported appetite as a secondary outcome in a controlled trial. Methods: We conducted a randomized, crossover intervention trial in 12 participants (4 men, 8 women) who completed 2 isocaloric 3-wk intervention phases of low EF (3 eating occasions/d) compared with high EF (8 eating occasions/d). On the last morning of each study phase, participants completed a 4-h appetite testing session. During the appetite testing session, participants completing the low EF phase consumed a meal at 0800. Participants completing the high EF intervention consumed the same meal spread evenly over 2 eating occasions at 0800 and 1030. Standardized ratings of hunger, desire to eat, fullness, thirst, and nausea were completed every 30 min with the use of paper-and-pencil semianchored 100-mm visual analog scales. A composite appetite score was calculated as the mean of hunger, desire to eat, and the inverse of fullness (calculated as 100-fullness rating). Linear regression analysis compared ratings between low EF and high EF conditions. Results: The mean composite appetite score was higher in the high EF condition for the total testing period (baseline through 1200) (P appetite. This trial was registered at clinicaltrials.gov as NCT02548026. PMID:26561409

Under-reporting of alcohol consumption in household surveys: a comparison of quantity-frequency, graduated-frequency and recent recall.

Science.gov (United States)

Stockwell, Tim; Donath, Susan; Cooper-Stanbury, Mark; Chikritzhs, Tanya; Catalano, Paul; Mateo, Cid

2004-08-01

To compare alternative survey methods for estimating (a) levels of at risk alcohol consumption and (b) total volume of alcohol consumed per capita in comparison with estimates from sales data and to investigate reasons for under-reporting. The homes of respondents who were eligible and willing to participate. A total of 21,674 Australians aged 14 years and older. A 2001 national household survey of drug use, experiences and attitudes with weights applied for age, sex, geographic location and day of week of interview. Self-completion questionnaire using quantity-frequency (QF) and graduated-frequency (GF) methods plus two questions about consumption 'yesterday': one in standard drinks, another with empirically based estimates of drink size and strength. The highest estimate of age 14 + per capita consumption of 7.00 l of alcohol derived from recall of consumption 'yesterday' or 76.8% of the official estimate. The lowest was QF with 49.8%. When amount consumed 'yesterday' was recalled in standard drinks this estimate was 5.27 l. GF questions yielded higher estimates than did QF questions both for total volume (5.25 versus 4.54 l) and also for the proportion of the population at risk of long-term alcohol-related harm (10.6%versus 8.1%). With the detailed 'yesterday' method 61% of all consumption was on high risk drinking days. Questions about typical quantities of alcohol consumed can lead to underestimates, as do questions about drinking 'standard drinks' of alcohol. Recent recall methods encourage fuller reporting of volumes plus more accurate estimates of unrecorded consumption and the proportion of total alcohol consumption that places drinkers at risk of harm. However, they do not capture longer-term drinking patterns. It is recommended that both recent recall and measures of longer-term drinking patterns are included in national surveys.

Statistics Report on TEQSA Registered Higher Education Providers

Science.gov (United States)

Australian Government Tertiary Education Quality and Standards Agency, 2015

2015-01-01

This statistics report provides a comprehensive snapshot of national statistics on all parts of the sector for the year 2013, by bringing together data collected directly by TEQSA with data sourced from the main higher education statistics collections managed by the Australian Government Department of Education and Training. The report provides…

Higher order mode damping in Kaon factory RF cavities

International Nuclear Information System (INIS)

Enegren, T.; Poirier, R.; Griffin, J.; Walling, L.; Thiessen, H.A.; Smythe, W.R.

1989-05-01

Proposed designs for Kaon factory accelerators require that the rf cavities support beam currents on the order of several amperes. The beam current has Fourier components at all multiples of the rf frequency. Empty rf buckets produce additional components at all multiples of the revolution frequency. If a Fourier component of the beam coincides with the resonant frequency of a higher order mode of the cavity, which is inevitable if the cavity has a large frequency swing, significant excitation of this mode can occur. The induced voltage may then excite coupled bunch mode instabilities. Effective means are required to damp higher order modes without significantly affecting the fundamental mode. A mode damping scheme based on coupled transmission lines has been investigated and is report

Piping system damping data at higher frequencies

International Nuclear Information System (INIS)

Ware, A.G.

1987-01-01

Research has been performed at the Idaho National Engineering Laboratory (INEL) for the United States Nuclear Regulatory Commission (USNRC) to determine best-estimate damping values for dynamic analyses of nuclear piping systems excited in the 20 to 100 Hz frequency range. Vibrations in this frequency range are typical of fluid-induced transients, for which no formal pipe damping guidelines exist. The available data found in the open literature and the USNRC/INEL nuclear piping damping data bank were reviewed, and a series of tests on a straight 3-in. (76-mm) piping system and a 5-in. (127-mm) system with several bends and elbows were conducted as part of this research program. These two systems were supported with typical nuclear piping supports that could be changed from test to test during the series. The resulting damping values were ≥ those of the Pressure Vessel Research Committee (PVRC) proposal for unisulated piping. Extending the PVRC damping curve from 20 to 100 Hz at 3% of critical damping would give a satisfactory representation of the test data. This position has been endorsed by the PVRC Technical Committee on Piping Systems. 14 refs

Calibration of higher eigenmodes of cantilevers

International Nuclear Information System (INIS)

Labuda, Aleksander; Kocun, Marta; Walsh, Tim; Meinhold, Jieh; Proksch, Tania; Meinhold, Waiman; Anderson, Caleb; Proksch, Roger; Lysy, Martin

2016-01-01

A method is presented for calibrating the higher eigenmodes (resonant modes) of atomic force microscopy cantilevers that can be performed prior to any tip-sample interaction. The method leverages recent efforts in accurately calibrating the first eigenmode by providing the higher-mode stiffness as a ratio to the first mode stiffness. A one-time calibration routine must be performed for every cantilever type to determine a power-law relationship between stiffness and frequency, which is then stored for future use on similar cantilevers. Then, future calibrations only require a measurement of the ratio of resonant frequencies and the stiffness of the first mode. This method is verified through stiffness measurements using three independent approaches: interferometric measurement, AC approach-curve calibration, and finite element analysis simulation. Power-law values for calibrating higher-mode stiffnesses are reported for several cantilever models. Once the higher-mode stiffnesses are known, the amplitude of each mode can also be calibrated from the thermal spectrum by application of the equipartition theorem.

Calibration of higher eigenmodes of cantilevers

Energy Technology Data Exchange (ETDEWEB)

Labuda, Aleksander; Kocun, Marta; Walsh, Tim; Meinhold, Jieh; Proksch, Tania; Meinhold, Waiman; Anderson, Caleb; Proksch, Roger [Asylum Research, an Oxford Instruments Company, Santa Barbara, California 93117 (United States); Lysy, Martin [Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2016-07-15

A method is presented for calibrating the higher eigenmodes (resonant modes) of atomic force microscopy cantilevers that can be performed prior to any tip-sample interaction. The method leverages recent efforts in accurately calibrating the first eigenmode by providing the higher-mode stiffness as a ratio to the first mode stiffness. A one-time calibration routine must be performed for every cantilever type to determine a power-law relationship between stiffness and frequency, which is then stored for future use on similar cantilevers. Then, future calibrations only require a measurement of the ratio of resonant frequencies and the stiffness of the first mode. This method is verified through stiffness measurements using three independent approaches: interferometric measurement, AC approach-curve calibration, and finite element analysis simulation. Power-law values for calibrating higher-mode stiffnesses are reported for several cantilever models. Once the higher-mode stiffnesses are known, the amplitude of each mode can also be calibrated from the thermal spectrum by application of the equipartition theorem.

Low frequency geomagnetic field fluctuations at low latitude during the passage of a higher pressure solar wind region

Directory of Open Access Journals (Sweden)

U. Villante

1997-06-01

Full Text Available The passage of a higher pressure solar wind region at the Earth's orbit marked the onset of low latitude (L=1.6 fluctuations in the frequency range (0.8–5.5 mHz for both the horizontal geomagnetic field components. Spectral peaks mostly occur at the same frequencies as the spectral enhancements which appeared in the long term analysis of experimental measurements from the same station and were tentatively interpreted in terms of ground signatures of global magnetospheric modes. A comparison with simultaneous observations discussed by previous investigations allows us to conclude that the same set of frequencies is enhanced in a wide portion of the Earth's magnetosphere.

Participant characteristics associated with errors in self-reported energy intake from the Women's Health Initiative food-frequency questionnaire.

Science.gov (United States)

Horner, Neilann K; Patterson, Ruth E; Neuhouser, Marian L; Lampe, Johanna W; Beresford, Shirley A; Prentice, Ross L

2002-10-01

Errors in self-reported dietary intake threaten inferences from studies relying on instruments such as food-frequency questionnaires (FFQs), food records, and food recalls. The objective was to quantify the magnitude, direction, and predictors of errors associated with energy intakes estimated from the Women's Health Initiative FFQ. Postmenopausal women (n = 102) provided data on sociodemographic and psychosocial characteristics that relate to errors in self-reported energy intake. Energy intake was objectively estimated as total energy expenditure, physical activity expenditure, and the thermic effect of food (10% addition to other components of total energy expenditure). Participants underreported energy intake on the FFQ by 20.8%; this error trended upward with younger age (P = 0.07) and social desirability (P = 0.09) but was not associated with body mass index (P = 0.95). The correlation coefficient between reported energy intake and total energy expenditure was 0.24; correlations were higher among women with less education, higher body mass index, and greater fat-free mass, social desirability, and dissatisfaction with perceived body size (all P diet and disease association studies.

Eating frequency is higher in weight loss maintainers and normal-weight individuals than in overweight individuals.

Science.gov (United States)

Bachman, Jessica L; Phelan, Suzanne; Wing, Rena R; Raynor, Hollie A

2011-11-01

Eating frequency has been negatively related to body mass index (BMI). The relationship between eating frequency and weight loss maintenance is unknown. This secondary analysis examined eating frequency (self-reported meals and snacks consumed per day) in weight loss maintainers (WLM) who had reduced from overweight/obese to normal weight, normal weight (NW) individuals, and overweight (OW) individuals. Data collected July 2006 to March 2007 in Providence, RI, included three 24-hour dietary recalls (2 weekdays, 1 weekend day) analyzed using Nutrient Data System for Research software from 257 adults (WLM n=96, 83.3% women aged 50.0±11.8 years with BMI 22.1±1.7; NW n=80, 95.0% women aged 46.1±11.5 years with BMI 21.1±1.4; OW n=81, 53.1% women aged 51.4±9.0 years with BMI 34.2±4.1) with plausible intakes. Participant-defined meals and snacks were ≥50 kcal and separated by more than 1 hour. Self-reported physical activity was highest in WLM followed by NW, and then OW (3,097±2,572 kcal/week, 2,062±1,286 kcal/week, and 785±901 kcal/week, respectively; Pmeals consumed (2.7±0.4 meals/day). Eating frequency, particularly in regard to a pattern of three meals and two snacks per day, may be important in weight loss maintenance. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

Effect of high-frequency excitation on natural frequencies of spinning discs

DEFF Research Database (Denmark)

Hansen, Morten Hartvig

2000-01-01

The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural frequenc......The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural...

Utah System of Higher Education 2015-16 Annual Report

Science.gov (United States)

Utah System of Higher Education, 2016

2016-01-01

This annual report describes Utah System of Higher Education's progress in the 2015-2016 academic year in the following areas: (1) Strategic plan; (2) Enrollment and completion; (3) Paying for college; (4) Funding higher education; (5) College preparation; (6) Concurrent enrollment and math; (7) Outreach and access; and (8) Industry and the…

Smoking, leisure-time exercise and frequency of self-reported common cold among the general population in northeastern China: a cross-sectional study.

Science.gov (United States)

Zhou, Ge; Liu, Hongjian; He, Minfu; Yue, Mengjia; Gong, Ping; Wu, Fangyuan; Li, Xuanxuan; Pang, Yingxin; Yang, Xiaodi; Ma, Juan; Liu, Meitian; Li, Jinghua; Zhang, Xiumin

2018-02-27

Physical activity (PA) and smoking have been reported to be associated with the duration and severity of common cold symptoms. However, few studies have addressed the associations between the frequency of leisure-time exercise, cigarette smoking status and the frequency of the common cold in a cold area. This study was designed to investigate these issues in northeastern China. This cross-sectional study included individuals who participated in a regular health examination conducted in Jilin Province, China. Information on episodes of the common cold, the frequency of leisure-time exercise and cigarette smoking status in the past year were collected by self-administered health questionnaires. Ordinal logistic regression models were used to analyse the associations between the frequency of leisure-time exercise, cigarette smoking status and the retrospective frequency of common cold. A total of 1413 employees participated in the study, with an average age of 38.92 ± 9.04 years and 44.4% of them were male. Of all participants, 80.8% reported having experienced the common cold in the past year. After adjustment, the risk of suffering from the common cold more than once (odds ratios (ORs), 1.59; 95% confidence interval (CI), 1.27-1.99) in passive smokers was 1.59 times as high as that in non-smokers. Nevertheless, the results of the adjusted analysis showed no statistically significant relation between current smoking and the frequency of the common cold. A high frequency of leisure-time exercise (≥3 days/week) was associated with a 26% reduced risk of having at least one episode of the common cold (OR, 0.74; 95% CI, 0.55-0.98) compared with a low frequency group (exercise appears not to be obvious (current smokers: OR, 0.68; 95% CI, 0.33-1.43; passive smokers: OR, 1.15; 95% CI, 0.69-1.93). Passive smoking was associated with a higher risk of having self-reported common cold at least once, while a high frequency of leisure-time exercise was related to a lower

Sinusoidal oscillators with lower gain requirements at higher frequencies based on an explicit tanh(x) nonlinearity

KAUST Repository

Elwakil, Ahmed S.

2009-04-28

Two novel sinusoidal oscillator structures with an explicit tanh(x) nonlinearity are proposed. The oscillators have the attractive feature: the higher the operating frequency, the lower the necessary gain required to start oscillations. A nonlinear model for the two oscillators is derived and verified numerically. Spice simulations using AMS BiCMOS 0.35 μ model parameters and experimental results are shown. Copyright © 2009 John Wiley & Sons, Ltd.

Associations between communication climate and the frequency of medical error reporting among pharmacists within an inpatient setting.

Science.gov (United States)

Patterson, Mark E; Pace, Heather A; Fincham, Jack E

2013-09-01

Although error-reporting systems enable hospitals to accurately track safety climate through the identification of adverse events, these systems may be underused within a work climate of poor communication. The objective of this analysis is to identify the extent to which perceived communication climate among hospital pharmacists impacts medical error reporting rates. This cross-sectional study used survey responses from more than 5000 pharmacists responding to the 2010 Hospital Survey on Patient Safety Culture (HSOPSC). Two composite scores were constructed for "communication openness" and "feedback and about error," respectively. Error reporting frequency was defined from the survey question, "In the past 12 months, how many event reports have you filled out and submitted?" Multivariable logistic regressions were used to estimate the likelihood of medical error reporting conditional upon communication openness or feedback levels, controlling for pharmacist years of experience, hospital geographic region, and ownership status. Pharmacists with higher communication openness scores compared with lower scores were 40% more likely to have filed or submitted a medical error report in the past 12 months (OR, 1.4; 95% CI, 1.1-1.7; P = 0.004). In contrast, pharmacists with higher communication feedback scores were not any more likely than those with lower scores to have filed or submitted a medical report in the past 12 months (OR, 1.0; 95% CI, 0.8-1.3; P = 0.97). Hospital work climates that encourage pharmacists to freely communicate about problems related to patient safety is conducive to medical error reporting. The presence of feedback infrastructures about error may not be sufficient to induce error-reporting behavior.

Increased Eating Frequency Is Associated with Lower Obesity Risk, But Higher Energy Intake in Adults: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Yue-Qiao Wang

2016-06-01

Full Text Available Body weight is regulated by energy intake which occurs several times a day in humans. In this meta-analysis, we evaluated whether eating frequency (EF is associated with obesity risk and energy intake in adults without any dietary restriction. Experimental and observational studies published before July 2015 were selected through English-language literature searches in several databases. These studies reported the association between EF and obesity risk (odd ratios, ORs in adults who were not in dietary restriction. R software was used to perform statistical analyses. Ten cross-sectional studies, consisting of 65,742 participants, were included in this analysis. ORs were considered as effect size for the analysis about the effect of EF on obesity risk. Results showed that the increase of EF was associated with 0.83 time lower odds of obesity (i.e., OR = 0.83, 95% confidence intervals (CI 0.70–0.99, p = 0.040. Analysis about the effect of EF on differences in participants’ energy intake revealed that increased EF was associated with higher energy intake (β = 125.36, 95% CI 21.76–228.97, p = 0.017. We conclude that increased EF may lead to lower obesity risk but higher energy intake. Clinical trials are warranted to confirm these results and to assess the clinical practice applicability.

Bimodal atomic force microscopy driving the higher eigenmode in frequency-modulation mode: Implementation, advantages, disadvantages and comparison to the open-loop case.

Science.gov (United States)

Ebeling, Daniel; Solares, Santiago D

2013-01-01

We present an overview of the bimodal amplitude-frequency-modulation (AM-FM) imaging mode of atomic force microscopy (AFM), whereby the fundamental eigenmode is driven by using the amplitude-modulation technique (AM-AFM) while a higher eigenmode is driven by using either the constant-excitation or the constant-amplitude variant of the frequency-modulation (FM-AFM) technique. We also offer a comparison to the original bimodal AFM method, in which the higher eigenmode is driven with constant frequency and constant excitation amplitude. General as well as particular characteristics of the different driving schemes are highlighted from theoretical and experimental points of view, revealing the advantages and disadvantages of each. This study provides information and guidelines that can be useful in selecting the most appropriate operation mode to characterize different samples in the most efficient and reliable way.

Occupational blood exposure among health care workers: I. Frequency and reporting

DEFF Research Database (Denmark)

Nelsing, S; Nielsen, T L; Nielsen, Jens Ole

1993-01-01

The frequency and reporting rate concerning occupational blood exposure were investigated among former and currently employed medical staff at a Department of Infectious Diseases (DID) having a high prevalence of HIV-positive patients. Subjects were asked to complete an anonymous questionnaire de...

Reducing barriers to energy efficiency in the German higher education sector. Final report

Energy Technology Data Exchange (ETDEWEB)

Schleich, J.; Boede, U.

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German higher education (HE) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of six case studies of energy management in German universities. The results are analysed using the theoretical framework developed for the BARRIERS project (Sorrell et al., 2000). The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the sector may be improved. The results of the study for the higher education sector in Germany are summarised in this executive summary under the following headings: - Characterising the higher education sector; - Case studies of energy management in the German higher education sector; - Evidence of barriers in the German higher education sector; - The role of energy service companies in the higher education sector; - Policy implications. (orig.)

Evaluation of the Problem Behavior Frequency Scale-Teacher Report Form for Assessing Behavior in a Sample of Urban Adolescents.

Science.gov (United States)

Farrell, Albert D; Goncy, Elizabeth A; Sullivan, Terri N; Thompson, Erin L

2018-02-01

This study evaluated the structure and validity of the Problem Behavior Frequency Scale-Teacher Report Form (PBFS-TR) for assessing students' frequency of specific forms of aggression and victimization, and positive behavior. Analyses were conducted on two waves of data from 727 students from two urban middle schools (Sample 1) who were rated by their teachers on the PBFS-TR and the Social Skills Improvement System (SSIS), and on data collected from 1,740 students from three urban middle schools (Sample 2) for whom data on both the teacher and student report version of the PBFS were obtained. Confirmatory factor analyses supported first-order factors representing 3 forms of aggression (physical, verbal, and relational), 3 forms of victimization (physical, verbal and relational), and 2 forms of positive behavior (prosocial behavior and effective nonviolent behavior), and higher-order factors representing aggression, victimization, and positive behavior. Strong measurement invariance was established over gender, grade, intervention condition, and time. Support for convergent validity was found based on correlations between corresponding scales on the PBFS-TR and teacher ratings on the SSIS in Sample 1. Significant correlations were also found between teacher ratings on the PBFS-TR and student ratings of their behavior on the Problem Behavior Frequency Scale-Adolescent Report (PBFS-AR) and a measure of nonviolent behavioral intentions in Sample 2. Overall the findings provided support for the PBFS-TR and suggested that teachers can provide useful data on students' aggressive and prosocial behavior and victimization experiences within the school setting. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Flood-frequency characteristics of Wisconsin streams

Science.gov (United States)

Walker, John F.; Peppler, Marie C.; Danz, Mari E.; Hubbard, Laura E.

2017-05-22

Flood-frequency characteristics for 360 gaged sites on unregulated rural streams in Wisconsin are presented for percent annual exceedance probabilities ranging from 0.2 to 50 using a statewide skewness map developed for this report. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of the equations presented in this report. The State was divided into eight areas of similar physiographic characteristics. The most significant basin characteristics are drainage area, soil saturated hydraulic conductivity, main-channel slope, and several land-use variables. The standard error of prediction for the equation for the 1-percent annual exceedance probability flood ranges from 56 to 70 percent for Wisconsin Streams; these values are larger than results presented in previous reports. The increase in the standard error of prediction is likely due to increased variability of the annual-peak discharges, resulting in increased variability in the magnitude of flood peaks at higher frequencies. For each of the unregulated rural streamflow-gaging stations, a weighted estimate based on the at-site log Pearson type III analysis and the multiple regression results was determined. The weighted estimate generally has a lower uncertainty than either the Log Pearson type III or multiple regression estimates. For regulated streams, a graphical method for estimating flood-frequency characteristics was developed from the relations of discharge and drainage area for selected annual exceedance probabilities. Graphs for the major regulated streams in Wisconsin are presented in the report.

Extending the ICRF to Higher Radio Frequencies: 24 and 43 GHz Astrometry

Science.gov (United States)

Jacobs, Christopher S.; Charlot, Patrick; Fomalont, Ed B.; Gordon, David; Lanyi, Gabor E.; Ma, Chopo; Naudet, Charles J.; Sovers, Ojars J.; Zhang, Liwei D.; Kq VLBI Survey Collaboration

2004-06-01

Celestial reference frames have been constructed at K-band (24 GHz) and Q-band (43 GHz) based on VLBI astrometric survey observations of active galactic nuclei. Five VLBA observing sessions covered the full 24 hours of right ascension and declinations down to -44°. K-band's 230 sources have median formal position uncertainties of 150 and 290 μas in α cos δ and δ, respectively; the corresponding uncertainties for 132 Q-band sources are 215 and 360 μas, respectively. K-band weighted RMS (WRMS) residuals were 33 ps and 48 fs/s in delay and rate, respectively. Comparison of the K-band frame to the S/X-band ICRF shows WRMS agreement of 330 and 590 μas in α cos δ and δ, respectively. The motivations for extending the ICRF to higher frequencies are to use more compact sources to construct a more stable frame, to provide phase calibrators, and to support spacecraft navigation at Ka-band.

The frequency of diagnostic errors in radiologic reports depends on the patient's age

International Nuclear Information System (INIS)

Diaz, Sandra; Ekberg, Olle

2010-01-01

Background: Patients who undergo treatment may suffer preventable medical errors. Some of these errors are due to diagnostic imaging procedures. Purpose: To compare the frequency of diagnostic errors in different age groups in an urban European population. Material and Methods: A total of 19 129 reported radiologic examinations were included. During a 6-month period, the analyzed age groups were: children (aged 0-9 years), adults (40-49 years), and elderly (86-95 years). Results: The frequency of radiologic examinations per year was 0.3 in children, 0.6 in adults, and 1.1 in elderly. Significant errors were significantly more frequent in the elderly (1.7%) and children (1.4%) compared with adults (0.8%). There were 60 false-positive reports and 232 false-negative reports. Most errors were made by staff radiologists after hours when they reported on examinations outside their area of expertise. Conclusion: Diagnostic errors are more frequent in children and the elderly compared with middle-aged adults

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

Science.gov (United States)

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.

Black American College Students Report Higher Memory of Love for Mothers in Childhood Than White Students.

Science.gov (United States)

Patihis, Lawrence; Jackson, Corai E; Diaz, Jonathan C; Stepanova, Elena V; Herrera, Mario E

2018-01-01

Cultural differences between Black and White individuals in the South are connected to the inequitable history of the United States. We wondered if these cultural differences would translate to a particularly precious aspect of life: memories of love felt in childhood toward one's parents. Some past studies have shown that Whites score higher on parental attachment measures to parents than Blacks, while other studies show no significant differences. However, no previous study has ever measured memory of feelings of love in relation to differences between ethnicities. In this study, Black ( n = 124) and White ( n = 125) undergraduates self-reported the strength and frequency of their past feelings of love toward their mother and father in first, sixth, and ninth grade as well as their current feelings of love. Results suggested that Black students reported feeling more love for their mothers in first, sixth, and ninth grades compared to White students. These findings were not explained when we statistically adjusted for age, gender, socioeconomic status, education levels, income, number of years spent living with mother or father, stress, or personality. Therefore, this relationship may be explained by unmeasured or unmeasurable cultural differences. The direction of this effect was in the opposite direction from what we expected based on past attachment research. Given the inequities in U.S. history and the current discussions around ethnicity and race in the United States, the finding that Blacks reported higher remembered feelings of love for their mothers in childhood is intriguing and worthy of dissemination and discussion.

Frequency and analysis of non-clinical errors made in radiology reports using the National Integrated Medical Imaging System voice recognition dictation software.

Science.gov (United States)

Motyer, R E; Liddy, S; Torreggiani, W C; Buckley, O

2016-11-01

Voice recognition (VR) dictation of radiology reports has become the mainstay of reporting in many institutions worldwide. Despite benefit, such software is not without limitations, and transcription errors have been widely reported. Evaluate the frequency and nature of non-clinical transcription error using VR dictation software. Retrospective audit of 378 finalised radiology reports. Errors were counted and categorised by significance, error type and sub-type. Data regarding imaging modality, report length and dictation time was collected. 67 (17.72 %) reports contained ≥1 errors, with 7 (1.85 %) containing 'significant' and 9 (2.38 %) containing 'very significant' errors. A total of 90 errors were identified from the 378 reports analysed, with 74 (82.22 %) classified as 'insignificant', 7 (7.78 %) as 'significant', 9 (10 %) as 'very significant'. 68 (75.56 %) errors were 'spelling and grammar', 20 (22.22 %) 'missense' and 2 (2.22 %) 'nonsense'. 'Punctuation' error was most common sub-type, accounting for 27 errors (30 %). Complex imaging modalities had higher error rates per report and sentence. Computed tomography contained 0.040 errors per sentence compared to plain film with 0.030. Longer reports had a higher error rate, with reports >25 sentences containing an average of 1.23 errors per report compared to 0-5 sentences containing 0.09. These findings highlight the limitations of VR dictation software. While most error was deemed insignificant, there were occurrences of error with potential to alter report interpretation and patient management. Longer reports and reports on more complex imaging had higher error rates and this should be taken into account by the reporting radiologist.

Frequency of Herpes Zoster Recurrence in Central District of Korea.

Science.gov (United States)

Ha, Jae Won; Lee, Jin Yong; Her, Young; Kim, Chul Woo; Kim, Sang Seok

2017-10-01

Herpes zoster is characterized by unilateral grouped vesicles along the distribution of a dermatome. A global recurrence rate as low as 0.5%∼6.2% has been reported for herpes zoster. The recurrence of herpes zoster is higher in immunocompromised patients and older patients. The purpose of this study is to assess the frequency of herpes zoster recurrence and factors that can influence its recurrence. From January 2005 to December 2015, 14,343 patients with herpes zoster were enrolled in this study. The patients were diagnosed at Hallym University Medical Centers and Kangwon National University Hospital in Seoul, Gyeonggi, and Gangwon. Herpes zoster recurrence and patient characteristics were surveyed by medical record review and a telephonic survey. The overall frequency of herpes zoster recurrence was 1.18%. The frequency of recurrence was higher in women than in men. It was also higher in patients aged 50∼70 years than in patients who were younger or older than this. Additionally, we assessed that the frequency of recurrence was statistically higher in patients with a compromised immune system and in patients who experienced longer lasting pain during their first episode. The frequency of herpes zoster recurrence is more common in women, older age, patient with longer pain duration and immunocompromised patients.

Sensitivity studies of a seismically isolated system to low frequency amplification

International Nuclear Information System (INIS)

Wu, T.S.; Seidensticker, R.W.

1987-06-01

Responses of a seismically isolated structure to earthquake motions will depend primarily on the input ground motion and the isolation system frequency. The isolation frequency generally is relatively low when isolating against horizontal ground motions. After installation, the isolation frequency could deviate from its designed value due to aging, manufacturing tolerance etc. In addition, under cettain soil conditions, the input motion could have high energy content at relatively low frequencies. This report covers the first of these two concerns by performing a sensitivity study of the variations in isolation frequency on the responses of a nuclear reactor module incorporated with an isolation system. Results from a number of ground motions have shown that, for most earthquake motions, a higher isolation frequency tends to yield higher maximum acceleration, higher transmitted shear force, and lower relative displacement between the isolated and unisolated parts of the structure. In one of the ground motions considered, a 7% increase in the isolation frequency from its original design value is observed to give over a 22% increase in the transmitted shear force. Other ground motions, especially those exhibiting sharp rise in spectral accelerations in the vicinity of the designed isolated frequency, yield responses following the same general trend

The driving frequency effects on the atmospheric pressure corona jet plasmas from low frequency to radio frequency

International Nuclear Information System (INIS)

Kim, Dan Bee; Jung, H.; Gweon, B.; Rhee, J. K.; Choe, W.; Moon, S. Y.

2011-01-01

Lately, the atmospheric pressure jet type corona plasma, which has been typically driven by dc to low frequency (LF: several tens of kHz), is often generated by using radio frequency of 13.56 MHz. Yet, the relationship between the plasma and its driving frequency has seldom been investigated. Hence, in this study, dependence of the atmospheric pressure corona plasma characteristics on the driving frequency was explored experimentally from LF to rf (5 kHz-13.56 MHz). The plasmas generated by the driving frequency under 2 MHz were cylindrical shape of several tens of millimeters long while the 13.56 MHz plasma is spherical and a few millimeters long. As the driving frequency was increased, the plasma length became shortened. At the lower driving frequencies (below 2 MHz), the plasmas existed as positive streamer and negative glow for each half period of the applied voltage, but the discharge was more continuous in time for the 13.56 MHz plasma. It was inferred from the measured I-V curves that the higher driving frequency induced higher discharge currents, and the gas temperature was increased as the driving frequency was increased.

Feasibility Studies on the Use of Higher Frequency Bands and Beamforming Selection Scheme for High Speed Train Communication

Directory of Open Access Journals (Sweden)

Ayotunde O. Laiyemo

2017-01-01

Full Text Available With increasing popularity of high speed trains and traffic forecast for future cellular networks, the need to provide improved data rates using higher frequency bands (HFBs for train passengers is becoming crucial. In this paper, we modify the OFDM frame structure for HST, taking into account the increasing sensitivity to speed at HFBs. A lower bound on the SNR/SINR for a given rate for reliable communication was derived considering the physical layer parameters from the OFDM frame. We also analyze different pathloss models in the context of examining the required gain needed to achieve the same performance as with microwave bands. Finally, we present a time-based analogue beamforming selection approach for HST. We observed that, irrespective of the pathloss models used, the required gains are within the same range. For the same SNR/SINR at different frequency bands, the achievable data rate varies with respect to the frequency bands. Our results show the potential of the use of HFBs. However, due to the increased sensitivity of some channel parameters, a maximum frequency band of 38 GHz is suggested. Evaluation of our proposed beamforming scheme indicates a close performance to the optimal SVD scheme with a marginal rate gap of less than 2 b/s/Hz.

Frequency of β-thalassemia trait and other hemoglobinopathies in northern and western India

Science.gov (United States)

Madan, Nishi; Sharma, Satendra; Sood, S. K.; Colah, Roshan; Bhatia, (Late) H. M.

2010-01-01

INTRODUCTION: India is an ethnically diverse country with an approximate population of 1.2 billion. The frequency of beta-thalassemia trait (βTT) has variously been reported from hemoglobinopathies in different regions and population groups in the country. A high frequency of Hb D has been reported from the North in the Punjabi population, Hb E in the eastern region of India and Hb S is mainly reported from populations of tribal origin from different parts of the country. OBJECTIVES: To study the gene frequency of βTT and other hemoglobinopathies in three regions East (Kolkata), West (Mumbai) and North (Delhi) in larghe population group (schoolchildren) for a more accurate assessment of gene frequency for planning of control programmes for haemoglobinopathies. MATERIALS AND METHODS: This study included 5408 children from 11 schools in Delhi, 5682 from 75 schools in Mumbai and 957 schoolchildren from Kolkata who were screened for βTT and haemoglobinopathies. These included 5684 children from 75 schools in Mumbai and 5408 children from 11 schools in Delhi. Children were 11-18 years of age of both sexes. The final report is, however, only on 11090 schoolchildren from Mumbai and Delhi as data from Kolkata was restricted both in numbers and objectives and could not be included for comparison. RESULTS: The overall gene frequency of βTT in Mumbai and Delhi was 4.05% being 2.68% and 5.47% in children of the two cities respectively. In Mumbai, the gene frequency was evenly distributed. Majority of the children with βTT from Mumbai were from Marathi (38.9%) and Gujarati (25%) speaking groups. Gene frequency was >5% in Bhatias, Khatris, Lohanas and Schedule Castes. In Delhi, a higher incidence was observed in schoolchildren of North and West Delhi (5.8-9.2%). The schoolchildren of North and West Delhi comprised predominantly of Punjabi origin compared to children in the South of the city (2.2%, 2.3%). When analyzed state-wise, the highest incidence was observed in

Extremely low frequencies. Health effects of extremely low frequency electromagnetic fields. Opinion of the Afsset. Collective expertise report

International Nuclear Information System (INIS)

Bounouh, Alexandre; Brugere, Henri; Clavel, Jacqueline; Febvre, Pascal; Lagroye, Isabelle; Vecchia, Paolo; Dore, Jean-Francois; Anfosso-Ledee, Fabienne; Berengier, Michel; Cesarini, Jean-Pierre; Cohen, Jean-Claude; Planton, Serge; Courant, Daniel; Tardif, Francois; Couturier, Frederic; Debouzy, Jean-Claude; El Khatib, Aicha; Flahaut, Emmanuel; Gaffet, Eric; Hours, Martine; Lambert, Jacques; Vallet, Michel; Job, Agnes; Labeyrie, Antoine; Laurier, Dominique; Le Bihan, Olivier; Lepoutre, Philippe; Marchal, Didier; Moch, Annie; Pirard, Philipe; Rumeau, Michel; De Seze, Rene; Attia, Dina; Merckel, Olivier; Fite, Johanna; Guichard, Alexandra; Saihi, Myriam; Guitton, Sophie; Saddoki, Sophia

2010-03-01

This report aims at proposing a synthesis of works of international expertise on the health effect of extremely low frequency electromagnetic fields, at performing a methodological analysis of the 'Expers' study (a study on the exposure of individuals), at performing a methodological analysis of a study performed by the Criirem in the western part of France, at assessing the contribution of different equipment and situations to the exposure of population to extremely-low-frequency electromagnetic fields, at making recommendations and proposals for a better assessment of the exposure level, and at proposing topics of investigation and research to improve knowledge on these issues. The report recalls the context, scope and modalities of the study, gives an overview of generalities on electromagnetic fields (nature, physical values, electromagnetic spectrum, artificial and natural electromagnetic field sources, exposure threshold values and regulatory context), addresses the assessment of exposure (notion of exposure, exposure assessment methods, analysis of available data, analysis of recent or current studies), gives an overview of biological and health effects of these electromagnetic fields (methodological aspects, interaction between fields and biological tissues, synthesis of the international expertise on health impacts). Recommendations are formulated

Effect of electromagnetic waves and higher harmonics in capacitively coupled plasma phenomena

International Nuclear Information System (INIS)

Upadhyay, R R; Sawada, I; Ventzek, P L G; Raja, L L

2013-01-01

High-resolution self-consistent numerical simulation of electromagnetic wave phenomena in an axisymmetric capacitively coupled plasma reactor is reported. A prominent centre-peaked plasma density profile is observed for driving frequencies of 60 MHz and is consistent with observations in the literature and accompanying experimental studies. A power spectrum of the simulated wave electric field reveals the presence of well-resolved high frequency harmonic content up to the 20th harmonic of the excitation frequency; an observation that has also been reported in experiments. Importantly, the simulation results reveal that the occurrence of higher harmonics is strongly correlated with the occurrence of a centre-peaked plasma density profile. (fast track communication)

Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

Energy Technology Data Exchange (ETDEWEB)

Franck, John M.; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R.; Freed, Jack H., E-mail: jhf3@cornell.edu [Department of Chemistry and Chemical Biology and National Biomedical Center for Advanced ESR Technology, Cornell University, Ithaca, New York 14853 (United States)

2015-06-07

The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

International Nuclear Information System (INIS)

Franck, John M.; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R.; Freed, Jack H.

2015-01-01

The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

DDC Descriptor Frequencies.

Science.gov (United States)

Klingbiel, Paul H.; Jacobs, Charles R.

This report summarizes the frequency of use of the 7144 descriptors used for indexing technical reports in the Defense Documentation Center (DDC) collection. The descriptors are arranged alphabetically in the first section and by frequency in the second section. The frequency data cover about 427,000 AD documents spanning the interval from March…

Higher balance task demands are associated with an increase in individual alpha peak frequency

Directory of Open Access Journals (Sweden)

Thorben eHülsdünker

2016-01-01

Full Text Available Balance control is fundamental for most daily motor activities, and its impairment is associated with an increased risk of falling. Growing evidence suggests the human cortex is essentially contributing to the control of standing balance. However, the exact mechanisms remain unclear and need further investigation. In a previous study we introduced a new protocol to identify electrocortical activity associated with performance of different continuous balance tasks with the eyes opened. The aim of this study was to extend our previous results by investigating the individual alpha peak frequency (iAPF, a neurophysiological marker of thalamo-cortical information transmission, which remained unconsidered so far in balance research. Thirty-seven subjects completed nine balance tasks varying in surface stability and base of support. Electroencephalography (EEG was recorded from 32 scalp locations throughout balancing with the eyes closed to ensure reliable identification of the iAPF. Balance performance was quantified as the sum of anterior-posterior and medio-lateral movements of the supporting platform. The iAPF, as well as power in the theta, lower alpha and upper alpha frequency bands were determined for each balance task after applying an ICA-based artifact rejection procedure. Higher demands on balance control were associated with a global increase in iAPF and a decrease in lower alpha power. These results may indicate increased thalamo-cortical information transfer and general cortical activation, respectively. In addition, a significant increase in upper alpha activity was observed in the fronto-central region whereas it decreased in the centro-parietal region. Furthermore, midline theta increased with higher task demands probably indicating activation of error detection/processing mechanisms. IAPF as well as theta and alpha power were correlated with platform movements. The results provide new insights into spectral and spatial characteristics

Investigating low-frequency compression using the Grid method

DEFF Research Database (Denmark)

Fereczkowski, Michal; Dau, Torsten; MacDonald, Ewen

2016-01-01

in literature. Moreover, slopes of the low-level portions of the BM I/O functions estimated at 500 Hz were examined, to determine whether the 500-Hz off-frequency forward masking curves were affected by compression. Overall, the collected data showed a trend confirming the compressive behaviour. However......There is an ongoing discussion about whether the amount of cochlear compression in humans at low frequencies (below 1 kHz) is as high as that at higher frequencies. It is controversial whether the compression affects the slope of the off-frequency forward masking curves at those frequencies. Here......, the Grid method with a 2-interval 1-up 3-down tracking rule was applied to estimate forward masking curves at two characteristic frequencies: 500 Hz and 4000 Hz. The resulting curves and the corresponding basilar membrane input-output (BM I/O) functions were found to be comparable to those reported...

A Methodology for Sustainability Evaluation and Reporting in Higher Education Institutions

Science.gov (United States)

Madeira, Ana C.; Carravilla, Maria Antonia; Oliveira, Jose F.; Costa, Carlos A. V.

2011-01-01

The purpose of this paper is to present a methodology that allows higher education institutions (HEIs) to promote, to evaluate and to report on sustainability. The ultimate goal of the afore-mentioned methodology is to help HEIs achieve sustainability. First, a model entitled Sustainability in Higher Education Institutions (SusHEI) that generally…

How does higher frequency monitoring data affect the calibration of a process-based water quality model?

Science.gov (United States)

Jackson-Blake, Leah; Helliwell, Rachel

2015-04-01

Process-based catchment water quality models are increasingly used as tools to inform land management. However, for such models to be reliable they need to be well calibrated and shown to reproduce key catchment processes. Calibration can be challenging for process-based models, which tend to be complex and highly parameterised. Calibrating a large number of parameters generally requires a large amount of monitoring data, spanning all hydrochemical conditions. However, regulatory agencies and research organisations generally only sample at a fortnightly or monthly frequency, even in well-studied catchments, often missing peak flow events. The primary aim of this study was therefore to investigate how the quality and uncertainty of model simulations produced by a process-based, semi-distributed catchment model, INCA-P (the INtegrated CAtchment model of Phosphorus dynamics), were improved by calibration to higher frequency water chemistry data. Two model calibrations were carried out for a small rural Scottish catchment: one using 18 months of daily total dissolved phosphorus (TDP) concentration data, another using a fortnightly dataset derived from the daily data. To aid comparability, calibrations were carried out automatically using the Markov Chain Monte Carlo - DiffeRential Evolution Adaptive Metropolis (MCMC-DREAM) algorithm. Calibration to daily data resulted in improved simulation of peak TDP concentrations and improved model performance statistics. Parameter-related uncertainty in simulated TDP was large when fortnightly data was used for calibration, with a 95% credible interval of 26 μg/l. This uncertainty is comparable in size to the difference between Water Framework Directive (WFD) chemical status classes, and would therefore make it difficult to use this calibration to predict shifts in WFD status. The 95% credible interval reduced markedly with the higher frequency monitoring data, to 6 μg/l. The number of parameters that could be reliably auto

Statistics Report on TEQSA Registered Higher Education Providers, 2016

Science.gov (United States)

Australian Government Tertiary Education Quality and Standards Agency, 2016

2016-01-01

This Statistics Report is the third release of selected higher education sector data held by the Australian Government Tertiary Education Quality and Standards Agency (TEQSA) for its quality assurance activities. It provides a snapshot of national statistics on all parts of the sector by bringing together data collected directly by TEQSA with data…

Congruence in reported frequency of parent-adolescent sexual health communication: A study from Mexico.

Science.gov (United States)

Atienzo, Erika E; Ortiz-Panozo, Eduardo; Campero, Lourdes

2015-08-01

Most studies on parent-adolescent sexual health communication come from developed countries and are based on either parents' or children's reports. In developing countries, there is little evidence about the agreement among reports of all parties involved in parent-adolescent sexual health communication. The objective of this study is to explore the congruence (agreement) between adolescents and their parents about how frequently they discuss on selected sexual health topics. A total of 1606 parent-adolescent dyads of adolescents attending the first year in public high schools and their parents, in Morelos, Mexico were sampled in this study. The participants completed a self-administered questionnaire that included the frequency of parent-adolescent communication about eight sexual health topics. An ordinal logistic threshold model was used to estimate intra-class correlation coefficients within parent-adolescent dyads (as a measure of congruence) and to test if thresholds were equal between parents and adolescents. Congruence in reported frequency of parent-adolescent sexual health communication ranged from 0.205 (menstruation) to 0.307 (condoms) for mother-adolescent dyads, and from 0.103 (ejaculation) to 0.380 (condoms) for father-adolescent dyads. The thresholds (i.e., the cutoff points that define the categories in the observed ordinal variable) differed between parents and adolescents for each of the sexual health topics explored (pcongruence between parents' and adolescents' reports on parent-adolescent sexual health communication. This might be due to interpretation of frequency and intensity of sexual health communication which differs between parents and adolescents.

Voltage, Temperature, Frequency Margin Test Report

DEFF Research Database (Denmark)

Denver, Troelz

1999-01-01

The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation......The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation...

Partner wealth predicts self-reported orgasm frequency in a sample of Chinese women

NARCIS (Netherlands)

Pollet, T.V.; Nettle, D.

There has been considerable speculation about the adaptive significance of the human female orgasm, with one hypothesis being that it promotes differential affiliation or conception with high-quality males. We investigated the relationship between women's self-reported orgasm frequency and the

Failure data analysis of the SuperHILAC radio frequency subsystem

International Nuclear Information System (INIS)

Chang, M.K.

1978-12-01

This report is a continuation of an earlier report by Liang with emphasis now on the Radio Frequency subsystem and its components, using current and improved data. It was stated in Liang's report that improvement in overall SuperHILAC availability, which must be very high for medical purposes, is best made by improving subsystems that are needed in all modes of operation. Two such subsystems were Radio Frequency (RF) and Other, with relatively low availabilities of .96 and .93 respectively. Since subsystem Other is not well defined, the RF became the object of this investigation. It was hoped that the components of the RF would show properties that were obscured at the higher level. The analytic procedure of this report is essentially identical to that in the earlier report, except that an operating period analysis is added

Frequency-swept laser light source at 1050 nm with higher bandwidth due to multiple semiconductor optical amplifiers in series

DEFF Research Database (Denmark)

Marschall, Sebastian; Thrane, Lars; Andersen, Peter E.

2009-01-01

We report on the development of an all-fiber frequency-swept laser light source in the 1050 nm range based on semiconductor optical amplifiers (SOA) with improved bandwidth due to multiple gain media. It is demonstrated that even two SOAs with nearly equal gain spectra can improve the performance...

Coral larvae settle at a higher frequency on red surfaces

Science.gov (United States)

Mason, B.; Beard, M.; Miller, M. W.

2011-09-01

Although chemical cues serve as the primary determinants of larval settlement and metamorphosis, light is also known to influence the behavior and the settlement of coral planulae. For example, Porites astreoides planulae settle preferentially on unconditioned red substrata. In order to test whether this behavior was a response to color and whether other species also demonstrate color preference, settlement choice experiments were conducted with P. astreoides and Acropora palmata. In these experiments, larvae were offered various types of plastic substrata representing three to seven different color choices. Both species consistently settled on red (or red and orange) substrata at a higher frequency than other colors. In one experiment, P. astreoides settled on 100% of red, plastic cable ties but failed to settle on green or white substrata. In a second experiment, 24% of larvae settled on red buttons, more than settled on six other colors combined. A. palmata settled on 80% of red and of orange cables ties but failed to settle on blue in one experiment and settled on a greater proportion of red acrylic squares than on four other colors or limestone controls in a second experiment. The consistency of the response across a variety of plastic materials suggests the response is related to long-wavelength photosensitivity. Fluorescence and reflectance spectra of experimental substrata demonstrated that the preferred substrata had spectra dominated by wavelengths greater than 550 nm with little or no reflection or emission of shorter wavelengths. These results suggest that some species of coral larvae may use spectral cues for fine-scale habitat selection during settlement. This behavior may be an adaptation to promote settlement in crustose coralline algae (CCA)-dominated habitats facilitating juvenile survival.

[Self-reported substance abuse related emergencies: frequency and nature].

Science.gov (United States)

Schäfer, G; Smoltczyk, H; Dengler, W; Buchkremer, G

2000-04-01

The aim of this study was to estimate the frequency and nature of self-reported and drug-related emergencies. 47 patients of a ward for opiate detoxification were interviewed about their experiences with drug-related emergencies. Typical categories had to be found like overdoses, seizures, accidents and suicide attempts respectively. 68% had own experience with drug-related emergency. A majority suffered opiate overdose with different extensions as unconsciousness or breath-depression. Alcohol and polydrug use was associated with overdose. Drug-related accidents were only reported by men. Half the number of drug-related emergencies were treated in hospital. Most emergencies occurred alone either in a home environment or outside. Harm reduction interventions like observed user rooms should be established. Furthermore other strategies to reduce the number of emergencies as sharing naloxon or resuscitation programs in wards for detoxification could also be an effective method to prevent near fatal or fatal overdoses in dependent subjects.

Low frequency phononic band structures in two-dimensional arc-shaped phononic crystals

International Nuclear Information System (INIS)

Xu, Zhenlong; Wu, Fugen; Guo, Zhongning

2012-01-01

The low frequency phononic band structures of two-dimensional arc-shaped phononic crystals (APCs) were studied by the transfer matrix method in cylindrical coordinates. The results showed the first phononic band gaps (PBGs) of APCs from zero Hz with low modes. Locally resonant (LR) gaps were obtained with higher-order rotation symmetry, due to LR frequencies corresponding to the speeds of acoustic waves in the materials. These properties can be efficiently used in a structure for low frequencies that are forbidden, or in a device that permits a narrow window of frequencies. -- Highlights: ► We report a new class of quasi-periodic hetero-structures, arc-shaped phononic crystals (APCs). ► The results show the first PBGs start with zero Hz with low modes. ► Locally resonant (LR) gaps were obtained with higher-order rotation symmetry, due to LR frequencies corresponding to the speeds of acoustic waves in the materials.

The Supply of Part-Time Higher Education in the UK. Research Report

Science.gov (United States)

Callender, Claire; Birkbeck, Anne Jamieson; Mason, Geoff

2010-01-01

This report explores the supply of part-time higher education in the UK, with particular consideration to the study of part-time undergraduate provision in England. It is the final publication in the series of reports on individual student markets that were commissioned by Universities UK following the publication of the reports on the Future size…

High frequency microphone measurements for transition detection on airfoils. NACA-0015 appendix report

DEFF Research Database (Denmark)

Døssing, Mads

Time series of pressure fluctuations has been obtained using high frequency microphones distributed over the surface of airfoils undergoing wind tunnel tests in the LM Windtunnel, owned by ’LM Glasfiber’, Denmark. The present report describes the dataanalysis, with special attention given to tran...

Regional price differences and food consumption frequency among elementary school children.

Science.gov (United States)

Sturm, R; Datar, A

2011-03-01

Food prices may affect diet and weight gain among youth and lead to geographic disparities in obesity. This paper examines the association between regional prices and consumption frequency of fruit/vegetables and snack items among elementary school children in the USA. Observational study using individual-level survey data of fifth-grade children (average age 11 years) and regional food prices based on store visits in 2004. Dependent variables are self-reported consumption frequency in fifth grade; primary explanatory variables are metropolitan area food prices relative to cost of living. Multivariate regression analysis. Price variation across metropolitan areas exists, and lower real prices for vegetables and fruits predict significantly higher intake frequency. Higher dairy prices predict lower frequency of milk consumption, while higher meat prices predict increased milk consumption. Similar price effects were not found for fast food or soft drink consumption. The geographic variation in food prices across the USA is sufficiently large to affect dietary patterns among youth for fruit, vegetables and milk. The price variation is either too small to affect children's consumption frequency of fast food or soft drinks, or the consumption of these foods is less price sensitive. Copyright © 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Occupational blood exposure among health care workers: I. Frequency and reporting

DEFF Research Database (Denmark)

Nelsing, S; Nielsen, T L; Nielsen, Jens Ole

1993-01-01

The frequency and reporting rate concerning occupational blood exposure were investigated among former and currently employed medical staff at a Department of Infectious Diseases (DID) having a high prevalence of HIV-positive patients. Subjects were asked to complete an anonymous questionnaire......, carries a real and serious risk of contracting infectious diseases due to occupational exposure to blood. The importance of reporting needs to be emphasized....... describing occupational percutaneous exposure (PCE) and mucocutaneous exposure (MCE) to blood, experienced during their employment at the DID. 135 out of 168 (80%) subjects responded. 45 subjects described 37 incidents of PCE and 15 of MCE. 44 of the exposures (85%) involved HIV-positive blood and 6 (11...

Parametric effects of word frequency effect in memory for mixed frequency lists

OpenAIRE

Lohnas, Lynn J.; Kahana, Michael J.

2013-01-01

The word frequency paradox refers to the finding that low frequency words are better recognized than high frequency words yet high frequency words are better recalled than low frequency words. Rather than comparing separate groups of low and high frequency words, we sought to quantify the functional relation between word frequency and memory performance across the broad range of frequencies typically used in episodic memory experiments. Here we report that both low frequency and high frequenc...

Quality Assurance in Transnational Higher Education. ENQA Workshop Report 11

Science.gov (United States)

Bennett, Paul; Bergan, Sjur; Cassar, Daniela; Hamilton, Marlene; Soinila, Michele; Sursock, Andree; Uvalic-Trumbic, Stamenka; Williams, Peter

2010-01-01

The present report is the product of an ENQA (European Association for Quality Assurance in Higher Education) Bologna Seminar "Quality Assurance in Transnational Education: from words to action" hosted by the Quality Assurance Agency (QAA, UK) in London in December, 2008. The seminar discussed the current trends in Transnational…

Breakfast frequency among adolescents

DEFF Research Database (Denmark)

Pedersen, Trine Pagh; Holstein, Bjørn E; Damsgaard, Mogens Trab

2016-01-01

OBJECTIVE: To investigate (i) associations between adolescents' frequency of breakfast and family functioning (close relations to parents, quality of family communication and family support) and (ii) if any observed associations between breakfast frequency and family functioning vary...... (n 3054) from a random sample of forty-one schools. RESULTS: Nearly one-quarter of the adolescents had low breakfast frequency. Low breakfast frequency was associated with low family functioning measured by three dimensions. The OR (95 % CI) of low breakfast frequency was 1·81 (1·40, 2......·33) for adolescents who reported no close relations to parents, 2·28 (1·61, 3·22) for adolescents who reported low level of quality of family communication and 2·09 (1·39, 3·15) for adolescents who reported low level of family support. Joint effect analyses suggested that the odds of low breakfast frequency among...

Self-reported versus informant-reported depressive symptoms in adults with mild intellectual disability.

Science.gov (United States)

Mileviciute, I; Hartley, S L

2015-02-01

Virtually nothing is known about potential differences in the types of depression symptoms reported by adults with mild intellectual disability (ID) on self-reported questionnaires as compared with the types of symptoms reported by caregivers on informant questionnaires. Moreover, little is known about how the presentation of depression among adults with mild ID varies based on socio-demographic characteristics. We compared findings from two self-reported questionnaires, the Self-Reported Depression Questionnaire (SRDQ) and the Glasgow Depression Scale for People with a Learning Disability (GDS), to that of an informant questionnaire of depressive symptoms, the Glasgow Depression Scale--Caregiver Supplement (CGDS), in 80 adults with mild ID. We also examined the association between age, sex, IQ and the presence of a co-occurring psychiatric disorder and frequency of affective, cognitive and somatic depressive symptoms in our sample of adults with mild ID. Adults with mild ID self-reported a higher frequency of affective and cognitive depressive symptoms than staff reported on the informant measure. Staff reported a higher frequency of somatic symptoms than adults with mild ID on one of the self-reported questionnaires (GDS) and a similar frequency on the other self-reported questionnaire (SRDQ). Important differences were found in the types of depressive symptoms based on their IQ, age and presence of a co-occurring psychiatric disorder. Informant questionnaires offer valuable information, but assessment should include self-reported questionnaires as these questionnaires add unique information about internalised experiences (affective and cognitive symptoms) of adults with mild ID that may not be apparent to caregivers. Health care providers should be made aware of the important differences in the presentation of depressive based on their IQ, age and presence of a co-occurring psychiatric disorder. © 2013 John Wiley & Sons Ltd, MENCAP & IASSID.

Radar network communication through sensing of frequency hopping

Science.gov (United States)

Dowla, Farid; Nekoogar, Faranak

2013-05-28

In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

Higher-order modulation instability in nonlinear fiber optics.

Science.gov (United States)

Erkintalo, Miro; Hammani, Kamal; Kibler, Bertrand; Finot, Christophe; Akhmediev, Nail; Dudley, John M; Genty, Goëry

2011-12-16

We report theoretical, numerical, and experimental studies of higher-order modulation instability in the focusing nonlinear Schrödinger equation. This higher-order instability arises from the nonlinear superposition of elementary instabilities, associated with initial single breather evolution followed by a regime of complex, yet deterministic, pulse splitting. We analytically describe the process using the Darboux transformation and compare with experiments in optical fiber. We show how a suitably low frequency modulation on a continuous wave field induces higher-order modulation instability splitting with the pulse characteristics at different phases of evolution related by a simple scaling relationship. We anticipate that similar processes are likely to be observed in many other systems including plasmas, Bose-Einstein condensates, and deep water waves. © 2011 American Physical Society

Eating frequency and risk of colorectal cancer.

Science.gov (United States)

Perrigue, Martine M; Kantor, Elizabeth D; Hastert, Theresa A; Patterson, Ruth; Potter, John D; Neuhouser, Marian L; White, Emily

2013-12-01

Eating frequency is a modifiable aspect of dietary behavior that may affect risk of colorectal cancer (CRC). Although most previous case-control studies indicate a positive association, two prospective studies suggest an inverse association between eating frequency and CRC risk, with evidence of effect modification by diet composition. We examined the association between eating frequency and CRC in a large, prospective cohort study, and explored whether this relationship was modified by sex, coffee consumption, or dietary glycemic load. Between 2000 and 2002, 67,912 western Washington residents aged 50-76 reported average daily meal and snack frequency using a mailed questionnaire as part of the vitamins and lifestyle study. Participants were followed for CRC through linkage with SEER through 2008, over which time 409 CRC cases developed. Hazard Ratios and 95 % Confidence Intervals were obtained using Cox regression. In age- and sex-adjusted models higher (5+ times/d) vs. lower (1-2 times/d) eating frequency was associated with a HR of 0.62 (95 % CI 0.43-0.88, Ptrend = 0.001). However, following further adjustment for BMI, race/ethnicity, alcohol, and other known CRC risk factors, the relationship was no longer statistically significant (HR: 0.76; 95 % CI 0.51, 1.14). No effect modification was observed by sex (Pinteraction = 0.45), coffee consumption (Pinteraction = 0.44), or dietary glycemic load (Pinteraction = 0.90). In subgroup analyses by tumor site, higher vs. lower eating frequency was associated with lower risk for colon (HR 0.65 95 % CI 0.39-1.07, Ptrend = 0.04), but not rectal cancers (HR = 1.08 95 % CI 0.54-2.18, Ptrend = 0.94). The weak inverse association observed between eating frequency and CRC is consistent with findings from other prospective studies. Modification of this relationship by diet quality and participant characteristics should be considered in the future studies.

Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

International Nuclear Information System (INIS)

Ju, S; Chae, S H; Choi, Y; Jun, S; Park, S M; Lee, S; Ji, C-H; Lee, H W

2013-01-01

This paper presents a non-resonant vibration energy harvester based on magnetoelectric transduction mechanism and mechanical frequency up-conversion using trampoline effect. The harvester utilizes a freely movable spherical permanent magnet which bounces off the aluminum springs integrated at both ends of the cavity, achieving frequency up-conversion from low frequency input vibration. Moreover, bonding method of magnetoelectric laminate composite has been optimized to provide higher strain to piezoelectric material and thus obtain a higher output voltage. A proof-of-concept energy harvesting device has been fabricated and tested. Maximum open-circuit voltage of 11.2V has been obtained and output power of 0.57μW has been achieved for a 50kΩ load, when the fabricated energy harvester was hand-shaken

Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

Science.gov (United States)

Ju, S.; Chae, S. H.; Choi, Y.; Jun, S.; Park, S. M.; Lee, S.; Lee, H. W.; Ji, C.-H.

2013-12-01

This paper presents a non-resonant vibration energy harvester based on magnetoelectric transduction mechanism and mechanical frequency up-conversion using trampoline effect. The harvester utilizes a freely movable spherical permanent magnet which bounces off the aluminum springs integrated at both ends of the cavity, achieving frequency up-conversion from low frequency input vibration. Moreover, bonding method of magnetoelectric laminate composite has been optimized to provide higher strain to piezoelectric material and thus obtain a higher output voltage. A proof-of-concept energy harvesting device has been fabricated and tested. Maximum open-circuit voltage of 11.2V has been obtained and output power of 0.57μW has been achieved for a 50kΩ load, when the fabricated energy harvester was hand-shaken.

Warfarin maintenance dose in older patients: higher average dose and wider dose frequency distribution in patients of African ancestry than those of European ancestry.

Science.gov (United States)

Garwood, Candice L; Clemente, Jennifer L; Ibe, George N; Kandula, Vijay A; Curtis, Kristy D; Whittaker, Peter

2010-06-15

Studies report that warfarin doses required to maintain therapeutic anticoagulation decrease with age; however, these studies almost exclusively enrolled patients of European ancestry. Consequently, universal application of dosing paradigms based on such evidence may be confounded because ethnicity also influences dose. Therefore, we determined if warfarin dose decreased with age in Americans of African ancestry, if older African and European ancestry patients required different doses, and if their daily dose frequency distributions differed. Our chart review examined 170 patients of African ancestry and 49 patients of European ancestry cared for in our anticoagulation clinic. We calculated the average weekly dose required for each stable, anticoagulated patient to maintain an international normalized ratio of 2.0 to 3.0, determined dose averages for groups 80 years of age and plotted dose as a function of age. The maintenance dose in patients of African ancestry decreased with age (PAfrican ancestry required higher average weekly doses than patients of European ancestry: 33% higher in the 70- to 79-year-old group (38.2+/-1.9 vs. 28.8+/-1.7 mg; P=0.006) and 52% in the >80-year-old group (33.2+/-1.7 vs. 21.8+/-3.8 mg; P=0.011). Therefore, 43% of older patients of African ancestry required daily doses >5mg and hence would have been under-dosed using current starting-dose guidelines. The dose frequency distribution was wider for older patients of African ancestry compared to those of European ancestry (PAfrican ancestry indicate that strategies for initiating warfarin therapy based on studies of patients of European ancestry could result in insufficient anticoagulation and thereby potentially increase their thromboembolism risk. Copyright 2010 Elsevier Inc. All rights reserved.

Frequency, stability and differentiation of self-reported school fear and truancy in a community sample

OpenAIRE

Steinhausen, Hans-Christoph; Müller, Nora; Metzke, Christa Winkler

2008-01-01

Abstract Background Surprisingly little is known about the frequency, stability, and correlates of school fear and truancy based on self-reported data of adolescents. Methods Self-reported school fear and truancy were studied in a total of N = 834 subjects of the community-based Zurich Adolescent Psychology and Psychopathology Study (ZAPPS) at two times with an average age of thirteen and sixteen years. Group definitions were based on two behavioural items of the Youth Self-Report (YSR). Comp...

Associations Between the Self-Reported Frequency of Hearing Chemical Alarms in Theater and Visuospatial Function in Gulf War Veterans.

Science.gov (United States)

Chao, Linda L

2016-10-01

The aim of this study was to examine the relationship between the self-reported frequencies of hearing chemical alarms during deployment and visuospatial function in Gulf War (GW) veterans. The relationship between the self-reported frequency of hearing chemical alarms, neurobehavioral, and volumetric brain imaging data was examined with correlational, regression, and mediation analyses. The self-reported frequency of hearing chemical alarms was inversely associated with and significantly predicted performance on a visuospatial task (ie, Block Design) over and above potentially confounding variables, including concurrent, correlated GW-related exposures. This effect was partially mediated by the relationship between hearing chemical alarms and lateral occipital cortex volume. Exposure to substances that triggered chemical alarms during GW deployment likely had adverse effects on veterans' brain structure and function, warranting further investigation of whether these GW veterans are at an increased risk for dementia.

Relative frequency and estimated minimal frequency of Lysosomal Storage Diseases in Brazil: Report from a Reference Laboratory

Directory of Open Access Journals (Sweden)

Roberto Giugliani

2017-03-01

Full Text Available Abstract Lysosomal storage diseases (LSDs comprise a heterogeneous group of more than 50 genetic conditions of inborn errors of metabolism (IEM caused by a defect in lysosomal function. Although there are screening tests for some of these conditions, diagnosis usually depends on specific enzyme assays, which are only available in a few laboratories around the world. A pioneer facility for the diagnosis of IEM and LSDs was established in the South of Brazil in 1982 and has served as a reference service since then. Over the past 34 years, samples from 72,797 patients were referred for investigation of IEM, and 3,211 were confirmed as having an LSD (4.41%, or 1 in 22, with 3,099 of these patients originating from Brazil. The rate of diagnosis has increased over time, in part due to the creation of diagnostic networks involving a large number of Brazilian services. These cases, referred from Brazilian regions, provide insight about the relative frequency of LSDs in the country. The large amount of data available allows for the estimation of the minimal frequency of specific LSDs in Brazil. The reported data could help to plan health care policies, as there are specific therapies available for most of the cases diagnosed.

Observation of negative-frequency waves in a water tank: a classical analogue to the Hawking effect?

Energy Technology Data Exchange (ETDEWEB)

Rousseaux, Germain [ACRI, Laboratoire Genimar, 260 route du Pin Montard, BP 234, 06904 Sophia-Antipolis Cedex (France); Mathis, Christian; Maissa, Philippe [Universite de Nice-Sophia Antipolis, Laboratoire J-A Dieudonne, UMR CNRS-UNSA 6621, Parc Valrose, 06108 Nice Cedex 02 (France); Philbin, Thomas G; Leonhardt, Ulf [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS, Scotland (United Kingdom)], E-mail: ulf@st-andrews.ac.uk

2008-05-15

The conversion of positive-frequency waves into negative-frequency waves at the event horizon is the mechanism at the heart of the Hawking radiation of black holes. In black-hole analogues, horizons are formed for waves propagating in a medium against the current when and where the flow exceeds the wave velocity. We report on the first direct observation of negative-frequency waves converted from positive-frequency waves in a moving medium. The measured degree of mode conversion is significantly higher than that expected from the theory.

A validity study of self-reported daily texting frequency, cell phone characteristics, and texting styles among young adults.

Science.gov (United States)

Gold, Judith E; Rauscher, Kimberly J; Zhu, Motao

2015-04-02

Texting is associated with adverse health effects including musculoskeletal disorders, sleep disturbances, and traffic crashes. Many studies have relied on self-reported texting frequency, yet the validity of self-reports is unknown. Our objective was to provide some of the first data on the validity of self-reported texting frequency, cell phone characteristics including input device (e.g. touchscreen), key configuration (e.g., QWERTY), and texting styles including phone orientation (e.g., horizontal) and hands holding the phone while texting. Data were collected using a self-administered questionnaire and observation of a texting task among college students ages 18 to 24. To gauge agreement between self-reported and phone bill-derived categorical number of daily text messages sent, we calculated percent of agreement, Spearman correlation coefficient, and a linear weighted kappa statistic. For agreement between self-reported and observed cell phone characteristics and texting styles we calculated percentages of agreement. We used chi-square tests to detect significant differences (α = 0.05) by gender and study protocol. There were 106 participants; 87 of which had complete data for texting frequency analyses. Among these 87, there was 26% (95% CI: 21-31) agreement between self-reported and phone bill-derived number of daily text messages sent with a Spearman's rho of 0.48 and a weighted kappa of 0.17 (95% CI: 0.06-0.27). Among those who did not accurately report the number of daily texts sent, 81% overestimated this number. Among the full sample (n = 106), there was high agreement between self-reported and observed texting input device (96%, 95% CI: 91-99), key configuration (89%, 95% CI: 81-94), and phone orientation while texting (93%, 95% CI: 86-97). No differences were found by gender or study protocol among any items. While young adults correctly reported their cell phone's characteristics and phone orientation while texting, most incorrectly

Frequency and distribution of Notch mutations in tumor cell lines

International Nuclear Information System (INIS)

Mutvei, Anders Peter; Fredlund, Erik; Lendahl, Urban

2015-01-01

Deregulated Notch signaling is linked to a variety of tumors and it is therefore important to learn more about the frequency and distribution of Notch mutations in a tumor context. In this report, we use data from the recently developed Cancer Cell Line Encyclopedia to assess the frequency and distribution of Notch mutations in a large panel of cancer cell lines in silico. Our results show that the mutation frequency of Notch receptor and ligand genes is at par with that for established oncogenes and higher than for a set of house-keeping genes. Mutations were found across all four Notch receptor genes, but with notable differences between protein domains, mutations were for example more prevalent in the regions encoding the LNR and PEST domains in the Notch intracellular domain. Furthermore, an in silico estimation of functional impact showed that deleterious mutations cluster to the ligand-binding and the intracellular domains of NOTCH1. For most cell line groups, the mutation frequency of Notch genes is higher than in associated primary tumors. Our results shed new light on the spectrum of Notch mutations after in vitro culturing of tumor cells. The higher mutation frequency in tumor cell lines indicates that Notch mutations are associated with a growth advantage in vitro, and thus may be considered to be driver mutations in a tumor cell line context. The online version of this article (doi:10.1186/s12885-015-1278-x) contains supplementary material, which is available to authorized users

Failure frequencies and probabilities applicable to BWR and PWR piping

International Nuclear Information System (INIS)

Bush, S.H.; Chockie, A.D.

1996-03-01

This report deals with failure probabilities and failure frequencies of nuclear plant piping and the failure frequencies of flanges and bellows. Piping failure probabilities are derived from Piping Reliability Analysis Including Seismic Events (PRAISE) computer code calculations based on fatigue and intergranular stress corrosion as failure mechanisms. Values for both failure probabilities and failure frequencies are cited from several sources to yield a better evaluation of the spread in mean and median values as well as the widths of the uncertainty bands. A general conclusion is that the numbers from WASH-1400 often used in PRAs are unduly conservative. Failure frequencies for both leaks and large breaks tend to be higher than would be calculated using the failure probabilities, primarily because the frequencies are based on a relatively small number of operating years. Also, failure probabilities are substantially lower because of the probability distributions used in PRAISE calculations. A general conclusion is that large LOCA probability values calculated using PRAISE will be quite small, on the order of less than 1E-8 per year (<1E-8/year). The values in this report should be recognized as having inherent limitations and should be considered as estimates and not absolute values. 24 refs 24 refs

Subjective sleep quality, unstimulated sexual arousal, and sexual frequency

Directory of Open Access Journals (Sweden)

Rui Costa

Full Text Available Introduction: REM sleep deprivation increases unstimulated erections in rats, and total sleep deprivation increases erections during audiovisual sexual stimulation in men, but the effects of sleep problems on human unstimulated sexual arousal are unknown. Objective: We examined the associations of subjective sleep quality with unstimulated sexual arousal, satisfaction with sex life, and sexual frequency and desire over the past month. Methods: 275 Portuguese (169 women reported their anxiety, sexual arousal and sexual desire during a resting state, and completed the Pittsburgh Sleep Quality Index, the sexual satisfaction subscale of the LiSat scale, the Desire dimensions of the Female Sexual Function Index (women only and International Index of Erectile Function (men only. They additionally reported how many days in the past month they engaged in penile-vaginal intercourse, noncoital sex, and masturbation. Salivary testosterone (T was assayed by luminescence immunoassays. Results: Poorer sleep quality correlated with greater unstimulated sexual arousal in men with higher T levels and in women with higher T levels not taking oral contraceptives. In women with lower T, poorer subjective sleep quality correlated with greater sexual dissatisfaction. In both sexes, sleep quality was uncorrelated with sexual desire and sexual frequency over the past month. Discussion: Consistently with other studies in humans and animals, the findings are congruent with the notion that lack of sleep can increase sexual arousal, but not sexual frequency. T might play a role in the sexual arousal caused by lack of appropriate sleep.

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

Directory of Open Access Journals (Sweden)

Reeves Gillian K

2011-06-01

Full Text Available Abstract Background How overall physical activity relates to specific activities and how reported activity changes over time may influence interpretation of observed associations between physical activity and health. We examine the relationships between various physical activities self-reported at different times in a large cohort study of middle-aged UK women. Methods At recruitment, Million Women Study participants completed a baseline questionnaire including questions on frequency of strenuous and of any physical activity. About 3 years later 589,896 women also completed a follow-up questionnaire reporting the hours they spent on a range of specific activities. Time spent on each activity was used to estimate the associated excess metabolic equivalent hours (MET-hours and this value was compared across categories of physical activity reported at recruitment. Additionally, 18,655 women completed the baseline questionnaire twice, at intervals of up to 4 years; repeatability over time was assessed using the weighted kappa coefficient (κweighted and absolute percentage agreement. Results The average number of hours per week women reported doing specific activities was 14.0 for housework, 4.5 for walking, 3.0 for gardening, 0.2 for cycling, and 1.4 for all strenuous activity. Time spent and the estimated excess MET-hours associated with each activity increased with increasing frequency of any or strenuous physical activity reported at baseline (tests for trend, P weighted = 0.71 for questionnaires administered less than 6 months apart, and 52% (κweighted = 0.51 for questionnaires more than 2 years apart. Corresponding values for any physical activity were 57% (κweighted = 0.67 and 47% (κweighted = 0.58. Conclusions In this cohort, responses to simple questions on the frequency of any physical activity and of strenuous activity asked at baseline were associated with hours spent on specific activities and the associated estimated excess MET

Low-frequency electromagnetic measurements as a zero-time discriminant of nuclear and chemical explosions - OSI research final report

International Nuclear Information System (INIS)

Sweeney, J.J.

1996-12-01

This is the final report on a series of investigations of low frequency (1-40 Hz) electromagnetic signals produced by above ground and underground chemical explosions and their use for confidence building under the Comprehensive Test-Ban Treaty. I conclude that low frequency electromagnetic measurements can be a very powerful tool for zero-time discrimination of chemical and nuclear explosions for yields of 1 Kt or greater, provided that sensors can be placed within 1-2 km of the suspected detonation point in a tamper-proof, low noise environment. The report includes descriptions and analyses of low frequency electromagnetic measurements associated with chemical explosions carried out in a variety of settings (shallow borehole, open pit mining, underground mining). I examine cavity pressure data from the Non-Proliferation Experiment (underground chemical explosion) and present the hypothesis that electromagnetic signals produced by underground chemical explosions could be produced during rock fracturing. I also review low frequency electromagnetic data from underground nuclear explosions acquired by Lawrence Livermore National Laboratory during the late 1980s. (author)

Frequency-domain interferometer simulation with higher-order spatial modes

International Nuclear Information System (INIS)

Freise, A; Heinzel, G; Lueck, H; Schilling, R; Willke, B; Danzmann, K

2004-01-01

FINESSE is a software simulation allowing one to compute the optical properties of laser interferometers used by interferometric gravitational-wave detectors today. This fast and versatile tool has already proven to be useful in the design and commissioning of gravitational-wave detectors. The basic algorithm of FINESSE numerically computes the light amplitudes inside an interferometer using Hermite-Gauss modes in the frequency domain. In addition, FINESSE provides a number of commands for easily generating and plotting the most common signals including power enhancement, error and control signals, transfer functions and shot-noise-limited sensitivities. Among the various simulation tools available to the gravitational wave community today, FINESSE provides an advanced and versatile optical simulation based on a general analysis of user-defined optical setups and is quick to install and easy to use

Frequency of Self-Reported Concussion Amongst Professional and Semi-Professional Footballers in Ireland During the 2014 Season: a Cross-Sectional Study.

Science.gov (United States)

Coffey, Nicola; Lawless, Martin; Kelly, Seamus; Buggy, Conor

2018-01-08

This paper examines the occupational risk of concussion amongst professional and semi-professional footballers in Ireland during the 2014 League of Ireland season. As part of a broader nationally representative study examining occupational safety and health (OSH) awareness amongst professional footballers, this empirical quantitative study, utilising a convenience sample is the first and largest investigation of the frequency of, and attitudes towards, concussion and concussion reporting amongst Irish senior professional and semi-professional footballers. A census survey using an anonymous questionnaire was provided to available League of Ireland clubs between March and May 2015. Permission to access players was provided by the Professional Footballers Association of Ireland. This convenience sample was determined by club availability in relation to match fixtures. Participation by the footballers was voluntary. At the time, there were 250 professional and semi-professional players within the League available to participate. A total of 149 footballers participated in the study. Sixty percent of the participants were employed on a semi-professional basis and the majority of all participants were aged between 18 and 30. 15.7% of the participants reported having received a concussion in the 2014 season with semi-professional players having a noticeably higher (though not significant) reporting rate. Analysis indicated that there was a significant association between playing position and concussion reporting with defenders having the greater odds of reporting a concussion than other playing positions. Professional and semi-professional footballers have a relatively equal risk of receiving a concussion. This research is the first major investigation of the self-reported frequency of, and attitudes towards, concussion amongst Irish senior professional and semi-professional footballers. The results have important implications for coaches, clinicians, parents, players and

Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants

Energy Technology Data Exchange (ETDEWEB)

Kovalchuk, O.; Kovalchuk, I.; Hohn, B. [Friedrich Miescher Institute, P.O. Box 2543, CH-4002 Basel (Switzerland); Arkhipov, A. [Chernobyl Scientific and Technical Center of International Research, Shkolnaya Str. 6, 255620 Chernobyl (Ukraine); Barylyak, I.; Karachov, I. [Ukrainian Scientific Genetics Center, Popudrenko Str. 50, 253660 Kiev (Ukraine); Titov, V. [Ivano-Frankivsk State Medical Academy, Galitska Str.2, 284000 Ivano-Frankivsk (Ukraine)

2000-04-03

different chemical composition, but equal radioactivity, exhibited different levels of HR, dependent upon the absorbed dose of radiation. Remarkably, we observed a much higher frequency of HR in plants exposed to chronic irradiation when compared to acutely irradiated plants. Although acute application of 0.1-0.5 Gy did not lead to an increase of frequency of HR, the chronic exposure of the plants to several orders of magnitude lower dose of 200 {mu}Gy led to a 5-6-fold induction of the frequency of HR as compared to the control.

Possible Explanation for Cancer in Rats due to Cell Phone Radio Frequency Radiation

Science.gov (United States)

Feldman, Bernard J.

Very recently, the National Toxicology Program reported a correlation between exposure to whole body 900 MHz radio frequency radiation and cancer in the brains and hearts of Sprague Dawley male rats. Assuming that the National Toxicology Program is statistically significant, I propose the following explanation for these results. The neurons around the brain and heart form closed electrical circuits and, following Faraday's Law, 900 MHz radio frequency radiation induces 900 MHz electrical currents in these neural circuits. In turn, these 900 MHz currents in the neural circuits generate sufficient localized heat in the neural cells to shift the equilibrium concentration of carcinogenic radicals to higher levels and thus, to higher incidences of cancer.

Alcohol marketing in televised international football: frequency analysis.

Science.gov (United States)

Adams, Jean; Coleman, James; White, Martin

2014-05-20

Alcohol marketing includes sponsorship of individuals, organisations and sporting events. Football (soccer) is one of the most popular spectator sports worldwide. No previous studies have quantified the frequency of alcohol marketing in a high profile international football tournament. The aims were to determine: the frequency and nature of visual references to alcohol in a representative sample of EURO2012 matches broadcast in the UK; and if frequency or nature varied between matches broadcast on public service and commercial channels, or between matches that did and did not feature England. Eight matches selected by stratified random sampling were recorded. All visual references to alcohol were identified using a tool with high inter-rater reliability. 1846 visual references to alcohol were identified over 1487 minutes of broadcast--an average of 1.24 references per minute. The mean number of references per minute was higher in matches that did vs did not feature England (p = 0.004), but did not differ between matches broadcast on public service vs commercial channels (p = 0.92). The frequency of visual references to alcohol was universally high and higher in matches featuring the only UK home team--England--suggesting that there may be targeting of particularly highly viewed matches. References were embedded in broadcasts, and not particular to commercial channels including paid-for advertising. New UK codes-of-conduct on alcohol marketing at sporting events will not reduce the level of marketing reported here.

Effect of low-frequency power on dual-frequency capacitively coupled plasmas

International Nuclear Information System (INIS)

Yuan, Q H; Xin, Y; Huang, X J; Sun, K; Ning, Z Y; Yin, G Q

2008-01-01

In low-pressure dual-frequency capacitively coupled plasmas driven with 60/13.56 MHz, the effect of low-frequency power on the plasma characteristics was investigated using a compensated Langmuir electrostatic probe. At lower pressures (about 10 mTorr), it was possible to control the plasma density and the ion bombardment energy independently. As the pressure increased, this independent control could not be achieved. As the low-frequency power increased for the fixed high-frequency power, the electron energy probability function (EEPF) changed from Druyvesteyn-like to Maxwellian-like at pressures of 50 mTorr and higher, along with a drop in electron temperature. The plasma parameters were calculated and compared with simulation results.

Frequency, stability and differentiation of self-reported school fear and truancy in a community sample

Directory of Open Access Journals (Sweden)

Metzke Christa

2008-07-01

Full Text Available Abstract Background Surprisingly little is known about the frequency, stability, and correlates of school fear and truancy based on self-reported data of adolescents. Methods Self-reported school fear and truancy were studied in a total of N = 834 subjects of the community-based Zurich Adolescent Psychology and Psychopathology Study (ZAPPS at two times with an average age of thirteen and sixteen years. Group definitions were based on two behavioural items of the Youth Self-Report (YSR. Comparisons included a control group without indicators of school fear or truancy. The three groups were compared across questionnaires measuring emotional and behavioural problems, life-events, self-related cognitions, perceived parental behaviour, and perceived school environment. Results The frequency of self-reported school fear decreased over time (6.9 vs. 3.6% whereas there was an increase in truancy (5.0 vs. 18.4%. Subjects with school fear displayed a pattern of associated internalizing problems and truants were characterized by associated delinquent behaviour. Among other associated psychosocial features, the distress coming from the perceived school environment in students with school fear is most noteworthy. Conclusion These findings from a community study show that school fear and truancy are frequent and display different developmental trajectories. Furthermore, previous results are corroborated which are based on smaller and selected clinical samples indicating that the two groups display distinct types of school-related behaviour.

On the frequency scalings of RF guns

International Nuclear Information System (INIS)

Lin, L.C.; Chen, S.C.; Wurtele, J.S.

1995-01-01

A frequency scaling law for RF guns is derived from the normalized Vlasov-Maxwell equations. It shows that higher frequency RF guns can generate higher brightness beams under the assumption that the accelerating gradient and all beam and structure parameters are scaled with the RF frequency. Numerical simulation results using MAGIC confirm the scaling law. A discussion of the range of applicability of the law is presented. copyright 1995 American Institute of Physics

Frequency Hopping Transceiver Multiplexer

Science.gov (United States)

1983-03-01

ATC 17 ULR IHQ OCLI CPCTR ULTRA HIGH "OQS" UP TO 4X HIGHER THAN BEST INDUS- TRY STANDARD (ATC 100). MICROWAVE POWER, CURRENT. AND 0 RATINGS5...Q"W were assigned to element (FigC-2); which will be modelled into the transformer previously ment td . The center frequencies, "Q", frequency range...of the TD 1288 system. Temperature stability, change with time or storage. Flexure Frequency, or non-linear change over bandwidth. * Humidity

Individual Differences in Diurnal Preference and Time-of-Exercise Interact to Predict Exercise Frequency.

Science.gov (United States)

Hisler, Garrett C; Phillips, Alison L; Krizan, Zlatan

2017-06-01

Diurnal preference (and chronotype more generally) has been implicated in exercise behavior, but this relation has not been examined using objective exercise measurements nor have potential psychosocial mediators been examined. Furthermore, time-of-day often moderates diurnal preference's influence on outcomes, and it is unknown whether time-of-exercise may influence the relation between chronotype and exercise frequency. The current study examined whether individual differences in diurnal preference ("morningness-eveningness") predict unique variance in exercise frequency and if commonly studied psychosocial variables mediate this relation (i.e., behavioral intentions, internal exercise control, external exercise control, and conscientiousness). Moreover, the study sought to test whether individuals' typical time-of-exercise moderated the impact of diurnal preference on exercise frequency. One hundred twelve healthy adults (mean age = 25.4; SD = 11.6 years) completed baseline demographics and then wore Fitbit Zips® for 4 weeks to objectively measure exercise frequency and typical time-of-exercise. At the end of the study, participants also self-reported recent exercise. Diurnal preference predicted both self-reported exercise and Fitbit-recorded exercise frequency. When evaluating mediators, only conscientiousness emerged as a partial mediator of the relation between diurnal preference and self-reported exercise. In addition, time-of-exercise moderated diurnal preference's relation to both self-reported exercise and Fitbit-recorded exercise frequency such that diurnal preference predicted higher exercise frequency when exercise occurred at a time that was congruent with one's diurnal preference. Based on these findings, diurnal preference is valuable, above and beyond other psychological constructs, in predicting exercise frequency and represents an important variable to incorporate into interventions seeking to increase exercise.

Microwave Frequency Multiplier

Science.gov (United States)

Velazco, J. E.

2017-02-01

High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing

High frequency dielectric reference materials BCR projekt 43. Final report of phase 1

International Nuclear Information System (INIS)

Chantry, G.

1980-01-01

The Group of High Frequency Specialists from Belgium, France, Germany, The Netherlands and the UK, was awarded contracts in 1975 to carry out a programme of measurements on the high frequency dielectric properties of materials. The object of this first phase of a projected three phase programme was to establish the reliability of existing methods of measurement and to examine the possibilities of specifying and producing some standard reference materials, both liquid and solid, which could be used for calibrating and checking the performance of industrial measurement equipment. The liquids chosen for the first phase were cyclohexane, cis and trans decalin, chlorobenzene and 0.1, 1, and 10% solutions of chlorobenzene in cyclohexane. Each group had a limited frequency range over which it could make meaningful measurements but there was sufficient overlap to ensure that all random and systematic errors could be quantitatively assayed. The real (epsilon') and imaginary (epsilon'') components of the complex permittivity for all the liquids were measured over the frequency range 10 - 3,000 GHz and for the two most lossy liquids (chlorobenzene and 10% chlorobenzene in cyclohexane) this range was extended downwards to one GHz. The programme established for the first time the possible experimental imprecisions to be expected in high frequency dielecric measurements and showed that the chosen liquids could be useful standard reference materials if sufficiently pure specimens could be obtained commercially at a reasonable price. The programme did however reveal an unexpected snag in that the liquids, especially cyclohexane, were found to be rather more liable to contamination than expected. Since cyclohexane is a very low-loss liquid, only a small amount of a lossy contaminant need be absorbed to make the observed loss increase dramatically. This report contains all the measured results in both tabular and graphical form and in addition full technical details are given of the

Environmental Reporting for Global Higher Education Institutions using the World Wide Web.

Science.gov (United States)

Walton, J.; Alabaster, T.; Richardson, S.; Harrison, R.

1997-01-01

Proposes the value of voluntary environmental reporting by higher education institutions as an aid to implementing environmental policies. Suggests that the World Wide Web can provide a fast, up-to-date, flexible, participatory, multidimensional medium for information exchange and management. Contains 29 references. (PVD)

Host-Parasite Interactions in Individuals with Type 1 and 2 Diabetes Result in Higher Frequency of Ascaris lumbricoides and Giardia lamblia in Type 2 Diabetic Individuals

Directory of Open Access Journals (Sweden)

Eleuza Rodrigues Machado

2018-01-01

Full Text Available Host-parasite interactions in diabetic patients might influence diabetes complications and intestinal parasitosis. The aim was to investigate the occurrence of enteroparasites in individuals with diabetes types 1 and 2. A descriptive study was designed to estimate frequencies of parasites and to compare them in individuals with diabetes types 1 and 2 from two Health Centers and one hospital in the Federal District of Brazil. Patients were allocated to the study by convenience. Three fecal samples of 156 diabetic individuals (120 type 1 and 36 type 2 were analyzed using two parasitological methods. Enteroparasites or commensals frequency in diabetics was 64%. Diabetics infected with up to six species of intestinal parasites or commensals were found. Frequencies of Ascaris lumbricoides and Giardia lamblia were higher in individuals with type 2 diabetes. The lower frequency of A. lumbricoides found in type 1 diabetes may be related to a strong Th2 response to parasites. Autoimmune response developed in type 1 diabetic individuals characterized by the production of Th1 cytokines could explain low frequency of G. lamblia. High frequency of parasites found in type 2 diabetes emphasizes the importance of periodic parasitological examinations in these individuals.

Impact and frequency of extra-genitourinary manifestations of prune belly syndrome.

Science.gov (United States)

Grimsby, G M; Harrison, S M; Granberg, C F; Bernstein, I H; Baker, L A

2015-10-01

Prune belly syndrome (PBS) extra-genitourinary (extra-GU) manifestations are serious comorbidities beyond the genitourinary (GU) anomalies of this disease. We hypothesized an underestimation of the reported frequency and understated impact on quality of life (QOL) of extra-GU comorbidities in PBS survivors beyond the newborn period. To assess this, the frequencies of extra-GU manifestations of PBS in a contemporary cohort of living patients were compared to compiled frequencies from published literature. Second, the impact of extra-GU PBS manifestations on patient/family QOL was assessed via a non-validated open-ended survey. From 2010 to 2013, PBS survivors were prospectively recruited locally or at three PBS Network National Conventions. The family/subject was asked to complete a detailed PBS questionnaire, non-validated QOL survey, and provide medical records for review. Clinical data were extracted from medical records for local patients. The frequencies of extra-GU manifestations were compared between the contemporary, living cohort and a published literature cohort derived from PubMed. Seven of 706 published studies met criteria for frequencies tabulation of extra-GU PBS manifestations. This largest reported living PBS patient cohort (n = 65) was 99% male with mean age 10 years (1 month-45 years). The living PBS cohort had a statistically significantly higher incidence of gastrointestinal (63%), orthopedic (65%), and cardiopulmonary (49%) diagnoses compared to the compiled published cohort (n = 204). Eleven PBS males and 32 family members completed the QOL survey. Of these, 47% listed at least one non-GU problem (i.e. lung disease, skeletal problems, constipation) as negatively affecting their QOL; 42% listed at least one GU problem (i.e. self-catheterization, recurrent UTIs) as negatively affecting their QOL; 56% reported musculoskeletal surgery and 21% reported gastrointestinal surgery/medication as positively impacting their QOL. In this large contemporary

Improving uniformity of atmospheric-pressure dielectric barrier discharges using dual frequency excitation

Science.gov (United States)

Liu, Y.; Peeters, F. J. J.; Starostin, S. A.; van de Sanden, M. C. M.; de Vries, H. W.

2018-01-01

This letter reports a novel approach to improve the uniformity of atmospheric-pressure dielectric barrier discharges using a dual-frequency excitation consisting of a low frequency (LF) at 200 kHz and a radio frequency (RF) at 13.56 MHz. It is shown that due to the periodic oscillation of the RF electric field, the electron acceleration and thus the gas ionization is temporally modulated, i.e. enhanced and suppressed during each RF cycle. As a result, the discharge development is slowed down with a lower amplitude and a longer duration of the LF discharge current. Hence, the RF electric field facilitates improved stability and uniformity simultaneously allowing a higher input power.

High-frequency homogenization of zero frequency stop band photonic and phononic crystals

CERN Document Server

Antonakakis, Tryfon; Guenneau, Sebastien

2013-01-01

We present an accurate methodology for representing the physics of waves, for periodic structures, through effective properties for a replacement bulk medium: This is valid even for media with zero frequency stop-bands and where high frequency phenomena dominate. Since the work of Lord Rayleigh in 1892, low frequency (or quasi-static) behaviour has been neatly encapsulated in effective anisotropic media. However such classical homogenization theories break down in the high-frequency or stop band regime. Higher frequency phenomena are of significant importance in photonics (transverse magnetic waves propagating in infinite conducting parallel fibers), phononics (anti-plane shear waves propagating in isotropic elastic materials with inclusions), and platonics (flexural waves propagating in thin-elastic plates with holes). Fortunately, the recently proposed high-frequency homogenization (HFH) theory is only constrained by the knowledge of standing waves in order to asymptotically reconstruct dispersion curves an...

Multiband Radio Frequency Interconnect (MRFI) Technology For Next Generation Mobile/Airborne Computing Systems

Science.gov (United States)

2017-02-01

between CPUs and memories , and then demodulated by the same frequency carriers to restore the data back to a parallel bus. This implies that one can...performance. With limited I/O pin count, higher bandwidth implies higher data rate per pin. As the data rate of double data rate (DDR) memory ...either expressed or implied , of Air Force Research Laboratory (AFRL) and the Defense Advanced Research Agency (DARPA) or the U.S. Government. Report

Utilization of multiple frequencies in 3D nonlinear microwave imaging

DEFF Research Database (Denmark)

Jensen, Peter Damsgaard; Rubæk, Tonny; Mohr, Johan Jacob

2012-01-01

The use of multiple frequencies in a nonlinear microwave algorithm is considered. Using multiple frequencies allows for obtaining the improved resolution available at the higher frequencies while retaining the regularizing effects of the lower frequencies. However, a number of different challenges...... at lower frequencies are used as starting guesses for reconstructions at higher frequencies. The performance is illustrated using simulated 2-D data and data obtained with the 3-D DTU microwave imaging system....

Lithographed Superconducting Resonator Development for Next-Generation Frequency Multiplexing Readout of Transition-Edge Sensors

Science.gov (United States)

Faramarzi, F.; De Haan, T.; Kusaka, A.; Lee, A.; Neuhauser, B.; Plambeck, R.; Raum, C.; Suzuki, A.; Westbrook, B.

2018-03-01

Ground-based cosmic microwave background (CMB) experiments are undergoing a period of exponential growth. Current experiments are observing with 1000-10,000 detectors, and the next-generation experiment (CMB stage 4) is proposing to deploy approximately 500,000 detectors. This order of magnitude increase in detector count will require a new approach for readout electronics. We have developed superconducting resonators for next-generation frequency-domain multiplexing (fMUX) readout architecture. Our goal is to reduce the physical size of resonators, such that resonators and detectors can eventually be integrated on a single wafer. To reduce the size of these resonators, we have designed spiral inductors and interdigitated capacitors that resonate around 10-100 MHz, an order of magnitude higher frequency compared to current fMUX readout systems. The higher frequency leads to a wider bandwidth and would enable higher multiplexing factor than the current ˜ 50 detectors per readout channel. We will report on the simulation, fabrication method, characterization technique, and measurement of quality factor of these resonators.

High Order Differential Frequency Hopping: Design and Analysis

Directory of Open Access Journals (Sweden)

Yong Li

2015-01-01

Full Text Available This paper considers spectrally efficient differential frequency hopping (DFH system design. Relying on time-frequency diversity over large spectrum and high speed frequency hopping, DFH systems are robust against hostile jamming interference. However, the spectral efficiency of conventional DFH systems is very low due to only using the frequency of each channel. To improve the system capacity, in this paper, we propose an innovative high order differential frequency hopping (HODFH scheme. Unlike in traditional DFH where the message is carried by the frequency relationship between the adjacent hops using one order differential coding, in HODFH, the message is carried by the frequency and phase relationship using two-order or higher order differential coding. As a result, system efficiency is increased significantly since the additional information transmission is achieved by the higher order differential coding at no extra cost on either bandwidth or power. Quantitative performance analysis on the proposed scheme demonstrates that transmission through the frequency and phase relationship using two-order or higher order differential coding essentially introduces another dimension to the signal space, and the corresponding coding gain can increase the system efficiency.

High frequency microphone measurements for transition detection on airfoils. Risø C2-18 appendix report

DEFF Research Database (Denmark)

Døssing, Mads

Time series of pressure fluctuations has been obtained using high frequency microphones distributed over the surface of airfoils undergoing wind tunnel tests in the LM Windtunnel, owned by ’LM Glasfiber’, Denmark. The present report describes the dataanalysis, with special attention given to tran...

High frequency microphone measurements for transition detection on airfoils. Risø B1-18 appendix report

DEFF Research Database (Denmark)

Døssing, Mads

Time series of pressure fluctuations has been obtained using high frequency microphones distributed over the surface of airfoils undergoing wind tunnel tests in the LM Windtunnel, owned by ’LM Glasfiber’, Denmark. The present report describes the dataanalysis, with special attention given to tran...

Fabrication of 3D Air-core MEMS Inductors for High Frequency Power Electronic Applications

DEFF Research Database (Denmark)

Lê Thanh, Hoà; Mizushima, Io; Nour, Yasser

2018-01-01

footprints have an inductance from 34.2 to 44.6 nH and a quality factor from 10 to 13 at frequencies ranging from 30 to 72 MHz. The air-core inductors show threefold lower parasitic capacitance and up to a 140% higher-quality factor and a 230% higher-operation frequency than silicon-core inductors. A 33 MHz...... boost converter mounted with an air-core toroidal inductor achieves an efficiency of 68.2%, which is better than converters mounted with a Si-core inductor (64.1%). Our inductors show good thermal cycling stability, and they are mechanically stable after vibration and 2-m-drop tests.......We report a fabrication technology for 3D air-core inductors for small footprint and very-high-frequency power conversions. Our process is scalable and highly generic for fabricating inductors with a wide range of geometries and core shapes. We demonstrate spiral, solenoid, and toroidal inductors...

Low frequency noise study.

Science.gov (United States)

2007-04-01

This report documents a study to investigate human response to the low-frequency : content of aviation noise, or low-frequency noise (LFN). The study comprised field : measurements and laboratory studies. The major findings were: : 1. Start-of-takeof...

Status report of the low frequency facility experiment, Virgo R and D

Energy Technology Data Exchange (ETDEWEB)

Di Virgilio, A.; Ballardin, G.; Braccini, S.; Bradaschia, C.; Calamai, G.; Casciano, C.; Cavalieri, R.; Cecchi, R.; Cella, G.; Chen, Sheng-Jui; Cuoco, E.; Dattilo, V.; Dominici, P.; Fabbroni, L.; Fazzi, M.; Frasca, S.; Ferrante, I.; Fidecaro, F.; Frasconi, F.; Gennaro, G.; Giazotto, A.; Guidi, G.; Holloway, L.; La Penna, P.; Lomtadze, T.; Losurdo, G.; Majorana, E.; Martelli, F.; Mazzoni, M.; Nenci, F.; Ni, Wei-Tou; Lelli, F.; Paoletti, F.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Perciballi, M.; Poggiani, R.; Porzio, A.; Puppo, P.; Raffaelli, F.; Rapagnani, P.; Ricci, F.; Ricciardi, I.; Solimeno, S.; Stanga, R.; Taddei, R.; Vetrano, F.; Vicere, A.; Zhang, Z

2003-11-10

The low frequency facility, a Virgo R and D experiment, is composed by a Fabry-Perot cavity attached and controlled by the Virgo suspension; the goal is to measure the thermal noise of the apparatus above 10 Hz, with a displacement sensitivity as high as 10{sup -18} m/{radical}Hz. Since September 2001 the apparatus, located inside the INFN-Pisa experimental area, has been completely built and put into operation. Vacuum facilities and the control loops have been set up. Transfer functions, necessary to control the cavity, absolute test mass displacement and the first demonstration of the cavity locking are reported.

Relationship between frequency of involuntary autobiographical memories and cognitive failure.

Science.gov (United States)

Kamiya, Shunji

2014-01-01

Involuntary autobiographical memories are memories of personal experiences that pop into mind without a conscious attempt at their retrieval. This study investigated individual differences in the number of involuntary autobiographical memories, and explored the relationship between the frequency of occurrence in involuntary autobiographical memory and cognitive failures in everyday memory, as indexed by metamemory questionnaires. A total of 24 undergraduate students reported involuntary autobiographical memories in controlled field interviews, and completed the Everyday Memory Questionnaire and the Cognitive Failures Questionnaire. The results showed that, despite controlled conditions, considerable individual differences were observed in the number of involuntary autobiographical memories reported while walking along a prescribed route on the campus, and that reported memories were predominantly serving self function. In addition, the number of involuntary autobiographical memories was positively related to cognitive failures in everyday memory: participants who acknowledged more problems in everyday memory had a higher frequency of involuntary memories. The implications of these results are discussed in terms of the complementary function of involuntary autobiographical memory in everyday life.

Specificity of the Human Frequency Following Response for Carrier and Modulation Frequency Assessed Using Adaptation.

Science.gov (United States)

Gockel, Hedwig E; Krugliak, Alexandra; Plack, Christopher J; Carlyon, Robert P

2015-12-01

The frequency following response (FFR) is a scalp-recorded measure of phase-locked brainstem activity to stimulus-related periodicities. Three experiments investigated the specificity of the FFR for carrier and modulation frequency using adaptation. FFR waveforms evoked by alternating-polarity stimuli were averaged for each polarity and added, to enhance envelope, or subtracted, to enhance temporal fine structure information. The first experiment investigated peristimulus adaptation of the FFR for pure and complex tones as a function of stimulus frequency and fundamental frequency (F0). It showed more adaptation of the FFR in response to sounds with higher frequencies or F0s than to sounds with lower frequency or F0s. The second experiment investigated tuning to modulation rate in the FFR. The FFR to a complex tone with a modulation rate of 213 Hz was not reduced more by an adaptor that had the same modulation rate than by an adaptor with a different modulation rate (90 or 504 Hz), thus providing no evidence that the FFR originates mainly from neurons that respond selectively to the modulation rate of the stimulus. The third experiment investigated tuning to audio frequency in the FFR using pure tones. An adaptor that had the same frequency as the target (213 or 504 Hz) did not generally reduce the FFR to the target more than an adaptor that differed in frequency (by 1.24 octaves). Thus, there was no evidence that the FFR originated mainly from neurons tuned to the frequency of the target. Instead, the results are consistent with the suggestion that the FFR for low-frequency pure tones at medium to high levels mainly originates from neurons tuned to higher frequencies. Implications for the use and interpretation of the FFR are discussed.

Autoantibody frequency in celiac disease

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Erkan Caglar

2009-01-01

Full Text Available AIM: In our study, we investigated the levels of glutamic acid decarboxylase antibody (anti-GAD, islet cell antibody (ICA, thyroperoxidase antibody (anti-TPO, thyroglobulin antibody (anti-TG, antinuclear antibodies (FANA, antibodies to double-stranded DNA (anti-ds DNA, antibody to Sjögren syndrome A antigen (anti-SSA, antibody to Sjögren syndrome B antigen (anti-SSB, Smith antibody (anti-Sm, smooth muscle antibodies (ASMA, and antimitochondrial antibody liver-kidney microsome (AMA-LKM in patients with celiac disease as compared to healthy controls and autoimmune hypothyroid patients. MATERIALS AND METHODS: A total of 31 patients with celiac disease, 34 patients with autoimmune hypothyroidism and 29 healthy subjects were included in this study. Anti-SSA, anti-SSB, anti-Sm, anti-ds DNA, anti-GAD, anti-TPO and anti-TG were studied by Enzyme-Linked Immunosorbent Assay (ELISA, and AMA-LKM, ASMA, ANA and ICA were studied by immunofluorescence. Clinical data and the results of free thyroxine-thyroid stimulating hormone (FT4-TSH were collected from the patients' files by retrospective analysis. SPSS ver 13.0 was used for data analysis, and the χ2 method was used for comparisons within groups. RESULTS: The frequency of anti-SSA, anti-SSB, anti-GAD, anti-Sm, anti-ds DNA, AMA-LKM, ASMA, ANA and ICA were not significantly different between the groups. Levels of anti-TPO and anti-TG antibodies were found to be significantly higher (<0.001 in autoimmune hypothyroid patients when compared with other groups. CONCLUSION: In previous studies, an increased frequency of autoimmune diseases of other systems has been reported in patients with celiac disease. We found that the frequency of autoimmune antibodies specific for other autoimmune diseases was not higher in celiac disease.

Frequency shifts in stimulated Raman scattering

International Nuclear Information System (INIS)

Zinth, W.; Kaiser, W.

1980-01-01

The nonresonant contributions to the nonlinear susceptibility chisup(()3) produce a frequency chirp during stimulated Raman scattering. In the case of transient stimulated Raman scattering, the spectrum of the generated Stokes pulse is found at higher frequencies than expected from spontaneous Raman data. The frequency difference can be calculated from the theory of stimulated Raman scattering. (orig.)

Low frequency electromagnetic fields in Switzerland and in Germany. Comprehensive report on various studies

International Nuclear Information System (INIS)

Stratmann, M.; Wernli, C.; Grigat, J. P.; Eisenbrandt, H.

1998-01-01

The work of two research groups has been combined in this report. Both groups have concerned themselves with the occurrence and the distribution of low-frequency magnetic fields in the human environment. The initiative for the joint documentation came from the Radiation Metrology Section of the Paul Scherrer Institute. This team has investigated the general exposure on the Swiss population due to 50 Hz magnetic fields and the exposure arising from 162/3 Hz magnetic fields in the passenger area of trains. In addition, source-related measurements and frequency analyses up to 200 kHz have been undertaken. As a second group, the 'Research Association: Electromagnetic tolerance of biological systems' of the Technical University of Braunschweig, under the direction of Prof. Karl Brinkmann, has participated in the preparation of this documentation. During the past years, the research association has prepared two extensive studies on the local and temporal distribution of magnetic field sources in human residential areas and has contributed its findings on the residential situation as a supplement to the treatment of the problems described here. Intentionally, the report has not been prepared as a scientific presentation, but rather as informative reading for specialists as well as for the general public. (author)

Recent sediment dynamics in hadal trenches: Evidence for the influence of higher-frequency (tidal, near-inertial) fluid dynamics

DEFF Research Database (Denmark)

Turnewitsch, Robert; Falahat, Saeed; Stehlikova, Jirina

2014-01-01

finds evidence for another mechanism that is superimposed on, and counteracts, the focussing mechanism. This superimposed mechanism is related to higher-frequency (tidal, near-inertial) fluid dynamics. In particular, there is evidence for a strong and negative relation between the intensity...... but significant influence on particulate-matter dynamics and food supply in hadal trenches in particular, but possibly also in the deep seas in general. A mechanism for the influence of internal tides on sediment dynamics is proposed. (C) 2014 Elsevier Ltd. All rights reserved.......In addition to high hydrostatic pressure, scarcity of food is viewed as a factor that limits the abundance and activity of heterotrophic organisms at great ocean depths, including hadal trenches. Supply of nutritious food largely relies on the flux of organic-rich particulate matter from...

DYEING OF KNITTED MICRO-VISCOSE IN THE PRESENCE OF ULTRASOUND WITH DIFFERENT FREQUENCIES

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MITIC Jelena

2014-05-01

Full Text Available In dyeing process, the object is to transport or diffuse dyes and chemicals into the fibre. Various novel processes, including ultrasound, are being introduced and studied as more environmentally friendly alternatives. Encouraging results have been reported for the use of ultrasound energy in dyeing processes of micro-viscose. The recent studies revealed major ultrasound applications advances: savings of processing time, energy, chemicals, as well as environmental protection. Influence of various ultrasound frequencies (40, 200 and 400 kHz on dyeing of micro-viscose knitted fabrics, by a reactive dye has been reported in this work. A method of reflection spectrophotometry has been employed to record reemission curves of the colored compounds. A software packet has been employed to calculate CIELab colored coordinates. Then, a comparison has been made with samples colored by conventional procedure according to CIELab76 and CMC (2:1 criteria. The use ultrasound in textile dyeing processing offers many potential advantages. The results prove better dye exhaustion by ultrasound and consequently the better fixing. The exhaustion for the bifunctional dye (containing two vinylsulphone groups reaches 71.75 % without ultrasound, and 83.69 % with 400 kHz ultrasound. The 40 kHz, 150 W ultrasound causes a cavitation of higher intensity, compared to 200 and 400 kHz ultrasounds. In this particular case, destruction of cavitation bubbles is very intensive. That is why a large amount of cavitation energy is being transformed into a heat, yielding the additional bath heating. The ultrasounds with higher frequencies (200 and 400 kHz cannot use such a strong power. The applied powering this case reaches 0.6 W. The cavitation bubbles are now smaller the cavitation disintegration is not so strong, and the energy loss is much smaller, i.e. a smaller amount of energy has been transformed into a heat. An ultrasound of an equal power, but of higher frequency contributes

Effects on Performance and Work Quality due to Low Frequency Ventilation Noise

Science.gov (United States)

Persson Waye, K.; Rylander, R.; Benton, S.; Leventhall, H. G.

1997-08-01

A pilot study was carried out to assess method evaluating effects of low frequency noise on performance. Of special interest was to study objective and subjective effects over time. Two ventilation noises were used, one of a predominantly mid frequency character and the other of a predominantly low frequency character. Both had an NC value of 35. For the study, 50 students were recruited and 30 selected on the basis of subjective reports of pressure on the eardrum after exposure to a low frequency noise. Of these, 14 randomly selected subjects aged 21 and 34 took part. The subjects performed three computerized cognitive tests in the mid frequency or the low frequency noise condition alternatively. Tests I and II were performed together with a secondary task.Questionnaires were used to evaluate subjective symptoms, effects on mood and estimated interference with the test results due to temperature, light and noise. The results showed that the subjective estimations of noise interference with performance were higher for the low frequency noise (psocial orientation (pstudied. The results further indicate that the NC curves do not fully assess the negative effects of low frequency noise on work performance.

Higher Ambitions Summit. Rapporteur Report

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Nash, Ian

2014-01-01

The Sutton Trust and Pearson two-day summit on higher ambitions in apprenticeships and vocational education drew more than 120 leaders in education, training and employment, policy makers, academics, and researchers to London. Delegates heard from political leaders stressing the importance they attach to high-quality apprenticeships. Presentations…

Public and Private Sectors in Asian Higher Education Systems: Issues and Prospects. Reports from the International Seminar on Higher Education in Asia (3rd, Hiroshima, Japan, 1987).

Science.gov (United States)

Hiroshima Univ. (Japan). Research Inst. for Higher Education.

The roles of public and private sectors of higher education in Asia and relationships to national systems are explored in reports from the Third International Seminar on Higher Education in Asia. The focus was China, Indonesia, Korea, the Philippines, Japan, and Thailand. Patterns by which national systems of higher education are differentiated…

Methods for peak-flow frequency analysis and reporting for streamgages in or near Montana based on data through water year 2015

Science.gov (United States)

Sando, Steven K.; McCarthy, Peter M.

2018-05-10

This report documents the methods for peak-flow frequency (hereinafter “frequency”) analysis and reporting for streamgages in and near Montana following implementation of the Bulletin 17C guidelines. The methods are used to provide estimates of peak-flow quantiles for 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities for selected streamgages operated by the U.S. Geological Survey Wyoming-Montana Water Science Center (WY–MT WSC). These annual exceedance probabilities correspond to 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals, respectively.Standard procedures specific to the WY–MT WSC for implementing the Bulletin 17C guidelines include (1) the use of the Expected Moments Algorithm analysis for fitting the log-Pearson Type III distribution, incorporating historical information where applicable; (2) the use of weighted skew coefficients (based on weighting at-site station skew coefficients with generalized skew coefficients from the Bulletin 17B national skew map); and (3) the use of the Multiple Grubbs-Beck Test for identifying potentially influential low flows. For some streamgages, the peak-flow records are not well represented by the standard procedures and require user-specified adjustments informed by hydrologic judgement. The specific characteristics of peak-flow records addressed by the informed-user adjustments include (1) regulated peak-flow records, (2) atypical upper-tail peak-flow records, and (3) atypical lower-tail peak-flow records. In all cases, the informed-user adjustments use the Expected Moments Algorithm fit of the log-Pearson Type III distribution using the at-site station skew coefficient, a manual potentially influential low flow threshold, or both.Appropriate methods can be applied to at-site frequency estimates to provide improved representation of long-term hydroclimatic conditions. The methods for improving at-site frequency estimates by weighting with regional

Wigner higher-order spectra: definition, properties, computation and application to transient signal analysis

OpenAIRE

Rodríguez Fonollosa, Javier; Nikias, Chrysostomos L.

1993-01-01

The Wigner higher order moment spectra (WHOS) are defined as extensions of the Wigner-Ville distribution (WD) to higher order moment spectra domains. A general class of time-frequency higher order moment spectra is also defined in terms of arbitrary higher order moments of the signal as generalizations of the Cohen’s general class of time-frequency representations. The properties of the general class of time-frequency higher order moment spectra can be related to the properties...

Validity and reliability of parental report of frequency, severity and risk factors of urinary tract infection and urinary incontinence in children.

Science.gov (United States)

Sureshkumar, Premala; Cumming, Robert G; Craig, Jonathan C

2006-06-01

We describe the validity and reliability of a questionnaire designed to determine frequency, severity and risk factors of urinary tract infection and daytime urinary incontinence in primary school-age children. Based on published validated questionnaires and advice from content experts, a questionnaire was developed and piloted in children attending outpatient clinics. Construct validity for parent report of frequency and severity of daytime urinary incontinence was tested by comparison with a daily accident diary in 52 primary school children, and criterion validity of parent report for UTI was verified by comparison with the reference standard (urine culture) in 100 primary school children. Test-retest reliability of the questionnaire was assessed in 106 children from primary schools. There was excellent agreement between the questionnaire and accident diary in severity (weighted kappa 0.94, 95% confidence intervals 0.85 to 1.03) and frequency of daytime urinary incontinence (0.88, 0.7 to 1.0). Parents reported urinary tract infection in 15% of children, compared to a positive urine culture in 8% (sensitivity 100% and specificity 68.5%). Test-retest reliability of the questionnaire was excellent (mean k 0.78, range 0.61 to 1.00). Parents overreport UTI by about 2-fold but can recall frequency and severity of daytime urinary incontinence well during a 3-month period. The developed questionnaire is a valid tool to estimate frequency, severity and risk factors of daytime urinary incontinence and UTI in primary school children.

Application of cascaded frequency multiplication to molecular spectroscopy

International Nuclear Information System (INIS)

Drouin, Brian J.; Maiwald, Frank W.; Pearson, John C.

2005-01-01

Laboratory molecular spectroscopy provides the basis for interpretation of atmospheric, planetary, and astrophysical data gathered by remote sensing. Laboratory studies of atomic and molecular signatures across the electromagnetic spectrum provide high-precision, quantitative data used to interpret the observed environment from remote measurements. Historically, the region of the spectrum above 500 GHz has been relatively unexplored due to atmospheric absorption and technical difficulties generating and detecting radiation. Laboratory spectroscopy at these frequencies has traditionally involved measurement of one or two absorption features and relied on fitting of models to the limited data. We report a new spectrometer built around a computer-controlled commercial synthesizer and millimeter-wave module driving a series of amplifiers followed by a series of wide-bandwidth frequency doublers and triplers. The spectrometer provides the ability to rapidly measure large pieces of frequency space with higher resolution, accuracy, and sensitivity than with Fourier transform infrared techniques. The approach is simple, modular, and requires no custom-built electronics or high voltage and facilitates the use of infrared data analysis techniques on complex submillimeter spectra

Frequency- and amplitude-transitioned waveforms mitigate the onset response in high-frequency nerve block

Science.gov (United States)

Gerges, Meana; Foldes, Emily L.; Ackermann, D. Michael; Bhadra, Narendra; Bhadra, Niloy; Kilgore, Kevin L.

2010-12-01

High-frequency alternating currents (HFAC) have proven to be a reversible and rapid method of blocking peripheral nerve conduction, holding promise for treatment of disorders associated with undesirable neuronal activity. The delivery of HFAC is characterized by a transient period of neural firing at its inception, termed the 'onset response'. The onset response is minimized for higher frequencies and higher amplitudes, but requires larger currents. However, the complete block can be maintained at lower frequencies and amplitudes, using lower currents. In this in vivo study on whole mammalian peripheral nerves, we demonstrate a method to minimize the onset response by initiating the block using a stimulation paradigm with a high frequency and large amplitude, and then transitioning to a low-frequency and low-amplitude waveform, reducing the currents required to maintain the conduction block. In five of six animals, it was possible to transition from a 30 kHz to a 10 kHz waveform without inducing any transient neural firing. The minimum transition time was 0.03 s. Transition activity was minimized or eliminated with longer transition times. The results of this study show that this method is feasible for achieving a nerve block with minimal onset responses and current amplitude requirements.

Reduced dream-recall frequency in left-handed adolescents: a replication.

Science.gov (United States)

Schredl, Michael; Beaton, Alan A; Henley-Einion, Josie; Blagrove, Mark

2014-01-01

The ability to recall a dream upon waking up in the morning has been linked to a broad variety of factors such as personality, creativity, sleep behaviour and cognitive function. There have been conflicting findings as to whether dream recall is related more to the right or to the left hemisphere, and conflicting findings regarding the relationship of dream-recall frequency to handedness. We have found previously that right- and mixed-handers report having more dreams than left-handers, a finding more pronounced among adolescents than adults. In the present sample of 3535 participants aged from 6 to 18 years, right-handedness and mixed/inconsistent handedness were associated with higher dream-recall frequency compared to that of left-handed persons, again especially in adolescents compared with children. Further research is required to uncover the reason for the lower frequency of dream recall by left-handers.

The effect of high-frequency ground motion on the MAPLE-X10 reactor

International Nuclear Information System (INIS)

Bhan, S.; Dunbar, S.

1989-06-01

The effect of high-frequency ground motion on structures and equipment in nuclear reactors is examined by subjecting simple linear models to selected recorded ground motions which exhibit low and high frequencies. Computed damage measures indicate that high-frequency short-duration ground motion, such as that observed in eastern North America, have a minimal effect on structures with low natural frequencies. Response spectra of high-frequency ground motion indicate that higher forces are induced in structures with high natural frequencies as compared to those induced by low-frequency ground motion. However, reported observations of earthquake damage in eastern North America suggest that high-frequency ground motion causes little of no damage to structures. This may be due to the energy absorption capability of structures. It is concluded that the response spectrum representative of ground motion observed in eastern North America may give an over-conservative measure of the response of structures with high natural frequencies, since it does not account for the typically observed short duration of high-frequency ground motion and for the energy absorption capability of structures. Detailed nonlinear analysis of specific structures with high natural frequencies should be performed to better predict the actual response. Recommendations for a nonlinear analysis of typical structures with high natural frequencies are made

Frequency control modelling - basics

DEFF Research Database (Denmark)

Hansen, Anca Daniela; Sørensen, Poul Ejnar; Zeni, Lorenzo

2016-01-01

The purpose of this report is to provide an introduction on how the system balance in an island system can be maintained by controlling the frequency. The power balance differential equation, which is fundamental in understanding the effect on the system frequency of the unbalance between...

Frequency of anomalies associated with chest deformity in physically fit male candidates reporting for military recruitment

International Nuclear Information System (INIS)

Haleem, A.; Hanif, M.S.; Majeed, F.A.; Deen, N.U.; Rahim, K.

2015-01-01

To identify the frequency of anomalies associated with chest deformity in physical fit male candidates reporting for military recruitment. Study Design: Observational. Place and Duration of Study: Department of Thoracic Surgery, CMH Rawalpindi from 1st Jan 2008 to 31 Dec 2011. Patients and Methods: Normal healthy physically fit young adolescents being recruited for army were scrolled and those exhibiting chest deformity were isolated and subjected to evaluation. Convenience sampling was carried out. All candidates of chest wall deformity thereafter underwent a thorough physical checkup, pulmonary function tests and echocardiography. Results: A total of 3735 candidates of chest deformity reported at our center for evaluation over this duration. Single deformity patients 3380 (90.5%), mixed deformity patients 355 (9.5%). We found that none of the candidates had any derangement of the lung function tests or electrocardiographic abnormality despite their deformity. However echocardiography detected an abnormality in 161 (4.3%) individuals who were otherwise asymptomatic. Conclusion: Chest deformity should be excluded before physical tests, in all the male candidates reporting for enrolment. If slightest of doubt exists that a candidate has chest deformity then he should be evaluated with echocardiography to exclude cardiac abnormality. Although the associated frequency is only 4.3% but this can subsequently result in a grave event like death. (author)

The Frequency of Reporting Ethical Issues in Human Subject Articles Published in Iranian Medical Journals: 2009-2013.

Science.gov (United States)

Astaneh, Behrooz; Khani, Parisa

2017-11-10

Researchers should strictly consider the participants' rights. They are required to document such protections as an ethical approval of the study proposal, the obtaining "informed consent", the authors' "conflict of interests", and the source of "financial support" in the published articles. The purpose of this study was to assess the frequency of reporting ethical issues in human subject articles published in Iranian medical journals during 2009-2013. In this cross-sectional study, we randomly reviewed 1460 human subject articles published in Iranian medical journals during 2009-2013 in two Persian and English language groups. Data collection was carried out by assessing articles, focusing on the documentation "ethics committee approval", patients' "informed consent", "financial support", "confidentiality", and "conflict of interest". Of 1460 evaluated articles, 443 (30.3%) reported "ethics committee approval", 686 (47.0%) reported "informed consent", 594 (40.7%) reported "financial support", and 341 (23.4%) reported "conflict of interest". 13% of the articles referred to patients' confidentiality in their text. There was a significant association between these ethical documentations and the year of publication. Articles published in English language journals reported "ethics committee approval", "financial support", and "conflict of interest" significantly more than Persian language journals, but the frequency of "informed consent" was similar. Ethical documentation rate in Iranian medical journals is not up to the expected standards of reputable journals which might be related to a lack of awareness and the education of the authors and the journal's editors. Precise reporting of ethical considerations in medical articles by authors are recommended. It is suggested journals and policymakers pay more attention to reporting this issue while providing standard guidelines in this regard.

Broadcast Communication by System Frequency Modulation

DEFF Research Database (Denmark)

Douglass, Philip James; You, Shi; Heussen, Kai

2012-01-01

Load controllers available today can measure AC system frequency and react to frequency deviations. A system operator can communicate to frequency sensitive loads by changing the set-points of the system’s dispatchable frequency regulation resources. Explicitly signaling system state by generating...... off-nominal system frequency values is a novel narrowband broadcast communications channel between system operators and frequency sensitive distributed energy resources (FS-DER). The feasibility of the proposed system is evaluated on an existing island power system in Denmark. This study shows...... that within standard frequency quality constraints, 4 distinct symbols are feasible on the island. However, the overarching imperative of system stability prevents the symbols from having arbitrary meanings. Higher frequency values must translate into greater consumption from loads, and vice versa. Within...

Dynamic conductivity from audio to optical frequencies of semiconducting manganites approaching the metal-insulator transition

Science.gov (United States)

Lunkenheimer, P.; Mayr, F.; Loidl, A.

2006-07-01

We report the frequency-dependent conductivity of the manganite system La1-xSrxMnO3 (x0.2) when approaching the metal-insulator transition from the insulating side. Results from low-frequency dielectric measurements are combined with spectra in the infrared region. For low doping levels the behavior is dominated by hopping transport of localized charge carriers at low frequencies and by phononic and electronic excitations in the infrared region. For the higher Sr contents the approach of the metallic state is accompanied by the successive suppression of the hopping contribution at low frequencies and by the development of polaronic excitations in the infrared region, which finally become superimposed by a strong Drude contribution in the fully metallic state.

Nonelite exercise-related injuries: participant reported frequency, management and perceptions of their consequences.

Science.gov (United States)

Grice, A; Kingsbury, S R; Conaghan, P G

2014-04-01

This mixed methods study explored the frequency of sport/exercise-related injuries in nonelite sport, participant-reported management and perceptions of potential injury consequences. Focus group participants, who trained two to four times a week and had previously sustained musculoskeletal sports-related injuries, reported seeking medical advice secondary to advice from teammates or online research. General practitioners were viewed as gatekeepers to specialist secondary care and less able to effectively treat sport-related injuries. Participants displayed limited awareness of potential future implications of injury, and considered physical and psychological benefits of exercise more valuable than potential injury-associated risks. In the survey of physically active people, over half reported sustaining an exercise-related injury (562/1002, 56%). Previously injured respondents were less likely to consider consulting a health professional for injury-related advice than those with no injury history (45% vs 64%; P sports-related injuries and a lack of awareness about appropriate injury management and potential consequences of injury, particularly in the long-term. © 2013 The Authors. Scandinavian Journal of Medicine & Science in Sports published by John Wiley & Sons Ltd.

Characterization of the frequency and nature of bleed air contamination events in commercial aircraft.

Science.gov (United States)

Shehadi, M; Jones, B; Hosni, M

2016-06-01

Contamination of the bleed air used to pressurize and ventilate aircraft cabins is of concern due to the potential health and safety hazards for passengers and crew. Databases from the Federal Aviation Administration, NASA, and other sources were examined in detail to determine the frequency of bleed air contamination incidents. The frequency was examined on an aircraft model basis with the intent of identifying aircraft make and models with elevated frequencies of contamination events. The reported results herein may help investigators to focus future studies of bleed air contamination incidents on smaller number of aircrafts. Incident frequency was normalized by the number of aircraft, number of flights, and flight hours for each model to account for the large variations in the number of aircraft of different models. The focus of the study was on aircraft models that are currently in service and are used by major airlines in the United States. Incidents examined in this study include those related to smoke, oil odors, fumes, and any symptom that might be related to exposure to such contamination, reported by crew members, between 2007 and 2012, for US-based carriers for domestic flights and all international flights that either originated or terminated in the US. In addition to the reported frequency of incidents for different aircraft models, the analysis attempted to identify propulsion engines and auxiliary power units associated with aircrafts that had higher frequencies of incidents. While substantial variations were found in frequency of incidents, it was found that the contamination events were widely distributed across nearly all common models of aircraft. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Laser frequency modulator for modulating a laser cavity

Science.gov (United States)

Erbert, Gaylen V.

1992-01-01

The present invention relates to a laser frequency modulator for modulating a laser cavity. It is known in the prior art to utilize a PZT (piezoelectric transducer) element in combination with a mirror to change the cavity length of a laser cavity (which changes the laser frequency). Using a PZT element to drive the mirror directly is adequate at frequencies below 10 kHz. However, in high frequency applications (100 kHz and higher) PZT elements alone do not provide a sufficient change in the cavity length. The present invention utilizes an ultrasonic concentrator with a PZT element and mirror to provide modulation of the laser cavity. With an ultrasonic concentrator, the mirror element at the end of a laser cavity can move at larger amplitudes and higher frequencies.

Potential applications of high-frequency dielectric heating in mechanical forest industry in Finland. Suurtaajuuskuivauksen kaeyttoemahdollisuudet mekaanisessa metsaeteollisuudessa

Energy Technology Data Exchange (ETDEWEB)

Siimes, H.; Tarvainen, V.; Peraeniitty, M.

1986-10-01

The present study of potential applications of dielectric technology in wood drying was made by using availaable literature and contacting experts and equipment manufacturers. The report gives an account of drying results and equipment applications. It also includes an overview of the principles of high-frequency drying, the equipment required for high-frequency energy production and the dielectric properties of wood. In conclusion, the economy of high-frequency drying and factors which influence it are evaluated and the most economic applications are defined. In high-frequency drying, wood warms up the most in interior sections with a high moisture content. The risk for overdrying of the surface is thus small, and the wood dries much faster than in convective drying. To be economic, the high capital and energy costs of high-frequency drying should be compensated by fewer drying defects, a higher yield in the final use of the wood, higher storehouse throughput, speedier deliveries and lower total energy consumption. Other characteristic features of economic high-frequency drying are that only a small amount of moisture is removed and the wood is thick, difficult to dry and expensive. High-frequency applications which merit further study in Finland are drying of thick joinery-quality sawn goods and redrying of veneers and chips.

Modernisation of Higher Education in Europe 2014: Access, Retention and Employability. Eurydice Report

Science.gov (United States)

Crosier, David; Horvath, Anna; Kerpanova, Viera; Kocanova, Daniela; Riiheläinen, Jari Matti

2014-01-01

The report sheds light on current national and institutional policies and practices aimed at increasing and widening access, reducing student dropout, and improving the employability of higher education graduates in Europe. The primary objective is to support Member States in their reform efforts by outlining and analysing national policies, and…

Component external leakage and rupture frequency estimates

International Nuclear Information System (INIS)

Eide, S.A.; Khericha, S.T.; Calley, M.B.; Johnson, D.A.; Marteeny, M.L.

1991-11-01

In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results

Frequency of chronic complications of type II diabetes

International Nuclear Information System (INIS)

Basit, A.; Hydrie, M.Z.I.; Ahmedani, M.Y.; Masood, Q.; Hakeem, R.

2004-01-01

Objective: To assess the frequency of chronic complications of type II diabetes in subjects attending a tertiary care Unit in Karachi, Pakistan. Subjects and Methods: Computerized clinical records of 2199 type II diabetic subjects were analyzed for this study. The clinical and laboratory variables were statistically evaluated with significance at p. Results: Means of glycosylated hemoglobin HbA1c, fasting and random plasma glucose levels, systolic blood pressure, triglycerides and high density lipoproteins (HDL) were higher than the risk indicator value for both genders (p<0.005). Mean body mass index and total blood cholesterol was higher for females only. Hyperglycemia was present in 88%, high HbA1c in 81%, low HDL in 81%, obesity in 66% and hypertriglyceridemia in 54%, neuropathy in 36% proteinuria in 28% and hypertension in 50% of the subjects. Frequency of obesity, low HDL and hypertension was higher among females (p<0.001 in each case). Retinopathy (p<0.05), nephropathy (p<0.005), neuropathy (p<0.005) and foot ulcers (p<0.001) were higher among males. Frequency of obesity was significantly higher among those with shorter duration and in younger group while frequency of other complications was higher among those with longer duration and in the older groups. Conclusion: Higher rates of complications were observed compared to previous studies. Certain variables showed significant association with gender and age as described above. (author)

Reported off-leash frequency and perception of risk for gastrointestinal parasitism are not associated in owners of urban park-attending dogs: A multifactorial investigation.

Science.gov (United States)

Smith, Anya F; Semeniuk, Christina A D; Rock, Melanie J; Massolo, Alessandro

2015-07-01

Associations between park use and infections with gastrointestinal (GI) parasites in dogs (Canis familiaris) have been previously observed, suggesting park use may pose risks for infection in dogs, and potentially, in humans. This study was conducted to establish the overall level of perceived risk of parasitism in dogs, the frequency of unleashing dogs in parks, and to determine if dog owners' risk perceptions of parasite transmission among humans and dogs are associated with the reported frequency of unleashing dogs. From June to September 2010, 635 surveys were administered to dog owners in nine city parks in Calgary, Alberta, by the lead author to explore dog-walking behaviors in parks under differing leashing regulations. From these, a subset of 316 questionnaires were analyzed to examine associations between behavioral and dog demographic factors, risk perception and acceptability of perceived risks of dog and human parasitism, and education regarding parasitism in dogs and humans. Multivariate statistics were conducted using three separate Chi-Square Automatic Interaction Detection (CHAID) decision trees to model risk perception of dogs becoming parasitized while in the park, risk perception of zoonotic transmission, and off-leash frequency. Predictors included recreational behaviors, dog demographics, risk perception of park-based and zoonotic transmission, education regarding parasites, and leashing regulations (e.g. on-leash, off-leash, or mixed management parks). The perceived risk of park-based transmission was relatively higher than perception of zoonotic transmission and the majority of people unleashed their dogs at least some of the time. Risk perception was not associated with off-leash frequency in dogs and risk perception and off-leash frequency were associated with factors other than each other. The results suggest owners may underestimate the potential risks for parasitism related to some dog-walking behaviours, and are relevant for public and

Frequency Response Analysis Tool

Energy Technology Data Exchange (ETDEWEB)

Etingov, Pavel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kosterev, Dmitry [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dai, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-12-01

Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

Associations between the self-reported frequency of hearing chemical alarms in theater and regional brain volume in Gulf War Veterans.

Science.gov (United States)

Chao, Linda L; Reeb, Rosemary; Esparza, Iva L; Abadjian, Linda R

2016-03-01

We previously reported evidence of reduced cortical gray matter (GM), white matter (WM), and hippocampal volume in Gulf War (GW) veterans with predicted exposure to low-levels of nerve agent according to the 2000 Khamisiyah plume model analysis. Because there is suggestive evidence that other nerve agent exposures may have occurred during the Gulf War, we examined the association between the self-reported frequency of hearing chemical alarms sound during deployment in the Gulf War and regional brain volume in GW veterans. Ninety consecutive GW veterans (15 female, mean age: 52±8years) participating in a VA-funded study underwent structural magnetic resonance imaging (MRI) on a 3T scanner. Freesurfer (version 5.1) was used to obtain regional measures of cortical GM, WM, hippocampal, and insula volume. Multiple linear regression was used to determine the association between the self-reported frequencies of hearing chemical alarms during the Gulf War and regional brain volume. There was an inverse association between the self-reported frequency of hearing chemical alarms sound and total cortical GM (adjusted p=0.007), even after accounting for potentially confounding demographic and clinical variables, the veterans' current health status, and other concurrent deployment-related exposures that were correlated with hearing chemical alarms. Post-hoc analyses extended the inverse relationship between the frequency of hearing chemical alarms to GM volume in the frontal (adjusted p=0.02), parietal (adjusted p=0.01), and occipital (adjusted p=0.001) lobes. In contrast, regional brain volumes were not significantly associated with predicted exposure to the Khamisiyah plume or with Gulf War Illness status defined by the Kansas or Centers for Disease Control and Prevention criteria. Many veterans reported hearing chemical alarms sound during the Gulf War. The current findings suggest that exposure to substances that triggered those chemical alarms during the Gulf War likely

Dynamic conductivity from audio to optical frequencies of semiconducting manganites approaching the metal-insulator transition

International Nuclear Information System (INIS)

Lunkenheimer, P.; Mayr, F.; Loidl, A.

2006-01-01

We report the frequency-dependent conductivity of the manganite system La 1-x Sr x MnO 3 (x≤0.2) when approaching the metal-insulator transition from the insulating side. Results from low-frequency dielectric measurements are combined with spectra in the infrared region. For low doping levels the behavior is dominated by hopping transport of localized charge carriers at low frequencies and by phononic and electronic excitations in the infrared region. For the higher Sr contents the approach of the metallic state is accompanied by the successive suppression of the hopping contribution at low frequencies and by the development of polaronic excitations in the infrared region, which finally become superimposed by a strong Drude contribution in the fully metallic state. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Interocular transfer of spatial adaptation is weak at low spatial frequencies.

Science.gov (United States)

Baker, Daniel H; Meese, Tim S

2012-06-15

Adapting one eye to a high contrast grating reduces sensitivity to similar target gratings shown to the same eye, and also to those shown to the opposite eye. According to the textbook account, interocular transfer (IOT) of adaptation is around 60% of the within-eye effect. However, most previous studies on this were limited to using high spatial frequencies, sustained presentation, and criterion-dependent methods for assessing threshold. Here, we measure IOT across a wide range of spatiotemporal frequencies, using a criterion-free 2AFC method. We find little or no IOT at low spatial frequencies, consistent with other recent observations. At higher spatial frequencies, IOT was present, but weaker than previously reported (around 35%, on average, at 8c/deg). Across all conditions, monocular adaptation raised thresholds by around a factor of 2, and observers showed normal binocular summation, demonstrating that they were not binocularly compromised. These findings prompt a reassessment of our understanding of the binocular architecture implied by interocular adaptation. In particular, the output of monocular channels may be available to perceptual decision making at low spatial frequencies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microwave Frequency Comb from a Semiconductor in a Scanning Tunneling Microscope.

Science.gov (United States)

Hagmann, Mark J; Yarotski, Dmitry A; Mousa, Marwan S

2017-04-01

Quasi-periodic excitation of the tunneling junction in a scanning tunneling microscope, by a mode-locked ultrafast laser, superimposes a regular sequence of 15 fs pulses on the DC tunneling current. In the frequency domain, this is a frequency comb with harmonics at integer multiples of the laser pulse repetition frequency. With a gold sample the 200th harmonic at 14.85 GHz has a signal-to-noise ratio of 25 dB, and the power at each harmonic varies inversely with the square of the frequency. Now we report the first measurements with a semiconductor where the laser photon energy must be less than the bandgap energy of the semiconductor; the microwave frequency comb must be measured within 200 μm of the tunneling junction; and the microwave power is 25 dB below that with a metal sample and falls off more rapidly at the higher harmonics. Our results suggest that the measured attenuation of the microwave harmonics is sensitive to the semiconductor spreading resistance within 1 nm of the tunneling junction. This approach may enable sub-nanometer carrier profiling of semiconductors without requiring the diamond nanoprobes in scanning spreading resistance microscopy.

Diversity Leadership in Higher Education. ASHE Higher Education Report, Volume 32, Number 3

Science.gov (United States)

Aguirre, Adalberto, Jr., Ed.; Martinez, Ruben O., Ed.

2006-01-01

This monograph examines and discusses the context for diversity leadership roles and practices in higher education by using research and theoretical and applied literatures from a variety of fields, including the social sciences, business, and higher education. Framing the discussion on leadership in this monograph is the perspective that American…

RF MEMS Fractal Capacitors With High Self-Resonant Frequencies

KAUST Repository

Elshurafa, Amro M.

2012-07-23

This letter demonstrates RF microelectromechanical systems (MEMS) fractal capacitors possessing the highest reported self-resonant frequencies (SRFs) in PolyMUMPS to date. Explicitly, measurement results show SRFs beyond 20 GHz. Furthermore, quality factors higher than 4 throughout a band of 1-15 GHz and reaching as high as 28 were achieved. Additional benefits that are readily attainable from implementing fractal capacitors in MEMS are discussed, including suppressing residual stress warping, eliminating the need for etching holes, and reducing parasitics. The latter benefits were acquired without any fabrication intervention. © 2011 IEEE.

Frequency of helicobacter pylori infection using /sup 13/C-UBT in asymptomatic individuals of Barakaho, Islamabad, Pakistan

International Nuclear Information System (INIS)

Rasheed, F.; Ahmad, T.; Bilal, R.

2011-01-01

High frequency of Helicobacter (H.) pylori infection has been reported in Pakistan mainly for dyspeptic patients, while the published data is inadequate regarding asymptomatic population. The non-invasive /sup 13/C urea breath test (UBT) was used to determine the frequency of H. pylori infection in 516 asymptomatic individuals and to find out its association with gender and age. Overall prevalence was 74.4% (384/516) while 63.5% (113/178) children were positive for 13C-UBT and the percentage increased with age in both the genders with significantly higher prevalence in adolescents (p=0.003) and adults (p < 0.001). Moreover, there was non-significant difference between the prevalence of H. pylori infection in males and females in all age categories. The reported high frequency of H. pylori infection warrants further studies to identify epidemiological and environmental risk factors. (author)

Parent-Adolescent Informant Discrepancies of Social Skill Importance and Social Skill Engagement for Higher-Functioning Adolescents with Autism Spectrum Disorder

Science.gov (United States)

McMahon, Camilla M.; Solomon, Marjorie

2015-01-01

Parent- and adolescent-report of social skill importance and social skill engagement on the Social Skills Rating System (Gresham & Elliott, 1990) were assessed in higher-functioning adolescents with Autism Spectrum Disorder (ASD). Compared to parents, adolescents reported that social skills were less important. Additionally, adolescents reported that they engaged in social skills more frequently than parents reported them to be engaging in social skills. Parents, but not adolescents, reported a discrepancy between importance and engagement, such that the importance of social skills was rated higher than the frequency of adolescent engagement in social skills. These results suggest that social skills interventions for individuals with ASD may need to target awareness of social skill importance and accurate monitoring of social skill engagement. PMID:26077952

Amplitude of Low-Frequency Fluctuations in Multiple-Frequency Bands in Acute Mild Traumatic Brain Injury.

Science.gov (United States)

Zhan, Jie; Gao, Lei; Zhou, Fuqing; Bai, Lijun; Kuang, Hongmei; He, Laichang; Zeng, Xianjun; Gong, Honghan

2016-01-01

Functional disconnectivity during the resting state has been observed in mild traumatic brain injury (mTBI) patients during the acute stage. However, it remains largely unknown whether the abnormalities are related to specific frequency bands of the low-frequency oscillations (LFO). Here, we used the amplitude of low-frequency fluctuations (ALFF) to examine the amplitudes of LFO in different frequency bands (slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.073 Hz; and typical: 0.01-0.08 Hz) in patients with acute mTBI. A total of 24 acute mTBI patients and 24 age-, sex-, and education-matched healthy controls participated in this study. In the typical band, acute mTBI patients showed lower standardized ALFF in the right middle frontal gyrus and higher standardized ALFF in the right lingual/fusiform gyrus and left middle occipital gyrus. Further analyses showed that the difference between groups was concentrated in a narrower (slow-4) frequency band. In the slow-5 band, mTBI patients only exhibited higher standardized ALFF in the occipital areas. No significant correlation between the mini-mental state examination score and the standardized ALFF value was found in any brain region in the three frequency bands. Finally, no significant interaction between frequency bands and groups was found in any brain region. We concluded that the abnormality of spontaneous brain activity in acute mTBI patients existed in the frontal lobe as well as in distributed brain regions associated with integrative, sensory, and emotional roles, and the abnormal spontaneous neuronal activity in different brain regions could be better detected by the slow-4 band. These findings might contribute to a better understanding of local neural psychopathology of acute mTBI. Future studies should take the frequency bands into account when measuring intrinsic brain activity of mTBI patients.

Amplitude of low-frequency fluctuations in multiple-frequency bands in acute mild traumatic brain injury

Directory of Open Access Journals (Sweden)

Jie eZhan

2016-02-01

Full Text Available Functional disconnectivity during the resting state has been observed in mild traumatic brain injury (mTBI patients during the acute stage. However, it remains largely unknown whether the abnormalities are related to specific frequency bands of the low-frequency oscillations (LFO. Here, we used the amplitude of low-frequency fluctuations (ALFF to examine the amplitudes of LFO in different frequency bands (slow-5: 0.01–0.027 Hz; slow-4: 0.027–0.073 Hz; and typical: 0.01–0.08 Hz in patients with acute mTBI. A total of 24 acute mTBI patients and 24 age-, sex-, and education-matched healthy controls (HC participated in this study. In the typical band, acute mTBI patients showed lower standardized ALFF in the right middle frontal gyrus and higher standardized ALFF in the right lingual/fusiform gyrus and left middle occipital gyrus. Further analyses showed that the difference between groups was concentrated in a narrower (slow-4 frequency band. In the slow-5 band, mTBI patients only exhibited higher standardized ALFF in the occipital areas. No significant correlation between the MMSE score and the standardized ALFF value was found in any brain region in the three frequency bands. Finally, no significant interaction between frequency bands and groups was found in any brain region. We concluded that the abnormality of spontaneous brain activity in acute mTBI patients existed in the frontal lobe as well as in distributed brain regions associated with integrative, sensory and emotional roles, and the abnormal spontaneous neuronal activity in different brain regions could be better detected by the slow-4 band. These findings might contribute to a better understanding of local neural psychopathology of acute mTBI. Future studies should take the frequency bands into account when measuring intrinsic brain activity of mTBI patients.

New Mexico Higher Education Department Annual Report, 2016

Science.gov (United States)

New Mexico Higher Education Department, 2016

2016-01-01

The New Mexico Higher Education Department strives to bring leadership, guidance, and assistance to New Mexico's higher education stakeholders. The HED is committed to promoting best practices, institutional fiscal responsibility, and student achievement. Everything the agency does is through the lens of supporting New Mexico's higher education…

Employability: A Review of the Literature 2012 to 2016. A Report for the Higher Education Academy

Science.gov (United States)

Artess, Jane; Hooley, Tristram; Mellors-Bourne, Robin

2017-01-01

This report for the Higher Education Academy, in partnership with the University of Derby and the Career Development Organisation, examined 187 pieces of research published between 2012 and 2016 that describe how the subject of employability has been addressed during this period. It draws out some of the key implications for higher education…

Frequency, severity and risk factors for urinary and faecal incontinence at 4 years postpartum: a prospective cohort.

Science.gov (United States)

Gartland, D; MacArthur, C; Woolhouse, H; McDonald, E; Brown, S J

2016-06-01

To investigate frequency, severity and risk factors for urinary incontinence and faecal incontinence 4 years after a first birth. Prospective pregnancy cohort study. Melbourne, Australia. A total of 1011 nulliparous women recruited in early pregnancy. Participants were followed up at 32 weeks of gestation; then at 3, 6, 9 and 12 months and 4 years postpartum. Frequency and severity of urinary and faecal incontinence. At 4 years, 29.6% of women reported urinary incontinence and 7.1% reported faecal incontinence. Compared with women having only spontaneous vaginal births, women who delivered exclusively by caesarean section were less likely to have urinary incontinence at 4 years postpartum (adjusted odds ratio 0.4, 95% confidence interval 0.3-0.6). Women who reported urinary incontinence before or during the index pregnancy, and those experiencing symptoms in the first year postpartum had increased odds of incontinence at 4 years, with the highest odds (6-12 times higher) among women who had previously reported moderate or severe symptoms. The odds of reporting faecal incontinence at 4 years were two to six times higher for women experiencing symptoms in pregnancy, and around four to eight times higher for those with symptoms in the first year postpartum. Urinary and faecal incontinence are prevalent conditions 4 years after a first birth. Women reporting urinary or faecal incontinence during pregnancy had markedly higher odds of reporting symptoms at 4 years postpartum, suggesting a need for further investigation and elucidation of aetiological pathways involving nonbirth-related risk factors. Moderate/severe incontinence prevalent 4 years after first birth in population cohort. Prior symptoms are biggest predictor. © 2015 Royal College of Obstetricians and Gynaecologists.

Coital frequency and infertility: which male factors predict less frequent coitus among infertile couples?

Science.gov (United States)

Perlis, Nathan; Lo, Kirk C; Grober, Ethan D; Spencer, Leia; Jarvi, Keith

2013-08-01

To determine the coital frequency among infertile couples and which factors are associated with less frequent coitus. Cross-sectional study. Tertiary-level male infertility clinic. A total of 1,298 infertile men. Administration of computer-based survey, semen analysis, and serum hormone evaluation. Monthly coital frequency. A total of 1,298 patients presented to clinic for infertility consultation and completed the computer-based survey. The median male age was 35 years (interquartile range [IQR] 32-39 years) and the median duration of infertility was 2 years (IQR 1-4 years) before consultation. Median monthly coital frequency was seven (IQR 5-10; range 0-40); 24% of couples were having intercourse ≤ 4 times per month. Overall, 0.6%, 2.7%, 4.8%, 5.8%, and 10.8% of the men reported having intercourse 0, 1, 2, 3, and 4 times per month, respectively. When simultaneously taking into account the influence of age, libido, erectile function, and semen volume on coital frequency, older patients had 1.05 times higher odds (per year of age) of less frequent coitus (odds ratio 1.05, 95% confidence interval 1.03-1.08). In addition, patients with better erectile function had 1.12 times higher odds (per point on Sexual Health Inventory for Men scale) of more frequent coitus (odds ratio 1.12, 95% confidence interval 1.09-1.18). Similar to the general population, most infertile couples report having coitus more than four times per month. Older male age and erectile dysfunction are independent risk factors for less frequent coitus among infertile men, which could have an impact on fertility. Coital frequency should be considered in infertility assessments. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Frogs Call at a Higher Pitch in Traffic Noise

Directory of Open Access Journals (Sweden)

Kirsten M. Parris

2009-06-01

Full Text Available Male frogs call to attract females for mating and to defend territories from rival males. Female frogs of some species prefer lower-pitched calls, which indicate larger, more experienced males. Acoustic interference occurs when background noise reduces the active distance or the distance over which an acoustic signal can be detected. Birds are known to call at a higher pitch or frequency in urban noise, decreasing acoustic interference from low-frequency noise. Using Bayesian linear regression, we investigated the effect of traffic noise on the pitch of advertisement calls in two species of frogs, the southern brown tree frog (Litoria ewingii and the common eastern froglet (Crinia signifera. We found evidence that L. ewingii calls at a higher pitch in traffic noise, with an average increase in dominant frequency of 4.1 Hz/dB of traffic noise, and a total effect size of 123 Hz. This frequency shift is smaller than that observed in birds, but is still large enough to be detected by conspecific frogs and confer a significant benefit to the caller. Mathematical modelling predicted a 24% increase in the active distance of a L. ewingii call in traffic noise with a frequency shift of this size. Crinia signifera may also call at a higher pitch in traffic noise, but more data are required to be confident of this effect. Because frog calls are innate rather than learned, the frequency shift demonstrated by L. ewingii may represent an evolutionary adaptation to noisy conditions. The phenomenon of frogs calling at a higher pitch in traffic noise could therefore constitute an intriguing trade-off between audibility and attractiveness to potential mates.

Low frequency noise in p-InAsSbP/n-InAs infrared photodiodes

Science.gov (United States)

Dyakonova, N.; Karandashev, S. A.; Levinshtein, M. E.; Matveev, B. A.; Remennyi, M. A.

2018-06-01

We report the first experimental study of low-frequency noise in p-InAsSbP/n-InAs infrared photodiodes. For forward bias, experiments have been carried out at 300 and 77 K, in the photovoltaic regime the measurements have been done at 300 K. At room temperature the current noise spectral density, SI , exhibits the ∼1/f frequency dependence. For low currents, I ≤ I 0 ∼ 4 × 10‑5 A, S I is proportional to I 2, at higher currents this dependence changes to S I ∼ I. At 77 K the noise spectral density is significantly higher than at 300 K, and Lorentzian contributions to noise are observed. The current dependences of spectral noise density can be approximately described as S I ∼ I 1.5 and show particularities suggesting the contribution of defects.

Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

Directory of Open Access Journals (Sweden)

Carlijn van den Boomen

Full Text Available Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed in a higher spatial frequency (reference frequency: 6 cycles per degree discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135. Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28 punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be

Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

Science.gov (United States)

van den Boomen, Carlijn; Peters, Judith Carolien

2017-01-01

Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed) in a higher spatial frequency (reference frequency: 6 cycles per degree) discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135). Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28) punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials) and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be used in future

Single frequency thermal wave radar: A next-generation dynamic thermography for quantitative non-destructive imaging over wide modulation frequency ranges.

Science.gov (United States)

Melnikov, Alexander; Chen, Liangjie; Ramirez Venegas, Diego; Sivagurunathan, Koneswaran; Sun, Qiming; Mandelis, Andreas; Rodriguez, Ignacio Rojas

2018-04-01

Single-Frequency Thermal Wave Radar Imaging (SF-TWRI) was introduced and used to obtain quantitative thickness images of coatings on an aluminum block and on polyetherketone, and to image blind subsurface holes in a steel block. In SF-TWR, the starting and ending frequencies of a linear frequency modulation sweep are chosen to coincide. Using the highest available camera frame rate, SF-TWRI leads to a higher number of sampled points along the modulation waveform than conventional lock-in thermography imaging because it is not limited by conventional undersampling at high frequencies due to camera frame-rate limitations. This property leads to large reduction in measurement time, better quality of images, and higher signal-noise-ratio across wide frequency ranges. For quantitative thin-coating imaging applications, a two-layer photothermal model with lumped parameters was used to reconstruct the layer thickness from multi-frequency SF-TWR images. SF-TWRI represents a next-generation thermography method with superior features for imaging important classes of thin layers, materials, and components that require high-frequency thermal-wave probing well above today's available infrared camera technology frame rates.

Single frequency thermal wave radar: A next-generation dynamic thermography for quantitative non-destructive imaging over wide modulation frequency ranges

Science.gov (United States)

Melnikov, Alexander; Chen, Liangjie; Ramirez Venegas, Diego; Sivagurunathan, Koneswaran; Sun, Qiming; Mandelis, Andreas; Rodriguez, Ignacio Rojas

2018-04-01

Single-Frequency Thermal Wave Radar Imaging (SF-TWRI) was introduced and used to obtain quantitative thickness images of coatings on an aluminum block and on polyetherketone, and to image blind subsurface holes in a steel block. In SF-TWR, the starting and ending frequencies of a linear frequency modulation sweep are chosen to coincide. Using the highest available camera frame rate, SF-TWRI leads to a higher number of sampled points along the modulation waveform than conventional lock-in thermography imaging because it is not limited by conventional undersampling at high frequencies due to camera frame-rate limitations. This property leads to large reduction in measurement time, better quality of images, and higher signal-noise-ratio across wide frequency ranges. For quantitative thin-coating imaging applications, a two-layer photothermal model with lumped parameters was used to reconstruct the layer thickness from multi-frequency SF-TWR images. SF-TWRI represents a next-generation thermography method with superior features for imaging important classes of thin layers, materials, and components that require high-frequency thermal-wave probing well above today's available infrared camera technology frame rates.

Charting the Future of US Higher Education: A Look at the Spellings Report Ten Years Later

Science.gov (United States)

Neuman, W. Russell

2017-01-01

September marked the tenth anniversary of the release of "A Test of Leadership: Charting the Future of US Higher Education," the report of the Secretary of Education's Commission on the Future of Higher Education, also known as the Spellings Commission. Blue ribbon panels rarely say much that is new or stimulate much sustained attention,…

Identification of low frequency anti-erythrocyte antibodies in chronically transfused patient with beta-thalassemia: a case report

Directory of Open Access Journals (Sweden)

Ana Rúbia Magalhães Ferreira

2015-02-01

Full Text Available The rate of erythrocyte alloimmunization in tranfusion-dependent patients can reach 50%, although the frequency of clinically relevant antibodies in transfused patients is not fully known, it is estimated that about 1% of patients are sensitized to each unit of transfused RBCs. The aim of this study is to report the case of  an 11-year-old girl with ?-thalassemia major, chronically transfused, which was detected in pre-transfusion protocol, the presence of two rare anti-erythrocyte antibodies: anti-Colton b (anti-Cob and anti-Lutheran 14 (anti-Lu14. To survey the clinical and laboratory patient history, research records filed in the archives of the university hospital in which the patient is monitored system was performed. The phenotyping erythrocyte in multitransfused patients is essential to decrease the risk of complications due to alloimmunization and estimate the availability of compatible blood. Thus, the report of this case may contribute to increase knowledge about of the real frequency of uncommon anti-erythrocyte antibodies in thalassemic patients.

Analysis of rail accident frequencies and severities for the assessment of radioactive material transport risk - Summary report

International Nuclear Information System (INIS)

Heywood, J.D.; Schwartz, G.; Fett, J.

2001-01-01

This shortened version of the final contractual report to the European Commission DGXVII summarises the work performed and the conclusions drawn from consideration, comparison and analysis of transport accident frequency and severity assessment methods for radioactive material transport by rail. This paper aims to provide an introduction to the study whose final report is 155 pages in length. The findings are based on a comprehensive review of transport risk assessment methods and related databases available to EU member states. The emphasis has been on the probabilistic accident severity and frequency assessment methodologies developed and used by the organisations involved in this EU-funded research project - AEA Technology and GRS. The results should be of major assistance in the understanding and development of standardised quantitative risk assessment models. Further work is suggested to underpin the development of a harmonised accident methodology including the collection of more detailed rail data and analysis on a year by year basis as well as further consideration of the assumptions made for fire accident scenarios. (author)

Modulation frequency as a cue for auditory speed perception.

Science.gov (United States)

Senna, Irene; Parise, Cesare V; Ernst, Marc O

2017-07-12

Unlike vision, the mechanisms underlying auditory motion perception are poorly understood. Here we describe an auditory motion illusion revealing a novel cue to auditory speed perception: the temporal frequency of amplitude modulation (AM-frequency), typical for rattling sounds. Naturally, corrugated objects sliding across each other generate rattling sounds whose AM-frequency tends to directly correlate with speed. We found that AM-frequency modulates auditory speed perception in a highly systematic fashion: moving sounds with higher AM-frequency are perceived as moving faster than sounds with lower AM-frequency. Even more interestingly, sounds with higher AM-frequency also induce stronger motion aftereffects. This reveals the existence of specialized neural mechanisms for auditory motion perception, which are sensitive to AM-frequency. Thus, in spatial hearing, the brain successfully capitalizes on the AM-frequency of rattling sounds to estimate the speed of moving objects. This tightly parallels previous findings in motion vision, where spatio-temporal frequency of moving displays systematically affects both speed perception and the magnitude of the motion aftereffects. Such an analogy with vision suggests that motion detection may rely on canonical computations, with similar neural mechanisms shared across the different modalities. © 2017 The Author(s).

Isoflurane Impairs Low-Frequency Feedback but Leaves High-Frequency Feedforward Connectivity Intact in the Fly Brain.

Science.gov (United States)

Cohen, Dror; van Swinderen, Bruno; Tsuchiya, Naotsugu

2018-01-01

Hierarchically organized brains communicate through feedforward (FF) and feedback (FB) pathways. In mammals, FF and FB are mediated by higher and lower frequencies during wakefulness. FB is preferentially impaired by general anesthetics in multiple mammalian species. This suggests FB serves critical functions in waking brains. The brain of Drosophila melanogaster (fruit fly) is also hierarchically organized, but the presence of FB in these brains is not established. Here, we studied FB in the fly brain, by simultaneously recording local field potentials (LFPs) from low-order peripheral structures and higher-order central structures. We analyzed the data using Granger causality (GC), the first application of this analysis technique to recordings from the insect brain. Our analysis revealed that low frequencies (0.1-5 Hz) mediated FB from the center to the periphery, while higher frequencies (10-45 Hz) mediated FF in the opposite direction. Further, isoflurane anesthesia preferentially reduced FB. Our results imply that the spectral characteristics of FF and FB may be a signature of hierarchically organized brains that is conserved from insects to mammals. We speculate that general anesthetics may induce unresponsiveness across species by targeting the mechanisms that support FB.

Frequency-tunable SRF cavities for microwave opto-mechanics

Science.gov (United States)

Castelli, Alessandro; Martinez, Luis; Pate, Jacob; Thompson, Johnathon; Chiao, Raymond; Sharping, Jay

Three dimensional SRF (Superconducting Radio Frequency) cavities are known for achieving high quality factors (Q =109 or higher) but suffer from limited frequency tunability once fabricated and cooled to superconducting temperatures. Our end-wall design allows for numerous applications of cavity tuning at temperatures as low as 40 millikelvin. Using a bimorphic piezoelectric transducer, we demonstrate approximately 15 MHz of resonance tunability for the TE011 mode at cryogenic temperatures in a cylindrical reactor grade niobium (Nb) cavity (10% of the range at room temperature). This range doubles when using tunable end-walls on both cavity ends. We report on techniques for improving the Q of multi-component cavities including the use of concave end-walls to reduce fields near the cylinder ends and indium O-rings to reduce resistive losses at the gaps. Three-dimensional SRF cavities of this type have potential applications to quantum information science, precision displacement metrology, and quantum electro-dynamics.

Frequency, Expected Effects, Obstacles, and Facilitators of Disclosure of Patient Safety Incidents: A Systematic Review.

Science.gov (United States)

Ock, Minsu; Lim, So Yun; Jo, Min-Woo; Lee, Sang-Il

2017-03-01

We performed a systematic review to assess and aggregate the available evidence on the frequency, expected effects, obstacles, and facilitators of disclosure of patient safety incidents (DPSI). We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for this systematic review and searched PubMed, Scopus, and the Cochrane Library for English articles published between 1990 and 2014. Two authors independently conducted the title screening and abstract review. Ninety-nine articles were selected for full-text reviews. One author extracted the data and another verified them. There was considerable variation in the reported frequency of DPSI among medical professionals. The main expected effects of DPSI were decreased intention of the general public to file medical lawsuits and punish medical professionals, increased credibility of medical professionals, increased intention of patients to revisit and recommend physicians or hospitals, higher ratings of quality of care, and alleviation of feelings of guilt among medical professionals. The obstacles to DPSI were fear of medical lawsuits and punishment, fear of a damaged professional reputation among colleagues and patients, diminished patient trust, the complexity of the situation, and the absence of a patient safety culture. However, the factors facilitating DPSI included the creation of a safe environment for reporting patient safety incidents, as well as guidelines and education for DPSI. The reported frequency of the experience of the general public with DPSI was somewhat lower than the reported frequency of DPSI among medical professionals. Although we identified various expected effects of DPSI, more empirical evidence from real cases is required.

E-cigarette use, dual use of e-cigarettes and tobacco cigarettes, and frequency of cannabis use among high school students.

Science.gov (United States)

Azagba, Sunday

2018-04-01

The proliferation of electronic vaping products raises many concerns, including whether these products will lead to risky behaviors among adolescents. Evidence suggests that e-cigarettes may be used to vaporize cannabis (marijuana). The current study examined associations between e-cigarette use, dual use of e-cigarettes and tobacco cigarettes, and frequency of cannabis use. Data on high school students (grades 9-12) were from the 2014-2015 Canadian Student Tobacco, Alcohol and Drugs Survey (n=23,429 respondents). Multinomial logistic regression analyses were used to examine frequency of cannabis use among those who reported using only e-cigarettes, only tobacco cigarettes, both products, and nonusers. Approximately 15% of respondents reported using cannabis at least once in the past month. Likelihood of using cannabis was significantly higher for e-cigarette only and cigarette- only users. Users of both products had increased odds for a higher frequency of cannabis use. These results indicated a sequential risk gradient in the use of cannabis for dual use, cigarette only, e-cigarette only, and non-use groups, respectively. Youth who reported use of e-cigarettes, tobacco cigarettes, and both products showed a heightened risk of using cannabis more frequently. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sleep Deprivation in Young and Healthy Subjects Is More Sensitively Identified by Higher Frequencies of Electrodermal Activity than by Skin Conductance Level Evaluated in the Time Domain

Directory of Open Access Journals (Sweden)

Hugo F. Posada-Quintero

2017-06-01

Full Text Available We analyzed multiple measures of the autonomic nervous system (ANS based on electrodermal activity (EDA and heart rate variability (HRV for young healthy subjects undergoing 24-h sleep deprivation. In this study, we have utilized the error awareness test (EAT every 2 h (13 runs total, to evaluate the deterioration of performance. EAT consists of trials where the subject is presented words representing colors. Subjects are instructed to press a button (“Go” trials or withhold the response if the word presented and the color of the word mismatch (“Stroop No-Go” trial, or the screen is repeated (“Repeat No-Go” trials. We measured subjects' (N = 10 reaction time to the “Go” trials, and accuracy to the “Stroop No-Go” and “Repeat No-Go” trials. Simultaneously, changes in EDA and HRV indices were evaluated. Furthermore, the relationship between reactiveness and vigilance measures and indices of sympathetic control based on HRV were analyzed. We found the performance improved to a stable level from 6 through 16 h of deprivation, with a subsequently sustained impairment after 18 h. Indices of higher frequencies of EDA related more to vigilance measures, whereas lower frequencies index (skin conductance leve, SCL measured the reactiveness of the subject. We conclude that indices of EDA, including those of the higher frequencies, termed TVSymp, EDASymp, and NSSCRs, provide information to better understand the effect of sleep deprivation on subjects' autonomic response and performance.

Report of the Two-Day National Seminar on New Directions in Higher Education, Organized by the Kerala State Higher Education Council on 12th and 13th July 2010

Science.gov (United States)

Praveen, C.

2010-01-01

This is a report of the Two-Day National Seminar on New Directions in Higher Education, organized by the Kerala State Higher Education Council on 12th and 13th July 2010. The objective of the seminar was to deliberate upon the reforms being undertaken by the Government of India in Higher Education. Reputed scholars from within and outside the…

Two-layer radio frequency MEMS fractal capacitors in PolyMUMPS for S-band applications

KAUST Repository

Elshurafa, Amro M.

2012-07-23

In this Letter, the authors fabricate for the first time MEMS fractal capacitors possessing two layers and compare their performance characteristics with the conventional parallel-plate capacitor and previously reported state-of-the-art single-layer MEMS fractal capacitors. Explicitly, a capacitor with a woven structure and another with an interleaved configuration were fabricated in the standard PolyMUMPS surface micromachining process and tested at S-band frequencies. The self-resonant frequencies of the fabricated capacitors were close to 10GHz, which is better than that of the parallel-plate capacitor, which measured only 5.5GHz. Further, the presented capacitors provided a higher capacitance when compared with the state-of-the-art-reported MEMS fractal capacitors created using a single layer at the expense of a lower quality factor. © 2012 The Institution of Engineering and Technology.

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

Science.gov (United States)

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 ...

Evaluation of a short food frequency questionnaire used among Norwegian children.

Science.gov (United States)

Lillegaard, Inger Therese L; Overby, Nina Cecilie; Andersen, Lene Frost

2012-01-01

The aim of this study was to evaluate a short food frequency questionnaire (FFQ) against a four-day precoded food diary (PFD) with regard to frequency of food intake among Norwegian 9- and 13-year-olds. A total of 733 9-year-olds and 904 13-year-olds completed first a short FFQ and one to two weeks later a four-day PFD. The short FFQ included questions about 23 food items, including different drinks, fruits, vegetables, bread, fish, pizza, sweets, chocolate and savoury snacks. The PFD covered the whole diet. When comparing mean intake from the PFD with comparable food items in the FFQ, all food items showed that increasing intake measured with the PFD corresponded with increasing intake with the short FFQ. However, participants reported a significantly higher frequency of intake for most foods with the short FFQ compared with PFD, except for soft drinks with sugar and sweets. The median Spearman correlation coefficient between the two methods was 0.36 among the 9-year-olds and 0.32 among the 13-year-olds. Often eaten foods such as fruits and vegetables had higher correlations than seldom eaten foods such as pizza and potato chips. The median correlation coefficients for drinks alone were higher (r=0.47) for both age groups. Results indicate that the short FFQ was able to identify high and low consumers of food intake and had a moderate capability to rank individuals according to food intake. Drinks, fruits and vegetables had better correlations with the PFD than infrequently eaten food items.

Low frequency electromagnetic field sensor

International Nuclear Information System (INIS)

Zhu Min; Zhou Yan; He Yicheng; Zheng Zhenxing; Liu Sunkun

2000-01-01

The measurement technique of low frequency electromagnetic field is reported. According to this principle, the authors have designed a sensor, which is used to measure the natural electromagnetic field, SLEMP and electromagnetic signals generated by some explosions. The frequency band of this sensor is from 0.08 Hz to 2 MHz

Low-frequency noise from large wind turbines

DEFF Research Database (Denmark)

Møller, Henrik; Pedersen, Christian Sejer

2011-01-01

As wind turbines get larger, worries have emerged that the turbine noise would move down in frequency and that the low-frequency noise would cause annoyance for the neighbors. The noise emission from 48 wind turbines with nominal electric power up to 3.6 MW is analyzed and discussed. The relative...... amount of low-frequency noise is higher for large turbines (2.3–3.6 MW) than for small turbines (≤ 2 MW), and the difference is statistically significant. The difference can also be expressed as a downward shift of the spectrum of approximately one-third of an octave. A further shift of similar size...... is suggested for future turbines in the 10-MW range. Due to the air absorption, the higher low-frequency content becomes even more pronounced, when sound pressure levels in relevant neighbor distances are considered. Even when A-weighted levels are considered, a substantial part of the noise is at low...

Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

Energy Technology Data Exchange (ETDEWEB)

Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K

2000-07-01

A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (autho000.

Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

International Nuclear Information System (INIS)

Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K.

2000-01-01

A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (author)

Low-frequency noise from large wind turbines.

Science.gov (United States)

Møller, Henrik; Pedersen, Christian Sejer

2011-06-01

As wind turbines get larger, worries have emerged that the turbine noise would move down in frequency and that the low-frequency noise would cause annoyance for the neighbors. The noise emission from 48 wind turbines with nominal electric power up to 3.6 MW is analyzed and discussed. The relative amount of low-frequency noise is higher for large turbines (2.3-3.6 MW) than for small turbines (≤ 2 MW), and the difference is statistically significant. The difference can also be expressed as a downward shift of the spectrum of approximately one-third of an octave. A further shift of similar size is suggested for future turbines in the 10-MW range. Due to the air absorption, the higher low-frequency content becomes even more pronounced, when sound pressure levels in relevant neighbor distances are considered. Even when A-weighted levels are considered, a substantial part of the noise is at low frequencies, and for several of the investigated large turbines, the one-third-octave band with the highest level is at or below 250 Hz. It is thus beyond any doubt that the low-frequency part of the spectrum plays an important role in the noise at the neighbors. © 2011 Acoustical Society of America

Coherent storage of temporally multimode light using a spin-wave atomic frequency comb memory

International Nuclear Information System (INIS)

Gündoğan, M; Mazzera, M; Ledingham, P M; Cristiani, M; De Riedmatten, H

2013-01-01

We report on the coherent and multi-temporal mode storage of light using the full atomic frequency comb memory scheme. The scheme involves the transfer of optical atomic excitations in Pr 3+ :Y 2 SiO 5 to spin waves in hyperfine levels using strong single-frequency transfer pulses. Using this scheme, a total of five temporal modes are stored and recalled on-demand from the memory. The coherence of the storage and retrieval is characterized using a time-bin interference measurement resulting in visibilities higher than 80%, independent of the storage time. This coherent and multimode spin-wave memory is promising as a quantum memory for light. (paper)

Benefits from the BESSY FEL Higher Harmonic Radiation

CERN Document Server

Goldammer, K

2005-01-01

In the FEL process, bunching and coherent radiation is produced at the fundamental frequency as well as its higher harmonics. BESSY proposes a linac-based cascaded High-Gain Harmonic-Generation (HGHG) free electron laser (FEL) multi-user facility. The BESSY soft X-ray FEL will be seeded by three lasers spanning the spectral range of 230nm to 460nm. Two to four HGHG stages downconvert the seed wavelength to the desired radiation range of 1.24nm to 51nm using higher harmonic bunching. As a surplus, higher harmonic radiation is intrinsically produced in each FEL stage. Radiation on a higher harmonic of the FEL frequency is of high interest because it yields the possibility to reduce the number of FEL stages. This paper details extensive studies of the higher harmonic content of the BESSY FEL radiation. Important aspects of FEL interaction on higher harmonics as resulting from theory and from numerical simulations are discussed. For the case of the BESSY FEL, methods for improving the harmonic content are present...

Frequency of depression among fertile and infertile women

International Nuclear Information System (INIS)

Qayyum, M.; Ahmed, S.; Kanwal, S.; Ishfaq, Y.; Hassan, H.; Waheed, N.

2014-01-01

To compare the frequency of depression among fertile and infertile women reporting in CMH Abbottabad. Study Design: A case control study. Place and Duration of Study: This study was conducted in Combined Military Hospital Abbottabad, over a period of six months from January 2013 to June 2013. Patients and Methods: The inclusion criteria were all those patients who were married. All the cases were selected from the women reporting in the obstetrics and gynecology department of CMH Abbottabad for investigation and treatment of infertility. A total of 200 patients, 100 fertile and 100 infertile women were included. Patients were given questionnaire form with their consent for research. Beck depression inventory (BDI) was used to assess depression among fertile and infertile women. Other factors such as age, educational level, and duration of infertility, pressure from family members, miscarriages, and support from husband were studied. Results: Depression was significantly higher in infertile women as compared to fertile women i.e. 95% vs. 63% (p < 0.001). It was higher among women with more than 1 year of duration of marriage as compared to those with infertility of one year duration or less. Conclusion: Infertility is associated with depression. (author)

High-power microwave generation from a frequency-stabilized virtual cathode source

International Nuclear Information System (INIS)

Fazio, M.V.; Hoeberling, R.F.; Kinross-Wright, J.

1988-01-01

The evolution of virtual cathode based high-power microwave-source technology has been directed primarily toward achieving higher peak-power levels. As peak powers in excess of 10 GW have been reported, attention has begun to focus on techniques for producing a more frequency- and phase-stable virtual cathode source. Free-running virtual cathode microwave sources characteristically exhibit bandwidths in a single pulse of tens of percent, which makes them unsuitable for many applications such as power sources for phased array antennas and microwave linear accelerators. Presented here are results of an experimental approach utilizing a high-Q, resonant cavity surrounding the oscillating virtual cathode to achieve frequency stabilization and repeatable narrow-band operation. A cylindrical cavity resonator is used with the microwave power being extracted radially through circumferential slot apertures into L-band waveguide

Designing Social Media into Higher Education Courses

OpenAIRE

Thapanee Seechaliao

2015-01-01

This research paper presents guiding on how to design social media into higher education courses. The research methodology used a survey approach. The research instrument was a questionnaire about guiding on how to design social media into higher education courses. Thirty-one lecturers completed the questionnaire. The data were scored by frequency and percentage. The research results were the lecturers' opinions concerning the designing social media into higher education ...

Bi-resonant structure with piezoelectric PVDF films for energy harvesting from random vibration sources at low frequency

DEFF Research Database (Denmark)

Liang, Shanshan; Crovetto, Andrea; Peng, Zhuoteng

2016-01-01

and experiments with piezoelectric elements show that the energy harvesting device with the bi-resonant structure can generate higher power output than that of the sum of the two separate devices from random vibration sources at low frequency, and hence significantly improves the vibration-to- electricity......This paper reports on a bi-resonant structure of piezoelectric PVDF films energy harvester (PPEH), which consists of two cantilevers with resonant frequencies of 15 Hz and 22 Hz. With increased acceleration, the vibration amplitudes of the two cantilever-mass structures are increased and collision...

Spatial Frequency Discrimination : Effects of Age, Reward, and Practice

OpenAIRE

van den Boomen, Carlijn; Peters, Judith Carolien

2017-01-01

Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effec...

Smoking status and self-reported race affect the frequency of clinically relevant oncogenic alterations in non-small-cell lung cancers at a United States-based academic medical practice.

Science.gov (United States)

Yamaguchi, Norihiro; Vanderlaan, Paul A; Folch, Erik; Boucher, David H; Canepa, Hannah M; Kent, Michael S; Gangadharan, Sidharta P; Majid, Adnan; Kocher, Olivier N; Goldstein, Michael A; Huberman, Mark S; Costa, Daniel B

2013-10-01

The identification of somatic genomic aberrations in non-small-cell lung cancer (NSCLC) is part of evidence-based practice guidelines for care of patients with NSCLC. We sought to establish the frequency and correlates with these changes in routine patient-tumor sample pairs. Clinicopathologic data and tumor genotype were retrospectively compiled and analyzed from an overall cohort of 381 patient-tumor samples. Of these patients, 75.9% self-reported White race, 13.1% Asian, 6.5% Black, 27.8% were never-smokers, 54.9% former-smokers and 17.3% current-smokers. The frequency of EGFR mutations was 23.9% (86/359), KRAS mutations 34.2% (71/207) and ALK FISH positivity 9.1% (23/252) in tumor samples, and almost all had mutually exclusive results for these oncogenes. In tumors from White, Black and Asian patients, the frequencies of EGFR mutations were 18.4%, 18.2% and 62%, respectively; of ALK FISH positivity 7.81%, 0% and 14.8%, respectively; and of KRAS mutations 41.6%, 20% and 0%. These patterns changed significant with increasing pack-year history of smoking. In White patients, the frequencies of EGFR mutations and ALK FISH positivity decreased with increasing pack-year cohorts; while the frequencies of KRAS mutations increased. Interestingly, in Asian patients the frequencies of EGFR mutations were similar in never smokers and in the cohorts with less than 45pack-year histories of smoking and only decreased in the 45pack-year plus cohort. The frequencies of somatic EGFR, KRAS, and ALK gene abnormalities using routine lung cancer tissue samples from our United States-based academic medical practice reflect the diverse ethnicity (with a higher frequency of EGFR mutations in Asian patients) and smoking patterns (with an inverse correlation between EGFR mutation and ALK rearrangement) of our tested population. These results may help other medical practices appreciate the expected results from introduction of routine tumor genotyping techniques into their day-to-day care

Frequency Correction for MIRO Chirp Transformation Spectroscopy Spectrum

Science.gov (United States)

Lee, Seungwon

2012-01-01

This software processes the flyby spectra of the Chirp Transform Spectrometer (CTS) of the Microwave Instrument for Rosetta Orbiter (MIRO). The tool corrects the effect of Doppler shift and local-oscillator (LO) frequency shift during the flyby mode of MIRO operations. The frequency correction for CTS flyby spectra is performed and is integrated with multiple spectra into a high signal-to-noise averaged spectrum at the rest-frame RF frequency. This innovation also generates the 8 molecular line spectra by dividing continuous 4,096-channel CTS spectra. The 8 line spectra can then be readily used for scientific investigations. A spectral line that is at its rest frequency in the frame of the Earth or an asteroid will be observed with a time-varying Doppler shift as seen by MIRO. The frequency shift is toward the higher RF frequencies on approach, and toward lower RF frequencies on departure. The magnitude of the shift depends on the flyby velocity. The result of time-varying Doppler shift is that of an observed spectral line will be seen to move from channel to channel in the CTS spectrometer. The direction (higher or lower frequency) in the spectrometer depends on the spectral line frequency under consideration. In order to analyze the flyby spectra, two steps are required. First, individual spectra must be corrected for the Doppler shift so that individual spectra can be superimposed at the same rest frequency for integration purposes. Second, a correction needs to be applied to the CTS spectra to account for the LO frequency shifts that are applied to asteroid mode.

Higher-order techniques in computational electromagnetics

CERN Document Server

Graglia, Roberto D

2016-01-01

Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.

Nonlinear frequency conversion in fiber lasers

DEFF Research Database (Denmark)

Svane, Ask Sebastian

The concept of nonlinear frequency conversion entails generating light at new frequencies other than those of the source light. The emission wavelength of typical fiber laser systems, relying on rare-earth dopants, are constrained within specific bands of the infrared region. By exploiting...... nonlinear processes, light from these specific wavelength bands can be used to generate light at new frequencies otherwise not obtainable by rare-earth elements. This thesis describes work covering Raman fiber lasers (RFLs) and amplifiers for nonlinear frequency down-conversion, and also the method...... of fiberoptic Cherenkov radiation (FCR) using ultrafast pulses as a means for generating tunable visible (VIS) light at higher frequencies. Two different polarization maintaining (PM) RFL cavities are studied with an emphasis on stability and spectral broadening. The cavities are formed by inscription of fiber...

On variation of word frequencies in Russian literary texts

Science.gov (United States)

Kargin, Vladislav

2016-03-01

We study the variation of word frequencies in Russian literary texts. Our findings indicate that the standard deviation of a word's frequency across texts depends on its average frequency according to a power law with exponent 1/2 volatility (that is, higher "burstiness"). A latent factor model has been estimated to investigate the structure of the word frequency distribution. The findings suggest that the dependence of a word's frequency volatility on its average frequency can be explained by the asymmetry in the distribution of latent factors.

The Changing Profile of College Students. ERIC/Higher Education Research Report No. 10, 1973.

Science.gov (United States)

Fenske, Robert H.; Scott, Craig S.

This report reviews recent literature concerning enrollment trends in higher education and also presents the results of a recently completed extensive survey of student characteristics. In general, there is a declining rate of enrollment, while at the same time diversity among students is on the increase. This study should be of value to those…

Transient severe motion artifact related to gadoxetate disodium-enhanced liver MRI. Frequency and risk evaluation at a German institution

Energy Technology Data Exchange (ETDEWEB)

Well, Lennart; Rausch, Vanessa Hanna; Adam, Gerhard; Henes, Frank Oliver; Bannas, Peter [Univ. Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. for Diagnostic and Interventional Radiology and Nuclear Medicine

2017-07-15

Varying frequencies (5 - 18%) of contrast-related transient severe motion (TSM) imaging artifacts during gadoxetate disodium-enhanced arterial phase liver MRI have been reported. Since previous reports originated from the United States and Japan, we aimed to determine the frequency of TSM at a German institution and to correlate it with potential risk factors and previously published results. Two age- and sex-matched groups were retrospectively selected (gadoxetate disodium n = 89; gadobenate dimeglumine n = 89) from dynamic contrast-enhanced MRI examinations in a single center. Respiratory motion-related artifacts in non-enhanced and dynamic phases were assessed independently by two readers blinded to contrast agents on a 4-point scale. Scores of ≥3 were considered as severe motion artifacts. Severe motion artifacts in arterial phases were considered as TSM if scores in all other phases were < 3. Potential risk factors for TSM were evaluated via logistic regression analysis. For gadoxetate disodium, the mean score for respiratory motion artifacts was significantly higher in the arterial phase (2.2 ± 0.9) compared to all other phases (1.6 ± 0.7) (p < 0.05). The frequency of TSM was significantly higher with gadoxetate disodium (n = 19; 21.1 %) than with gadobenate dimeglumine (n = 1; 1.1%) (p < 0.001). The frequency of TSM at our institution is similar to some, but not all previously published findings. Logistic regression analysis did not show any significant correlation between TSM and risk factors (all p>0.05). We revealed a high frequency of TSM after injection of gadoxetate disodium at a German institution, substantiating the importance of a diagnosis-limiting phenomenon that so far has only been reported from the United States and Japan. In accordance with previous studies, we did not identify associated risk factors for TSM.

Does frequency count? Parental input and the acquisition of vocabulary.

Science.gov (United States)

Goodman, Judith C; Dale, Philip S; Li, Ping

2008-08-01

Studies examining factors that influence when words are learned typically investigate one lexical category or a small set of words. We provide the first evaluation of the relation between input frequency and age of acquisition for a large sample of words. The MacArthur-Bates Communicative Development Inventory provides norming data on age of acquisition for 562 individual words collected from the parents of children aged 0 ; 8 to 2 ; 6. The CHILDES database provides estimates of frequency with which parents use these words with their children (age: 0 ; 7-7 ; 5; mean age: 36 months). For production, across all words higher parental frequency is associated with later acquisition. Within lexical categories, however, higher frequency is related to earlier acquisition. For comprehension, parental frequency correlates significantly with the age of acquisition only for common nouns. Frequency effects change with development. Thus, frequency impacts vocabulary acquisition in a complex interaction with category, modality and developmental stage.

Frequency of Psychological Disorders amongst Children in Urban Areas of Tehran

Directory of Open Access Journals (Sweden)

Narges Joshaghani

2010-06-01

Full Text Available Objective: To evaluate the frequency of different psychiatric disorders among 7 to 12 years old children in urban areas of Tehran. "nMethod: A sample of 799 children (6 to 11 years old were selected from 250 clusters of the entire 22 municipality areas of Tehran using a multistage sampling method from 250 clusters from the entire 22 municipality areas of Tehran. . After responding to a Persian version of the Strengths and Difficulties Questionnaire (SDQ parent-report form, the Persian version of Kiddie Schedule for Affective Disorders and Schizophrenia - Present and Lifetime (K-SADS-PL was administered to 241 children and their families. The frequency of child psychological disorders was determined using the results of K-SADS-PL. "n Results:The overall frequency of any psychological disorders in the sample of children was 17.9 percent. Among the interviewed children childrenwho were interviewed, the most prevalent diagnoses were Attention-Deficit/ Hyperactivity Disorder (ADHD (8.6 percent8.6%, Oppositional Defiant Disorder (ODD (7.3 percent7.3%, and separation anxiety disorder (SAD (5.9 percent5.9%. There were not any statistically significant differences between sexes in the frequency of psychological disorders except enuresis that was more frequent in the boys and anorexia nervosa that was observed more frequently in the girls . "nConclusion:Higher frequency of ADHD and ODD and SAD among the studied children warrantswarrants more specific evaluation of frequency and possible causes of these high frequency rates. The frequency of psychological disorders in the studied children was comparable to the that of other studies.

Frequency, Expected Effects, Obstacles, and Facilitators of Disclosure of Patient Safety Incidents: A Systematic Review

Directory of Open Access Journals (Sweden)

Minsu Ock

2017-03-01

Full Text Available Objectives We performed a systematic review to assess and aggregate the available evidence on the frequency, expected effects, obstacles, and facilitators of disclosure of patient safety incidents (DPSI. Methods We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA guidelines for this systematic review and searched PubMed, Scopus, and the Cochrane Library for English articles published between 1990 and 2014. Two authors independently conducted the title screening and abstract review. Ninety-nine articles were selected for full-text reviews. One author extracted the data and another verified them. Results There was considerable variation in the reported frequency of DPSI among medical professionals. The main expected effects of DPSI were decreased intention of the general public to file medical lawsuits and punish medical professionals, increased credibility of medical professionals, increased intention of patients to revisit and recommend physicians or hospitals, higher ratings of quality of care, and alleviation of feelings of guilt among medical professionals. The obstacles to DPSI were fear of medical lawsuits and punishment, fear of a damaged professional reputation among colleagues and patients, diminished patient trust, the complexity of the situation, and the absence of a patient safety culture. However, the factors facilitating DPSI included the creation of a safe environment for reporting patient safety incidents, as well as guidelines and education for DPSI. Conclusions The reported frequency of the experience of the general public with DPSI was somewhat lower than the reported frequency of DPSI among medical professionals. Although we identified various expected effects of DPSI, more empirical evidence from real cases is required.

Females with paired occurrence of cancers in the UADT and genital region have a higher frequency of either Glutathione S-transferase M1/T1 null genotype

Directory of Open Access Journals (Sweden)

Jhavar Sameer G

2005-03-01

Full Text Available Abstract Upper Aero digestive Tract (UADT is the commonest site for the development of second cancer in females after primary cervical cancer. Glutathione S-transferase (GSTM1 and / or T1 null genotype modulates the risk of developing UADT cancer (primary as well as second cancer. The aim of this study was to evaluate the difference in GST null genotype frequencies in females with paired cancers in the UADT and genital region as compared to females with paired cancers in the UADT and non-genital region. Forty-nine females with a cancer in the UADT and another cancer (at all sites-genital and non-genital were identified from a database of patients with multiple primary neoplasms and were analyzed for the GSTM1 and T1 genotype in addition to known factors such as age, tobacco habits, alcohol habits and family history of cancer. Frequencies of GSTM1 null, GSTT1 null, and either GSTM1/T1 null were higher in females with paired occurrence of cancer in the UADT and genital site (54%, 33% and 75% respectively in comparison to females with paired occurrence of cancer in the UADT and non-genital sites (22%, 6% and 24% respectively. The significantly higher inherited frequency of either GSTM1/T1 null genotype in females with a paired occurrence of cancers in UADT and genital region (p = 0.01, suggests that these females are more susceptible to damage by carcinogens as compared to females who have UADT cancers in association with cancers at non-genital sites.

Pulse-coupled Belousov-Zhabotinsky oscillators with frequency modulation

Science.gov (United States)

Horvath, Viktor; Epstein, Irving R.

2018-04-01

Inhibitory perturbations to the ferroin-catalyzed Belousov-Zhabotinsky (BZ) chemical oscillator operated in a continuously fed stirred tank reactor cause long term changes to the limit cycle: the lengths of the cycles subsequent to the perturbation are longer than that of the unperturbed cycle, and the unperturbed limit cycle is recovered only after several cycles. The frequency of the BZ reaction strongly depends on the acid concentration of the medium. By adding strong acid or base to the perturbing solutions, the magnitude and the direction of the frequency changes concomitant to excitatory or inhibitory perturbations can be controlled independently of the coupling strength. The dynamics of two BZ oscillators coupled through perturbations carrying a coupling agent (activator or inhibitor) and a frequency modulator (strong acid or base) was explored using a numerical model of the system. Here, we report new complex temporal patterns: higher order, partially synchronized modes that develop when inhibitory coupling is combined with positive frequency modulation (FM), and complex bursting patterns when excitatory coupling is combined with negative FM. The role of time delay between the peak and perturbation (the analog of synaptic delays in networks of neurons) has also been studied. The complex patterns found under inhibitory coupling and positive FM vanish when the delay is significant, whereas a sufficiently long time delay is required for the complex temporal dynamics to occur when coupling is excitatory and FM is negative.

String Stretching, Frequency Modulation, and Banjo Clang

OpenAIRE

Politzer, David

2014-01-01

The banjo’s floating bridge, string break angle, and flexible drumhead all contribute to substantial audio range frequency modulation. From the world of electronic music synthesis, it is known that modulating higher frequency sounds with lower acoustic frequencies leads to metallic and bell-like tone. The mechanics of the banjo does just that quite naturally, modulating fundamentals and harmonics with the motion of the bridge. In technical terms, with a floating bridge, string stretching is f...

Low-Frequency Pulsed Current Versus Kilohertz-Frequency Alternating Current: A Scoping Literature Review.

Science.gov (United States)

Vaz, Marco Aurélio; Frasson, Viviane Bortoluzzi

2018-04-01

To compare the effectiveness of low-frequency pulsed current versus kilohertz-frequency alternating current in terms of evoked force, discomfort level, current intensity, and muscle fatigability; to discuss the physiological mechanisms of each neuromuscular electrical stimulation type; and to determine if kilohertz-frequency alternating current is better than low-frequency pulsed current for clinical treatment. Articles were obtained from PubMed, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, MEDLINE, and SPORTSDiscus databases using the terms Russian current or kilohertz current or alternating current or pulsed current or Aussie current and torque or discomfort or fatigue or current intensity, and through citation tracking up to July 2017. Two independent reviewers selected studies comparing the use of the 2 neuromuscular electrical stimulation currents. Studies describing maximal current intensity tolerated and the main effects of the 2 different current types on discomfort, muscle force, and fatigability were independently reviewed. Data were systematized according to (1) methodology; (2) electrical current characteristics; and (3) outcomes on discomfort level, evoked force, current intensity, and muscle fatigability. The search revealed 15 articles comparing the 2 current types. Kilohertz-frequency alternated current generated equal or less force, similar discomfort, similar current intensity for maximal tolerated neuromuscular electrical stimulation, and more fatigue compared with low-frequency pulsed current. Similar submaximal levels of evoked force revealed higher discomfort and current intensity for kilohertz-frequency alternated current compared with low-frequency pulsed current. Available evidence does not support the idea that kilohertz-frequency alternated current is better than low-frequency pulsed current for strength training and rehabilitation. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier

Equal Educational Opportunity. The Status of Black Americans in Higher Education, 1975-1977. ISEP Third Status Report.

Science.gov (United States)

Howard Univ., Washington, DC. Inst. for the Study of Educational Policy.

This report analyzes the status of black Americans in higher education from 1975-1977. The book opens with a review of basic concepts of equal educational opportunity and the Federal role in guaranteeing equal opportunity. The social and economic context for higher education is then examined with a focus on the national commitment to higher…

The associations among family meal frequency, food preparation frequency, self-efficacy for cooking, and food preparation techniques in children and adolescents.

Science.gov (United States)

Woodruff, Sarah J; Kirby, Ashley R

2013-01-01

The purpose of this study was to describe family dinner frequency (FDF) by food preparation frequency (prep), self-efficacy for cooking (SE), and food preparation techniques (techniques) among a small sample in southwestern Ontario, Canada. A cross-sectional survey was administered under the supervision of the research team. After-school programs, sports programs, and 1 elementary school. The sample included 145 participants (41% boys, 59% girls) in grades 4-8. Demographics, prep, SE, techniques, FDF, and family meal attitudes and behaviors. Exploratory 1-way ANOVA and chi-square analyses were used. An ordinal regression analysis was used to determine the associations between FDF with descriptor variables (sex, grade, and ethnicity) and prep, SE, techniques, FDF, and family meal attitudes and behaviors (P < .05). Approximately 59% reported family dinners on 6 or 7 days per week. Half of participants were involved with prep 1-6 times per week. Mean SE was 25.3 (scale 1-32), and girls performed more techniques than boys (P = .02). Participants with greater SE (odds ratio = 1.15) and higher family meal attitudes and behaviors (odds ratio = 1.15) were more likely to have a higher FDF. Future health promotion strategies for family meals should aim at increasing children's and adolescents' SE. Copyright © 2013 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Eating episode frequency and fruit and vegetable consumption among Italian university students.

Science.gov (United States)

Poscia, Andrea; Teleman, Adele Anna; Azzolini, Elena; de Waure, Chiara; Maged, Davide; Virdis, Andrea; Ricciardi, Walter; Di Pietro, Maria Luisa

2017-01-01

To analyze breakfast consumption, regularity of meals, fruit and vegetable consumption in the Italian university student population on a national level. Descriptive analysis evaluating data taken from the Sportello Salute Giovani (SSG) questionnaire. 12 000 university students who self-administered a confidential survey. 8292 questionnaires were analyzed. Age; sex; self-reported economic status; BMI; number of breakfast and portions of vegetables and portions of fruit usually consumed per week; number of eating episodes per day; intended weight loss. Descriptive and logistic regression analyses were conducted. Gender and age differences were tested by c2 and Mann-Whitney tests. 15.8% of males and 26.3% of females declared to consume at least one portion of fruit every day. Similar results were found for vegetable consumption. Age does not influence fruit or vegetables consumption, frequency of eating episodes or breakfast habit. Both a regular breakfast and a higher number of eating episodes are significantly associated both with a higher frequency of fruit and vegetables intake. This study underlines the need to promote nutritional education campaigns to increase adherence to nutritional guidelines.

Measuring Study Habits in Higher Education: The Way Forward?

International Nuclear Information System (INIS)

Fitkov-Norris, E D; Yeghiazarian, A

2013-01-01

This article reviews existing study habit measurement instruments and discusses their drawbacks, in the light of new evidence from neuroscience on the workings of the brain. It is suggested that in addition to traditional frequency based past behavioural measures, the predictive accuracy of study habit measurement instruments could be improved by including measures of habit strength that take into account behaviour automaticity and efficacy, such as the Self-Report Habit Index (SRHI) developed by [1]. The SRHI has shown high reliability and internal validity in a wide range of contexts and its applicability and validity in the context of learning and higher education as an enhancement to study habit measurement instruments is as yet to be tested

Radio frequency system for nuclear fusion

International Nuclear Information System (INIS)

Kozeki, Shoichiro; Sagawa, Norimoto; Takizawa, Teruhiro

1987-01-01

The importance of radio frequency waves has been increasing in the area of nuclear fusion since they are indispensable for heating of plasma, etc. This report outlines radio frequency techniques used for nuclear fusion and describes the development of radio frequency systems (radio frequency plasma heating system and current drive system). Presently, in-depth studies are underway at various research institutes to achieve plasma heating by injection of radio frequency electric power. Three ranges of frequencies, ICRF (ion cyclotron range of frequency), LHRF (lower hybrid range of frequency) and ECRF (electron cyclotron range of frequency), are considered promissing for radio frequency heating. Candidate waves for plasma current driving include ECW (electron cyclotron wave), LHW (lower hybrid wave), MSW (magnetic sound wave), ICW (ion cyclotron wave) with minority component, and FW (fast wave). FW is the greatest in terms of current drive efficiency. In general, a radio frequency system for nuclear fusion consists of a radio frequency power source, transmission/matching circuit component and plasma connection component. (Nogami, K.)

Unlocking higher harmonics in atomic force microscopy with gentle interactions.

Science.gov (United States)

Santos, Sergio; Barcons, Victor; Font, Josep; Verdaguer, Albert

2014-01-01

In dynamic atomic force microscopy, nanoscale properties are encoded in the higher harmonics. Nevertheless, when gentle interactions and minimal invasiveness are required, these harmonics are typically undetectable. Here, we propose to externally drive an arbitrary number of exact higher harmonics above the noise level. In this way, multiple contrast channels that are sensitive to compositional variations are made accessible. Numerical integration of the equation of motion shows that the external introduction of exact harmonic frequencies does not compromise the fundamental frequency. Thermal fluctuations are also considered within the detection bandwidth of interest and discussed in terms of higher-harmonic phase contrast in the presence and absence of an external excitation of higher harmonics. Higher harmonic phase shifts further provide the means to directly decouple the true topography from that induced by compositional heterogeneity.

Regular meal frequency creates more appropriate insulin sensitivity and lipid profiles compared with irregular meal frequency in healthy lean women.

Science.gov (United States)

Farshchi, H R; Taylor, M A; Macdonald, I A

2004-07-01

To investigate the impact of irregular meal frequency on circulating lipids, insulin, glucose and uric acid concentrations which are known cardiovascular risk factors. A randomised crossover dietary intervention study. Nottingham, UK--Healthy free-living women. A total of nine lean healthy women aged 18-42 y recruited via advertisement. A randomised crossover trial with two phases of 14 days each. In Phase 1, subjects consumed their normal diet on either 6 occasions per day (regular) or by following a variable meal frequency (3-9 meals/day, irregular). In Phase 2, subjects followed the alternative meal pattern to that followed in Phase 1, after a 2-week (wash-out) period. Subjects were asked to come to the laboratory after an overnight fast at the start and end of each phase. Blood samples were taken for measurement of circulating glucose, lipids, insulin and uric acid concentrations before and for 3 h after consumption of a high-carbohydrate test meal. Fasting glucose and insulin values were not affected by meal frequency, but peak insulin and AUC of insulin responses to the test meal were higher after the irregular compared to the regular eating patterns (P meal frequency was associated with higher fasting total (P meal frequency appears to produce a degree of insulin resistance and higher fasting lipid profiles, which may indicate a deleterious effect on these cardiovascular risk factors. : The Ministry of Health and Medical Education, IR Iran.

Relative validity of a food frequency questionnaire to assess nutrient intake in pregnant women.

Science.gov (United States)

McGowan, C A; Curran, S; McAuliffe, F M

2014-04-01

To date, there are no food frequency questionnaires that have been validated to assess nutrient intakes in pregnant women in Ireland. The present study aimed to assess the relative validity of a self-administered food frequency questionnaire during pregnancy. The food frequency questionnaire was administered once during pregnancy between 12 and 34 weeks. Participants also completed a 3-day food diary during each trimester of pregnancy (reference method) and intakes from both the food frequency questionnaire and the mean of the 3-day food diaries were compared in a sample of 130 participants from the control arm of an intervention study. Energy-adjusted Pearson's correlation coefficients ranged from 0.24 (riboflavin) to 0.59 (magnesium) and were all statistically significant (P food frequency questionnaire tended to report higher energy and nutrient intakes compared to the food diaries. On average, 74% of participants were classified into the same ± 1 quartile and 7% into opposing quartiles by the two methods. Overall, our food frequency questionnaire showed good relative validity. We conclude that a single administration of a food frequency questionnaire is a valid tool for ranking women in accordance with their nutrient intakes during pregnancy. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

Improving mental task classification by adding high frequency band information.

Science.gov (United States)

Zhang, Li; He, Wei; He, Chuanhong; Wang, Ping

2010-02-01

Features extracted from delta, theta, alpha, beta and gamma bands spanning low frequency range are commonly used to classify scalp-recorded electroencephalogram (EEG) for designing brain-computer interface (BCI) and higher frequencies are often neglected as noise. In this paper, we implemented an experimental validation to demonstrate that high frequency components could provide helpful information for improving the performance of the mental task based BCI. Electromyography (EMG) and electrooculography (EOG) artifacts were removed by using blind source separation (BSS) techniques. Frequency band powers and asymmetry ratios from the high frequency band (40-100 Hz) together with those from the lower frequency bands were used to represent EEG features. Finally, Fisher discriminant analysis (FDA) combining with Mahalanobis distance were used as the classifier. In this study, four types of classifications were performed using EEG signals recorded from four subjects during five mental tasks. We obtained significantly higher classification accuracy by adding the high frequency band features compared to using the low frequency bands alone, which demonstrated that the information in high frequency components from scalp-recorded EEG is valuable for the mental task based BCI.

Overview: 2017 Professionals in Higher Education Salary Report

Science.gov (United States)

Bichsel, Jacqueline; McChesney, Jasper

2017-01-01

The "Faculty in Higher Education Survey" collects data from approximately 700 higher education institutions on nearly 250,000 full-time faculty (tenure track and non-tenure track), as well as academic department heads and adjunct (pay-per-course) faculty. Data collected for full-time faculty include: salary, supplemental salary and…

Parent and Child Reporting of Corporal Punishment: New Evidence from the Fragile Families and Child Wellbeing Study.

Science.gov (United States)

Schneider, William; MacKenzie, Michael; Waldfogel, Jane; Brooks-Gunn, Jeanne

2015-06-01

This paper provides new evidence on parent and child reporting of corporal punishment, drawing on data from the Fragile Families and Child Wellbeing Study, a birth cohort study of families in 20 medium to large US cities. In separate interviews, 9 year olds and their mothers (N=1,180 families) were asked about the frequency of corporal punishment in the past year. Mothers and children were asked questions with slightly different response categorize which are harmonized in our analysis. Overall, children reported more high frequency corporal punishment (spanking or other physical punishment more than 10 times per year) than their mothers did; this discrepancy was seen in both African-American and Hispanic families (but not White families), and was evident for both boys and girls. These results suggest that reporting of frequency of corporal punishment is sensitive to the identity of the reporter and that in particular child reports may reveal more high frequency punishment than maternal reports do. However, predictors of high frequency punishment were similar regardless of reporter identity; in both cases, risk of high frequency punishment was higher when the child was African-American or had high previous levels of behavior problems.

Social motivation in prospective memory: higher importance ratings and reported performance rates for social tasks.

Science.gov (United States)

Penningroth, Suzanna L; Scott, Walter D; Freuen, Margaret

2011-03-01

Few studies have addressed social motivation in prospective memory (PM). In a pilot study and two main studies, we examined whether social PM tasks possess a motivational advantage over nonsocial PM tasks. In the pilot study and Study 1, participants listed their real-life important and less important PM tasks. Independent raters categorized the PM tasks as social or nonsocial. Results from both studies showed a higher proportion of tasks rated as social when important tasks were requested than when less important tasks were requested. In Study 1, participants also reported whether they had remembered to perform each PM task. Reported performance rates were higher for tasks rated as social than for those rated as nonsocial. Finally, in Study 2, participants rated the importance of two hypothetical PM tasks, one social and one nonsocial. The social PM task was rated higher in importance. Overall, these findings suggest that social PM tasks are viewed as more important than nonsocial PM tasks and they are more likely to be performed. We propose that consideration of the social relevance of PM will lead to a more complete and ecologically valid theoretical description of PM performance. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

Bias in spontaneous reporting of adverse drug reactions in Japan.

Directory of Open Access Journals (Sweden)

Shinichi Matsuda

Full Text Available Attitudes of healthcare professionals regarding spontaneous reporting of adverse drug reactions (ADRs in Japan are not well known, and Japan's unique system of surveillance, called early post-marketing phase vigilance (EPPV, may affect these reporting attitudes. Our objectives were to describe potential effects of EPPV and to test whether ADR seriousness, prominence, and frequency are related to changes in reporting over time.A manufacturer's database of spontaneous ADR reports was used to extract data from individual case safety reports for 5 drugs subject to EPPV. The trend of reporting and the time lag between ADR onset and reporting to the manufacturer were examined. The following indices for ADRs occurring with each drug were calculated and analyzed to assess reporting trends: Serious:Non-serious ratio, High prominence:Low prominence ratio, and High frequency:Low frequency ratio.For all 5 drugs, the time lag between ADR onset and reporting to the manufacturer was shorter in the EPPV period than in the post-EPPV period. All drugs showed higher Serious:Non-serious ratios in the post-EPPV period. No specific patterns were observed for the High prominence:Low prominence ratio. The High frequency:Low frequency ratio for peginterferon alpha-2a and sevelamer hydrochloride decreased steadily throughout the study period.Healthcare professionals may be more likely to report serious ADRs than to report non-serious ADRs, but the effect of event prominence on reporting trends is still unclear. Factors associated with ADR reporting attitude in Japan might be different from those in other countries because of EPPV and the involvement of medical representatives in the spontaneous reporting process. Pharmacovigilance specialists should therefore be cautious when comparing data between different time periods or different countries. Further studies are needed to elucidate the underlying mechanism of spontaneous ADR reporting in Japan.

Manufacturing technologies for ultrasonic transducers in a broad frequency range

OpenAIRE

Gebhardt, Sylvia; Hohlfeld, Kai; Günther, Paul; Neubert, Holger

2018-01-01

According to the application field, working frequency of ultrasonic transducers needs to be tailored to a certain value. Low frequency ultrasonic transducers with working frequencies of 1 kHz to 1 MHz are especially interesting for sonar applications, whereas high frequency ultrasonic transducers with working frequencies higher than 15 MHz are favorable for high-resolution imaging in biomedical and non-destructive evaluation. Conventional non-destructive testing devices and clinical ultrasoun...

Acceleration test with mixed higher harmonics in HIMAC

International Nuclear Information System (INIS)

Kanazawa, M.; Sugiura, A.; Misu, T.

2004-01-01

In HIMAC synchrotron, beam tests with a magnetic ally loaded cavity have been performed. This cavity has very low Q-value of about 0.5, and can be added higher harmonics with fundamental acceleration frequency. In our tested system for higher harmonics, wave form of a DDS (Direct Digital Synthesizer) can be rewrite, and arbitrary wave form can be used for beam acceleration. In the beam test, second and third harmonic wave were added on the fundamental acceleration frequency, and increases of the accelerated beam intensity have been achieved. In this paper, results of the beam test and the acceleration system are presented. (author)

FY-2016 Methyl Iodide Higher NOx Adsorption Test Report

Energy Technology Data Exchange (ETDEWEB)

Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-01

Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2016 under the Department of Energy (DOE) Fuel Cycle Technology (FCT) Program Offgas Sigma Team to further research and advance the technical maturity of solid sorbents for capturing iodine-129 in off-gas streams during used nuclear fuel reprocessing. Adsorption testing with higher levels of NO (approximately 3,300 ppm) and NO2 (up to about 10,000 ppm) indicate that high efficiency iodine capture by silver aerogel remains possible. Maximum iodine decontamination factors (DFs, or the ratio of iodine flowrate in the sorbent bed inlet gas compared to the iodine flowrate in the outlet gas) exceeded 3,000 until bed breakthrough rapidly decreased the DF levels to as low as about 2, when the adsorption capability was near depletion. After breakthrough, nearly all of the uncaptured iodine that remains in the bed outlet gas stream is no longer in the form of the original methyl iodide. The methyl iodide molecules are cleaved in the sorbent bed, even after iodine adsorption is no longer efficient, so that uncaptured iodine is in the form of iodine species soluble in caustic scrubber solutions, and detected and reported here as diatomic I2. The mass transfer zone depths were estimated at 8 inches, somewhat deeper than the 2-5 inch range estimated for both silver aerogels and silver zeolites in prior deep-bed tests, which had lower NOx levels. The maximum iodine adsorption capacity and silver utilization for these higher NOx tests, at about 5-15% of the original sorbent mass, and about 12-35% of the total silver, respectively, were lower than for trends from prior silver aerogel and silver zeolite tests with lower NOx levels. Additional deep-bed testing and analyses are recommended to expand the database for organic iodide adsorption and increase the technical maturity if iodine adsorption processes.

Frequency of precancerous lesions in endoscopic gastric biopsies in chronic gastritis

International Nuclear Information System (INIS)

Haroon, S.; Faridi, N.; Lodhi, F. R.; Mujtaba, S.

2013-01-01

Objective: To determine the frequency of precancerous lesions in endoscopic gastric biopsies of patients with chronic gastritis. Study Design: A case series. Place and Duration of Study: Department of Histopathology, Liaquat National Hospital, Karachi, from July 2008 to January 2009. Methodology: Over 6 months, 375 endoscopic gastric biopsies of patients with age group of 15-65 years having endoscopic chronic gastritis were included. From final biopsy report, basic information like patient demographics and presence of precancerous lesions i.e. activity (chronic active gastritis), atrophy (atrophic gastritis), intestinal metaplasia and dysplasia were recorded on proforma. Results were described as proportions and frequency. Results: The frequency of precancerous lesions in endoscopic gastric biopsies of patients with chronic gastritis in Karachi was markedly high. Most common lesion was chronic active gastritis as depicted by activity (48.3%); dysplasia (1.3%) was the least common. Proportion of more aggressive precancerous lesions were markedly higher in older age group (> 40 years). Conclusion: The precancerous lesions are frequent in endoscopic gastric biopsies of patients with chronic gastritis. (author)

Sampling frequency affects ActiGraph activity counts

DEFF Research Database (Denmark)

Brønd, Jan Christian; Arvidsson, Daniel

that is normally performed at frequencies higher than 2.5 Hz. With the ActiGraph model GT3X one has the option to select sample frequency from 30 to 100 Hz. This study investigated the effect of the sampling frequency on the ouput of the bandpass filter.Methods: A synthetic frequency sweep of 0-15 Hz was generated...... in Matlab and sampled at frequencies of 30-100 Hz. Also, acceleration signals during indoor walking and running were sampled at 30 Hz using the ActiGraph GT3X and resampled in Matlab to frequencies of 40-100 Hz. All data was processed with the ActiLife software.Results: Acceleration frequencies between 5......-15 Hz escaped the bandpass filter when sampled at 40, 50, 70, 80 and 100 Hz, while this was not the case when sampled at 30, 60 and 90 Hz. During the ambulatory activities this artifact resultet in different activity count output from the ActiLife software with different sampling frequency...

Frequency-dependent ultrasound-induced transformation in E. coli.

Science.gov (United States)

Deeks, Jeremy; Windmill, James; Agbeze-Onuma, Maduka; Kalin, Robert M; Argondizza, Peter; Knapp, Charles W

2014-12-01

Ultrasound-enhanced gene transfer (UEGT) is continuing to gain interest across many disciplines; however, very few studies investigate UEGT efficiency across a range of frequencies. Using a variable frequency generator, UEGT was tested in E. coli at six ultrasonic frequencies. Results indicate frequency can significantly influence UEGT efficiency positively and negatively. A frequency of 61 kHz improved UEGT efficiency by ~70 % higher, but 99 kHz impeded UEGT to an extent worse than no ultrasound exposure. The other four frequencies (26, 133, 174, and 190 kHz) enhanced transformation compared to no ultrasound, but efficiencies did not vary. The influence of frequency on UEGT efficiency was observed across a range of operating frequencies. It is plausible that frequency-dependent dynamics of mechanical and chemical energies released during cavitational-bubble collapse (CBC) are responsible for observed UEGT efficiencies.

Direct comparison of low- and mid-frequency Raman spectroscopy for quantitative solid-state pharmaceutical analysis.

Science.gov (United States)

Lipiäinen, Tiina; Fraser-Miller, Sara J; Gordon, Keith C; Strachan, Clare J

2018-02-05

This study considers the potential of low-frequency (terahertz) Raman spectroscopy in the quantitative analysis of ternary mixtures of solid-state forms. Direct comparison between low-frequency and mid-frequency spectral regions for quantitative analysis of crystal form mixtures, without confounding sampling and instrumental variations, is reported for the first time. Piroxicam was used as a model drug, and the low-frequency spectra of piroxicam forms β, α2 and monohydrate are presented for the first time. These forms show clear spectral differences in both the low- and mid-frequency regions. Both spectral regions provided quantitative models suitable for predicting the mixture compositions using partial least squares regression (PLSR), but the low-frequency data gave better models, based on lower errors of prediction (2.7, 3.1 and 3.2% root-mean-square errors of prediction [RMSEP] values for the β, α2 and monohydrate forms, respectively) than the mid-frequency data (6.3, 5.4 and 4.8%, for the β, α2 and monohydrate forms, respectively). The better performance of low-frequency Raman analysis was attributed to larger spectral differences between the solid-state forms, combined with a higher signal-to-noise ratio. Copyright © 2017 Elsevier B.V. All rights reserved.

Bendable, low-loss Topas fibers for the terahertz frequency range

DEFF Research Database (Denmark)

Nielsen, Kristian; Rasmussen, Henrik K.; Adam, Aurèle J.L.

2009-01-01

structure proves that the fiber is single-moded over a wide frequency range, and we see the onset of higher-order modes at high frequencies as well as indication of microporous guiding at low frequencies and high porosity of the fiber. Transmission spectroscopy demonstrates low-loss propagation (

Micronuclei Frequency in Radiation Worker

International Nuclear Information System (INIS)

Sudprasert, Wanwisa; Jungtanasombut, Amornrat; Pakkong, Pannee

2009-07-01

Full text: The purpose of this study is to determine the micronuclei (MN) frequency in peripheral blood lymphocytes of 31 individuals occupationally exposed to radiation compared to 24 controls. The effect of donor gender, age, alcoholic consumption, tea/coffee consumption and radiation burden on MN frequency was studied. The results showed that MN frequencies observed for exposed employees were significantly higher than in controls (p = 0.000). The average MN frequency in control was 39.1 ± 3.7 MN/1000 BN while those of exposed group were 60.9 ± 12.3, 61.6 ± 13.0 and 62.6 ± 11.8 MN/1000 BN for the range of accumulative doses at 0.01-3.00, 3.01-6.00 and 6.01-9.00 mSv, respectively. Moreover, MN frequency showed a positive trend with increased accumulative doses as a linear-quadratic relation (R 2 = 0.4754). No correlation of MN frequency with gender, age and alcoholic consumption could be observed in both exposed and control groups. However, the effect of tea/coffee consumption on MN frequency was clearly observed in the exposed individuals (t-test = -2.018, sig. (2-tailed) = 0.030). These results indicate that the increased MN frequency, an indicator of chromosomal aberration, is associated with occupational exposure to low doses of ionizing radiation

The frequency of gestational diyabetes mellitus in a maternity hospital antepartum clinic

Directory of Open Access Journals (Sweden)

Abdulkadir Turgut

2011-09-01

Full Text Available Objectives: The aim of this study was to determine gestational diabetes mellitus (GDM frequency and age related frequency with GDM screening tests in patients whom referred to our hospital’s antepartum clinic for routine follow-up.Materials and methods: Totally, 2617 pregnant women who did not have any risk factors for GDM and attended to our antepartum clinic for routine follow-up between August 2009 and March 2011 enrolled in this study. A 50-g glucose challenge test (GCT applied at 24-28 weeks’ gestation. The patients who had a value of blood glucose ≥ 140 mg/dl undergone 100-g oral glucose tolerance test (OGTT. Patients who had a value of ≥200 mg/dl blood glucose in GCT or one value of ≥200 mg/dl in OGTT or had two values exceeded normal ranges in OGTT were accepted as GDM. Age related GDM frequency was also determined.Results: Of the 2617 pregnant women 110 patients diagnosed as GDM (4.2%. For the age related frequency, there was a tendency towards GDM after the age of 33. The age 44 was the most risky with a 33% ratio of GDM occurrence rate.Conclusion: In this study the GDM frequency in our hospital’s routine follow-up clinic was found as compatible with the 1% to 6% frequency reported in the literature. The higher frequency of GDM was found in advanced age pregnancies.

Librarian co-authors correlated with higher quality reported search strategies in general internal medicine systematic reviews.

Science.gov (United States)

Rethlefsen, Melissa L; Farrell, Ann M; Osterhaus Trzasko, Leah C; Brigham, Tara J

2015-06-01

To determine whether librarian and information specialist authorship was associated with better reported systematic review (SR) search quality. SRs from high-impact general internal medicine journals were reviewed for search quality characteristics and reporting quality by independent reviewers using three instruments, including a checklist of Institute of Medicine Recommended Standards for the Search Process and a scored modification of the Peer Review of Electronic Search Strategies instrument. The level of librarian and information specialist participation was significantly associated with search reproducibility from reported search strategies (Χ(2) = 23.5; P Librarian co-authored SRs had significantly higher odds of meeting 8 of 13 analyzed search standards than those with no librarian participation and six more than those with mentioned librarian participation. One-way ANOVA showed that differences in total search quality scores between all three groups were statistically significant (F2,267 = 10.1233; P librarian or information specialist co-authors are correlated with significantly higher quality reported search strategies. To minimize bias in SRs, authors and editors could encourage librarian engagement in SRs including authorship as a potential way to help improve documentation of the search strategy. Copyright © 2015 Elsevier Inc. All rights reserved.

A MEMS-based high frequency x-ray chopper

Energy Technology Data Exchange (ETDEWEB)

Siria, A; Schwartz, W; Chevrier, J [Institut Neel, CNRS-Universite Joseph Fourier Grenoble, BP 166, F-38042 Grenoble Cedex 9 (France); Dhez, O; Comin, F [ESRF, 6 rue Jules Horowitz, F-38043 Grenoble Cedex 9 (France); Torricelli, G [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

2009-04-29

Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

The Investigation of Median Frequency Changes in Paraspinal Muscles Following Fatigue

Directory of Open Access Journals (Sweden)

Saeed Talebian

2009-10-01

Conclusion: Median frequency shift toward low values following fatigue in global and local paraspinal muscles was seen. However, median frequency values for the local stabilizer muscle were higher than median frequency values for the global muscles.

Suppressing Two-Plasmon Decay with Laser Frequency Detuning

Science.gov (United States)

Follett, R. K.; Shaw, J. G.; Myatt, J. F.; Palastro, J. P.; Short, R. W.; Froula, D. H.

2018-03-01

Three-dimensional laser-plasma interaction simulations show that laser frequency detuning by an amount achievable with current laser technology can be used to suppress the two-plasmon decay (TPD) instability and the corresponding hot-electron generation. For the plasma conditions and laser configuration in a direct-drive inertial confinement fusion implosion on the OMEGA laser, the simulations show that ˜0.7 % laser frequency detuning is sufficient to eliminate TPD-driven hot-electron generation in current experiments. This allows for higher ablation pressures in future implosion designs by using higher laser intensities.

Higher frequency of cholelithiasis in eosinophilic cholecystitis, an unusual finding

International Nuclear Information System (INIS)

Sarfraz, T.; Tariq, H.; Bashir, S.

2015-01-01

To determine the frequency of cholelithiasis in eosinophilic cholecystitis in our population. Study Design: Prospective descriptive study. Place and Duration of Study: Histopathology department, Combined Military Hospital (CMH), Peshawar (Pakistan) from Dec 2011 to Nov 2014. Material and Methods: Eighteen hundred (1800) cholecystectomy specimens were included in the study. The specimens which were properly fixed in 10% formalin were included in the specimen, while poorly fixed and autolysed specimens were excluded. The specimens were examined grossly, measured and block selection was done. The slides made were examined under light microscope by one histopathologist and findings were analyzed. Results: Out of 1800 cholecystectomy specimens, 25 cases (1.38%) were diagnosed as eosinophilic cholecystitis. Out of these 25 cases, 20 (80%) were females having an age range of 30-50 years, while 5 (20%) were males with an age range of 35-55 years. Out of these 25 cases of eosinophilic cholecystitis, 22 (88%) were having cholelithiasis, while 3 (12%) were acalculous eosiniophilic cholecystitis. Conclusion: Eosinophilic cholecystitis in our population is mostly calculous which is very significant finding contrary to data given in western literature, where most of eosinophilic cholecystitis is aclculous. This needs further evaluation to determine any genetic, geographic, environmental, dietary, microbiological or any other factor responsible in etiopathogenesis of calculous eosinophilic cholecystitis in our population, which could be helpful in prevention and management of this disease. (author)

Single and multi-frequency impedance characterization of symmetric activated carbon single capacitor cells

Directory of Open Access Journals (Sweden)

Suzana Sopčić

2018-05-01

Full Text Available Electrochemical impedance spectroscopy (EIS technique is used for characterization of single cell symmetric capacitors having different mass loadings of activated carbon (AC. Relevant values of charge storage capacitance (CT and internal resistance (ESR were evaluated by the single frequency and multi-frequency analyses of measured impedance spectra. Curve fittings were based on the non-ideal R-C model that takes into account the parasitic inductance, contributions from electrode materials/contacts and the effects of AC porosity. Higher CT and lower ESR values were obtained not only for the cell with higher mass of AC, but also using the single vs. multi-frequency approach. Lower CT and higher values of ESR that are generally obtained using the multi-frequency method and curve fittings should be related to the not ideal capacitive response of porous AC material and too high frequency chosen in applying the single frequency analysis.

Gyrocon Radio-Frequency-Generator project for FY-78 and -79

International Nuclear Information System (INIS)

Tallerico, P.J.; Rankin, J.E.

1980-09-01

The gyrocon is a high-power, high-efficiency amplifier that operates by deflection modulation of an electron beam. The bunching is better than that in a klystron, especially for very high powers and UHF frequencies, so the overall efficiency and the maximum output power can be higher than in a klystron. The present theory includes the effects of large signals, space charge, and finite beam size. The equations of motion are relativistically correct, and the space-charge fields are correct to first order in v/c. The theory is derived and a computer code to solve these equations is discussed. The code is then used to obtain several specific examples of gyrocon designs that have significant advantages over klystrons or gridded tubes in the 0.2- to 1.0-GHz frequency range. Several embodiments of the gyrocon are possible: the radial style and the spherical style are discussed in this report. The radial style has a bender magnet to increase the deflection of the beam, whereas the spherical gyrocon does not employ the bender magnet. The optimum frequency range for the spherical gyrocon is from 1.0 to 2.5 GHz

A low phase noise microwave frequency synthesis for a high-performance cesium vapor cell atomic clock

Energy Technology Data Exchange (ETDEWEB)

François, B.; Boudot, R. [FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l' Epitaphe, 25030 Besançon (France); Calosso, C. E. [INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Danet, J. M. [LNE-SYRTE, Observatoire de Paris, CNRS-UPMC, 61 avenue de l' Observatoire, 75014 Paris (France)

2014-09-15

We report the development, absolute phase noise, and residual phase noise characterization of a 9.192 GHz microwave frequency synthesis chain devoted to be used as a local oscillator in a high-performance cesium vapor cell atomic clock based on coherent population trapping (CPT). It is based on frequency multiplication of an ultra-low phase noise 100 MHz oven-controlled quartz crystal oscillator using a nonlinear transmission line-based chain. Absolute phase noise performances of the 9.192 GHz output signal are measured to be −42, −100, −117 dB rad{sup 2}/Hz and −129 dB rad{sup 2}/Hz at 1 Hz, 100 Hz, 1 kHz, and 10 kHz offset frequencies, respectively. Compared to current results obtained in a state-of-the-art CPT-based frequency standard developed at LNE-SYRTE, this represents an improvement of 8 dB and 10 dB at f = 166 Hz and f = 10 kHz, respectively. With such performances, the expected Dick effect contribution to the atomic clock short term frequency stability is reported at a level of 6.2 × 10{sup −14} at 1 s integration time, that is a factor 3 higher than the atomic clock shot noise limit. Main limitations are pointed out.

Frequency Control Performance Measurement and Requirements

Energy Technology Data Exchange (ETDEWEB)

Illian, Howard F.

2010-12-20

Frequency control is an essential requirement of reliable electric power system operations. Determination of frequency control depends on frequency measurement and the practices based on these measurements that dictate acceptable frequency management. This report chronicles the evolution of these measurements and practices. As technology progresses from analog to digital for calculation, communication, and control, the technical basis for frequency control measurement and practices to determine acceptable performance continues to improve. Before the introduction of digital computing, practices were determined largely by prior experience. In anticipation of mandatory reliability rules, practices evolved from a focus primarily on commercial and equity issues to an increased focus on reliability. This evolution is expected to continue and place increased requirements for more precise measurements and a stronger scientific basis for future frequency management practices in support of reliability.

Resonant-frequency discharge in a multi-cell radio frequency cavity

International Nuclear Information System (INIS)

Popović, S.; Upadhyay, J.; Nikolić, M.; Vušković, L.; Mammosser, J.

2014-01-01

We are reporting experimental results on a microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency cryo-module. This discharge offers a mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the issues related to resonant detuning due to sustained multi-cell cavity plasma. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal

Resonant-frequency discharge in a multi-cell radio frequency cavity

Energy Technology Data Exchange (ETDEWEB)

Popovic, S; Upadhyay, J; Mammosser, J; Nikolic, M; Vuskovic, L

2014-11-07

We are reporting experimental results on microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency (SRF) cryomodule (in situ operation). This discharge offers an efficient mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the problems related to generation and sustaining the multi-cell cavity plasma, which are breakdown and resonant detuning. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal.

Mit Expertenwissen zu Aussagen über künftige Entwicklungen — der Horizon Report Higher Education

Directory of Open Access Journals (Sweden)

Rudolf Mumenthaler

2014-03-01

Full Text Available Der Horizon Report Higher Education dient auch für Hochschulbibliotheken als wichtige Referenz zur Bewertung aktueller Trends und künftiger Entwicklungen. Der Autor stellt die dem Report zugrunde liegende Methode vor, beleuchtet diese kritisch und reflektiert die Aussagekraft der Prognosen. Die Stärken des Horizon Report liegen in der breiten Abstützung, der Offenheit des Verfahrens und der Publikation sowie der Ausarbeitung der von Expertinnen und Experten ausgewählten Themen. Gewisse Schwächen sieht der Autor in der Abhängigkeit von anderen Trendstudien sowie beim Auswahlverfahren der Trendthemen.

Cerebrospinal fluid levels of glial cell-derived neurotrophic factor correlate with spinal cord stimulation frequency in patients with neuropathic pain: a preliminary report.

Science.gov (United States)

McCarthy, K F; McCrory, C

2014-08-01

Case series. To evaluate relationships between spinal cord stimulation (SCS) parameters and levels of glial cell-derived neurotrophic factor (GDNF). Ambulatory pain clinic of St James's Hospital, Dublin, Ireland. Nine patients with an implanted SCS and Failed Back Surgery Syndrome (FBSS) were administered the Brief Pain Inventory and Short Form (36) Health Survey. Following a lumbar puncture, levels of GDNF in cerebrospinal fluid (CSF) were assayed and correlated with stimulation parameters. Controls were patients with arthritic back pain who were matched for age, gender and SF-36 score. Concentrations of GDNF in CSF are higher in patients with FBSS than controls (P=0.002) and correlate with SCS frequency (P=0.029). Concentrations of GDNF in CSF are higher in neuropathic pain and appear to be related to stimulation frequency. Further work is needed to evaluate this potential relationship, both in neuropathic pain and in other contexts such as locomotor dysfunction.

Two frequency ICRF operation on TFTR

International Nuclear Information System (INIS)

Rogers, J.H.; Majeski, R.; Wilson, J.R.; Hosea, J.C.; Schilling, G.; Stevens, J.; Phillips, C.K.

1993-01-01

Modifications have been made recently to allow two of the ICRF antennas (bays L and M) on TFTR to operate at either of two frequencies, 43 MHz or 64 MHz. This was accomplished by lengthening the resonant loops (2Λ at 43 MHz, 3Λ at 64 MHz) and replacing the conventional quarter wave impedance transformers with a tapered impedance design. The other two antennas (bays K and N) will operate at a fixed frequency, 43 MHz. The two frequency operation will allow a combination of 3 He-minority and H-minority heating at near full field on TFTR. The higher frequency, 64 MHz, may also be useful in direct electron heating and current drive experiments at lower toroidal fields. Models of the antenna, resonant loops and impedance matching system are presented

Extracting Low-Frequency Information from Time Attenuation in Elastic Waveform Inversion

Science.gov (United States)

Guo, Xuebao; Liu, Hong; Shi, Ying; Wang, Weihong

2017-03-01

Low-frequency information is crucial for recovering background velocity, but the lack of low-frequency information in field data makes inversion impractical without accurate initial models. Laplace-Fourier domain waveform inversion can recover a smooth model from real data without low-frequency information, which can be used for subsequent inversion as an ideal starting model. In general, it also starts with low frequencies and includes higher frequencies at later inversion stages, while the difference is that its ultralow frequency information comes from the Laplace-Fourier domain. Meanwhile, a direct implementation of the Laplace-transformed wavefield using frequency domain inversion is also very convenient. However, because broad frequency bands are often used in the pure time domain waveform inversion, it is difficult to extract the wavefields dominated by low frequencies in this case. In this paper, low-frequency components are constructed by introducing time attenuation into the recorded residuals, and the rest of the method is identical to the traditional time domain inversion. Time windowing and frequency filtering are also applied to mitigate the ambiguity of the inverse problem. Therefore, we can start at low frequencies and to move to higher frequencies. The experiment shows that the proposed method can achieve a good inversion result in the presence of a linear initial model and records without low-frequency information.

Effect of grazing frequency and intensity on Lolium perenne L ...

African Journals Online (AJOL)

) system. Low frequency, low intensity grazing produced lower CDMD and herbage N levels than higher grazing frequencies and intensities. These differences were, however, generally small. Overall, levels of herbage digestibility (estimated ...

Higher songs of city birds may not be an individual response to noise.

Science.gov (United States)

Zollinger, Sue Anne; Slater, Peter J B; Nemeth, Erwin; Brumm, Henrik

2017-08-16

It has been observed in many songbird species that populations in noisy urban areas sing with a higher minimum frequency than do matched populations in quieter, less developed areas. However, why and how this divergence occurs is not yet understood. We experimentally tested whether chronic noise exposure during vocal learning results in songs with higher minimum frequencies in great tits ( Parus major ), the first species for which a correlation between anthropogenic noise and song frequency was observed. We also tested vocal plasticity of adult great tits in response to changing background noise levels by measuring song frequency and amplitude as we changed noise conditions. We show that noise exposure during ontogeny did not result in songs with higher minimum frequencies. In addition, we found that adult birds did not make any frequency or song usage adjustments when their background noise conditions were changed after song crystallization. These results challenge the common view of vocal adjustments by city birds, as they suggest that either noise itself is not the causal force driving the divergence of song frequency between urban and forest populations, or that noise induces population-wide changes over a time scale of several generations rather than causing changes in individual behaviour. © 2017 The Author(s).

Is mobile phone radiation genotoxic? An analysis of micronucleus frequency in exfoliated buccal cells.

Science.gov (United States)

de Oliveira, F M; Carmona, A M; Ladeira, C

2017-10-01

Electromagnetic fields (EMF) are classified as "possibly carcinogenic" by the International Agency for Research on Cancer (IARC). Some publications have reported associations between EMF exposure and DNA damage, but many other studies contradict such findings. Cytomorphological changes, such as micronuclei (MN), indicative of genomic damage, are biomarkers of genotoxicity. To test whether mobile phone-associated EMF exposure affects the MN frequency in exfoliated buccal cells, we obtained cells smears from the left and right inner cheeks of healthy mobile phone users, aged 18-30 (n=86), who also completed a characterization survey. MN frequencies were tested for potential confounding factors and for duration of phone use and preferential side of mobile phone use. No relationship was observed between MN frequency and duration of mobile phone use in daily calls. Cells ipsilateral to mobile phone use did not present a statistically significantly higher MN frequency, compared to cells contralateral to exposure. A highly statistically significant (pphone-associated EMF do not to induce MN formation in buccal cells at the observed exposure levels. Copyright © 2017 Elsevier B.V. All rights reserved.

Frequency band adjustment match filtering based on variable frequency GPR antennas pairing scheme for shallow subsurface investigations

Science.gov (United States)

Shaikh, Shahid Ali; Tian, Gang; Shi, Zhanjie; Zhao, Wenke; Junejo, S. A.

2018-02-01

Ground penetrating Radar (GPR) is an efficient tool for subsurface geophysical investigations, particularly at shallow depths. The non-destructiveness, cost efficiency, and data reliability are the important factors that make it an ideal tool for the shallow subsurface investigations. Present study encompasses; variations in central frequency of transmitting and receiving GPR antennas (Tx-Rx) have been analyzed and frequency band adjustment match filters are fabricated and tested accordingly. Normally, the frequency of both the antennas remains similar to each other whereas in this study we have experimentally changed the frequencies of Tx-Rx and deduce the response. Instead of normally adopted three pairs, a total of nine Tx-Rx pairs were made from 50 MHz, 100 MHz, and 200 MHz antennas. The experimental data was acquired at the designated near surface geophysics test site of the Zhejiang University, Hangzhou, China. After the impulse response analysis of acquired data through conventional as well as varied Tx-Rx pairs, different swap effects were observed. The frequency band and exploration depth are influenced by transmitting frequencies rather than the receiving frequencies. The impact of receiving frequencies was noticed on the resolution; the more noises were observed using the combination of high frequency transmitting with respect to low frequency receiving. On the basis of above said variable results we have fabricated two frequency band adjustment match filters, the constant frequency transmitting (CFT) and the variable frequency transmitting (VFT) frequency band adjustment match filters. By the principle, the lower and higher frequency components were matched and then incorporated with intermediate one. Therefore, this study reveals that a Tx-Rx combination of low frequency transmitting with high frequency receiving is a better choice. Moreover, both the filters provide better radargram than raw one, the result of VFT frequency band adjustment filter is

Integrated InP frequency discriminator for Phase-modulated microwave photonic links.

Science.gov (United States)

Fandiño, J S; Doménech, J D; Muñoz, P; Capmany, J

2013-02-11

We report the design, fabrication and characterization of an integrated frequency discriminator on InP technology for microwave photonic phase modulated links. The optical chip is, to the best of our knowledge, the first reported in an active platform and the first to include the optical detectors. The discriminator, designed as a linear filter in intensity, features preliminary SFDR values the range between 67 and 79 dB.Hz(2/3) for signal frequencies in the range of 5-9 GHz limited, in principle, by the high value of the optical losses arising from the use of several free space coupling devices in our experimental setup. As discussed, these losses can be readily reduced by the use of integrated spot-size converters improving the SFDR by 17.3 dB (84-96 dB.Hz(2/3)). Further increase up to a range of (104-116 dB.Hz(2/3)) is possible by reducing the system noise eliminating the EDFA employed in the setup and using a commercially available laser source providing higher output power and lower relative intensity noise. Other paths for improvement requiring a filter redesign to be linear in the optical field are also discussed.

Time-Frequency Analysis of Signals Generated by Rotating Machines

Directory of Open Access Journals (Sweden)

R. Zetik

1999-06-01

Full Text Available This contribution is devoted to the higher order time-frequency analyses of signals. Firstly, time-frequency representations of higher order (TFRHO are defined. Then L-Wigner distribution (LWD is given as a special case of TFRHO. Basic properties of LWD are illustrated based on the analysis of mono-component and multi-component synthetic signals and acoustical signals generated by rotating machine. The obtained results confirm usefulness of LWD application for the purpose of rotating machine condition monitoring.

Time resolved high frequency spectrum of Br2 molecules using pulsed photoacoustic technique.

Science.gov (United States)

Yehya, Fahem; Chaudhary, A K

2013-11-01

The paper reports the time resolved spectral distribution of higher order acoustic modes generated in Br2 molecules using pulsed Photoacoustic (PA) technique. New time resolved vibrational spectrum of Br2 molecules are recorded using a single 532nm, pulses of 7ns duration at 10Hz repetition rate obtained from Q-switched Nd:YAG laser. Frank-Condon principle based assignments confirms the presence of 12 numbers of (ν″-ν') vibrational transitions covered by a single 532+2nm pulse profile. Inclusions of higher order zeroth modes in Bassel's function expansion series shows the probability of overlapping of different types of acoustic modes in the designed PA cells. These modes appear in the form of clusters which occupies higher frequency range. The study of decay behavior of PA signal with respect to time confirms the photolysis of Br2 at 532nm wavelength. In addition, the shifting and clustering effect of cavity eigen modes in Br2 molecules have been studied between 1 and 10ms time scale. The estimated Q-factor of PA cell (l=16cm, R=1.4cm) is 145±4 at 27kHz frequency. Copyright © 2013 Elsevier B.V. All rights reserved.

Frequency of self-reported COPD exacerbation and airflow obstruction in five Latin American cities: the Proyecto Latinoamericano de Investigacion en Obstruccion Pulmonar (PLATINO) study.

Science.gov (United States)

Montes de Oca, Maria; Tálamo, Carlos; Halbert, Ronald J; Perez-Padilla, Rogelio; Lopez, Maria Victorina; Muiño, Adriana; Jardim, José Roberto B; Valdivia, Gonzalo; Pertuzé, Julio; Moreno, Dolores; Menezes, Ana Maria B

2009-07-01

Recurrent exacerbations are common in COPD patients. Limited information exists regarding exacerbation frequency in COPD patients from epidemiologic studies. We examined the frequency of self-reported exacerbations and the factors influencing exacerbation frequency among COPD patients in a population-based study conducted in Latin America. We used a post-bronchodilator FEV(1)/FVC ratio of < 0.70 to define COPD. Exacerbation was self-reported and defined by symptoms (deterioration of breathing symptoms that affected usual daily activities or caused missed work). Spirometry was performed in 5,314 subjects. There were 759 subjects with airflow limitation; of these, 18.2% reported ever having had an exacerbation, 7.9% reported having an exacerbation, and 6.2% reported having an exacerbation requiring at least a doctor visit within the past year. The proportion of individuals with an exacerbation significantly increased by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages, from 4.2% in stage 1 to 28.9% in stages 3 and 4. The self-reported exacerbation rate was 0.58 exacerbations per year. The rate of exacerbations requiring at least a doctor visit and length of stay in hospital due to exacerbations also increased as COPD severity progressed. The factors associated with having an exacerbation in the past year were dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and disease severity of GOLD stages 3 and 4. The proportion of individuals with airflow limitation and self-reported exacerbation increases as the disease severity progresses. Dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and more severe obstruction were significantly associated with having an exacerbation in the past year.

Pulse frequency dependency of photobiomodulation on the bioenergetic functions of human dental pulp stem cells.

Science.gov (United States)

Kim, Hong Bae; Baik, Ku Youn; Choung, Pill-Hoon; Chung, Jong Hoon

2017-11-21

Photobiomodulation (PBM) therapy contributes to pain relief, wound healing, and tissue regeneration. The pulsed wave (PW) mode has been reported to be more effective than the continuous wave (CW) mode when applying PBM to many biological systems. However, the reason for the higher effectiveness of PW-PBM is poorly understood. Herein, we suggest using delayed luminescence (DL) as a reporter of mitochondrial activity after PBM treatment. DL originates mainly from mitochondrial electron transport chain systems, which produce reactive oxygen species (ROS) and adenosine triphosphate (ATP). The decay time of DL depends on the pulse frequencies of applied light, which correlate with the biological responses of human dental pulp stem cells (hDPSCs). Using a low-power light whose wavelength is 810 nm and energy density is 38 mJ/cm 2 , we find that a 300-Hz pulse frequency prolonged the DL pattern and enhanced alkaline phosphatase activity. In addition, we analyze mitochondrial morphological changes and their volume density and find evidence supporting mitochondrial physiological changes from PBM treatment. Our data suggest a new methodology for determining the effectiveness of PBM and the specific pulse frequency dependency of PBM in the differentiation of hDPSCs.

Nonmonotonic low frequency losses in HTSCs

International Nuclear Information System (INIS)

Castro, H; Gerber, A; Milner, A

2007-01-01

A calorimetric technique has been used in order to study ac-field dissipation in ceramic BSCCO samples at low frequencies between 0.05 and 250 Hz, at temperatures from 65 to 90 K. In contrast to previous studies, where ac losses have been reported with a linear dependence on magnetic field frequency, we find a nonmonotonic function presenting various maxima. Frequencies corresponding to local maxima of dissipation depend on the temperature and the amplitude of the ac magnetic field. Flux creep is argued to be responsible for this behaviour. A simple model connecting the characteristic vortex relaxation times (flux creep) and the location of dissipation maxima versus frequency is proposed

Frequency threshold for ion beam formation in expanding RF plasma

Science.gov (United States)

Chakraborty Thakur, Saikat; Harvey, Zane; Biloiu, Ioana; Hansen, Alex; Hardin, Robert; Przybysz, William; Scime, Earl

2008-11-01

We observe a threshold frequency for ion beam formation in expanding, low pressure, argon helicon plasma. Mutually consistent measurements of ion beam energy and density relative to the background ion density obtained with a retarding field energy analyzer and laser induced fluorescence indicate that a stable ion beam of 15 eV appears for source frequencies above 11.5 MHz. Reducing the frequency increases the upstream beam amplitude. Downstream of the expansion region, a clear ion beam is seen only for the higher frequencies. At lower frequencies, large electrostatic instabilities appear and an ion beam is not observed. The upstream plasma density increases sharply at the same threshold frequency that leads to the appearance of a stable double layer. The observations are consistent with the theoretical prediction that downstream electrons accelerated into the source by the double layer lead to increased ionization, thus balancing the higher loss rates upstream [1]. 1. M. A. Lieberman, C. Charles and R. W. Boswell, J. Phys. D: Appl. Phys. 39 (2006) 3294-3304

Dropout and completion in higher education in Europe: main report

NARCIS (Netherlands)

Vossensteyn, Johan J.; Kottmann, Andrea; Jongbloed, Benjamin W.A.; Kaiser, Franciscus; Cremonini, Leon; Stensaker, Bjorn; Hovdhaugen, Elisabeth; Wollscheid, Sabine

2015-01-01

Improving completion and reducing dropout in higher education are key concerns for higher education in Europe. This study on dropout and completion in higher education in Europe demonstrates that national governments and higher education institutions use three different study success objectives:

RELATIONSHIP BETWEEN LOW AND HIGH FREQUENCIES IN δ SCUTI STARS: PHOTOMETRIC KEPLER AND SPECTROSCOPIC ANALYSES OF THE RAPID ROTATOR KIC 8054146

International Nuclear Information System (INIS)

Breger, M.; Robertson, P.; Fossati, L.; Balona, L.; Kurtz, D. W.; Bohlender, D.; Lenz, P.; Müller, I.; Lüftinger, Th.; Clarke, Bruce D.; Hall, Jennifer R.; Ibrahim, Khadeejah A.

2012-01-01

Two years of Kepler data of KIC 8054146 (δ Sct/γ Dor hybrid) revealed 349 statistically significant frequencies between 0.54 and 191.36 cycles day –1 (6.3 μHz to 2.21 mHz). The 117 low frequencies cluster in specific frequency bands, but do not show the equidistant period spacings predicted for gravity modes of successive radial order, n, and reported for at least one other hybrid pulsator. The four dominant low frequencies in the 2.8-3.0 cycles day –1 (32-35 μHz) range show strong amplitude variability with timescales of months and years. These four low frequencies also determine the spacing of the higher frequencies in and beyond the δ Sct pressure-mode frequency domain. In fact, most of the higher frequencies belong to one of three families with spacings linked to a specific dominant low frequency. In the Fourier spectrum, these family regularities show up as triplets, high-frequency sequences with absolutely equidistant frequency spacings, side lobes (amplitude modulations), and other regularities in frequency spacings. Furthermore, within two families the amplitude variations between the low and high frequencies are related. We conclude that the low frequencies (gravity modes, rotation) and observed high frequencies (mostly pressure modes) are physically connected. This unusual behavior may be related to the very rapid rotation of the star: from a combination of high- and low-resolution spectroscopy we determined that KIC 8054146 is a very fast rotator (υ sin i = 300 ± 20 km s –1 ) with an effective temperature of 7600 ± 200 K and a surface gravity log g of 3.9 ± 0.3. Several astrophysical ideas explaining the origin of the relationship between the low and high frequencies are explored.

The many places of frequency: evidence for a novel locus of the lexical frequency effect in word production.

Science.gov (United States)

Knobel, Mark; Finkbeiner, Matthew; Caramazza, Alfonso

2008-03-01

The effect of lexical frequency on language-processing tasks is exceptionally reliable. For example, pictures with higher frequency names are named faster and more accurately than those with lower frequency names. Experiments with normal participants and patients strongly suggest that this production effect arises at the level of lexical access. Further work has suggested that within lexical access this effect arises at the level of lexical representations. Here we present patient E.C. who shows an effect of lexical frequency on his nonword error rate. The best explanation of his performance is that there is an additional locus of frequency at the interface of lexical and segmental representational levels. We confirm this hypothesis by showing that only computational models with frequency at this new locus can produce a similar error pattern to that of patient E.C. Finally, in an analysis of a large group of Italian patients, we show that there exist patients who replicate E.C.'s pattern of results and others who show the complementary pattern of frequency effects on semantic error rates. Our results combined with previous findings suggest that frequency plays a role throughout the process of lexical access.

Modulation of the Object/Background Interaction by Spatial Frequency

Directory of Open Access Journals (Sweden)

Yanju Ren

2011-05-01

Full Text Available With regard to the relationship between object and background perception in the natural scene images, functional isolation hypothesis and interactive hypothesis were proposed. Based on previous studies, the present study investigated the role of spatial frequency in the relationship between object and background perception in the natural scene images. In three experiments, participants reported the object, background, or both after seeing each picture for 500 ms followed by a mask. The authors found that (a backgrounds were identified more accurately when they contained a consistent rather than an inconsistent object, independently of spatial frequency; (b objects were identified more accurately in a consistent than an inconsistent background under the condition of low spatial frequencies but not high spatial frequencies; (c spatial frequency modulation remained when both objects and backgrounds were reported simultaneously. The authors conclude that object/background interaction is partially dependent on spatial frequency.

A wideband, frequency up-converting bounded vibration energy harvester for a low-frequency environment

International Nuclear Information System (INIS)

Ashraf, K; Md Khir, M H; Baharudin, Z; Dennis, J O

2013-01-01

This paper presents a bounded vibration energy harvester to effectively harvest energy from a wide band of low-frequency environmental vibrations ranging from 10 to 18 Hz. Rigid mechanical stoppers are used to confine the seismic mass movement within the elastic limits of the spring. Experimental results show the effectiveness of the proposed technique in increasing the efficiency of the energy harvester. When excited at a frequency of 10 Hz with a peak acceleration of 1 g, the harvester responds at a higher frequency of 20 Hz and gives a peak power of 2.68 mW and a peak to peak voltage of 2.62 V across a load of 220 Ω. The average power density of 65.74 μW cm −3 obtained at 10 Hz 1 g excitation monotonically increases with frequency up to 341.86 μW cm −3 at 18 Hz. An analytical model describing the nonlinear dynamics of the proposed harvester is also presented. A simple technique to estimate the energy losses during impact and thereof a method to incorporate these losses in the model are suggested. The presented model not only predicts the experimental voltage waveform and frequency response of the device with good similarity but also predicts the RMS voltage from the harvester for the whole range of operating frequencies with an RMS error of 5.2%. (paper)

Improvement of frequency variability of the folded-coaxial radio-frequency quadrupole linac by installing a detachable stem in its resonator

International Nuclear Information System (INIS)

Kamigaito, Osamu; Goto, Akira; Miyazawa, Yoshitoshi; Chiba, Toshiya; Hemmi, Masatake; Kase, Masayuki; Kohara, Shigeo; Yano, Yasushige

1995-01-01

The beneficial effect of adding a detachable stem to the folded-coaxial resonator of the frequency-variable radio-frequency quadrupole (RFQ) linac previously reported was examined experimentally using a half-scale model as well as by numerical analyses. As a result, this simple modification was found to extend variable frequencies to a high region without increase of rf power consumption. (author)

Reproducibility of frequency-dependent low frequency fluctuations in reaction time over time and across tasks.

Science.gov (United States)

Liu, Zan-Zan; Qu, Hui-Jie; Tian, Zhuo-Ling; Han, Meng-Jian; Fan, Yi; Ge, Lie-Zhong; Zang, Yu-Feng; Zhang, Hang

2017-01-01

Increased levels of reaction time variability (RTV) are characteristics of sustained attention deficits. The clinical significance of RTV has been widely recognized. However, the reliability of RTV measurements has not been widely studied. The present study aimed to assess the test-retest reliability of RTV conventional measurements, e.g., the standard deviation (SD), the coefficient of variation (CV), and a new measurement called the amplitude of low frequency fluctuation (ALFF) of RT. In addition, we aimed to assess differences and similarities of these measurements between different tasks. Thirty-seven healthy college students participated in 2 tasks, i.e., an Eriksen flanker task (EFT) and a simple reaction task (SRT), twice over a mean interval of 56 days. Conventional measurements of RTV including RT-SD and RT-CV were assessed first. Then the RT time series were converted into frequency domains, and RT-ALFF was further calculated for the whole frequency band (0.0023-0.167 Hz) and for a few sub-frequency bands including Slow-6 (frequency bands (Slow-3), but SRT RT-ALFF values showed slightly higher ICC values than EFT values in lower frequency bands (Slow-5 and Slow-4). 2) RT-ALFF magnitudes in each sub-frequency band were greater for the SRT than those for the EFT. 3) The RT-ALFF in the Slow-4 of the EFT was found to be correlated with the RT-ALFF in the Slow-5 of the SRT for both two visits, but no consistently significant correlation was found between the same frequency bands. These findings reveal good test-retest reliability for conventional measurements and for the RT-ALFF of RTV. The RT-ALFF presented frequency-dependent similarities across tasks. All of our results reveal the presence of different frequency structures between the two tasks, and thus the frequency-dependent characteristics of different tasks deserve more attention in future studies.

High-frequency EPR on high-spin transition-metal sites

NARCIS (Netherlands)

Mathies, Guinevere

2012-01-01

The electronic structure of transition-metal sites can be probed by electron-paramagnetic-resonance (EPR) spectroscopy. The study of high-spin transition-metal sites benefits from EPR spectroscopy at frequencies higher than the standard 9.5 GHz. However, high-frequency EPR is a developing field. In

A propagation-measurement-based evaluation of channel characteristics and models pertinent to the expansion of mobile radio systems to frequencies beyond 2 GHz

NARCIS (Netherlands)

Bultitude, R.J.C.; Schenk, T.C.W.; Op de Kamp, N.A.A.; Adnani, N.

2007-01-01

64This paper concerns the measurement-based comparison of urban microcellular mobile radio channel characteristics at 1.9 GHz and a higher frequency, i.e., 5.8 GHz, where future wireless systems could operate. Characteristics that are reported include transmission loss, root-mean-square delay

Associations between children’s video game playing and psychosocial health: information from both parent and child reports.

Science.gov (United States)

Lobel, Adam; Granic, Isabela; Stone, Lisanne L; Engels, Rutger C M E

2014-10-01

Video games are a highly heterogeneous form of entertainment. As recent reviews highlight, this heterogeneity makes likely that video games have both positive and negative consequences for child development. This study investigated the associations between gaming frequency and psychosocial health among children younger than 12 years of age, an understudied cohort in this field. Both parents and children reported children's gaming frequency, with parents also reporting on children's psychosocial health. Given that children may be too young to report the time they spend playing video games accurately, children's reports were scaffolded by a developmentally appropriate measure. We further investigated the potential bias of having parents report both their children's gaming frequency and their children's psychosocial health (i.e., a single source bias). Parental reports of children's gaming frequency were higher than their children's reports. However, a direct test of the potential single source bias rendered null results. Notably, however, while parental reports showed negative associations between gaming and psychosocial health, children's reports showed no associations. Specifically, based on parent reports, children's gaming was associated with more conduct and peer problems, and less prosocial behavior. As children's reports produced no associations between gaming and psychosocial health, parental reports in this study may belie an erroneous set of conclusions. We therefore caution against relying on just one reporter when assessing children's gaming frequency.

Stabilized operation of the Spallation Neutron Source radio-frequency quadrupole

Directory of Open Access Journals (Sweden)

Sang-ho Kim

2010-07-01

Full Text Available The Spallation Neutron Source (SNS radio-frequency quadrupole (RFQ had resonance control instabilities at duty factors higher than approximately 4%. Systematic investigations have been carried out to understand the cause of the instability and to ensure the operational stability of the RFQ. The most critical source of the instability is revealed to be an interaction between hydrogen released by beam bombardments and the RFQ rf field resulting in a discharge, which consumes additional rf power and could cause the RFQ to operate in an unstable region. This paper reports improvement of the SNS RFQ operational stability based on the findings during the SNS operation.

Stakeholder Engagement in Sustainability Reporting in Higher Education: An Analysis of Key Internal Stakeholders' Expectations

Science.gov (United States)

Ferrero-Ferrero, Idoya; Fernández-Izquierdo, María Ángeles; Muñoz-Torres, María Jesús; Bellés-Colomer, Lucía

2018-01-01

Purpose: The purpose of this study is to improve the understanding of stakeholder engagement in the context of sustainability reporting (SR) for higher education institutions (HEIs), together with the materiality principle and stakeholder expectations. Design/methodology/approach: This research uses an exploratory approach based on content…

Frequency and turmoil

African Journals Online (AJOL)

level of popular unrest focused on 'service delivery protests', but in recent years the broader conception of ... Drawing on the Centre for Social Change's archive of media reports, the largest database of its kind, and by comparing its data with .... impact on frequencies. The variation evident in the table is not accidental but is ...

Active Control of High-Speed Free Jets Using High-Frequency Excitation

Science.gov (United States)

Upadhyay, Puja

global suppression of turbulence intensities for all axial locations, also evidenced by a longer potential core and overall reduced jet spreading. The resulting impact on the noise signature is estimated via far-field acoustic measurements. Noise reduction was observed at low to moderate frequencies for all observation angles. Direct comparison of these results with that of steady microjet injection revealed some notable differences in the initial development of streamwise vorticity and the redistribution of peak turbulence in the azimuthal direction. However, despite significant differences in the near nozzle aerodynamics, the downstream evolution of the jet appeared to approach near similar conditions with both high-frequency and steady microjet injection. Moreover, the impact on far-field noise was also comparable between the two injection methods as well as with others reported in the literature. Finally, for jets at higher Mach numbers and elevated temperatures, the effect of control was observed to vary with jet conditions. While the impact of the two control mechanisms were fairly comparable on non-shock containing jets, high-frequency forcing was observed to produce significantly larger reductions in screech and broadband shock-associated noise (BBSN) at select under-expanded jet conditions. The observed variations in control effects at different jet conditions call for further investigation.

Perspectives on and obstacles to the internal reporting reform at higher education institutions – Case of Bosnia and Herzegovina, Croatia and Slovenia

Directory of Open Access Journals (Sweden)

Martina Dragija Kostić

2017-01-01

Full Text Available Higher education institutions are going through a different reform processes that differ from country to country. However, the common challenge of higher education institutions is to assure the financial sustainability and only those institutions that have stable financial structure will be able to fulfil their missions and goals in conditions of limited financial resources. One of very important preconditions for assuring financial sustainability is a high quality reporting system, providing comprehensive and detailed information about all aspects of the activities, performed by an institution of higher education and, especially, its full costs. The objective of the paper is two-fold. On the one hand, its aim is to address reform processes regarding reporting systems at higher education institutions in selected countries; Bosnia and Herzegovina, Croatia and Slovenia, and on the other hand, to highlight most important obstacles for development of efficient internal reporting systems. The empirical research was conducted in 2016 and data collection was based on the survey method. The questionnaires were sent to all public higher education institutions in Bosnia and Herzegovina, Croatia and Slovenia. The results of research have shown that, even though there is a positive perception regarding the need to improve existing internal reporting systems, there are significant differences in obstacles for development of efficient internal reporting systems in observed countries.

LOW-FREQUENCY OSCILLATIONS IN XTE J1550-564

International Nuclear Information System (INIS)

Rao Fengyun; Belloni, Tomaso; Stella, Luigi; Zhang Shuangnan; Li Tipei

2010-01-01

We present the results of a timing analysis of the low-frequency quasi-periodic oscillation (QPO) in the Rossi X-Ray Timing Explorer data of the black hole binary XTE J1550-564 during its 1998 outburst. The QPO frequency is observed to vary on timescales between ∼100 s and days, correlated with the count rate contribution from the optically thick accretion disk: we studied this correlation and discuss its influence on the QPO width. In all observations, the quality factors (ν 0 /FWHM) of the fundamental and second harmonic peaks were observed to be consistent, suggesting that the quasi-periodic nature of the oscillation is due to frequency modulation. In addition to the QPO and its harmonic peaks, a new 1.5ν component was detected in the power spectra. This component is broad, with a quality factor of ∼0.6. From this, we argue that the peak observed at half the QPO frequency, usually referred to as 'sub-harmonic', could be the fundamental frequency, leading to the sequence 1:2:3:4. We also studied the energy dependence of the timing features and conclude that the two continuum components observed in the power spectrum, although both more intense at high energies, show a different dependence on energy. At low energies, the lowest-frequency component dominates, while at high energies the higher-frequency one has a higher fractional rms. An interplay between these two components was also observed as a function of their characteristic frequency. In this source, the transition between the low/hard state and the hard-intermediate state appears to be a smooth process.

Slot Machine Response Frequency Predicts Pathological Gambling

DEFF Research Database (Denmark)

Linnet, Jakob; Rømer Thomsen, Kristine; Møller, Arne

2013-01-01

Slot machines are among the most addictive forms of gambling, and pathological gambling slot machine players represent the largest group of treatment seekers, accounting for 35% to 93% of the population. Pathological gambling sufferers have significantly higher response frequency (games / time......) on slot machines compared with non-problem gamblers, which may suggest increased reinforcement of the gambling behavior in pathological gambling. However, to date it is unknown whether or not the increased response frequency in pathological gambling is associated with symptom severity of the disorder....... This study tested the hypothesis that response frequency is associated with symptom severity in pathological gambling. We tested response frequency among twenty-two pathological gambling sufferers and twenty-one non-problem gamblers on a commercially available slot machine, and screened for pathological...

Buying higher welfare poultry products? Profiling Flemish consumers who do and do not.

Science.gov (United States)

Vanhonacker, F; Verbeke, W

2009-12-01

A substantial number of studies has already investigated differences within the consumer market with regard to attitudes and perceptions in relation to farm animal welfare. Likewise, several studies focused on the gap that exists between positive attitudes and reported consumption or purchase intentions for sustainable food products in general and higher welfare products more specific, and on the factors influencing this attitude-behavior gap. Little or no studies, however, have started from reported pro-welfare behavior to distinguish between consumer groups and to explore the motivations of the respective behavior. With this study, we aim to group consumers according to their reported buying frequency of higher welfare eggs and higher welfare chicken meat. Similarities and dissimilarities between these groups are mapped in terms of individual characteristics, product attribute importance, perceived consumer effectiveness, perception of higher welfare products, and attitude toward a welfare label. The research methodology applied was a quantitative study with cross-sectional consumer survey data collected in Flanders in spring 2007 (n = 469). Pro-welfare behavior was unevenly distributed across different consumer segments, despite a general interest and concern for bird welfare. A consistent choice for standard (no welfare premium) poultry products was related to strong perceived price and availability barriers, to a low importance attached to ethical issues as product attributes, and to a low perceived consumer effectiveness. A consistent choice for products with higher welfare standards to the contrast associated with a high importance attached to ethical issues; a low effect of price and availability perception; a strong association of higher welfare products with product attributes like health, taste, and quality; and a high perceived consumer effectiveness. The identification of market segments with common characteristics is essential for positioning higher

Simultaneous multi-band channel sounding at mm-Wave frequencies

DEFF Research Database (Denmark)

Müller, Robert; Häfner, Stephan; Dupleich, Diego

2016-01-01

The vision of multi Gbit/s data rates in future mobile networks requires the change to millimeter wave (mm-Wave) frequencies for increasing bandwidth. As a consequence, new technologies have to be deployed to tackle the drawbacks of higher frequency bands, e.g. increased path loss. Development an...

Frequency-domain method for separating signal and noise

Institute of Scientific and Technical Information of China (English)

王正明; 段晓君

2000-01-01

A new method for separation of signal and noise (SSN) is put forward. Frequency is redefined according to the features of signal and its derivative in the sampling time interval, thus double orthogonal basis (DOB) is constructed so that a signal can be precisely signified with a linear combination of low-frequency DOB. Under joint consideration in time domain (TD) and frequency domain (FD), a method on SSN with high accuracy is derived and a matched algorithm is designed and analyzed. This method is applicable to SSN in multiple frequency bands, and convenient in applying signal characteristics in TD and FD synthetically with higher accuracy.

Quality of Higher Education: Organisational or Educational? A Content Analysis of Chinese University Self-Evaluation Reports

Science.gov (United States)

Zou, Yihuan; Du, Xiangyun; Rasmussen, Palle

2012-01-01

Based on a study of Chinese university self-evaluation reports, this paper argues that higher education institutions are trying to manage the tensions between educational and organisational quality and the increasing and worldwide concerns about quality assurance. After 30 years of dramatic educational reform, China has established a nationwide…

Sustainability in Higher Education's Annual Reports: An Empirical Study on Australian and Austrian Universities

Science.gov (United States)

Schaffhauser-Linzatti, Michaela Maria; Ossmann, Stefan F.

2018-01-01

Purpose: Higher education institutions are regarded as forerunners and pioneers of sustainability. However, it is to question whether they actually fulfill their role model function. This paper aims to reveal whether selected universities in Australia and Austria meet the reporting expectations about their activities on sustainability in very…

Dynamic shear stabilization of hydromagnetic instabilities in low-beta plasma column by a frequency near the ion cyclotron frequency

International Nuclear Information System (INIS)

Minami, Kazuo; Sato, Kazunori.

1978-09-01

The dynamic shear stabilization of the hydromagnetic instability in low-beta plasmas by an axial RF current whose frequency is not much smaller than the ion cyclotron frequency ωsub(ci) is analyzed in some detail. We adopt the simple model of a uniform plasma column with infinite conductivity. Attention is limited to the case of the m = 1 kink mode with long wave lengths. The Mathieu equation, in which the effect of the ion cyclotron motion is taken into account, is derived. It is shown that the dynamic shear stabilization is still effective, even if the frequency of the applied RF current is of the order of ωsub(ci), which is considerably higher than the frequencies believed to be available in the previous analyses. (author)

Sparse Frequency Waveform Design for Radar-Embedded Communication

Directory of Open Access Journals (Sweden)

Chaoyun Mai

2016-01-01

Full Text Available According to the Tag application with function of covert communication, a method for sparse frequency waveform design based on radar-embedded communication is proposed. Firstly, sparse frequency waveforms are designed based on power spectral density fitting and quasi-Newton method. Secondly, the eigenvalue decomposition of the sparse frequency waveform sequence is used to get the dominant space. Finally the communication waveforms are designed through the projection of orthogonal pseudorandom vectors in the vertical subspace. Compared with the linear frequency modulation waveform, the sparse frequency waveform can further improve the bandwidth occupation of communication signals, thus achieving higher communication rate. A certain correlation exists between the reciprocally orthogonal communication signals samples and the sparse frequency waveform, which guarantees the low SER (signal error rate and LPI (low probability of intercept. The simulation results verify the effectiveness of this method.

Spin-wave resonance frequency in ferromagnetic thin film with interlayer exchange coupling and surface anisotropy

Science.gov (United States)

Zhang, Shuhui; Rong, Jianhong; Wang, Huan; Wang, Dong; Zhang, Lei

2018-01-01

We have investigated the dependence of spin-wave resonance(SWR) frequency on the surface anisotropy, the interlayer exchange coupling, the ferromagnetic layer thickness, the mode number and the external magnetic field in a ferromagnetic superlattice film by means of the linear spin-wave approximation and Green's function technique. The SWR frequency of the ferromagnetic thin film is shifted to higher values corresponding to those of above factors, respectively. It is found that the linear behavior of SWR frequency curves of all modes in the system is observed as the external magnetic field is increasing, however, SWR frequency curves are nonlinear with the lower and the higher modes for different surface anisotropy and interlayer exchange coupling in the system. In addition, the SWR frequency of the lowest (highest) mode is shifted to higher (lower) values when the film thickness is thinner. The interlayer exchange coupling is more important for the energetically higher modes than for the energetically lower modes. The surface anisotropy has a little effect on the SWR frequency of the highest mode, when the surface anisotropy field is further increased.

Resonant circuit which provides dual frequency excitation for rapid cycling of an electromagnet

Science.gov (United States)

Praeg, Walter F.

1984-01-01

Disclosed is a ring magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the cosinusoidal guide field of the ring magnet during particle acceleration. the control circuit generates cosinusoidal excitation currents of different frequencies in the half waves. During radio frequency acceleration of the particles in the synchrotron, the control circuit operates with a lower frequency cosine wave and thereafter the electromagnets are reset with a higher frequency half cosine wave. Flat-bottom and flat-top wave shaping circuits maintain the magnetic guide field in a relatively time-invariant mode during times when the particles are being injected into the ring magnets and when the particles are being ejected from the ring magnets.

System Frequency as Information Carrier in AC Power Systems

DEFF Research Database (Denmark)

Douglass, Philip James; Heussen, Kai; You, Shi

2015-01-01

Power generators contain control systems able to regulate system frequency, but the frequency setpoint values are only rarely modified from nominal values. This paper describes design considerations for a communication system from generators to frequency sensitive distributed energy resourc es (FS......-DER) using changes to frequency setpoint values of genera- tors. Signaling discrete system states by generating off-nominal system frequency values can be used as a novel narrowband unidirectional broadcast communications channel. This paper describes two protocols for utilizing off-nominal frequencies...... to carry information: First, a protocol for dispatching blocks of FS- DER that is suitable for systems restricted to relatively slow rates of change of frequency (ROCOF). Second, for systems that allow higher ROCOF values, the feasibility of using power generation resources as a power line communication...

Relationships between the frequency and severity of non-suicidal self-injury and suicide attempts in youth with borderline personality disorder.

Science.gov (United States)

Andrewes, Holly E; Hulbert, Carol; Cotton, Susan M; Betts, Jennifer; Chanen, Andrew M

2017-07-18

Non-suicidal self-injury (NSSI) is a recognized indicator of suicide risk. Yet, the ubiquity of this behaviour in borderline personality disorder (BPD) limits its utility as a predictor of risk. Consequently, this study aimed to elucidate the relationship between other features of NSSI, including frequency and severity, and suicide attempts. Participants included 107 youth (15 to 25 year olds) with BPD who were assessed for BPD severity, depressive symptoms, 12-month frequency of NSSI and suicide attempts, as well as the levels of treatment sought following each self-harm event. Three-quarters (75.7%) of youth with BPD reported NSSI and two-thirds (66.4%) reported a suicide attempt over the previous 12 months. The frequency of NSSI over the previous 12 months did not show a linear or quadratic relationship with the number of suicide attempts when adjusting for severity of depression, impulsivity and interpersonal problems. NSSI severity was not associated with more frequent suicide attempts. Only impulsivity and depression were uniquely predictive of suicide attempt frequency. A relative increase in the frequency and severity of NSSI occurred in the months prior to a suicide attempt. The prevalence of NSSI and suicide attempts among youth presenting for their first treatment of BPD appear to be perilously high, considerably higher than rates reported by adults with BPD. Findings suggest that clinicians should give more weight to average levels of impulsivity and depression, rather than the absolute frequency and severity of NSSI, when assessing for risk of suicide attempts. Notwithstanding this, a relative increase in the frequency and severity of NSSI appears to be predictive of a forthcoming suicide attempt. © 2017 John Wiley & Sons Australia, Ltd.

The Hunt Report and Higher Education Policy in the Republic of Ireland: "An International Solution to an Irish Problem?"

Science.gov (United States)

Walsh, John; Loxley, Andrew

2015-01-01

The "National Strategy for Higher Education to 2030" in the Republic of Ireland (universally known as the Hunt Report) represents the latest and most assertive attempt by the Irish state to re-construct higher education in accordance with economic utilitarian objectives. This paper sets out to analyse the historical context, key themes…

High frequency oscillations in brain hemodynamic response

Science.gov (United States)

Akin, Ata; Bolay, Hayrunnisa

2007-07-01

Tight autoregulation of vessel tone guarantees proper delivery of nutrients to the tissues. This regulation is maintained at a more delicate level in the brain since any decrease in the supply of glucose and oxygen to neuronal tissues might lead to unrecoverable injury. Functional near infrared spectroscopy has been proposed as a new tool to monitor the cerebrovascular response during cognitive activity. We have observed that during a Stroop task three distinct oscillatory patterns govern the control of the cerebrovascular reactivity: very low frequency (0.02-0.05 Hz), low frequency (0.08-0.12 Hz) and high frequency (0.12-0.18 Hz). High frequency oscillations have been shown to be related to stress level of the subjects. Our findings indicate that as the stress level is increased so does the energy of the high frequency component indicating a higher stimulation from the autonomic nervous system.

Frequency dependence of p-mode frequency shifts induced by magnetic activity in Kepler solar-like stars

Science.gov (United States)

Salabert, D.; Régulo, C.; Pérez Hernández, F.; García, R. A.

2018-04-01

The variations of the frequencies of the low-degree acoustic oscillations in the Sun induced by magnetic activity show a dependence on radial order. The frequency shifts are observed to increase towards higher-order modes to reach a maximum of about 0.8 μHz over the 11-yr solar cycle. A comparable frequency dependence is also measured in two other main sequence solar-like stars, the F-star HD 49933, and the young 1 Gyr-old solar analog KIC 10644253, although with different amplitudes of the shifts of about 2 μHz and 0.5 μHz, respectively. Our objective here is to extend this analysis to stars with different masses, metallicities, and evolutionary stages. From an initial set of 87 Kepler solar-like oscillating stars with known individual p-mode frequencies, we identify five stars showing frequency shifts that can be considered reliable using selection criteria based on Monte Carlo simulations and on the photospheric magnetic activity proxy Sph. The frequency dependence of the frequency shifts of four of these stars could be measured for the l = 0 and l = 1 modes individually. Given the quality of the data, the results could indicate that a physical source of perturbation different from that in the Sun is dominating in this sample of solar-like stars.

Frequency adjustable MEMS vibration energy harvester

Science.gov (United States)

Podder, P.; Constantinou, P.; Amann, A.; Roy, S.

2016-10-01

Ambient mechanical vibrations offer an attractive solution for powering the wireless sensor nodes of the emerging “Internet-of-Things”. However, the wide-ranging variability of the ambient vibration frequencies pose a significant challenge to the efficient transduction of vibration into usable electrical energy. This work reports the development of a MEMS electromagnetic vibration energy harvester where the resonance frequency of the oscillator can be adjusted or tuned to adapt to the ambient vibrational frequency. Micro-fabricated silicon spring and double layer planar micro-coils along with sintered NdFeB micro-magnets are used to construct the electromagnetic transduction mechanism. Furthermore, another NdFeB magnet is adjustably assembled to induce variable magnetic interaction with the transducing magnet, leading to significant change in the spring stiffness and resonance frequency. Finite element analysis and numerical simulations exhibit substantial frequency tuning range (25% of natural resonance frequency) by appropriate adjustment of the repulsive magnetic interaction between the tuning and transducing magnet pair. This demonstrated method of frequency adjustment or tuning have potential applications in other MEMS vibration energy harvesters and micromechanical oscillators.

Frequency adjustable MEMS vibration energy harvester

International Nuclear Information System (INIS)

Podder, P; Constantinou, P; Roy, S; Amann, A

2016-01-01

Ambient mechanical vibrations offer an attractive solution for powering the wireless sensor nodes of the emerging “Internet-of-Things”. However, the wide-ranging variability of the ambient vibration frequencies pose a significant challenge to the efficient transduction of vibration into usable electrical energy. This work reports the development of a MEMS electromagnetic vibration energy harvester where the resonance frequency of the oscillator can be adjusted or tuned to adapt to the ambient vibrational frequency. Micro-fabricated silicon spring and double layer planar micro-coils along with sintered NdFeB micro-magnets are used to construct the electromagnetic transduction mechanism. Furthermore, another NdFeB magnet is adjustably assembled to induce variable magnetic interaction with the transducing magnet, leading to significant change in the spring stiffness and resonance frequency. Finite element analysis and numerical simulations exhibit substantial frequency tuning range (25% of natural resonance frequency) by appropriate adjustment of the repulsive magnetic interaction between the tuning and transducing magnet pair. This demonstrated method of frequency adjustment or tuning have potential applications in other MEMS vibration energy harvesters and micromechanical oscillators. (paper)

The frequency range of TMJ sounds.

Science.gov (United States)

Widmalm, S E; Williams, W J; Djurdjanovic, D; McKay, D C

2003-04-01

There are conflicting opinions about the frequency range of temporomandibular joint (TMJ) sounds. Some authors claim that the upper limit is about 650 Hz. The aim was to test the hypothesis that TMJ sounds may contain frequencies well above 650 Hz but that significant amounts of their energy are lost if the vibrations are recorded using contact sensors and/or travel far through the head tissues. Time-frequency distributions of 172 TMJ clickings (three subjects) were compared between recordings with one microphone in the ear canal and a skin contact transducer above the clicking joint and between recordings from two microphones, one in each ear canal. The energy peaks of the clickings recorded with a microphone in the ear canal on the clicking side were often well above 650 Hz and always in a significantly higher area (range 117-1922 Hz, P 375 Hz) or in microphone recordings from the opposite ear canal (range 141-703 Hz). Future studies are required to establish normative frequency range values of TMJ sounds but need methods also capable of recording the high frequency vibrations.

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

Science.gov (United States)

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

2016-04-19

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

Frequency and temperature dependent mobility of a charged carrier and randomly interrupted strand

International Nuclear Information System (INIS)

Kumar, N.; Jayannavar, A.M.

1981-05-01

Randomly interrupted strand model of a one-dimensional conductor is considered. Exact analytical expression is obtained for the temperature dependent as mobility for a finite segment drawn at random, taking into account the reflecting barriers at the two open ends. The real part of mobility shows a broad resonance as a function of both frequency and tempeature, and vanishes quadratically in the dc limit. The frequency (temperature) maximum shifts to higher values for higher temperatures (frequencies). (author)

Investigation of the Relationship Between Electrical Stimulation Frequency and Muscle Frequency Response Under Submaximal Contractions.

Science.gov (United States)

Papcke, Caluê; Krueger, Eddy; Olandoski, Marcia; Nogueira-Neto, Guilherme Nunes; Nohama, Percy; Scheeren, Eduardo Mendonça

2018-03-25

Neuromuscular electrical stimulation (NMES) is a common tool that is used in clinical and laboratory experiments and can be combined with mechanomyography (MMG) for biofeedback in neuroprostheses. However, it is not clear if the electrical current applied to neuromuscular tissues influences the MMG signal in submaximal contractions. The objective of this study is to investigate whether the electrical stimulation frequency influences the mechanomyographic frequency response of the rectus femoris muscle during submaximal contractions. Thirteen male participants performed three maximal voluntary isometric contractions (MVIC) recorded in isometric conditions to determine the maximal force of knee extensors. This was followed by the application of nine modulated NMES frequencies (20, 25, 30, 35, 40, 45, 50, 75, and 100 Hz) to evoke 5% MVIC. Muscle behavior was monitored by the analysis of MMG signals, which were decomposed into frequency bands by using a Cauchy wavelet transform. For each applied electrical stimulus frequency, the mean MMG spectral/frequency response was estimated for each axis (X, Y, and Z axes) of the MMG sensor with the values of the frequency bands used as weights (weighted mean). Only with respect to the Z (perpendicular) axis of the MMG signal, the stimulus frequency of 20 Hz did not exhibit any difference with the weighted mean (P = 0.666). For the frequencies of 20 and 25 Hz, the MMG signal displayed the bands between 12 and 16 Hz in the three axes (P frequencies from 30 to 100 Hz, the muscle presented a higher concentration of the MMG signal between the 22 and 29 Hz bands for the X and Z axes, and between 16 and 34 Hz bands for the Y axis (P frequency, because their frequency contents tend to mainly remain between the 20- and 25-Hz bands. Hence, NMES does not interfere with the use of MMG in neuroprosthesis. © 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Structural higher education reform - design and evaluation: synthesis report

NARCIS (Netherlands)

File, Jonathan M.; Huisman, Jeroen; de Boer, Harry F.; Seeber, Marco; Vukasovic, Martina; Westerheijden, Donald F.

2016-01-01

This study analyses how different types of system-level (or ‘landscape’) structural reforms in higher education have been designed and implemented in selected higher education systems. In the 12 case studies that form the core of the project, the researchers examine reforms aimed at: - Increasing

THE LOW-FREQUENCY CHARACTERISTICS OF PSR J0437–4715 OBSERVED WITH THE MURCHISON WIDE-FIELD ARRAY

Energy Technology Data Exchange (ETDEWEB)

Bhat, N. D. R.; Ord, S. M.; Tremblay, S. E.; Tingay, S. J.; Oronsaye, S.; Emrich, D. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); Deshpande, A. A. [Raman Research Institute, Bangalore 560080 (India); Van Straten, W.; Briggs, F. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Curtin University, Bentley, WA 6102 (Australia); Bernardi, G. [Square Kilometre Array South Africa, 3rd Floor, The Park, Park Road, Pinelands, 7405 (South Africa); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Cappallo, R. J.; Corey, B. E. [MIT Haystack Observatory, Westford, MA 01886 (United States); Goeke, R.; Hewitt, J. N. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Greenhill, L. J.; Kasper, J. C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hazelton, B. J. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Kaplan, D. L. [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201 (United States); and others

2014-08-20

We report on the detection of the millisecond pulsar PSR J0437–4715 with the Murchison Wide-field Array (MWA) at a frequency of 192 MHz. Our observations show rapid modulations of pulse intensity in time and frequency that arise from diffractive scintillation effects in the interstellar medium (ISM), as well as prominent drifts of intensity maxima in the time-frequency plane that arise from refractive effects. Our analysis suggests that the scattering screen is located at a distance of ∼80-120 pc from the Sun, in disagreement with a recent claim that the screen is closer (∼10 pc). Comparisons with higher frequency data from Parkes reveal a dramatic evolution of the pulse profile with frequency, with the outer conal emission becoming comparable in strength to that from the core and inner conal regions. As well as demonstrating the high time resolution science capabilities currently possible with the MWA, our observations underscore the potential to conduct low-frequency investigations of timing-array millisecond pulsars, which may lead to increased sensitivity in the detection of nanoHertz gravitational waves via the accurate characterization of ISM effects.

The subjective effect of low frequency content in road traffic noise.

Science.gov (United States)

Torija, Antonio J; Flindell, Ian H

2015-01-01

Based on subjective listening trials, Torija and Flindell [J. Acoust. Soc. Am. 135, 1-4 (2014)] observed that low frequency content in typical urban main road traffic noise appeared to make a smaller contribution to reported annoyance than might be inferred from its objective or physical dominance. This paper reports a more detailed study which was aimed at (i) identifying the difference in sound levels at which low frequency content becomes subjectively dominant over mid and high frequency content and (ii) investigating the relationship between loudness and annoyance under conditions where low frequency content is relatively more dominant, such as indoors where mid and high frequency content is reduced. The results suggested that differences of at least +30 dB between the low frequency and the mid/high frequency content are needed for changes in low frequency content to have as much subjective effect as equivalent changes in mid and high frequency content. This suggests that common criticisms of the A-frequency weighting based on a hypothesized excessive downweighting of the low frequency content may be relatively unfounded in this application area.

Optimization of a phased-array transducer for multiple harmonic imaging in medical applications: frequency and topology.

Science.gov (United States)

Matte, Guillaume M; Van Neer, Paul L M J; Danilouchkine, Mike G; Huijssen, Jacob; Verweij, Martin D; de Jong, Nico

2011-03-01

Second-harmonic imaging is currently one of the standards in commercial echographic systems for diagnosis, because of its high spatial resolution and low sensitivity to clutter and near-field artifacts. The use of nonlinear phenomena mirrors is a great set of solutions to improve echographic image resolution. To further enhance the resolution and image quality, the combination of the 3rd to 5th harmonics--dubbed the superharmonics--could be used. However, this requires a bandwidth exceeding that of conventional transducers. A promising solution features a phased-array design with interleaved low- and high-frequency elements for transmission and reception, respectively. Because the amplitude of the backscattered higher harmonics at the transducer surface is relatively low, it is highly desirable to increase the sensitivity in reception. Therefore, we investigated the optimization of the number of elements in the receiving aperture as well as their arrangement (topology). A variety of configurations was considered, including one transmit element for each receive element (1/2) up to one transmit for 7 receive elements (1/8). The topologies are assessed based on the ratio of the harmonic peak pressures in the main and grating lobes. Further, the higher harmonic level is maximized by optimization of the center frequency of the transmitted pulse. The achievable SNR for a specific application is a compromise between the frequency-dependent attenuation and nonlinearity at a required penetration depth. To calculate the SNR of the complete imaging chain, we use an approach analogous to the sonar equation used in underwater acoustics. The generated harmonic pressure fields caused by nonlinear wave propagation were modeled with the iterative nonlinear contrast source (INCS) method, the KZK, or the Burger's equation. The optimal topology for superharmonic imaging was an interleaved design with 1 transmit element per 6 receive elements. It improves the SNR by ~5 dB compared with

Precision Teaching, Frequency-Building, and Ballet Dancing

Science.gov (United States)

Lokke, Gunn E. H.; Lokke, Jon A.; Arntzen, Erick

2008-01-01

This article reports the effectiveness of a brief intervention aimed at achieving fluency in basic ballet moves in a 9-year-old Norwegian girl by use of frequency-building and Precision Teaching procedures. One nonfluent ballet move was pinpointed, and instructional and training procedures designed to increase the frequency of accurate responding…

The effects of industrial noise of higher spectrum on the workers’ auditory perception abilities.

Science.gov (United States)

Mihailović, Dobrivoje; Đurić, Nenad; Kovačević, Ivana; Mihailović, Đorđe

2016-08-01

Results of previous studies gave support to the idea that machines in power plants produce noise of different levels of loudness and frequency, and that it could cause deterioration of the hearing ability of workers. As a matter of fact, noiseinduced hearing loss is the most widespread occupational disease nowadays. As noise is a complex acoustic phenomenon, more factors have to be considered when studying it, such as frequency, intensity and the period of exposure. The aim of this study was to find if there are differences in the absolute threshold of hearing between workers in the factory production lines that are constantly exposed to the industrial noise of higher spectrum and those exposed to the noise of standard spectrum at different frequencies of sound. In the research plan, there were 308 workers employed in the production line of the Factory “Knjaz Miloš”, Aranđelovac. A total of 205 of them were working in the conditions of higher spectrum noise (4,000 Hz – 8,000 Hz) and 103 workers were exposed to standard noise spectrum (31.5 Hz – 2,000.0 Hz). The objective measures of noise (frequency and amplitude) were acquired by phonometer, and measures of absolute threshold of hearing for both ears were obtained by audiometer by exposure to nine sound frequency levels. Data were statistically analyzed by establishing the significance of differences between absolute thresholds of hearing for both groups and for all nine frequency levels. It was found that the absolute threshold of hearing is significantly higher for the group exposed to highfrequency noise at the 4,000 Hz and 8,000 Hz levels of frequency. Reduction of hearing sensitivity is evident for those exposed to higher spectrum noise, which is particularly evident at the higher frequency levels. Employees are often unaware of its effects because they are the results of prolonged exposure. Therefore, working in those conditions requires preventive measures and regular testing of the hearing

A higher meal frequency may be associated with diminished weight loss after bariatric surgery

OpenAIRE

RIBEIRO, Angela Gadelha; COSTA, Maria José de Carvalho; FAINTUCH, Joel; DIAS, Maria Carolina Gonçalves

2009-01-01

OBJECTIVE: This study aimed to investigate the relationship between meal frequency, the occurrence of vomiting and weight loss among patients submitted to Roux-en-Y gastric bypass up to 9 months after surgery. METHODS: Female patients (n = 80) were followed at 3-month intervals for 9 months. Weight, BMI, 24-hour dietary recall, drug consumption and vomiting episodes were recorded and compared with nutritional outcome. RESULTS: The BMI values at 3, 6 and 9 months were 45.1 ± 9.7, 39.9 ± 7.6 an...

Frequency-Modulated Wave Dielectrophoresis of Vesicles And Cells: Periodic U-Turns at the Crossover Frequency

Science.gov (United States)

Frusawa, Hiroshi

2018-06-01

We have formulated the dielectrophoretic force exerted on micro/nanoparticles upon the application of frequency-modulated (FM) electric fields. By adjusting the frequency range of an FM wave to cover the crossover frequency f X in the real part of the Clausius-Mossotti factor, our theory predicts the reversal of the dielectrophoretic force each time the instantaneous frequency periodically traverses f X . In fact, we observed periodic U-turns of vesicles, leukemia cells, and red blood cells that undergo FM wave dielectrophoresis (FM-DEP). It is also suggested by our theory that the video tracking of the U-turns due to FM-DEP is available for the agile and accurate measurement of f X . The FM-DEP method requires a short duration, less than 30 s, while applying the FM wave to observe several U-turns, and the agility in measuring f X is of much use for not only salty cell suspensions but also nanoparticles because the electric-field-induced solvent flow is suppressed as much as possible. The accuracy of f X has been verified using two types of experiment. First, we measured the attractive force exerted on a single vesicle experiencing alternating-current dielectrophoresis (AC-DEP) at various frequencies of sinusoidal electric fields. The frequency dependence of the dielectrophoretic force yields f X as a characteristic frequency at which the force vanishes. Comparing the AC-DEP result of f X with that obtained from the FM-DEP method, both results of f X were found to coincide with each other. Second, we investigated the conductivity dependencies of f X for three kinds of cell by changing the surrounding electrolytes. From the experimental results, we evaluated simultaneously both of the cytoplasmic conductivities and the membrane capacitances using an elaborate theory on the single-shell model of biological cells. While the cytoplasmic conductivities, similar for these cells, were slightly lower than the range of previous reports, the membrane capacitances obtained

Frequency of self-reported sexual aggression and victimization in Brazil: a literature review

Directory of Open Access Journals (Sweden)

Lylla Winzer

2016-01-01

Full Text Available Abstract: The lack of official data on rape has been a challenge for researchers in Brazil. Two recently published studies were based on law enforcement and medical records. Although these studies represent important progress in research on rape in the country, they have several limitations. In order to obtain more realistic rates, the current article reviews Brazilian studies on self-reported sexual aggression and victimization in individuals over 14 years of age. Forty-one studies were identified through electronic searches and reference verification. From 1% to 40% of women and 1% to 35% of men reported some form of victimization in the previous year. The male perpetration incidence ranged from 2% to 44%. Despite the wide variability, these rates were much higher than those provided by official data. The results suggest that sexual orientation is associated with vulnerability. Mixed findings were found concerning race. Most studies were based on convenience samples and focused on female victimization. Male victimization has received increasing attention, but studies on self-reported perpetration are still limited.

Active Faraday optical frequency standard.

Science.gov (United States)

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.

Individual differences in frequency and saliency of speech-accompanying gestures: the role of cognitive abilities and empathy.

Science.gov (United States)

Chu, Mingyuan; Meyer, Antje; Foulkes, Lucy; Kita, Sotaro

2014-04-01

The present study concerns individual differences in gesture production. We used correlational and multiple regression analyses to examine the relationship between individuals' cognitive abilities and empathy levels and their gesture frequency and saliency. We chose predictor variables according to experimental evidence of the functions of gesture in speech production and communication. We examined 3 types of gestures: representational gestures, conduit gestures, and palm-revealing gestures. Higher frequency of representational gestures was related to poorer visual and spatial working memory, spatial transformation ability, and conceptualization ability; higher frequency of conduit gestures was related to poorer visual working memory, conceptualization ability, and higher levels of empathy; and higher frequency of palm-revealing gestures was related to higher levels of empathy. The saliency of all gestures was positively related to level of empathy. These results demonstrate that cognitive abilities and empathy levels are related to individual differences in gesture frequency and saliency.

Comparison of frequency of vertigo in elderly with and without arterial hypertension

Directory of Open Access Journals (Sweden)

Marchiori, Luciana Lozza de Moraes

2010-12-01

Full Text Available Introduction: The otologic symptoms associated with hypertension are discussed for decades, yet its etiology remains obscure. Objective: To compare the frequency of vertigo in elderly patients with and without hypertension. Method:A prospective study of 238 individuals. We administered a questionnaire to fill in systematic data for verification of hypertension and vertigo-based protocol for audiological anamnesis used in routine care. Results and Discussion: There were a higher proportion of women in both groups. As for age, mean age was similar between the groups between the two groups. Regarding the use of medication, all were using some kind of medication continuously. In the study population with hypertension, 106 (90% were using antihypertensive drugs. From 99 individuals who reported dizziness 22 (15.15% of seniors were using anti-vertigo. Hypertensive patients 58 (23.8% subjects reported dizziness and 41 non-hypertensive (16% subjects reported dizziness. There was no significance between vertigo and hypertension in the study group, this probably by some criteria as to exclude individuals with diseases and use of medications capable of producing dizziness, which could not be avoided during the implementation, since most of them had associated disorders, common in the elderly. Conclusion: It was observed in the elderly with and without hypertension, high frequency of vertigo, although we have not achieved significant relationship between vertigo and hypertension in this population.

The potential for very high-frequency gravitational wave detection

International Nuclear Information System (INIS)

Cruise, A M

2012-01-01

The science case for observing gravitational waves at frequencies in the millihertz-kilohertz range using LIGO, VIRGO, GEO600 or LISA is very strong and the first results are expected at these frequencies. However, as gravitational wave astronomy progresses beyond the first detections, other frequency bands may be worth exploring. Early predictions of gravitational wave emission from discrete sources at very much higher frequencies (megahertz and above) have been published and more recent studies of cosmological signals from inflation, Kaluza-Klein modes from gravitational interactions in brane worlds and plasma instabilities surrounding violent astrophysical events, are all possible sources. This communication examines current observational possibilities and the detector technology required to make meaningful observations at these frequencies. (paper)

Manipulating Noise Frequencies Alters Hemispheric Contributions to Decision Making

Science.gov (United States)

Gallagher, Patrick; Dagenbach, Dale

2007-01-01

Participants listened to the Asian disease problem framed in terms of either gains or losses and chose between two plans to combat the disease. All participants heard the problem embedded in other sounds; for some it was the relatively lower-frequency information, and for others it was the relatively higher-frequency information. The classic…

Increased Ventricular Premature Contraction Frequency During REM Sleep in Patients with Coronary Artery Disease and Obstructive Sleep Apnea

Directory of Open Access Journals (Sweden)

Mari A. Watanabe

2008-11-01

Full Text Available Background Patients with obstructive sleep apnea are reported to have a peak of sudden cardiac death at night, in contrast to patients without apnea whose peak is in the morning. We hypothesized that ventricular premature contraction (VPC frequency would correlate with measures of apnea and sympathetic activity.Methods Electrocardiograms from a sleep study of 125 patients with coronary artery disease were evaluated. Patients were categorized by apnea-hypopnea index (AHI into Moderate (AHI 15 apnea groups. Sleep stages studied were Wake, S1, S2, S34, and rapid eye movement (REM. Parameters of a potent autonomically-based risk predictor for sudden cardiac death called heart rate turbulence were calculated.Results There were 74 Moderate and 51 Severe obstructive sleep apnea patients. VPC frequency was affected significantly by sleep stage (Wake, S2 and REM, F=5.8, p<.005 and by AHI (F=8.7, p<.005. In Severe apnea patients, VPC frequency was higher in REM than in Wake (p=.011. In contrast, patients with Moderate apnea had fewer VPCs and exhibited no sleep stage dependence (p=.19. Oxygen desaturation duration per apnea episode correlated positively with AHI (r2=.71, p<.0001, and was longer in REM than in non-REM (p<.0001. The heart rate turbulence parameter TS correlated negatively with oxygen desaturation duration in REM (r2=.06, p=.014.Conclusions Higher VPC frequency coupled with higher sympathetic activity caused by longer apnea episodes in REM sleep may be one reason for increased nocturnal death in apneic patients.

Ultrasound breast imaging using frequency domain reverse time migration

Science.gov (United States)

Roy, O.; Zuberi, M. A. H.; Pratt, R. G.; Duric, N.

2016-04-01

Conventional ultrasonography reconstruction techniques, such as B-mode, are based on a simple wave propagation model derived from a high frequency approximation. Therefore, to minimize model mismatch, the central frequency of the input pulse is typically chosen between 3 and 15 megahertz. Despite the increase in theoretical resolution, operating at higher frequencies comes at the cost of lower signal-to-noise ratio. This ultimately degrades the image contrast and overall quality at higher imaging depths. To address this issue, we investigate a reflection imaging technique, known as reverse time migration, which uses a more accurate propagation model for reconstruction. We present preliminary simulation results as well as physical phantom image reconstructions obtained using data acquired with a breast imaging ultrasound tomography prototype. The original reconstructions are filtered to remove low-wavenumber artifacts that arise due to the inclusion of the direct arrivals. We demonstrate the advantage of using an accurate sound speed model in the reverse time migration process. We also explain how the increase in computational complexity can be mitigated using a frequency domain approach and a parallel computing platform.

Intrinsic frequency biases and profiles across human cortex.

Science.gov (United States)

Mellem, Monika S; Wohltjen, Sophie; Gotts, Stephen J; Ghuman, Avniel Singh; Martin, Alex

2017-11-01

Recent findings in monkeys suggest that intrinsic periodic spiking activity in selective cortical areas occurs at timescales that follow a sensory or lower order-to-higher order processing hierarchy (Murray JD, Bernacchia A, Freedman DJ, Romo R, Wallis JD, Cai X, Padoa-Schioppa C, Pasternak T, Seo H, Lee D, Wang XJ. Nat Neurosci 17: 1661-1663, 2014). It has not yet been fully explored if a similar timescale hierarchy is present in humans. Additionally, these measures in the monkey studies have not addressed findings that rhythmic activity within a brain area can occur at multiple frequencies. In this study we investigate in humans if regions may be biased toward particular frequencies of intrinsic activity and if a full cortical mapping still reveals an organization that follows this hierarchy. We examined the spectral power in multiple frequency bands (0.5-150 Hz) from task-independent data using magnetoencephalography (MEG). We compared standardized power across bands to find regional frequency biases. Our results demonstrate a mix of lower and higher frequency biases across sensory and higher order regions. Thus they suggest a more complex cortical organization that does not simply follow this hierarchy. Additionally, some regions do not display a bias for a single band, and a data-driven clustering analysis reveals a regional organization with high standardized power in multiple bands. Specifically, theta and beta are both high in dorsal frontal cortex, whereas delta and gamma are high in ventral frontal cortex and temporal cortex. Occipital and parietal regions are biased more narrowly toward alpha power, and ventral temporal lobe displays specific biases toward gamma. Thus intrinsic rhythmic neural activity displays a regional organization but one that is not necessarily hierarchical. NEW & NOTEWORTHY The organization of rhythmic neural activity is not well understood. Whereas it has been postulated that rhythms are organized in a hierarchical manner across

Gender-heterogeneous working groups produce higher quality science.

Directory of Open Access Journals (Sweden)

Lesley G Campbell

Full Text Available Here we present the first empirical evidence to support the hypothesis that a gender-heterogeneous problem-solving team generally produced journal articles perceived to be higher quality by peers than a team comprised of highly-performing individuals of the same gender. Although women were historically underrepresented as principal investigators of working groups, their frequency as PIs at the National Center for Ecological Analysis and Synthesis is now comparable to the national frequencies in biology and they are now equally qualified, in terms of their impact on the accumulation of ecological knowledge (as measured by the h-index. While women continue to be underrepresented as working group participants, peer-reviewed publications with gender-heterogeneous authorship teams received 34% more citations than publications produced by gender-uniform authorship teams. This suggests that peers citing these publications perceive publications that also happen to have gender-heterogeneous authorship teams as higher quality than publications with gender uniform authorship teams. Promoting diversity not only promotes representation and fairness but may lead to higher quality science.

Gender-heterogeneous working groups produce higher quality science.

Science.gov (United States)

Campbell, Lesley G; Mehtani, Siya; Dozier, Mary E; Rinehart, Janice

2013-01-01

Here we present the first empirical evidence to support the hypothesis that a gender-heterogeneous problem-solving team generally produced journal articles perceived to be higher quality by peers than a team comprised of highly-performing individuals of the same gender. Although women were historically underrepresented as principal investigators of working groups, their frequency as PIs at the National Center for Ecological Analysis and Synthesis is now comparable to the national frequencies in biology and they are now equally qualified, in terms of their impact on the accumulation of ecological knowledge (as measured by the h-index). While women continue to be underrepresented as working group participants, peer-reviewed publications with gender-heterogeneous authorship teams received 34% more citations than publications produced by gender-uniform authorship teams. This suggests that peers citing these publications perceive publications that also happen to have gender-heterogeneous authorship teams as higher quality than publications with gender uniform authorship teams. Promoting diversity not only promotes representation and fairness but may lead to higher quality science.

Educational Technology Research Journals: "The Internet and Higher Education", 2001-2010

Science.gov (United States)

Drysdale, Jeffery S.; Matthews, Michael; Terekhova-Nan, Vera; Woodfield, Wendy; West, Richard E.

2013-01-01

This article analyzes articles published in "The Internet and Higher Education" from 2001-2010. The researchers analyzed the frequency of author-provided keywords and common abstract words, type and frequency of authorship, the type of research method employed, and the number of citations the journal and specific articles received. Words…

Low frequency noise peak near magnon emission energy in magnetic tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Liu, Liang; Xiang, Li; Guo, Huiqiang; Wei, Jian, E-mail: weijian6791@pku.edu.cn [International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China and Collaborative Innovation Center of Quantum Matter, Beijing (China); Li, D. L.; Yuan, Z. H.; Feng, J. F., E-mail: jiafengfeng@iphy.ac.cn; Han, X. F. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Coey, J. M. D. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

2014-12-15

We report on the low frequency (LF) noise measurements in magnetic tunnel junctions (MTJs) below 4 K and at low bias, where the transport is strongly affected by scattering with magnons emitted by hot tunnelling electrons, as thermal activation of magnons from the environment is suppressed. For both CoFeB/MgO/CoFeB and CoFeB/AlO{sub x}/CoFeB MTJs, enhanced LF noise is observed at bias voltage around magnon emission energy, forming a peak in the bias dependence of noise power spectra density, independent of magnetic configurations. The noise peak is much higher and broader for unannealed AlO{sub x}-based MTJ, and besides Lorentzian shape noise spectra in the frequency domain, random telegraph noise (RTN) is visible in the time traces. During repeated measurements the noise peak reduces and the RTN becomes difficult to resolve, suggesting defects being annealed. The Lorentzian shape noise spectra can be fitted with bias-dependent activation of RTN, with the attempt frequency in the MHz range, consistent with magnon dynamics. These findings suggest magnon-assisted activation of defects as the origin of the enhanced LF noise.

Low frequency noise peak near magnon emission energy in magnetic tunnel junctions

Directory of Open Access Journals (Sweden)

Liang Liu

2014-12-01

Full Text Available We report on the low frequency (LF noise measurements in magnetic tunnel junctions (MTJs below 4 K and at low bias, where the transport is strongly affected by scattering with magnons emitted by hot tunnelling electrons, as thermal activation of magnons from the environment is suppressed. For both CoFeB/MgO/CoFeB and CoFeB/AlOx/CoFeB MTJs, enhanced LF noise is observed at bias voltage around magnon emission energy, forming a peak in the bias dependence of noise power spectra density, independent of magnetic configurations. The noise peak is much higher and broader for unannealed AlOx-based MTJ, and besides Lorentzian shape noise spectra in the frequency domain, random telegraph noise (RTN is visible in the time traces. During repeated measurements the noise peak reduces and the RTN becomes difficult to resolve, suggesting defects being annealed. The Lorentzian shape noise spectra can be fitted with bias-dependent activation of RTN, with the attempt frequency in the MHz range, consistent with magnon dynamics. These findings suggest magnon-assisted activation of defects as the origin of the enhanced LF noise.

High frequency breakdown voltage

International Nuclear Information System (INIS)

Chu, Thanh Duy.

1992-03-01

This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O degrees C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f c , the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f ce , is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions' concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance

Optimization of Quantum-state-preserving Frequency Conversion by Changing the Input Signal

DEFF Research Database (Denmark)

Andersen, Lasse Mejling; Reddy, D. V.; McKinstrie, C. J.

We optimize frequency conversion based on four-wave mixing by using the input modes of the system. We find a 10-25 % higher conversion efficiency relative to a pump-shaped input signal.......We optimize frequency conversion based on four-wave mixing by using the input modes of the system. We find a 10-25 % higher conversion efficiency relative to a pump-shaped input signal....

Flipped Classroom Implementation: A Case Report of Two Higher Education Institutions in the United States and Australia

Science.gov (United States)

McLaughlin, Jacqueline E.; White, Paul J.; Khanova, Julia; Yuriev, Elizabeth

2016-01-01

This case report explored the implementation of flipped classrooms at two higher education institutions. Experiences and publications from the institutions were used to identify and describe common themes, including successes and challenges encountered along with potential solutions to common misalignments, particularly as related to…

Maximizing power output from continuous-wave single-frequency fiber amplifiers.

Science.gov (United States)

Ward, Benjamin G

2015-02-15

This Letter reports on a method of maximizing the power output from highly saturated cladding-pumped continuous-wave single-frequency fiber amplifiers simultaneously, taking into account the stimulated Brillouin scattering and transverse modal instability thresholds. This results in a design figure of merit depending on the fundamental mode overlap with the doping profile, the peak Brillouin gain coefficient, and the peak mode coupling gain coefficient. This figure of merit is then numerically analyzed for three candidate fiber designs including standard, segmented acoustically tailored, and micro-segmented acoustically tailored photonic-crystal fibers. It is found that each of the latter two fibers should enable a 50% higher output power than standard photonic crystal fiber.

Ultrafast electron diffraction with megahertz MeV electron pulses from a superconducting radio-frequency photoinjector

Energy Technology Data Exchange (ETDEWEB)

Feng, L. W.; Lin, L.; Huang, S. L.; Quan, S. W.; Hao, J. K.; Zhu, F.; Wang, F.; Liu, K. X., E-mail: kxliu@pku.edu.cn [Institute of Heavy Ion Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Jiang, T.; Zhu, P. F.; Fu, F.; Wang, R.; Zhao, L.; Xiang, D., E-mail: dxiang@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China)

2015-11-30

We report ultrafast relativistic electron diffraction operating at the megahertz repetition rate where the electron beam is produced in a superconducting radio-frequency (rf) photoinjector. We show that the beam quality is sufficiently high to provide clear diffraction patterns from gold and aluminium samples. With the number of electrons, several orders of magnitude higher than that from a normal conducting photocathode rf gun, such high repetition rate ultrafast MeV electron diffraction may open up many new opportunities in ultrafast science.

Myelography with iohexol (Omnipaque); a clinical report with special reference to the adverse effects

International Nuclear Information System (INIS)

Skalpe, I.O.; Nakstad, P.

1988-01-01

One thousand myelographies (370 cervical, 77 thoracic and 553 lumbar examinations) with iohexol (Omnipaque) were performed in 922 patients. No convulsions were seen. Transient hallucinations were reported in one patient. Headache occurred in 38%. The highest frequency of headache (52%) was reported following cervical myelography with lumbar puncture technique, placing the patient horizontally after the examination. The lowest frequency (20%) occurred following cervical myelography with the C1-C2 puncture technique, placing the patient in bed with the head end elevated 20 degrees. Lumbar myelography was performed on an out-patient basis in 243 patients. The frequency of headache was slightly higher (49%) in this group than in the other lumbar myelography patients (34-44%), but no serious complications were seen. (orig.)

Reactor Materials Program process water piping indirect failure frequency

International Nuclear Information System (INIS)

Daugherty, W.L.

1989-01-01

Following completion of the probabilistic analyses, the LOCA Definition Project has been subject to various external reviews, and as a result the need for several revisions has arisen. This report updates and summarizes the indirect failure frequency analysis for the process water piping. In this report, a conservatism of the earlier analysis is removed, supporting lower failure frequency estimates. The analysis results are also reinterpreted in light of subsequent review comments

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

Directory of Open Access Journals (Sweden)

Ariko Fukushima

Full Text Available 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.

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

Science.gov (United States)

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.

Effect of Ku80 deficiency on mutation frequencies and spectra at a LacZ reporter locus in mouse tissues and cells.

Directory of Open Access Journals (Sweden)

Rita A Busuttil

Full Text Available Non-homologous end joining (NHEJ is thought to be an important mechanism for preventing the adverse effects of DNA double strand breaks (DSBs and its absence has been associated with premature aging. To investigate the effect of inactivated NHEJ on spontaneous mutation frequencies and spectra in vivo and in cultured cells, we crossed a Ku80-deficient mouse with mice harboring a lacZ-plasmid-based mutation reporter. We analyzed various organs and tissues, as well as cultured embryonic fibroblasts, for mutations at the lacZ locus. When comparing mutant with wild-type mice, we observed a significantly higher number of genome rearrangements in liver and spleen and a significantly lower number of point mutations in liver and brain. The reduced point mutation frequency was not due to a decrease in small deletion mutations thought to be a hallmark of NHEJ, but could be a consequence of increased cellular responses to unrepaired DSBs. Indeed, we found a substantial increase in persistent 53BP1 and gammaH2AX DNA damage foci in Ku80-/- as compared to wild-type liver. Treatment of cultured Ku80-deficient or wild-type embryonic fibroblasts, either proliferating or quiescent, with hydrogen peroxide or bleomycin showed no differences in the number or type of induced genome rearrangements. However, after such treatment, Ku80-deficient cells did show an increased number of persistent DNA damage foci. These results indicate that Ku80-dependent repair of DNA damage is predominantly error-free with the effect of alternative more error-prone pathways creating genome rearrangements only detectable after extended periods of time, i.e., in young adult animals. The observed premature aging likely results from a combination of increased cellular senescence and an increased load of stable, genome rearrangements.

A novel differential frequency micro-gyroscope

KAUST Repository

Nayfeh, A. H.

2013-07-10

We present a frequency-domain method to measure angular speeds using electrostatic micro-electro-mechanical system actuators. Towards this end, we study a single-axis gyroscope made of a micro-cantilever and a proof-mass coupled to two fixed electrodes. The gyroscope possesses two orthogonal axes of symmetry and identical flexural mode shapes along these axes. We develop the equations of motion describing the coupled bending modes in the presence of electrostatic and Coriolis forces. Furthermore, we derive a consistent closed-form higher-order expression for the natural frequencies of the coupled flexural modes. The closed-form expression is verified by comparing its results to those obtained from numerical integration of the equations of motion. We find that rotations around the beam axis couple each pair of identical bending modes to produce a pair of global modes. They also split their common natural frequency into a pair of closely spaced natural frequencies. We propose the use of the difference between this pair of frequencies, which is linearly proportional to the speed of rotation around the beam axis, as a detector for the angular speed.

Fundamental frequency characteristics of Jordanian Arabic speakers.

Science.gov (United States)

Natour, Yaser S; Wingate, Judith M

2009-09-01

This study is the first in a series of investigations designed to test the acoustic characteristics of the normal Arabic voice. The subjects were three hundred normal Jordanian Arabic speakers (100 adult males, 100 adult females, and 100 children). The subjects produced a sustained phonation of the vowel /a:/ and stated their complete names (i.e. first, second, third and surname) using a carrier phrase. The samples were analyzed using the Multi Dimensional Voice Program (MDVP). Fundamental frequency (F0) from the /a:/ and speaking fundamental frequency (SF0) from the sentence were analyzed. Results revealed a significant difference of both F0 and SF0 values among adult Jordanian Arabic-speaking males (F0=131.34Hz +/- 18.65, SF0=137.45 +/- 18.93), females (F0=231.13Hz +/- 20.86, SF0=230.84 +/- 16.50) and children (F0=270.93Hz +/- 20.01, SF0=278.04 +/- 32.07). Comparison with other ethnicities indicated that F0 values of adult Jordanian Arabic-speaking males and females are generally consistent with adult Caucasian and African-American values. However, for Jordanian Arabic-speaking children, a higher trend in F0 values was present than their Western counterparts. SF0 values for adult Jordanian Arabic-speaking males are generally consistent with the adult Caucasian male SF0 values. However, SF0 values of adult Jordanian-speaking females and children were relatively higher than the reported Western values. It is recommended that speech-language pathologists in Arabic-speaking countries, Jordan in specific, utilize the new data provided (F0 and SF0) when evaluating and/or treating Arabic-speaking patients. Due to its cross-linguistic variability, SF0 emerged as a preferred measurement when conducting cross-cultural comparisons of voice features.

Higher prices, higher quality? Evidence from German nursing homes.

Science.gov (United States)

Herr, Annika; Hottenrott, Hanna

2016-02-01

This study investigates the relationship between prices and quality of 7400 German nursing homes. We use a cross section of public quality reports for all German nursing homes, which had been evaluated between 2010 and 2013 by external institutions. Our analysis is based on multivariate regressions in a two stage least squares framework, where we instrument prices to explain their effect on quality controlling for income, nursing home density, demographics, labour market characteristics, and infrastructure at the regional level. Descriptive analysis shows that prices and quality do not only vary across nursing homes, but also across counties and federal states and that quality and prices correlate positively. Second, the econometric analysis, which accounts for the endogenous relation between negotiated price and reported quality, shows that quality indeed positively depends on prices. In addition, more places in nursing homes per people in need are correlated with both lower prices and higher quality. Finally, unobserved factors at the federal state level capture some of the variation of reported quality across nursing homes. Our results suggest that higher prices increase quality. Furthermore, since reported quality and prices vary substantially across federal states, we conclude that the quality and prices of long-term care facilities may well be compared within federal states but not across. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Encoding of frequency-modulation (FM) rates in human auditory cortex.

Science.gov (United States)

Okamoto, Hidehiko; Kakigi, Ryusuke

2015-12-14

Frequency-modulated sounds play an important role in our daily social life. However, it currently remains unclear whether frequency modulation rates affect neural activity in the human auditory cortex. In the present study, using magnetoencephalography, we investigated the auditory evoked N1m and sustained field responses elicited by temporally repeated and superimposed frequency-modulated sweeps that were matched in the spectral domain, but differed in frequency modulation rates (1, 4, 16, and 64 octaves per sec). The results obtained demonstrated that the higher rate frequency-modulated sweeps elicited the smaller N1m and the larger sustained field responses. Frequency modulation rate had a significant impact on the human brain responses, thereby providing a key for disentangling a series of natural frequency-modulated sounds such as speech and music.

Variable frequency matching to a radiofrequency source immersed in vacuum

International Nuclear Information System (INIS)

Charles, C; Boswell, R W; Bish, A

2013-01-01

A low-weight (0.12 kg) low-volume fixed ceramic capacitor impedance matching system is developed for frequency agile tuning of a radiofrequency (rf) Helicon plasma thruster. Three fixed groups of capacitors are directly mounted onto a two loop rf antenna with the thruster immersed in a vacuum chamber. Optimum plasma tuning at the resonance frequency is demonstrated via measurements of the load impedance, power transfer efficiency and plasma density versus driving frequency in the 12.882–14.238 MHz range. The resonance frequency with the plasma on is higher than the resonance frequency in vacuum. The minimum rf power necessary for ignition decreases when the ignition frequency is shifted downwards from the resonance frequency. This development has direct applications in space qualification and space use of rf plasma thrusters. (paper)

Frequency Domain Electroretinography in Retinitis Pigmentosa versus Normal Eyes

Directory of Open Access Journals (Sweden)

Homa Hassan-Karimi

2012-01-01

Full Text Available Purpose: To compare electroretinogram (ERG characteristics in patients with retinitis pigmentosa (RP and normal subjects using frequency domain analysis. Methods: Five basic ERG recordings were performed in normal subjects and patients with a clinical diagnosis of RP according to the ISCEV (International Society of Clinical Electrophysiology of Vision protocol. Frequency domain analysis was performed by MATLAB software. Different frequency domain parameters were compared between the study groups. Results: Peak frequency (Fmod of flicker and oscillatory responses in RP patients showed significant (P<0.0001 high pass response as compared to normal controls. Peak frequency (Fmod of the other responses was not significantly different between the two groups. Conclusion: In addition to conventional ERG using time domain methods, frequency domain analysis may be useful for diagnosis of RP. Oscillatory and flicker responses may be analyzed in frequency domain. Fast Fourier transform may reveal two distinct high pass responses (shift to higher frequencies in Fmod. Time and frequency domain analyses may be performed simultaneously with many modern ERG machines and may therefore be recommended in RP patients.

Micro-Doppler Signal Time-Frequency Algorithm Based on STFRFT

Directory of Open Access Journals (Sweden)

Cunsuo Pang

2016-09-01

Full Text Available This paper proposes a time-frequency algorithm based on short-time fractional order Fourier transformation (STFRFT for identification of a complicated movement targets. This algorithm, consisting of a STFRFT order-changing and quick selection method, is effective in reducing the computation load. A multi-order STFRFT time-frequency algorithm is also developed that makes use of the time-frequency feature of each micro-Doppler component signal. This algorithm improves the estimation accuracy of time-frequency curve fitting through multi-order matching. Finally, experiment data were used to demonstrate STFRFT’s performance in micro-Doppler time-frequency analysis. The results validated the higher estimate accuracy of the proposed algorithm. It may be applied to an LFM (Linear frequency modulated pulse radar, SAR (Synthetic aperture radar, or ISAR (Inverse synthetic aperture radar, for improving the probability of target recognition.

Micro-Doppler Signal Time-Frequency Algorithm Based on STFRFT.

Science.gov (United States)

Pang, Cunsuo; Han, Yan; Hou, Huiling; Liu, Shengheng; Zhang, Nan

2016-09-24

This paper proposes a time-frequency algorithm based on short-time fractional order Fourier transformation (STFRFT) for identification of a complicated movement targets. This algorithm, consisting of a STFRFT order-changing and quick selection method, is effective in reducing the computation load. A multi-order STFRFT time-frequency algorithm is also developed that makes use of the time-frequency feature of each micro-Doppler component signal. This algorithm improves the estimation accuracy of time-frequency curve fitting through multi-order matching. Finally, experiment data were used to demonstrate STFRFT's performance in micro-Doppler time-frequency analysis. The results validated the higher estimate accuracy of the proposed algorithm. It may be applied to an LFM (Linear frequency modulated) pulse radar, SAR (Synthetic aperture radar), or ISAR (Inverse synthetic aperture radar), for improving the probability of target recognition.

A Meta-analysis on Resting State High-frequency Heart Rate Variability in Bulimia Nervosa.

Science.gov (United States)

Peschel, Stephanie K V; Feeling, Nicole R; Vögele, Claus; Kaess, Michael; Thayer, Julian F; Koenig, Julian

2016-09-01

Autonomic nervous system function is altered in eating disorders. We aimed to quantify differences in resting state vagal activity, indexed by high-frequency heart rate variability comparing patients with bulimia nervosa (BN) and healthy controls. A systematic search of the literature to identify studies eligible for inclusion and meta-analytical methods were applied. Meta-regression was used to identify potential covariates. Eight studies reporting measures of resting high-frequency heart rate variability in individuals with BN (n = 137) and controls (n = 190) were included. Random-effects meta-analysis revealed a sizeable main effect (Z = 2.22, p = .03; Hedge's g = 0.52, 95% CI [0.06;0.98]) indicating higher resting state vagal activity in individuals with BN. Meta-regression showed that body mass index and medication intake are significant covariates. Findings suggest higher vagal activity in BN at rest, particularly in unmedicated samples with lower body mass index. Potential mechanisms underlying these findings and implications for routine clinical care are discussed. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

The Frequency of AVN Following Reconstructive Hip Surgery in Children With Cerebral Palsy: A Systematic Review.

Science.gov (United States)

Hesketh, Kim; Leveille, Lise; Mulpuri, Kishore

2016-03-01

Children with cerebral palsy (CP) undergoing reconstructive hip surgery are at risk for developing avascular necrosis (AVN). The purpose of this systematic review was to investigate the reported frequency of AVN, the amount and quality of literature available, and possibly identity risk factors for developing AVN following reconstructive surgery for hip displacement in children with CP. We performed a review of the literature using EMBASE and MEDLINE databases. Studies investigating the outcome of reconstructive hip surgery in patients with CP that identified the presence or absence of AVN were included. Study quality was assessed using the Methodological Index for Non-Randomized Studies and the Oxford Centre for Evidence-Based Medicine scale. Three hundred and ninety-nine articles were identified using our search strategy. Twenty-nine studies were included for data extraction after full-text review. The frequency of AVN ranged from 0% to 46% with an overall rate across studies of 7.5%. Presence of AVN was the primary outcome in 2 studies. The frequency of AVN in these studies was significantly higher than other studies at 37% and 46%. No statistically significant associations were found between age at surgery, severity of hip subluxation, length of follow-up, or type of surgery (combined varus derotation osteotomy and pelvic osteotomy vs. varus derotation osteotomy alone), and the rate of AVN. The majority of studies did not comment on methods used for determining diagnosis or severity of AVN and clinical significance was not well documented. Children with CP undergoing reconstructive hip surgery are at risk of developing AVN. Frequency and severity of this complication is poorly documented in the literature. On the basis of current evidence no significant risk factors were identified; however, it is not possible to draw firm conclusions about them. Incidence of AVN was higher in studies in which AVN was a primary outcome suggesting that the true frequency of AVN

Population based allele frequencies of disease associated polymorphisms in the Personalized Medicine Research Project.

Science.gov (United States)

Cross, Deanna S; Ivacic, Lynn C; Stefanski, Elisha L; McCarty, Catherine A

2010-06-17

There is a lack of knowledge regarding the frequency of disease associated polymorphisms in populations and population attributable risk for many populations remains unknown. Factors that could affect the association of the allele with disease, either positively or negatively, such as race, ethnicity, and gender, may not be possible to determine without population based allele frequencies.Here we used a panel of 51 polymorphisms previously associated with at least one disease and determined the allele frequencies within the entire Personalized Medicine Research Project population based cohort. We compared these allele frequencies to those in dbSNP and other data sources stratified by race. Differences in allele frequencies between self reported race, region of origin, and sex were determined. There were 19544 individuals who self reported a single racial category, 19027 or (97.4%) self reported white Caucasian, and 11205 (57.3%) individuals were female. Of the 11,208 (57%) individuals with an identifiable region of origin 8337 or (74.4%) were German.41 polymorphisms were significantly different between self reported race at the 0.05 level. Stratification of our Caucasian population by self reported region of origin revealed 19 polymorphisms that were significantly different (p = 0.05) between individuals of different origins. Further stratification of the population by gender revealed few significant differences in allele frequencies between the genders. This represents one of the largest population based allele frequency studies to date. Stratification by self reported race and region of origin revealed wide differences in allele frequencies not only by race but also by region of origin within a single racial group. We report allele frequencies for our Asian/Hmong and American Indian populations; these two minority groups are not typically selected for population allele frequency detection. Population wide allele frequencies are important for the design and

Associations between family dinner frequency and specific food behaviors among grade six, seven, and eight students from Ontario and Nova Scotia.

Science.gov (United States)

Woodruff, Sarah J; Hanning, Rhona M

2009-05-01

Family dinner frequency has recently been associated in the literature with improved dietary profiles and healthy body weight in children and adolescents. However, it is not known whether family dinners are associated with other commonly reported food behaviors (fast food and soft drink consumption, breakfast skipping, and dieting) and attitudes (body weight concerns and self-efficacy for healthy eating) among Canadian students in grades 6, 7, and 8. A total of 3223 participants from Northern Ontario (Porcupine Region), Southern Ontario (Peel Region, Region of Waterloo, Toronto District), and Nova Scotia completed the Food Behavior Questionnaire during the 2005-2006 academic school year. Ordinal logistic regression analyses were used to determine the associations between family dinner frequency and food behaviors and attitudes. Higher family dinner frequency was significantly associated with less soft drink consumption, consuming breakfast on the day of the survey, the absence of a high body weight concern, having higher self-efficacy for healthy eating when at home with family, and during social times with friends. Researchers and clinicians should be aware of these associations when planning family based healthy eating strategies.

Sociodemographic characteristics and frequency of consuming home-cooked meals and meals from out-of-home sources: cross-sectional analysis of a population-based cohort study.

Science.gov (United States)

Mills, Susanna; Adams, Jean; Wrieden, Wendy; White, Martin; Brown, Heather

2018-04-11

To identify sociodemographic characteristics associated with frequency of consuming home-cooked meals and meals from out-of-home sources. Cross-sectional analysis of a population-based cohort study. Frequency of consuming home-cooked meals, ready meals, takeaways and meals out were derived from a participant questionnaire. Sociodemographic characteristics regarding sex, age, ethnicity, working overtime and socio-economic status (SES; measured by household income, educational attainment, occupational status and employment status) were self-reported. Sociodemographic differences in higher v. lower meal consumption frequency were explored using logistic regression, adjusted for other key sociodemographic variables. Cambridgeshire, UK. Fenland Study participants (n 11 326), aged 29-64 years at baseline. Eating home-cooked meals more frequently was associated with being female, older, of higher SES (measured by greater educational attainment and household income) and not working overtime. Being male was associated with a higher frequency of consumption for all out-of-home meal types. Consuming takeaways more frequently was associated with lower SES (measured by lower educational attainment and household income), whereas eating out more frequently was associated with higher SES (measured by greater educational attainment and household income) and working overtime. Sociodemographic characteristics associated with frequency of eating meals from different out-of-home sources varied according to meal source. Findings may be used to target public health policies and interventions for promoting healthier diets and dietary-related health towards people consuming home-cooked meals less frequently, such as men, those with lower educational attainment and household income, and overtime workers.

Sex differences in Hadza eating frequency by food type.

Science.gov (United States)

Berbesque, J Colette; Marlowe, Frank W; Crittenden, Alyssa N

2011-01-01

We investigate sex differences in frequencies of adults eating in a foraging population-the Hadza of Tanzania. We use eating frequency data from instantaneous scan observations of the Hadza, to see to how much sharing of foods taken back to camp compensates for the targeting of different foods by each sex while out foraging. Eating in camp differs by sex in terms of overall eating frequency, as well as in terms of diet composition (frequencies of eating each food type). We also control for sex-differences in time spent in camp and still find sex-differences in eating frequencies-women are observed eating significantly more frequently than men. There are also sex-differences in the eating frequencies of particular food types both with and without controlling for presence in camp. Finally, we use data on acquisition of each food type by sex and find that both sexes are more frequently observed eating women's foods in camp than men's foods. At least in the case of the Hadza, we see pronounced sex differences in the in-camp diet. Hadza men are eating a higher quality diet than are women, but women are able to eat far more frequently, and spend less time foraging than men. It is not yet clear whether a regular caloric intake of lower quality foods would be more beneficial for maintaining fecundity than a more variable diet consisting of higher quality foods. Copyright © 2011 Wiley-Liss, Inc.

Higher frequency of secretor phenotype in O blood group ? its benefits in prevention and/or treatment of some diseases

OpenAIRE

Jaff, Mohamad Salih

2010-01-01

Mohamad Salih JaffPathology Department, Hawler Medical University (Formerly Salahaddin University), Erbil, Kurdistan Region, IraqAbstract: ABO blood groups and secretor status are important in clinical and forensic medicine and in relation to some diseases. There are geographic and racial differences in their frequencies, but the frequency of secretor status in different ABO blood group systems has not been determined yet. Therefore, the aim of this study was mainly to determine this point. B...

Frequency division using a micromechanical resonance cascade

Energy Technology Data Exchange (ETDEWEB)

Qalandar, K. R., E-mail: kamala@engineering.ucsb.edu; Gibson, B.; Sharma, M.; Ma, A.; Turner, K. L. [Department of Mechanical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106 (United States); Strachan, B. S. [Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48823 (United States); Department of Electrical Engineering, Michigan State University, East Lansing, Michigan 48823 (United States); Shaw, S. W. [Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48823 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48823 (United States)

2014-12-15

A coupled micromechanical resonator array demonstrates a mechanical realization of multi-stage frequency division. The mechanical structure consists of a set of N sequentially perpendicular microbeams that are connected by relatively weak elastic elements such that the system vibration modes are localized to individual microbeams and have natural frequencies with ratios close to 1:2:⋯:2{sup N}. Conservative (passive) nonlinear inter-modal coupling provides the required energy transfer between modes and is achieved by finite deformation kinematics. When the highest frequency beam is excited, this arrangement promotes a cascade of subharmonic resonances that achieve frequency division of 2{sup j} at microbeam j for j = 1, …, N. Results are shown for a capacitively driven three-stage divider in which an input signal of 824 kHz is passively divided through three modal stages, producing signals at 412 kHz, 206 kHz, and 103 kHz. The system modes are characterized and used to delineate the range of AC input voltages and frequencies over which the cascade occurs. This narrow band frequency divider has simple design rules that are scalable to higher frequencies and can be extended to a larger number of modal stages.

Higher frequency of brain abnormalities in neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome.

Science.gov (United States)

Gu, Li-Na; Zhang, Min; Zhu, Hui; Liu, Jing-Yao

2016-10-01

Neuromyelitis optica spectrum disorder often co-exists with primary Sjögren's syndrome. We compared the clinical features of 16 neuromyelitis optica spectrum disorder patients with ( n = 6) or without primary Sjögren's syndrome ( n = 10). All patients underwent extensive clinical, laboratory, and MRI evaluations. There were no statistical differences in demographics or first neurological involvement at onset between neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome. The laboratory findings of cerebrospinal fluid oligoclonal banding, serum C-reactive protein, antinuclear autoantibody, anti-Sjögren's-syndrome-related antigen A antibodies, anti-Sjögren's-syndrome-related antigen B antibodies, and anti-Sm antibodies were significantly higher in patients with primary Sjögren's syndrome than those without. Anti-aquaporin 4 antibodies were detectable in 67% (4/6) of patients with primary Sjögren's syndrome and in 60% (6/10) of patients without primary Sjögren's syndrome. More brain abnormalities were observed in patients without primary Sjögren's syndrome than in those with primary Sjögren's syndrome. Segments lesions (> 3 centrum) were noted in 50% (5/10) of patients without primary Sjögren's syndrome and in 67% (4/6) of patients with primary Sjögren's syndrome. These findings indicate that the clinical characteristics of neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome are similar. However, neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome have a high frequency of brain abnormalities.

Limitations in THz Power Generation with Schottky Diode Varactor Frequency Multipliers

DEFF Research Database (Denmark)

Krozer, Viktor; Loata, G.; Grajal, J.

2002-01-01

, at increasing frequencies the power drops with f-3 instead of the f-2 predicted by theory. In this contribution we provide an overview of state-of-the-art results. A comparison with theoretically achievable multiplier performance reveals that the devices employed at higher frequencies are operating...... inefficiently and the design and fabrication capabilities have not reached the maturity encountered at lower THz frequencies....

Increased somatic cell mutant frequency in atomic bomb survivors

International Nuclear Information System (INIS)

Hakoda, Masayuki; Akiyama, Mitoshi; Kyoizumi, Seishi; Awa, A.A.; Yamakido, Michio; Otake, Masanori.

1988-05-01

Frequencies of mutant T-cells in peripheral blood, which are deficient in the activity of hypoxanthine guanine phosphoribosyltransferase (HPRT) were determined for atomic bomb survivors by direct clonal assay using a previously reported method. Results from 30 exposed survivors (exposed to more than 1 rad) and 17 age- and sex-matched controls (exposed to less than 1 rad) were analyzed. The mean mutant frequency (Mf) in the exposed (5.2 x 10 -6 ; range 0.8 - 14.4 x 10 -6 ) was significantly higher than in controls (3.4 x 10 -6 ; range 1.3 - 9.3 x 10 -6 ), a fact not attributable to lower nonmutant cell cloning efficiencies in the exposed group since cell cloning efficiencies were virtually identical in both groups. An initial analysis of the data did not reveal a significant correlation between individual Mfs and individual radiation dose estimates when the latter were defined by the original, tentative estimates (T65D), even though there was a significant positive correlation of Mfs with individual frequency of lymphocytes bearing chromosome aberration. However, reanalysis using the newer revised individual dose estimates (DS86) for 27 exposed survivors and 17 controls did reveal a significant but shallow positive correlation between T-cell Mf values and individual exposure doses. These results indicate that HPRT mutation in vivo in human T-cells could be detected in these survivors 40 years after the presumed mutational event. (author)

Energy harvesting from radio frequency propagation using piezoelectric cantilevers

KAUST Repository

Al Ahmad, Mahmoud; Alshareef, Husam N.

2012-01-01

This work reports an induced strain in a piezoelectric cantilever due to radio frequency signal propagation. The piezoelectric actuator is coupled to radio frequency (RF) line through a gap of 0.25 mm. When a voltage signal of 10 Vpp propagates

Differential invariants for higher-rank tensors. A progress report

International Nuclear Information System (INIS)

Tapial, V.

2004-07-01

We outline the construction of differential invariants for higher-rank tensors. In section 2 we outline the general method for the construction of differential invariants. A first result is that the simplest tensor differential invariant contains derivatives of the same order as the rank of the tensor. In section 3 we review the construction for the first-rank tensors (vectors) and second-rank tensors (metrics). In section 4 we outline the same construction for higher-rank tensors. (author)

Effect of combined mutagenic treatments on sensitivity and mutation frequency in rice

International Nuclear Information System (INIS)

Gopinathan Nair, V.

1977-01-01

Rice seeds were subjected to two sets of combination treatments of radiations and NMH. The effects of mutagenic treatments in the M 1 and M 2 generations were recorded and discussed. Mutation frequencies estimated as number of mutations per 100 M 1 years were not higher than the values expected on the basis of additive effects. When estimated as number of mutants per 100 M 2 plants, the frequencies revealed more than additive effects. The synergistic effect on mutant frequencies was due to increase in the segregation ratio of mutants. This effect was more pronounced at the higher dose combinations of fast neutrons and NMH. (author)

The Process of Change in Higher Education Institutions. AAHE-ERIC/Higher Education Research Report, No. 7, 1982.

Science.gov (United States)

Nordvall, Robert C.

Conditions that inhibit change in higher education institutions and various models of the change process are described. Attention is also directed to: organizational character, structural features, planning procedures, key individuals in the change process, and practical advice about change. The major change models for higher education…

Transport accident frequency data, their sources and their application in risk assessment

International Nuclear Information System (INIS)

Appleton, P.R.

1988-08-01

Base transport accident frequency data and sources of these data are presented. Both generic information and rates specific to particular routes or packages are included. Strong packages, such as those containing significant quantities of radioactive materials, will survive most of the accidents represented by these base frequencies without a containment breach. The association of severity probability distributions with a base frequency, and package and contents response, leading to the quantification of release frequency and magnitude, are often more important in risk assessment than the base frequency itself. This paper therefore also includes brief comments on techniques adopted to utilize the base frequencies. This paper reports an accident frequency data survey undertaken at the end of 1986. It has not been updated to take account of work published between January 1987 and the Report publication date. (author)

T-gate aligned nanotube radio frequency transistors and circuits with superior performance.

Science.gov (United States)

Che, Yuchi; Lin, Yung-Chen; Kim, Pyojae; Zhou, Chongwu

2013-05-28

In this paper, we applied self-aligned T-gate design to aligned carbon nanotube array transistors and achieved an extrinsic current-gain cutoff frequency (ft) of 25 GHz, which is the best on-chip performance for nanotube radio frequency (RF) transistors reported to date. Meanwhile, an intrinsic current-gain cutoff frequency up to 102 GHz is obtained, comparable to the best value reported for nanotube RF transistors. Armed with the excellent extrinsic RF performance, we performed both single-tone and two-tone measurements for aligned nanotube transistors at a frequency up to 8 GHz. Furthermore, we utilized T-gate aligned nanotube transistors to construct mixing and frequency doubling analog circuits operated in gigahertz frequency regime. Our results confirm the great potential of nanotube-based circuit applications and indicate that nanotube transistors are promising building blocks in high-frequency electronics.

SRS Process Facility Significance Fire Frequency

Energy Technology Data Exchange (ETDEWEB)

Sarrack, A.G. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1995-10-01

This report documents the method and assumptions of a study performed to determine a site generic process facility significant fire initiator frequency and explains the proper way this value should be used.

SRS Process Facility Significance Fire Frequency

International Nuclear Information System (INIS)

Sarrack, A.G.

1995-10-01

This report documents the method and assumptions of a study performed to determine a site generic process facility significant fire initiator frequency and explains the proper way this value should be used

B-cell infiltration and frequency of cytokine producing cells differ between localized and disseminated human cutaneous leishmaniases

Directory of Open Access Journals (Sweden)

MGS Vieira

2002-10-01

Full Text Available Biopsies from human localized cutaneous lesions (LCL n = 7 or disseminated lesions (DL n = 8 cases were characterized according to cellular infiltration,frequency of cytokine (IFN-g, TNF-alpha or iNOS enzyme producing cells. LCL, the most usual form of the disease with usually one or two lesions, exhibits extensive tissue damage. DL is a rare form with widespread lesions throughout the body; exhibiting poor parasite containment but less tissue damage. We demonstrated that LCL lesions exhibit higher frequency of B lymphocytes and a higher intensity of IFN-gamma expression. In both forms of the disease CD8+ were found in higher frequency than CD4+ T cells. Frequency of TNF-alpha and iNOS producing cells, as well as the frequency of CD68+ macrophages, did not differ between LCL and DL. Our findings reinforce the link between an efficient control of parasite and tissue damage, implicating higher frequency of IFN-gamma producing cells, as well as its possible counteraction by infiltrated B cells and hence possible humoral immune response in situ.

Frequency Doubling Broadband Light in Multiple Crystals

International Nuclear Information System (INIS)

Alford, William J.; Smith, Arlee V.

2000-01-01

The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth

Mixed frequency excitation of an electrostatically actuated resonator

KAUST Repository

Ramini, Abdallah

2015-04-24

We investigate experimentally and theoretically the dynamics of a capacitive resonator under mixed frequency excitation of two AC harmonic signals. The resonator is composed of a proof mass suspended by two cantilever beams. Experimental measurements are conducted using a laser Doppler vibrometer to reveal the interesting dynamics of the system when subjected to two-source excitation. A nonlinear single-degree-of-freedom model is used for the theoretical investigation. The results reveal combination resonances of additive and subtractive type, which are shown to be promising to increase the bandwidth of the resonator near primary resonance frequency. Our results also demonstrate the ability to shift the combination resonances to much lower or much higher frequency ranges. We also demonstrate the dynamic pull-in instability under mixed frequency excitation. © 2015 Springer-Verlag Berlin Heidelberg

Neighbourhood frequency effects in visual word recognition and naming

NARCIS (Netherlands)

Grainger, I.J.

1988-01-01

Two experiments are reported that examine the influence of a given word's ortllographic neighbours (orthographically similar words) on the recognition and pronunciation of that word. In Experiment 1 (lexical decision) neighbourhood frequency as opposed to stimulus-word frequency was shown to have a

Self-reported advertising exposure to sugar-sweetened beverages among US youth.

Science.gov (United States)

Kumar, Gayathri; Onufrak, Stephen; Zytnick, Deena; Kingsley, Beverly; Park, Sohyun

2015-05-01

According to the Federal Trade Commission, in 2009, the top food category with teen-directed marketing expenditures was sugar-sweetened beverages (SSB). The present study reports on exposure to SSB advertisements using self-report data from adolescents. Cross-sectional study design using descriptive statistics to assess self-reported frequency of exposure to SSB advertisements and multivariable logistic regression to examine associations between frequency of SSB advertising exposure and sociodemographic variables. Online survey conducted at home. US adolescents aged 12-17 years (n 847). Among the surveyed adolescents, 42 % to 54 % reported seeing/hearing SSB advertisements ≥1 time/d. Those aged 14-15 years were more likely to report seeing/hearing soda, sports drink and energy drink advertisements ≥1 time/d than 16- to 17-year-olds. Males were more likely to report seeing/hearing sports drink advertising ≥1 time/d than females. Non-Hispanic black adolescents were more likely to report seeing/hearing fruit drink and sports drink advertisements ≥1 time/d than non-Hispanic white adolescents. Adolescents whose parents had high-school education or less were more likely to report seeing/hearing soda, fruit drink and energy drink advertisements ≥1 time/d than adolescents whose parents were college graduates. Almost half of the adolescents sampled reported daily SSB advertising exposure, with higher exposure among African Americans and adolescents with less educated parents. These data can help inform potential actions that decision makers might take, such as education of adolescents and their caregivers on the potential impact of beverage advertising, especially among groups at higher risk for obesity.

Constant Switching Frequency Self-Oscillating Controlled Class-D Amplifiers

DEFF Research Database (Denmark)

Nguyen-Duy, Khiem; Knott, Arnold; Andersen, Michael A. E.

2014-01-01

The self-oscillating control approach has been used extensively in class-D amplifiers. It has several advantages such as high bandwidth and high audio performance. However, one of the primary disadvantages in a self-oscillating controlled system is that the switching frequency of the amplifier...... varies with the ratio of the output voltage to the input rail voltage. In other words, the switching frequency varies with the duty cycle of the output. The drop in the frequency results in lower control bandwidth and higher output voltage ripple, which are undesirable. This paper proposes a new self-oscillating...... control scheme that maintains a constant switching frequency over the full range of output voltage. The frequency difference is processed by a compensator whose output adjusts the total loop gain of the control system. It has been proven by simulation that a con-stant switching frequency self-oscillating...

Basal ganglia dysfunction in OCD: subthalamic neuronal activity correlates with symptoms severity and predicts high-frequency stimulation efficacy.

Science.gov (United States)

Welter, M-L; Burbaud, P; Fernandez-Vidal, S; Bardinet, E; Coste, J; Piallat, B; Borg, M; Besnard, S; Sauleau, P; Devaux, B; Pidoux, B; Chaynes, P; Tézenas du Montcel, S; Bastian, A; Langbour, N; Teillant, A; Haynes, W; Yelnik, J; Karachi, C; Mallet, L

2011-05-03

Functional and connectivity changes in corticostriatal systems have been reported in the brains of patients with obsessive-compulsive disorder (OCD); however, the relationship between basal ganglia activity and OCD severity has never been adequately established. We recently showed that deep brain stimulation of the subthalamic nucleus (STN), a central basal ganglia nucleus, improves OCD. Here, single-unit subthalamic neuronal activity was analysed in 12 OCD patients, in relation to the severity of obsessions and compulsions and response to STN stimulation, and compared with that obtained in 12 patients with Parkinson's disease (PD). STN neurons in OCD patients had lower discharge frequency than those in PD patients, with a similar proportion of burst-type activity (69 vs 67%). Oscillatory activity was present in 46 and 68% of neurons in OCD and PD patients, respectively, predominantly in the low-frequency band (1-8 Hz). In OCD patients, the bursty and oscillatory subthalamic neuronal activity was mainly located in the associative-limbic part. Both OCD severity and clinical improvement following STN stimulation were related to the STN neuronal activity. In patients with the most severe OCD, STN neurons exhibited bursts with shorter duration and interburst interval, but higher intraburst frequency, and more oscillations in the low-frequency bands. In patients with best clinical outcome with STN stimulation, STN neurons displayed higher mean discharge, burst and intraburst frequencies, and lower interburst interval. These findings are consistent with the hypothesis of a dysfunction in the associative-limbic subdivision of the basal ganglia circuitry in OCD's pathophysiology.

SU-E-I-52: Validation of Multi-Frequency Electrical Impedance Tomography Using Computed Tomography

Energy Technology Data Exchange (ETDEWEB)

Kohli, K; Liu, F; Krishnan, K [BC Cancer Agency, Surrey, BC (United Kingdom)

2014-06-01

Purpose: Multi-frequency EIT has been reported to be a potential tool in distinguishing a tissue anomaly from background. In this study, we investigate the feasibility of acquiring functional information by comparing multi-frequency EIT images in reference to the structural information from the CT image through fusion. Methods: EIT data was acquired from a slice of winter melon using sixteen electrodes around the phantom, injecting a current of 0.4mA at 100, 66, 24.8 and 9.9 kHz. Differential EIT images were generated by considering different combinations of pair frequencies, one serving as reference data and the other as test data. The experiment was repeated after creating an anomaly in the form of an off-centered cavity of diameter 4.5 cm inside the melon. All EIT images were reconstructed using Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS) package in 2-D differential imaging mode using one-step Gaussian Newton minimization solver. CT image of the melon was obtained using a Phillips CT Scanner. A segmented binary mask image was generated based on the reference electrode position and the CT image to define the regions of interest. The region selected by the user was fused with the CT image through logical indexing. Results: Differential images based on the reference and test signal frequencies were reconstructed from EIT data. Result illustrated distinct structural inhomogeneity in seeded region compared to fruit flesh. The seeded region was seen as a higherimpedance region if the test frequency was lower than the base frequency in the differential EIT reconstruction. When the test frequency was higher than the base frequency, the signal experienced less electrical impedance in the seeded region during the EIT data acquisition. Conclusion: Frequency-based differential EIT imaging can be explored to provide additional functional information along with structural information from CT for identifying different tissues.

SU-E-I-52: Validation of Multi-Frequency Electrical Impedance Tomography Using Computed Tomography

International Nuclear Information System (INIS)

Kohli, K; Liu, F; Krishnan, K

2014-01-01

Purpose: Multi-frequency EIT has been reported to be a potential tool in distinguishing a tissue anomaly from background. In this study, we investigate the feasibility of acquiring functional information by comparing multi-frequency EIT images in reference to the structural information from the CT image through fusion. Methods: EIT data was acquired from a slice of winter melon using sixteen electrodes around the phantom, injecting a current of 0.4mA at 100, 66, 24.8 and 9.9 kHz. Differential EIT images were generated by considering different combinations of pair frequencies, one serving as reference data and the other as test data. The experiment was repeated after creating an anomaly in the form of an off-centered cavity of diameter 4.5 cm inside the melon. All EIT images were reconstructed using Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS) package in 2-D differential imaging mode using one-step Gaussian Newton minimization solver. CT image of the melon was obtained using a Phillips CT Scanner. A segmented binary mask image was generated based on the reference electrode position and the CT image to define the regions of interest. The region selected by the user was fused with the CT image through logical indexing. Results: Differential images based on the reference and test signal frequencies were reconstructed from EIT data. Result illustrated distinct structural inhomogeneity in seeded region compared to fruit flesh. The seeded region was seen as a higherimpedance region if the test frequency was lower than the base frequency in the differential EIT reconstruction. When the test frequency was higher than the base frequency, the signal experienced less electrical impedance in the seeded region during the EIT data acquisition. Conclusion: Frequency-based differential EIT imaging can be explored to provide additional functional information along with structural information from CT for identifying different tissues

High-frequency parameters of magnetic films showing magnetization dispersion

International Nuclear Information System (INIS)

Sidorenkov, V.V.; Zimin, A.B.; Kornev, Yu.V.

1988-01-01

Magnetization dispersion leads to skewed resonance curves shifted towards higher magnetizing fields, together with considerable reduction in the resonant absorption, while the FMR line width is considerably increased. These effects increase considerably with frequency, in contrast to films showing magnetic-anisotropy dispersion, where they decrease. It is concluded that there may be anomalies in the frequency dependence of the resonance parameters for polycrystalline magnetic films

Higher Education.

Science.gov (United States)

Hendrickson, Robert M.

This chapter reports 1982 cases involving aspects of higher education. Interesting cases noted dealt with the federal government's authority to regulate state employees' retirement and raised the questions of whether Title IX covers employment, whether financial aid makes a college a program under Title IX, and whether sex segregated mortality…

Synthesis of High-Frequency Ground Motion Using Information Extracted from Low-Frequency Ground Motion

Science.gov (United States)

Iwaki, A.; Fujiwara, H.

2012-12-01

Broadband ground motion computations of scenario earthquakes are often based on hybrid methods that are the combinations of deterministic approach in lower frequency band and stochastic approach in higher frequency band. Typical computation methods for low-frequency and high-frequency (LF and HF, respectively) ground motions are the numerical simulations, such as finite-difference and finite-element methods based on three-dimensional velocity structure model, and the stochastic Green's function method, respectively. In such hybrid methods, LF and HF wave fields are generated through two different methods that are completely independent of each other, and are combined at the matching frequency. However, LF and HF wave fields are essentially not independent as long as they are from the same event. In this study, we focus on the relation among acceleration envelopes at different frequency bands, and attempt to synthesize HF ground motion using the information extracted from LF ground motion, aiming to propose a new method for broad-band strong motion prediction. Our study area is Kanto area, Japan. We use the K-NET and KiK-net surface acceleration data and compute RMS envelope at four frequency bands: 0.5-1.0 Hz, 1.0-2.0 Hz, 2.0-4.0 Hz, .0-8.0 Hz, and 8.0-16.0 Hz. Taking the ratio of the envelopes of adjacent bands, we find that the envelope ratios have stable shapes at each site. The empirical envelope-ratio characteristics are combined with low-frequency envelope of the target earthquake to synthesize HF ground motion. We have applied the method to M5-class earthquakes and a M7 target earthquake that occurred in the vicinity of Kanto area, and successfully reproduced the observed HF ground motion of the target earthquake. The method can be applied to a broad band ground motion simulation for a scenario earthquake by combining numerically-computed low-frequency (~1 Hz) ground motion with the empirical envelope ratio characteristics to generate broadband ground motion

High quality factor gigahertz frequencies in nanomechanical diamond resonators

OpenAIRE

Gaidarzhy, Alexei; Imboden, Matthias; Mohanty, Pritiraj; Rankin, Janet; Sheldon, Brian W.

2007-01-01

We report actuation and detection of gigahertz-range resonance frequencies in nano-crystalline diamond mechanical resonators. High order transverse vibration modes are measured in coupled-beam resonators exhibiting frequencies up to 1.441 GHz. The cantilever-array design of the resonators translates the gigahertz-range resonant motion of micron-long cantilever elements to the displacement of the central supporting structure. Use of nano-crystalline diamond further increases the frequency comp...

Analysis of the frequency response of a TeO{sub 2} slow shear wave acousto-optic cell exposed to radiation

Energy Technology Data Exchange (ETDEWEB)

Erteza, I.A.

1995-04-01

Radiation testing of photonic components is not new, however component level testing to date has not completely addressed quantities which are important to system behavior. One characteristic that is of particular importance for optical processing systems is the frequency response. In this report, we present the analysis of data from an experiment designed to provide a preliminary understanding of the effects of radiation on the frequency response of acousto-optic devices. The goal of the analysis is to describe possible physical mechanisms responsible for the radiation effects and to discuss the effects on signal processing functionality. The experiment discussed in this report was designed by Sandia National Laboratories and performed by Sandia and Phillips Laboratory personnel at White Sands Missile Range (WSMR). In the experiment, a TeO{sub 2} slow shear wave acousto-optic cell was exposed to radiation from the WSMR linear accelerator. The TeO{sub 2} cell was placed in an experimental configuration which allowed swept frequency diffracted power measurements to be taken during radiation exposure and recovery. A series of exposures was performed. Each exposure consisted of between 1 to 800, 1{mu}sec radiation pulses (yielding exposures of 2.25 kRad(Si) to 913 kRad(Si)), followed by recovery time. At low total and cumulative doses, the bandshape of the frequency response (i.e. diffracted power vs. frequency) remained almost identical during and after radiation. At the higher exposures, however, the amplitude and width of the frequency response changed as the radiation continued, but returned to the original shape slowly after the radiation stopped and recovery proceeded. It is interesting to note that the location of the Bragg degeneracy does not change significantly with radiation. In this report, we discuss these effects from the perspective of anisotropic Bragg diffraction and momentum mismatch, and we discuss the effect on the signal processing functionality.

Influence of horizontally curved roadway section characteristics on motorcycle-to-barrier crash frequency.

Science.gov (United States)

Gabauer, Douglas J; Li, Xiaolong

2015-04-01

The purpose of this study was to investigate motorcycle-to-barrier crash frequency on horizontally curved roadway sections in Washington State using police-reported crash data linked with roadway data and augmented with barrier presence information. Data included 4915 horizontal curved roadway sections with 252 of these sections experiencing 329 motorcycle-to-barrier crashes between 2002 and 2011. Negative binomial regression was used to predict motorcycle-to-barrier crash frequency using horizontal curvature and other roadway characteristics. Based on the model results, the strongest predictor of crash frequency was found to be curve radius. This supports a motorcycle-to-barrier crash countermeasure placement criterion based, at the very least, on horizontal curve radius. With respect to the existing horizontal curve criterion of 820 feet or less, curves meeting this criterion were found to increase motorcycle-to-barrier crash frequency rate by a factor of 10 compared to curves not meeting this criterion. Other statistically significant predictors were curve length, traffic volume and the location of adjacent curves. Assuming curves of identical radius, the model results suggest that longer curves, those with higher traffic volume, and those that have no adjacent curved sections within 300 feet of either curve end would likely be better candidates for a motorcycle-to-barrier crash countermeasure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Frequency of discrimination, harassment, and violence in lesbian, gay men, and bisexual in Italy.

Science.gov (United States)

Pelullo, Concetta P; Di Giuseppe, Gabriella; Angelillo, Italo F

2013-01-01

This cross-sectional study assessed the frequency of discrimination, harassment, and violence and the associated factors among a random sample of 1000 lesbian, gay men, and bisexual women and men recruited from randomly selected public venues in Italy. A face-to-face interview sought information about: socio-demographics, frequency of discrimination, verbal harassment, and physical and sexual violence because of their sexual orientation, and their fear of suffering each types of victimization. In the whole sample, 28.3% and 11.9% self-reported at least one episode of victimization because of the sexual orientation in their lifetime and in the last year. Those unmarried, compared to the others, and with a college degree or higher, compared to less educated respondents, were more likely to have experienced an episode of victimization in their lifetime. Lesbians, compared to bisexual, had almost twice the odds of experiencing an episode of victimization. The most commonly reported experiences across the lifetime were verbal harassment, discrimination, and physical or sexual violence. Among those who had experienced one episode of victimization in their lifetime, 42.1% self-reported one episode in the last year. Perceived fear of suffering violence because of their sexual orientation, measured on a 10-point Likert scale with a higher score indicative of greater fear, ranges from 5.7 for verbal harassment to 6.4 for discrimination. Participants were more likely to have fear of suffering victimization because of their sexual orientation if they were female (compared to male), lesbian and gay men (compared to bisexual women and men), unmarried (compared to the others), and if they have already suffered an episode of victimization (compared to those who have not suffered an episode). The study provides important insights into the violence experiences of lesbian, gay men, and bisexual women and men and the results may serve for improving policy initiatives to reduce such

Energy harvesting from radio frequency propagation using piezoelectric cantilevers

KAUST Repository

Al Ahmad, Mahmoud

2012-02-01

This work reports an induced strain in a piezoelectric cantilever due to radio frequency signal propagation. The piezoelectric actuator is coupled to radio frequency (RF) line through a gap of 0.25 mm. When a voltage signal of 10 Vpp propagates in the line it sets an alternating current in the actuator electrodes. This flowing current drives the piezoelectric cantilever to mechanical movement, especially when the frequency of the RF signal matches the mechanical resonant frequency of the cantilever. Output voltage signals versus frequency for both mechanical vibrational and RF signal excitations have been measured using different loads.© 2011 Elsevier Ltd. All rights reserved.

Fundamental Frequency Estimation using Polynomial Rooting of a Subspace-Based Method

DEFF Research Database (Denmark)

Jensen, Jesper Rindom; Christensen, Mads Græsbøll; Jensen, Søren Holdt

2010-01-01

improvements compared to HMUSIC. First, by using the proposed method we can obtain an estimate of the fundamental frequency without doing a grid search like in HMUSIC. This is due to that the fundamental frequency is estimated as the argument of the root lying closest to the unit circle. Second, we obtain...... a higher spectral resolution compared to HMUSIC which is a property of polynomial rooting methods. Our simulation results show that the proposed method is applicable to real-life signals, and that we in most cases obtain a higher spectral resolution than HMUSIC....

High-frequency performance for a spiral-shaped piezoelectric bimorph

Science.gov (United States)

Huang, Fang Sheng; Feng, Zhi Hua; Ma, Yu Ting; Pan, Qiao Sheng; Zhang, Lian Sheng; Liu, Yong Bin; He, Liang Guo

2018-04-01

Piezoelectric cantilever is suitable as an actuator for micro-flapping-wing aircraft. Higher resonant frequency brings about stronger flight energy, and the flight amplitude can be compensated by displacement-amplification mechanism, such as lever. To obtain a higher resonant frequency, straight piezoelectric bimorph was rolled into spiral-shaped piezoelectric bimorph with identical effective length in this study, which is verified in COMSOL simulations. Simulation results show that compared with the straight piezoelectric bimorph, the spiral-shaped piezoelectric bimorph with two turns has higher inherent frequencies (from 204.79 Hz to 504.84 Hz in terms of axial oscillation mode, and from 319.77 Hz to 704.48 Hz in terms of tangential torsional mode). The spiral-shaped piezoelectric bimorph is fabricated by a precise laser cutting process and consists of two turns with effective length of 60 mm, width of 2.5 mm, and thickness of 1.6 mm, respectively. With the excitation voltage of 100 Vpp applying an electric field across the thickness of the bimorph, the tip displacement of the actuator in the axial oscillation and tangential torsional modes are 85 μm and 15 μm, respectively.

Excitation of higher radial modes of azimuthal surface waves in the electron cyclotron frequency range by rotating relativistic flow of electrons in cylindrical waveguides partially filled by plasmas

Science.gov (United States)

Girka, Igor O.; Pavlenko, Ivan V.; Thumm, Manfred

2018-05-01

Azimuthal surface waves are electromagnetic eigenwaves of cylindrical plasma-dielectric waveguides which propagate azimuthally nearby the plasma-dielectric interface across an axial external stationary magnetic field. Their eigenfrequency in particular can belong to the electron cyclotron frequency range. Excitation of azimuthal surface waves by rotating relativistic electron flows was studied in detail recently in the case of the zeroth radial mode for which the waves' radial phase change within the layer where the electrons gyrate is small. In this case, just the plasma parameters cause the main influence on the waves' dispersion properties. In the case of the first and higher radial modes, the wave eigenfrequency is higher and the wavelength is shorter than in the case of the zeroth radial mode. This gain being of interest for practical applications can be achieved without any change in the device design. The possibility of effective excitation of the higher order radial modes of azimuthal surface waves is demonstrated here. Getting shorter wavelengths of the excited waves in the case of higher radial modes is shown to be accompanied by decreasing growth rates of the waves. The results obtained here are of interest for developing new sources of electromagnetic radiation, in nano-physics and in medical physics.

Frequency and amplitude stabilization in MEMS and NEMS oscillators

Science.gov (United States)

Chen, Changyao; Lopez, Omar Daniel; Czaplewski, David A.

2017-06-14

This invention comprises a nonlinear micro- and nano-mechanical resonator that can maintain frequency of operation and amplitude of operation for a period of time after all external power has been removed from the device. Utilizing specific nonlinear dynamics of the micromechanical resonator, mechanical energy at low frequencies can be input and stored in higher frequencies modes, thus using the multiple degrees of freedom of the resonator to extend its energy storage capacity. Furthermore, the energy stored in multiple vibrational modes can be used to maintain the resonator oscillating for a fixed period of time, even without an external power supply. This is the first demonstration of an "autonomous" frequency source that can maintain a constant frequency and vibrating amplitude when no external power is provided, making it ideal for applications requiring an oscillator in low power, or limited and intermittent power supplies.

The Role of Higher Harmonics In Musical Interval Perception

Science.gov (United States)

Krantz, Richard; Douthett, Jack

2011-10-01

Using an alternative parameterization of the roughness curve we make direct use of critical band results to investigate the role of higher harmonics on the perception of tonal consonance. We scale the spectral amplitudes in the complex home tone and complex interval tone to simulate acoustic signals of constant energy. Our analysis reveals that even with a relatively small addition of higher harmonics the perfect fifth emerges as a consonant interval with more, musically important, just intervals emerging as consonant as more and more energy is shifted into higher frequencies.

Sound field control for a low-frequency test facility

DEFF Research Database (Denmark)

Pedersen, Christian Sejer; Møller, Henrik

2013-01-01

The two largest problems in controlling the reproduction of low-frequency sound for psychoacoustic experiments is the effect of the room due to standing waves and the relatively large sound pressure levels needed. Anechoic rooms are limited downward in frequency and distortion may be a problem even...... at moderate levels, while pressure-field playback can give higher sound pressures but is limited upwards in frequency. A new solution that addresses both problems has been implemented in the laboratory of Acoustics, Aalborg University. The solution uses one wall with 20 loudspeakers to generate a plane wave...... that is actively absorbed when it reaches the 20 loudspeakers on the opposing wall. This gives a homogeneous sound field in the majority of the room with a flat frequency response in the frequency range 2-300 Hz. The lowest frequencies are limited to sound pressure levels in the order of 95 dB. If larger levels...

Nonlinear frequency shift of a coherent dust-acoustic wave in the presence of dust-acoustic turbulence

International Nuclear Information System (INIS)

Yi Sumin; Ryu, C.-M.; Yoon, Peter H.

2003-01-01

The nonlinear frequency shift of a low-frequency, coherent dust-acoustic wave in the presence of higher frequency dust-acoustic turbulence is investigated in the framework of weak turbulence theory. It is found that the frequency shift of the dust-acoustic wave in an unmagnetized dusty plasma is always positive irrespective of the propagation direction of the coherent wave. It is also found that turbulent waves propagating in the same direction as the coherent wave are shown to give rise to a much higher frequency shift than the opposite case. Finally, it is shown that the nonlinear frequency shift of a dust-acoustic wave is more pronounced than in the case of the customary ion-acoustic waves in fully ionized plasmas

High-performance radio frequency transistors based on diameter-separated semiconducting carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Cao, Yu; Che, Yuchi; Zhou, Chongwu, E-mail: chongwuz@usc.edu [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Seo, Jung-Woo T.; Hersam, Mark C. [Department of Materials Science and Engineering and Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States); Gui, Hui [Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089 (United States)

2016-06-06

In this paper, we report the high-performance radio-frequency transistors based on the single-walled semiconducting carbon nanotubes with a refined average diameter of ∼1.6 nm. These diameter-separated carbon nanotube transistors show excellent transconductance of 55 μS/μm and desirable drain current saturation with an output resistance of ∼100 KΩ μm. An exceptional radio-frequency performance is also achieved with current gain and power gain cut-off frequencies of 23 GHz and 20 GHz (extrinsic) and 65 GHz and 35 GHz (intrinsic), respectively. These radio-frequency metrics are among the highest reported for the carbon nanotube thin-film transistors. This study provides demonstration of radio frequency transistors based on carbon nanotubes with tailored diameter distributions, which will guide the future application of carbon nanotubes in radio-frequency electronics.

An analysis of low frequency noise from large wind turbines

DEFF Research Database (Denmark)

Pedersen, Christian Sejer; Møller, Henrik

2010-01-01

As wind turbines get larger, worries have emerged, that the noise emitted by the turbines would move down in frequency, and that the contents of low-frequency noise would be enough to cause significant annoyance for the neighbors. The sound emission from 48 wind turbines with nominal electric power......-third-octave-band spectra shows that the relative noise emission is higher in the 63-250 Hz frequency range from turbines above 2 MW than from smaller turbines. The observations confirm a downward shift of the spectrum....

Is attention based on spatial contextual memory preferentially guided by low spatial frequency signals?

Science.gov (United States)

Patai, Eva Zita; Buckley, Alice; Nobre, Anna Christina

2013-01-01

A popular model of visual perception states that coarse information (carried by low spatial frequencies) along the dorsal stream is rapidly transmitted to prefrontal and medial temporal areas, activating contextual information from memory, which can in turn constrain detailed input carried by high spatial frequencies arriving at a slower rate along the ventral visual stream, thus facilitating the processing of ambiguous visual stimuli. We were interested in testing whether this model contributes to memory-guided orienting of attention. In particular, we asked whether global, low-spatial frequency (LSF) inputs play a dominant role in triggering contextual memories in order to facilitate the processing of the upcoming target stimulus. We explored this question over four experiments. The first experiment replicated the LSF advantage reported in perceptual discrimination tasks by showing that participants were faster and more accurate at matching a low spatial frequency version of a scene, compared to a high spatial frequency version, to its original counterpart in a forced-choice task. The subsequent three experiments tested the relative contributions of low versus high spatial frequencies during memory-guided covert spatial attention orienting tasks. Replicating the effects of memory-guided attention, pre-exposure to scenes associated with specific spatial memories for target locations (memory cues) led to higher perceptual discrimination and faster response times to identify targets embedded in the scenes. However, either high or low spatial frequency cues were equally effective; LSF signals did not selectively or preferentially contribute to the memory-driven attention benefits to performance. Our results challenge a generalized model that LSFs activate contextual memories, which in turn bias attention and facilitate perception.

Amplification of flood frequencies with local sea level rise and emerging flood regimes

Science.gov (United States)

Buchanan, Maya K.; Oppenheimer, Michael; Kopp, Robert E.

2017-06-01

The amplification of flood frequencies by sea level rise (SLR) is expected to become one of the most economically damaging impacts of climate change for many coastal locations. Understanding the magnitude and pattern by which the frequency of current flood levels increase is important for developing more resilient coastal settlements, particularly since flood risk management (e.g. infrastructure, insurance, communications) is often tied to estimates of flood return periods. The Intergovernmental Panel on Climate Change’s Fifth Assessment Report characterized the multiplication factor by which the frequency of flooding of a given height increases (referred to here as an amplification factor; AF). However, this characterization neither rigorously considered uncertainty in SLR nor distinguished between the amplification of different flooding levels (such as the 10% versus 0.2% annual chance floods); therefore, it may be seriously misleading. Because both historical flood frequency and projected SLR are uncertain, we combine joint probability distributions of the two to calculate AFs and their uncertainties over time. Under probabilistic relative sea level projections, while maintaining storm frequency fixed, we estimate a median 40-fold increase (ranging from 1- to 1314-fold) in the expected annual number of local 100-year floods for tide-gauge locations along the contiguous US coastline by 2050. While some places can expect disproportionate amplification of higher frequency events and thus primarily a greater number of historically precedented floods, others face amplification of lower frequency events and thus a particularly fast growing risk of historically unprecedented flooding. For example, with 50 cm of SLR, the 10%, 1%, and 0.2% annual chance floods are expected respectively to recur 108, 335, and 814 times as often in Seattle, but 148, 16, and 4 times as often in Charleston, SC.

Spatial-frequency dependent binocular imbalance in amblyopia.

Science.gov (United States)

Kwon, MiYoung; Wiecek, Emily; Dakin, Steven C; Bex, Peter J

2015-11-25

While amblyopia involves both binocular imbalance and deficits in processing high spatial frequency information, little is known about the spatial-frequency dependence of binocular imbalance. Here we examined binocular imbalance as a function of spatial frequency in amblyopia using a novel computer-based method. Binocular imbalance at four spatial frequencies was measured with a novel dichoptic letter chart in individuals with amblyopia, or normal vision. Our dichoptic letter chart was composed of band-pass filtered letters arranged in a layout similar to the ETDRS acuity chart. A different chart was presented to each eye of the observer via stereo-shutter glasses. The relative contrast of the corresponding letter in each eye was adjusted by a computer staircase to determine a binocular Balance Point at which the observer reports the letter presented to either eye with equal probability. Amblyopes showed pronounced binocular imbalance across all spatial frequencies, with greater imbalance at high compared to low spatial frequencies (an average increase of 19%, p imbalance may be useful for diagnosing amblyopia and as an outcome measure for recovery of binocular vision following therapy.

The Frequency of Incipient Fires at the Savannah River Site

International Nuclear Information System (INIS)

Blanchard, A.

1999-01-01

Fire is a significant hazard in most industrial and nuclear facilities. As such it is important that adequate safeguards be provided to ensure a responsible level of safety. In determining this level of safety it is necessary to know three key parameters. These are the frequency of the incipient fire, the probability that a fire will grow from the incipient stage to cause the potential consequence, and the potential consequences (i.e., losses) from an unwanted fire. Consequence predictions have been modeled and evaluated extensively and can be readily confirmed by comparison with historic loss records. These loss records can also provide significant insight into the probability that given a fire it grows to create a defined consequence. The other key parameter, frequency, is the focus of this report. this report determines an alternative method for estimating Savannah River Site (SRS) building fire frequencies as a function of floor area to the linear method previously used. The frequency of an incipient fire is not easily derived from existing fire loss records. This occurs because the fire loss records do not make reference to the sample population. To derive an initiating frequency both the number of events (incipient fires) and the population (number of buildings and years in service) must be known. this report documents an evaluation that estimates the frequency of incipient fires in industrial and nuclear facilities. these estimates were developed from the unique historical record that has been maintained at the Savannah River Site

Demand as Frequency Controlled Reserve

DEFF Research Database (Denmark)

Xu, Zhao; Togeby, Mikael; Østergaard, Jacob

This report summaries the research outcomes of the project ‘Demand as Frequency Controlled Reserve (DFR)’, which has received the support from Energinet.dk’s PSO program, Grant no. 2005-2-6380. The objective of this project is to investigate the technology of using electricity demands for providing...

Electron heating of voltage-driven and matched dual frequency discharges

International Nuclear Information System (INIS)

Lieberman, M A; Lichtenberg, A J

2010-01-01

In a dual frequency capacitive sheath, a high frequency uniform sheath motion is coupled with a low frequency Child law sheath motion. For current-driven high and low frequency sheaths, the high frequency sheath motion generates most of the ohmic and stochastic heating of the discharge electrons. The low frequency motion, in addition to its primary purpose of establishing the ion bombarding energy, also increases the heating by widening the sheath width and transporting the oscillating electrons to regions of lower plasma density, and hence higher sheath velocity. In this work, we show that for voltage-driven high and low frequency sheaths, increasing the low frequency voltage reduces the heating, due to the reduced high frequency current that flows through the sheath under voltage-driven conditions. We determine the dependence of the heating on various parameters and compare the results with the current-driven case. Particle-in-cell simulations are used to confirm this result. Discharges generally employ a matching network to maximize the power transmitted to the plasma. We obtain analytic expressions for the effect of the low frequency source under matched conditions and, again, find that the low frequency source reduces the heating.

Modulation of high frequency noise by engine tones of small boats.

Science.gov (United States)

Pollara, Alexander; Sutin, Alexander; Salloum, Hady

2017-07-01

The effect of modulation of high frequency ship noise by propeller rotation frequencies is well known. This modulation is observed with the Detection of Envelope Modulation on Noise (DEMON) algorithm. Analysis of the DEMON spectrum allows the revolutions per minute and number of blades of the propeller to be determined. This work shows that the high frequency noise of a small boat can also be modulated by engine frequencies. Prior studies have not reported high frequency noise amplitude modulated at engine frequencies. This modulation is likely produced by bubbles from the engine exhaust system.

High frequency conductivity in carbon nanotubes

Directory of Open Access Journals (Sweden)

S. S. Abukari

2012-12-01

Full Text Available We report on theoretical analysis of high frequency conductivity in carbon nanotubes. Using the kinetic equation with constant relaxation time, an analytical expression for the complex conductivity is obtained. The real part of the complex conductivity is initially negative at zero frequency and become more negative with increasing frequency, until it reaches a resonance minimum at ω ∼ ωB for metallic zigzag CNs and ω < ωB for armchair CNs. This resonance enhancement is indicative for terahertz gain without the formation of current instabilities induced by negative dc conductivity. We noted that due to the high density of states of conduction electrons in metallic zigzag carbon nanotubes and the specific dispersion law inherent in hexagonal crystalline structure result in a uniquely high frequency conductivity than the corresponding values for metallic armchair carbon nanotubes. We suggest that this phenomenon can be used to suppress current instabilities that are normally associated with a negative dc differential conductivity.

Enhancement of Frequency Stability Using Synchronization of a Cantilever Array for MEMS-Based Sensors

Directory of Open Access Journals (Sweden)

Francesc Torres

2016-10-01

Full Text Available Micro and nano electromechanical resonators have been widely used as single or multiple-mass detection sensors. Smaller devices with higher resonance frequencies and lower masses offer higher mass responsivities but suffer from lower frequency stability. Synchronization phenomena in multiple MEMS resonators have become an important issue because they allow frequency stability improvement, thereby preserving mass responsivity. The authors present an array of five cantilevers (CMOS-MEMS system that are forced to vibrate synchronously to enhance their frequency stability. The frequency stability has been determined in closed-loop configuration for long periods of time by calculating the Allan deviation. An Allan deviation of 0.013 ppm (@ 1 s averaging time for a 1 MHz cantilever array MEMS system was obtained at the synchronized mode, which represents a 23-fold improvement in comparison with the non-synchronized operation mode (0.3 ppm.

Pulsed-High Field/High-Frequency EPR Spectroscopy

Science.gov (United States)

Fuhs, Michael; Moebius, Klaus

Pulsed high-field/high-frequency electron paramagnetic resonance (EPR) spectroscopy is used to disentangle many kinds of different effects often obscured in continuous wave (cw) EPR spectra at lower magnetic fields/microwave frequencies. While the high magnetic field increases the resolution of G tensors and of nuclear Larmor frequencies, the high frequencies allow for higher time resolution for molecular dynamics as well as for transient paramagnetic intermediates studied with time-resolved EPR. Pulsed EPR methods are used for example for relaxation-time studies, and pulsed Electron Nuclear DOuble Resonance (ENDOR) is used to resolve unresolved hyperfine structure hidden in inhomogeneous linewidths. In the present article we introduce the basic concepts and selected applications to structure and mobility studies on electron transfer systems, reaction centers of photosynthesis as well as biomimetic models. The article concludes with an introduction to stochastic EPR which makes use of an other concept for investigating resonance systems in order to increase the excitation bandwidth of pulsed EPR. The limited excitation bandwidth of pulses at high frequency is one of the main limitations which, so far, made Fourier transform methods hardly feasible.

Low-frequency plasmons in metallic carbon nanotubes

International Nuclear Information System (INIS)

Lin, M.F.; Chuu, D.S.; Shung, K.W.

1997-01-01

A metallic carbon nanotube could exhibit a low-frequency plasmon, while a semiconducting carbon nanotube or a graphite layer could not. This plasmon is due to the free carriers in the linear subbands intersecting at the Fermi level. The low-frequency plasmon, which corresponds to the vanishing transferred angular momentum, belongs to an acoustic plasmon. For a smaller metallic nanotube, it could exist at larger transferred momenta, and its frequency is higher. Such a plasmon behaves as that in a one-dimensional electron gas (EGS). However, it is very different from the π plasmons in all carbon nanotubes. Intertube Coulomb interactions in a metallic multishell nanotube and a metallic nanotube bundle have been included. They have a strong effect on the low-frequency plasmon. The intertube coupling among coaxial nanotubes markedly modifies the acoustic plasmons in separate metallic nanotubes. When metallic carbon nanotubes are packed in the bundle form, the low-frequency plasmon would change into an optical plasmon, and behave like that in a three-dimensional EGS. Experimental measurements could be used to distinguish metallic and semiconducting carbon nanotubes. copyright 1997 The American Physical Society

Carbon nanotube transistor based high-frequency electronics

Science.gov (United States)

Schroter, Michael

At the nanoscale carbon nanotubes (CNTs) have higher carrier mobility and carrier velocity than most incumbent semiconductors. Thus CNT based field-effect transistors (FETs) are being considered as strong candidates for replacing existing MOSFETs in digital applications. In addition, the predicted high intrinsic transit frequency and the more recent finding of ways to achieve highly linear transfer characteristics have inspired investigations on analog high-frequency (HF) applications. High linearity is extremely valuable for an energy efficient usage of the frequency spectrum, particularly in mobile communications. Compared to digital applications, the much more relaxed constraints for CNT placement and lithography combined with already achieved operating frequencies of at least 10 GHz for fabricated devices make an early entry in the low GHz HF market more feasible than in large-scale digital circuits. Such a market entry would be extremely beneficial for funding the development of production CNTFET based process technology. This talk will provide an overview on the present status and feasibility of HF CNTFET technology will be given from an engineering point of view, including device modeling, experimental results, and existing roadblocks. Carbon nanotube transistor based high-frequency electronics.

Loads as a Resource: Frequency Responsive Demand

Energy Technology Data Exchange (ETDEWEB)

Kalsi, Karanjit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Tess L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Marinovici, Laurentiu D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Elizondo, Marcelo A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lian, Jianming [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-11-30

Demand-side frequency control can complement traditional generator controls to maintain the stability of large electric systems in the face of rising uncertainty and variability associated with renewable energy resources. This report presents a hierarchical frequency-based load control strategy that uses a supervisor to flexibly adjust control gains that a population of end-use loads respond to in a decentralized manner to help meet the NERC BAL-003-1 frequency response standard at both the area level and interconnection level. The load model is calibrated and used to model populations of frequency-responsive water heaters in a PowerWorld simulation of the U.S. Western Interconnection (WECC). The proposed design is implemented and demonstrated on physical water heaters in a laboratory setting. A significant fraction of the required frequency response in the WECC could be supplied by electric water heaters alone at penetration levels of less than 15%, while contributing to NERC requirements at the interconnection and area levels.

Comparing childhood meal frequency to current meal frequency, routines, and expectations among parents.

Science.gov (United States)

Friend, Sarah; Fulkerson, Jayne A; Neumark-Sztainer, Dianne; Garwick, Ann; Flattum, Colleen Freeh; Draxten, Michelle

2015-02-01

Little is known about the continuation of family meals from childhood to parenthood. This study aims to examine associations between parents' report of eating family meals while growing up and their current family meal frequency, routines, and expectations. Baseline data were used from the Healthy Home Offerings via the Mealtime Environment (HOME) Plus study, a randomized controlled trial with a program to promote healthful behaviors and family meals at home. Participants (160 parent/child dyads) completed data collection in 2011-2012 in the Minneapolis/St. Paul, MN metropolitan area. Parents were predominately female (95%) and white (77%) with a mean age of 41.3 years. General linear modeling examined relationships between parents' report of how often they ate family meals while growing up and their current family meal frequency, routines, and expectations as parents, controlling for parent age, education level, and race. Parental report of eating frequent family meals while growing up was positively and significantly associated with age, education, and self-identification as white (all p meals less than three times/week or four to five times/week, parents who ate six to seven family meals/week while growing up reported significantly more frequent family meals with their current family (4.0, 4.2 vs. 5.3 family meals/week, p = .001). Eating frequent family meals while growing up was also significantly and positively associated with having current regular meal routines and meal expectations about family members eating together (both p meals with children may have long-term benefits over generations. PsycINFO Database Record (c) 2015 APA, all rights reserved.

34 CFR 686.33 - Frequency of payment.

Science.gov (United States)

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Frequency of payment. 686.33 Section 686.33 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION TEACHER EDUCATION ASSISTANCE FOR COLLEGE AND HIGHER EDUCATION (TEACH) GRANT PROGRAM...

A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

Energy Technology Data Exchange (ETDEWEB)

Moral, A. del, E-mail: delmoral@unizar.es [Laboratorio de Magnetismo, Departamento de Física de Materia Condensada and Instituto de Ciencia de Materiales, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza (Spain); Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain); Azanza, María J., E-mail: mjazanza@unizar.es [Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain)

2015-03-01

A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate (“frequency”), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca{sup 2+} Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD–CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD–CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B{sub 0}≅0.2–15 mT) AC-MF of frequency f{sub M}=50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation. - Highlights: • Neuron pair synchronization under low frequency alternating (AC) magnetic field (MF). • Superdiamagnetism and Ca{sup 2+} Coulomb explosion for AC MF effect in synchronized frequency. • Membrane lipid electrical quadrupolar pair interaction as synchronization mechamism. • Good agreement of model with electrophysiological experiments on mollusc Helix neurons.

A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

International Nuclear Information System (INIS)

Moral, A. del; Azanza, María J.

2015-01-01

A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate (“frequency”), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca 2+ Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD–CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD–CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B 0 ≅0.2–15 mT) AC-MF of frequency f M =50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation. - Highlights: • Neuron pair synchronization under low frequency alternating (AC) magnetic field (MF). • Superdiamagnetism and Ca 2+ Coulomb explosion for AC MF effect in synchronized frequency. • Membrane lipid electrical quadrupolar pair interaction as synchronization mechamism. • Good agreement of model with electrophysiological experiments on mollusc Helix neurons

Multilevel Fast Multipole Method for Higher Order Discretizations

DEFF Research Database (Denmark)

Borries, Oscar Peter; Meincke, Peter; Jorgensen, Erik

2014-01-01

The multi-level fast multipole method (MLFMM) for a higher order (HO) discretization is demonstrated on high-frequency (HF) problems, illustrating for the first time how an efficient MLFMM for HO can be achieved even for very large groups. Applying several novel ideas, beneficial to both lower...... order and higher order discretizations, results from a low-memory, high-speed MLFMM implementation of a HO hierarchical discretization are shown. These results challenge the general view that the benefits of HO and HF-MLFMM cannot be combined....

School-Based Racial and Gender Discrimination among African American Adolescents: Exploring Gender Variation in Frequency and Implications for Adjustment.

Science.gov (United States)

Cogburn, Courtney D; Chavous, Tabbye M; Griffin, Tiffany M

2011-01-03

The present study examined school-based racial and gender discrimination experiences among African American adolescents in Grade 8 (n = 204 girls; n = 209 boys). A primary goal was exploring gender variation in frequency of both types of discrimination and associations of discrimination with academic and psychological functioning among girls and boys. Girls and boys did not vary in reported racial discrimination frequency, but boys reported more gender discrimination experiences. Multiple regression analyses within gender groups indicated that among girls and boys, racial discrimination and gender discrimination predicted higher depressive symptoms and school importance and racial discrimination predicted self-esteem. Racial and gender discrimination were also negatively associated with grade point average among boys but were not significantly associated in girls' analyses. Significant gender discrimination X racial discrimination interactions resulted in the girls' models predicting psychological outcomes and in boys' models predicting academic achievement. Taken together, findings suggest the importance of considering gender- and race-related experiences in understanding academic and psychological adjustment among African American adolescents.

Optical parametric amplification and oscillation assisted by low-frequency stimulated emission

OpenAIRE

Longhi, Stefano

2016-01-01

Optical parametric amplification/oscillation provide a powerful tool for coherent light generation in spectral regions inaccessible to lasers. Parametric gain is based on a frequency {\\it down-conversion} process, and thus it can not be realized for signal waves at a frequency $\\omega_3$ {\\it higher} than the frequency of the pump wave $\\omega_1$. In this work we suggest a route toward the realization of {\\it up-conversion} optical parametric amplification and oscillation, i.e. amplification ...

Ferrite Film Loaded Frequency Selective Metamaterials for Sub-GHz Applications

Directory of Open Access Journals (Sweden)

Bo Gao

2016-12-01

Full Text Available Electromagnetic metamaterials are constructed with sub-wavelength structures that exhibit particular electromagnetic properties under a certain frequency range. Because the form-factor of the substructures has to be comparable to the wavelength of the operating frequency, few papers have discussed the metamaterials under GHz frequency. In this paper, we developed an innovative method to reduce the resonant frequency of metamaterals. By integrating the meta-structures with ferrite materials of higher permeability, the cell size of the meta-structure can be scaled down. This paper describes the methodology, design, and development of low-profile GHz ferrite loaded metamaterials. A ferrite film with a permeability of 20 could reduce the resonant frequency of metamaterials by up to 50%. A prototype has been fabricated and the measurement data align well with the simulation results. Because of the lowered operational frequency, the proposed ferrite loaded metamaterials offer more flexibility for various sub-GHz microwave applications, such as cloaks, absorbers, and frequency selective surfaces.

Breakdown criteria due to radio-frequency fields in vacuum. Final report

International Nuclear Information System (INIS)

Reid, D.W.; Lohsen, R.A.

1982-01-01

The factors that affect the voltage at which vacuum gaps break down are analyzed. Based on the literature and some simplifying assumptions, a functional dependence is hypothesized. The hypothesis is related to a proposed experiment using radio-frequency power to generate the breakdown voltage

Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

International Nuclear Information System (INIS)

Nakamura, T.; Naganawa, S.; Fukatsu, H.; Sakurai, Y.; Ishigaki, T.; Aoki, I.; Ninomiya, A.; Nakashima, T.

2003-01-01

There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

Energy Technology Data Exchange (ETDEWEB)

Nakamura, T; Naganawa, S; Fukatsu, H; Sakurai, Y; Ishigaki, T [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, 466-8550, Shouwa-ku, Nagoya (Japan); Aoki, I; Ninomiya, A [Medical Systems Company, Toshiba Corporation, Nasu Operations, Otawara-shi, Tochigi (Japan); Nakashima, T [Department of Otorhinolaryngology, Nagoya University School of Medicine, Shouwa-ku, Nagoya (Japan)

2003-09-01

There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

Systematic review on the prevalence, frequency and comparative value of adverse events data in social media

Science.gov (United States)

Golder, Su; Norman, Gill; Loke, Yoon K

2015-01-01

Aim The aim of this review was to summarize the prevalence, frequency and comparative value of information on the adverse events of healthcare interventions from user comments and videos in social media. Methods A systematic review of assessments of the prevalence or type of information on adverse events in social media was undertaken. Sixteen databases and two internet search engines were searched in addition to handsearching, reference checking and contacting experts. The results were sifted independently by two researchers. Data extraction and quality assessment were carried out by one researcher and checked by a second. The quality assessment tool was devised in-house and a narrative synthesis of the results followed. Results From 3064 records, 51 studies met the inclusion criteria. The studies assessed over 174 social media sites with discussion forums (71%) being the most popular. The overall prevalence of adverse events reports in social media varied from 0.2% to 8% of posts. Twenty-nine studies compared the results from searching social media with using other data sources to identify adverse events. There was general agreement that a higher frequency of adverse events was found in social media and that this was particularly true for ‘symptom’ related and ‘mild’ adverse events. Those adverse events that were under-represented in social media were laboratory-based and serious adverse events. Conclusions Reports of adverse events are identifiable within social media. However, there is considerable heterogeneity in the frequency and type of events reported, and the reliability or validity of the data has not been thoroughly evaluated. PMID:26271492

Tender frequency and market concentration in balancing power markets

International Nuclear Information System (INIS)

Knaut, Andreas; Obermueller, Frank; Weiser, Florian

2017-01-01

Balancing power markets ensure the short-term balance of supply and demand in electricity markets and their importance may increase with a higher share of fluctuating renewable electricity production. While it is clear that shorter tender frequencies, e.g. daily or hourly, are able to increase the efficiency compared to a weekly procurement, it remains unclear in which respect market concentration will be affected. Against this background, we develop a numerical electricity market model to quantify the possible effects of shorter tender frequencies on costs and market concentration. We find that shorter time spans of procurement are able to lower the costs by up to 15%. While market concentration decreases in many markets, we - surprisingly - identify cases in which shorter time spans lead to higher concentration.

Tender frequency and market concentration in balancing power markets

Energy Technology Data Exchange (ETDEWEB)

Knaut, Andreas; Obermueller, Frank; Weiser, Florian

2017-01-15

Balancing power markets ensure the short-term balance of supply and demand in electricity markets and their importance may increase with a higher share of fluctuating renewable electricity production. While it is clear that shorter tender frequencies, e.g. daily or hourly, are able to increase the efficiency compared to a weekly procurement, it remains unclear in which respect market concentration will be affected. Against this background, we develop a numerical electricity market model to quantify the possible effects of shorter tender frequencies on costs and market concentration. We find that shorter time spans of procurement are able to lower the costs by up to 15%. While market concentration decreases in many markets, we - surprisingly - identify cases in which shorter time spans lead to higher concentration.