Bigger ? Better: The Comprehensiveness and Strength of School Wellness Policies Varies by School District Size

ERIC Educational Resources Information Center

Meendering, Jessica; Kranz, Emily; Shafrath, Tara; McCormack, Lacey

2016-01-01

Background: District size has been shown to impact the anticipated barriers to wellness policy creation and implementation. Therefore, the purpose of the present study was to determine if strength and comprehensiveness of wellness policies differs among school districts of varying size. Methods: Wellness policies were collected from 10 large, 29…

Acquiring Foreign Language Vocabulary through Meaningful Linguistic Context: Where Is the Limit to Vocabulary Learning?

ERIC Educational Resources Information Center

de la Garza, Bernardo; Harris, Richard Jackson

2017-01-01

The present studies examined the effects of varying degrees of unfamiliar vocabulary within written discourse on individuals' abilities to use linguistic context for the purposes of translation and comprehension (i.e., lexical inferencing). Prose varied in the number of foreign words introduced into each sentence (e.g., 0 through 7 content words…

Physico-chemical parameters and Ichthyofauna diversity of Arasalar estuary in southeast coast of India

NASA Astrophysics Data System (ADS)

Raju, C.; Sridharan, G.; Mariappan, P.; Chelladurai, G.

2017-03-01

The physico-chemical changes may have the tendency to accumulate in the various organs of estuarine organisms, especially fish which may in turn enter into the human metabolism through consumption causing serious hazards. Hence, the present study was carried out to dete rmine the physico-chemical characteristics of water and Ichthyofauna in Arasalar estuary in southeast coast of India for the period of 1 year during September 2012-August 2013. The environmental parameters such as, temperature, pH, salinity, DO, silicate, nitrate and phosphate were observed from Department of Zoology, Rajah Serfoji Goverment College, Thanjavur, Tamil Nadu, India. During the period of study, air temperature varied from 28.8 to 35 °C. The surface water temperature also varied from 25 to 31.5 °C. The monthly mean values of hydrogen ion concentration of water varied from 7.1 to 8.2. The salinity of water varied from 5.5 ‰ to 34. Dissolved oxygen in Arasalar estuary was varied from 3.5 to 7.2 mg/l. The total phosphorus varied from 0.29 to 2.15 µg/1. The nitrate varied from 0.47 to 3.75 µg/l. The silicate content varied from 28.25 to 98.74 µg/l. Totally 866 fishes were collected belonging to 4 orders and 5 families. Mystus gulio was found to be the dominant species (25.40 %) in the study area.

Sweeping shunted electro-magnetic tuneable vibration absorber: Design and implementation

NASA Astrophysics Data System (ADS)

Turco, E.; Gardonio, P.

2017-10-01

This paper presents a study on the design and implementation of a time-varying shunted electro-magnetic Tuneable Vibration Absorber for broad-band vibration control of thin structures. A time-varying RL-shunt is used to harmonically vary the stiffness and damping properties of the Tuneable Vibration Absorber so that its mechanical fundamental natural frequency is continuously swept in a given broad frequency band whereas its mechanical damping is continuously adapted to maximize the vibration absorption from the hosting structure where it is mounted. The paper first recalls the tuning and positioning criteria for the case where a classical Tuneable Vibration Absorber is installed on a thin walled cylindrical structure to reduce the response of a resonating flexural mode. It then discusses the design of the time-varying shunt circuit to produce the desired stiffness and damping variations in the electro-magnetic Tuneable Vibration Absorber. Finally, it presents a numerical study on the flexural vibration and interior sound control effects produced when an array of these shunted electro-magnetic Tuneable Vibration Absorbers are mounted on a thin walled cylinder subject to a rain-on-the-roof stochastic excitation. The study shows that the array of proposed systems effectively controls the cylinder flexural response and interior noise over a broad frequency band without need of tuning and thus system identification of the structure. Therefore, the systems can be successfully used also on structures whose physical properties vary in time because of temperature changes or tensioning effects for example.

Suitability of Spatial Interpolation Techniques in Varying Aquifer Systems of a Basaltic Terrain for Monitoring Groundwater Availability

NASA Astrophysics Data System (ADS)

Katpatal, Y. B.; Paranjpe, S. V.; Kadu, M. S.

2017-12-01

Geological formations act as aquifer systems and variability in the hydrological properties of aquifers have control over groundwater occurrence and dynamics. To understand the groundwater availability in any terrain, spatial interpolation techniques are widely used. It has been observed that, with varying hydrogeological conditions, even in a geologically homogenous set up, there are large variations in observed groundwater levels. Hence, the accuracy of groundwater estimation depends on the use of appropriate interpretation techniques. The study area of the present study is Venna Basin of Maharashtra State, India which is a basaltic terrain with four different types of basaltic layers laid down horizontally; weathered vesicular basalt, weathered and fractured basalt, highly weathered unclassified basalt and hard massive basalt. The groundwater levels vary with topography as different types of basalts are present at varying depths. The local stratigraphic profiles were generated at different types of basaltic terrains. The present study aims to interpolate the groundwater levels within the basin and to check the co-relation between the estimated and the observed values. The groundwater levels for 125 observation wells situated in these different basaltic terrains for 20 years (1995 - 2015) have been used in the study. The interpolation was carried out in Geographical Information System (GIS) using ordinary kriging and Inverse Distance Weight (IDW) method. A comparative analysis of the interpolated values of groundwater levels is carried out for validating the recorded groundwater level dataset. The results were co-related to various types of basaltic terrains present in basin forming the aquifer systems. Mean Error (ME) and Mean Square Errors (MSE) have been computed and compared. It was observed that within the interpolated values, a good correlation does not exist between the two interpolation methods used. The study concludes that in crystalline basaltic terrain, interpolation methods must be verified with the changes in the geological profiles.

Shelf gradients of echinoid assemblages from the Miocene of Sardinia

NASA Astrophysics Data System (ADS)

Nebelsick, James; Andrea, Mancosu

2017-04-01

Well exposed Miocene echinoid assemblages from Sardinia representing various environmental settings including both siliciclastics and carbonates have been studied with respect to reconstructing palaeoenvironmental conditions along a shelf gradient. The basis of this study includes 1) detailed logging of sedimentary facies in the field, 2) interpreting their behavior and life habits of the preserved echinoids by applying functional morphological reconstructions of the echinoid skeletons and comparing them to related Recent echinoid taxa, 3) quantifying taphonomic features of test preservation including predation, abrasion, fragmentation, encrustation and bioerosion, and finally 4) analyzing accompanying fauna and flora as well as trace fossils. The assemblages included clypeasteroid dominated assemblages in shallow water settings where often mass accumulations of sand dollars are present. Spatangoid dominated assemblages are found in more offshore settings where diversity is determined by varying burrowing depths, feeding strategies and resource partitioning accompanied by varying rates of bioturbation and episodes of sediment deposition by storms. Mixed assemblages also occur ranging from shallow to deeper water with varying substrates including sea grass, as well as coarser and finer sediments. Finally, deeper water monotypic assemblages are present in storm-dominated siliciclastic shelf environments including both regular and irregular echinoids. In general, echinoid presence is determined by the ecological preferences of the taxa involved, their propensities for gregarious behavior, the differential preservation potentials of the varied skeletal architectures present as well as sedimentary environment in which they occur.

Dressed to Present: Ratings of Classroom Presentations Vary with Attire

ERIC Educational Resources Information Center

Gurung, Regan A. R.; Kempen, Laura; Klemm, Kayla; Senn, Rebecca; Wysocki, Rosie

2014-01-01

This study investigates the effects of formality of dress on ratings of classroom presentations. Participants (N = 65, 66% women) from a Midwestern university in the United States rated three female students giving a presentation designed for a health psychology class in one of four outfits: casual, party, business casual, or business formal.…

Biofiltration of air contaminated by styrene vapors on inorganic filtering media: an experimental study.

PubMed

St-Pierre, Marie-Claude Dion; Avalos Ramirez, Antonio; Heitz, Michèle

2009-05-01

This paper presents a study on the biofiltration of styrene by using two inorganic filtering materials. The effects of styrene inlet load and nitrogen concentration present in the nutrient solution on biofilter performance were studied. The styrene inlet concentration was varied from 65 to 1115 parts per million by volume (ppmv), whereas the contaminated airflow rate was fixed at 1 m3/hr. The nitrogen concentration in nutrient solution was varied from 1 to 4 gN/L. The maximum elimination capacity obtained was 105 g/m3-hr, which corresponded to a removal efficiency of 80% for a styrene inlet load of 130 g/m3-hr. This study shows that the nitrogen content in the nutrient solution affects the removal rate of styrene, with an optimal nitrogen concentration of 3 gN/L. The performance comparison between two different inorganic bed types was undertaken and a comparative study on biofiltration of two aromatic compounds, styrene and toluene, is also presented.

Individual and household characteristics of persons with Plasmodium falciparum malaria in sites with varying endemicities in Kinshasa Province, Democratic Republic of the Congo.

PubMed

Mwandagalirwa, Melchior Kashamuka; Levitz, Lauren; Thwai, Kyaw L; Parr, Jonathan B; Goel, Varun; Janko, Mark; Tshefu, Antoinette; Emch, Michael; Meshnick, Steven R; Carrel, Margaret

2017-11-09

The Democratic Republic of the Congo (DRC) bears a large share of global malaria burden despite efforts to control and eliminate the disease. More detailed understanding of individual and household level characteristics associated with malaria are needed, as is an understanding of how these characteristics vary spatiotemporally and across different community-level malaria endemicities. An ongoing study in Kinshasa Province is designed to address gaps in prior malaria surveillance in the DRC by monitoring malaria across seasons, age groups and in high and low malaria sites. Across seven sites, 242 households and 1591 individuals are participating in the study. Results of the enrollment questionnaire, rapid diagnostic tests and PCR testing of dried blood spots are presented. Overall malaria prevalence in the study cohort is high, 27% by rapid diagnostic test and 31% by polymerase chain reaction, and malaria prevalence is highly varied across very small geographic distances. Malaria prevalence is highest in children aged 6-15. While the majority of households own bed nets, bed net usage is less than 50%. The study cohort will provide an understanding of how malaria persists in populations that have varying environmental exposures, varying community-level malaria, and varying access to malaria control efforts.

Does parent-child agreement vary based on presenting problems? Results from a UK clinical sample.

PubMed

Cleridou, Kalia; Patalay, Praveetha; Martin, Peter

2017-01-01

Discrepancies are often found between child and parent reports of child psychopathology, nevertheless the role of the child's presenting difficulties in relation to these is underexplored. This study investigates whether parent-child agreement on the conduct and emotional scales of the Strengths and Difficulties Questionnaire (SDQ) varied as a result of certain child characteristics, including the child's presenting problems to clinical services, age and gender. The UK-based sample consisted of 16,754 clinical records of children aged 11-17, the majority of which were female (57%) and White (76%). The dataset was provided by the Child Outcomes Research Consortium , which collects outcome measures from child services across the UK. Clinicians reported the child's presenting difficulties, and parents and children completed the SDQ. Using correlation analysis, the main findings indicated that agreement varied as a result of the child's difficulties for reports of conduct problems, and this seemed to be related to the presence or absence of externalising difficulties in the child's presentation. This was not the case for reports of emotional difficulties. In addition, agreement was higher when reporting problems not consistent with the child's presentation; for instance, agreement on conduct problems was greater for children presenting with internalising problems. Lastly, the children's age and gender did not seem to have an impact on agreement. These findings demonstrate that certain child presenting difficulties, and in particular conduct problems, may be related to informant agreement and need to be considered in clinical practice and research. Trial Registration This study was observational and as such did not require trial registration.

Study on reservoir time-varying design flood of inflow based on Poisson process with time-dependent parameters

NASA Astrophysics Data System (ADS)

Li, Jiqing; Huang, Jing; Li, Jianchang

2018-06-01

The time-varying design flood can make full use of the measured data, which can provide the reservoir with the basis of both flood control and operation scheduling. This paper adopts peak over threshold method for flood sampling in unit periods and Poisson process with time-dependent parameters model for simulation of reservoirs time-varying design flood. Considering the relationship between the model parameters and hypothesis, this paper presents the over-threshold intensity, the fitting degree of Poisson distribution and the design flood parameters are the time-varying design flood unit period and threshold discriminant basis, deduced Longyangxia reservoir time-varying design flood process at 9 kinds of design frequencies. The time-varying design flood of inflow is closer to the reservoir actual inflow conditions, which can be used to adjust the operating water level in flood season and make plans for resource utilization of flood in the basin.

Free surface profiles in river flows: Can standard energy-based gradually-varied flow computations be pursued?

NASA Astrophysics Data System (ADS)

Cantero, Francisco; Castro-Orgaz, Oscar; Garcia-Marín, Amanda; Ayuso, José Luis; Dey, Subhasish

2015-10-01

Is the energy equation for gradually-varied flow the best approximation for the free surface profile computations in river flows? Determination of flood inundation in rivers and natural waterways is based on the hydraulic computation of flow profiles. This is usually done using energy-based gradually-varied flow models, like HEC-RAS, that adopts a vertical division method for discharge prediction in compound channel sections. However, this discharge prediction method is not so accurate in the context of advancements over the last three decades. This paper firstly presents a study of the impact of discharge prediction on the gradually-varied flow computations by comparing thirteen different methods for compound channels, where both energy and momentum equations are applied. The discharge, velocity distribution coefficients, specific energy, momentum and flow profiles are determined. After the study of gradually-varied flow predictions, a new theory is developed to produce higher-order energy and momentum equations for rapidly-varied flow in compound channels. These generalized equations enable to describe the flow profiles with more generality than the gradually-varied flow computations. As an outcome, results of gradually-varied flow provide realistic conclusions for computations of flow in compound channels, showing that momentum-based models are in general more accurate; whereas the new theory developed for rapidly-varied flow opens a new research direction, so far not investigated in flows through compound channels.

Simple Model with Time-Varying Fine-Structure ``Constant''

NASA Astrophysics Data System (ADS)

Berman, M. S.

2009-10-01

Extending the original version written in colaboration with L.A. Trevisan, we study the generalisation of Dirac's LNH, so that time-variation of the fine-structure constant, due to varying electrical and magnetic permittivities is included along with other variations (cosmological and gravitational ``constants''), etc. We consider the present Universe, and also an inflationary scenario. Rotation of the Universe is a given possibility in this model.

Effects of amphetamine on delay discounting in rats depend upon the manner in which delay is varied

PubMed Central

Maguire, David R; Henson, Cedric; France, Charles P

2014-01-01

Whether stimulant drugs like amphetamine increase or decrease choice of larger delayed reinforcers over smaller immediately available reinforcers under delay discounting procedures can depend on several factors, including the order in which delay is presented. This study examined whether the order of delay presentation impacts drug effects on discounting in rats (n=8) trained and tested under an ascending order, a descending order, as well as under a fixed delay condition. Responses on one lever delivered 1 food pellet immediately and responses on the other lever delivered 3 food pellets immediately or after a delay (4–32 s). In Experiment 1, the delay to the larger reinforcer varied within session and the order of delay presentation (ascending or descending) varied across conditions. In Experiment 2, the same delay value was presented in all blocks of the session (i.e., delay was fixed), and delay varied across phases. Under the ascending order of delay, amphetamine (0.32–1.78 mg/kg) increased choice of the larger reinforcer in some rats and decreased choice in others. In the same rats responding under the descending and fixed delay conditions, amphetamine markedly decreased choice of the larger reinforcer even in the component associated with no delay. In some subjects, the effects of amphetamine differed depending on the manner in which delay was presented, indicating that drug-induced changes in performance were due, in part, to mechanisms other than altered sensitivity to reinforcer delay. These results also suggest that a history of responding under both orders of delay presentation can modulate drug effects. PMID:24780379

Study on the number density of nanobubbles at varying concentration of ethanol in ethanol-water solution

NASA Astrophysics Data System (ADS)

Rajib, Md. Mahadi; Farzeen, Parisa; Ali, Mohammad

2017-12-01

In recent years, nanobubble technology has drawn great attention due to its extensive incorporation to substantial aspects of science and technology such as water treatment, drug delivery enhancement to cells, solvent and nutritional supplements manufacturing and many others. Bulk nanobubbles may be present in most aqueous solutions, possibly being constantly created by cosmic radiation and agitation and surface nanobubbles are present at most surfaces [1,2]. But, for utilizing these nanobubbles in a definitive way it's important to know whether an added amount of solution making substance has constructive or adverse effect on the nanobubble. In this work, the change of number density of nanobubbles in ethanol-water solution was studied by varying the ethanol concentration.

Understanding Bullying and Victimization during Childhood and Adolescence: A Mixed Methods Study

ERIC Educational Resources Information Center

Guerra, Nancy G.; Williams, Kirk R.; Sadek, Shelly

2011-01-01

In the present study, quantitative and qualitative data are presented to examine individual and contextual predictors of bullying and victimization and how they vary by age and gender. Two waves of survey data were collected from 2,678 elementary, middle, and high school youth attending 59 schools. In addition, 14 focus groups were conducted with…

The effects of varied versus constant high-, medium-, and low-preference stimuli on performance.

PubMed

Wine, Byron; Wilder, David A

2009-01-01

The purpose of the current study was to compare the delivery of varied versus constant high-, medium-, and low-preference stimuli on performance of 2 adults on a computer-based task in an analogue employment setting. For both participants, constant delivery of the high-preference stimulus produced the greatest increases in performance over baseline; the varied presentation produced performance comparable to constant delivery of medium-preference stimuli. Results are discussed in terms of their implications for the selection and delivery of stimuli as part of employee performance-improvement programs in the field of organizational behavior management.

Nonlinear dynamics under varying temperature conditions of the resonating beams of a differential resonant accelerometer

NASA Astrophysics Data System (ADS)

Zhang, Jing; Wang, Yagang; Zega, Valentina; Su, Yan; Corigliano, Alberto

2018-07-01

In this work the nonlinear dynamic behaviour under varying temperature conditions of the resonating beams of a differential resonant accelerometer is studied from the theoretical, numerical and experimental points of view. A complete analytical model based on the Hamilton’s principle is proposed to describe the nonlinear behaviour of the resonators under varying temperature conditions and numerical solutions are presented in comparison with experimental data. This provides a novel perspective to examine the relationship between temperature and nonlinearity, which helps predicting the dynamic behaviour of resonant devices and can guide their optimal design.

Stimulus variation as a means of enhancing punishment effects.

PubMed

Charlop, M H; Burgio, L D; Iwata, B A; Ivancic, M T

1988-01-01

We compared the effects of varied punishers (presentation of one of three available punishers) with the single presentation of one of the punishers on the occurrence of inappropriate behaviors with three developmentally delayed children. Two children were presented with varied-punisher conditions in which either overcorrection, time-out, or a verbal "no" was presented contingent upon inappropiate behavior. A loud noise was substituted for overcorrection for a third child. Results of the multielement with reversal design indicated that both punishment formats produced a decrease in the target behaviors with the varied-punisher format slightly more effective than the single presentations of the punishers. The results suggest the use of varied punishers as a means of enhancing the effects of less intrusive procedures to effectively reduce inappropriate behaviors.

Time-varying effect moderation using the structural nested mean model: estimation using inverse-weighted regression with residuals

PubMed Central

Almirall, Daniel; Griffin, Beth Ann; McCaffrey, Daniel F.; Ramchand, Rajeev; Yuen, Robert A.; Murphy, Susan A.

2014-01-01

This article considers the problem of examining time-varying causal effect moderation using observational, longitudinal data in which treatment, candidate moderators, and possible confounders are time varying. The structural nested mean model (SNMM) is used to specify the moderated time-varying causal effects of interest in a conditional mean model for a continuous response given time-varying treatments and moderators. We present an easy-to-use estimator of the SNMM that combines an existing regression-with-residuals (RR) approach with an inverse-probability-of-treatment weighting (IPTW) strategy. The RR approach has been shown to identify the moderated time-varying causal effects if the time-varying moderators are also the sole time-varying confounders. The proposed IPTW+RR approach provides estimators of the moderated time-varying causal effects in the SNMM in the presence of an additional, auxiliary set of known and measured time-varying confounders. We use a small simulation experiment to compare IPTW+RR versus the traditional regression approach and to compare small and large sample properties of asymptotic versus bootstrap estimators of the standard errors for the IPTW+RR approach. This article clarifies the distinction between time-varying moderators and time-varying confounders. We illustrate the methodology in a case study to assess if time-varying substance use moderates treatment effects on future substance use. PMID:23873437

Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses.

PubMed

Keogh, Ruth H; Mangtani, Punam; Rodrigues, Laura; Nguipdop Djomo, Patrick

2016-01-05

Traditional analyses of standard case-control studies using logistic regression do not allow estimation of time-varying associations between exposures and the outcome. We present two approaches which allow this. The motivation is a study of vaccine efficacy as a function of time since vaccination. Our first approach is to estimate time-varying exposure-outcome associations by fitting a series of logistic regressions within successive time periods, reusing controls across periods. Our second approach treats the case-control sample as a case-cohort study, with the controls forming the subcohort. In the case-cohort analysis, controls contribute information at all times they are at risk. Extensions allow left truncation, frequency matching and, using the case-cohort analysis, time-varying exposures. Simulations are used to investigate the methods. The simulation results show that both methods give correct estimates of time-varying effects of exposures using standard case-control data. Using the logistic approach there are efficiency gains by reusing controls over time and care should be taken over the definition of controls within time periods. However, using the case-cohort analysis there is no ambiguity over the definition of controls. The performance of the two analyses is very similar when controls are used most efficiently under the logistic approach. Using our methods, case-control studies can be used to estimate time-varying exposure-outcome associations where they may not previously have been considered. The case-cohort analysis has several advantages, including that it allows estimation of time-varying associations as a continuous function of time, while the logistic regression approach is restricted to assuming a step function form for the time-varying association.

Developmental Differences in Frequency Judgments of Words and Pictures.

ERIC Educational Resources Information Center

Ghatala, Elizabeth S.; Levin, Joel R.

Children in kindergarten, third grade, and fifth grade were presented a list of either pictures or words (with items presented varying numbers of times on the study trail). In both picture and word conditions, half of the subjects estimated how many times each item had been presented (absolute judgments) and the other half judged which of two…

Emotions in freely varying and mono-pitched vowels, acoustic and EGG analyses.

PubMed

Waaramaa, Teija; Palo, Pertti; Kankare, Elina

2015-12-01

Vocal emotions are expressed either by speech or singing. The difference is that in singing the pitch is predetermined while in speech it may vary freely. It was of interest to study whether there were voice quality differences between freely varying and mono-pitched vowels expressed by professional actors. Given their profession, actors have to be able to express emotions both by speech and singing. Electroglottogram and acoustic analyses of emotional utterances embedded in expressions of freely varying vowels [a:], [i:], [u:] (96 samples) and mono-pitched protracted vowels (96 samples) were studied. Contact quotient (CQEGG) was calculated using 35%, 55%, and 80% threshold levels. Three different threshold levels were used in order to evaluate their effects on emotions. Genders were studied separately. The results suggested significant gender differences for CQEGG 80% threshold level. SPL, CQEGG, and F4 were used to convey emotions, but to a lesser degree, when F0 was predetermined. Moreover, females showed fewer significant variations than males. Both genders used more hypofunctional phonation type in mono-pitched utterances than in the expressions with freely varying pitch. The present material warrants further study of the interplay between CQEGG threshold levels and formant frequencies, and listening tests to investigate the perceptual value of the mono-pitched vowels in the communication of emotions.

A New Time-varying Concept of Risk in a Changing Climate.

PubMed

Sarhadi, Ali; Ausín, María Concepción; Wiper, Michael P

2016-10-20

In a changing climate arising from anthropogenic global warming, the nature of extreme climatic events is changing over time. Existing analytical stationary-based risk methods, however, assume multi-dimensional extreme climate phenomena will not significantly vary over time. To strengthen the reliability of infrastructure designs and the management of water systems in the changing environment, multidimensional stationary risk studies should be replaced with a new adaptive perspective. The results of a comparison indicate that current multi-dimensional stationary risk frameworks are no longer applicable to projecting the changing behaviour of multi-dimensional extreme climate processes. Using static stationary-based multivariate risk methods may lead to undesirable consequences in designing water system infrastructures. The static stationary concept should be replaced with a flexible multi-dimensional time-varying risk framework. The present study introduces a new multi-dimensional time-varying risk concept to be incorporated in updating infrastructure design strategies under changing environments arising from human-induced climate change. The proposed generalized time-varying risk concept can be applied for all stochastic multi-dimensional systems that are under the influence of changing environments.

The manual control of vehicles undergoing slow transitions in dynamic characteristics

NASA Technical Reports Server (NTRS)

Moriarty, T. E.

1974-01-01

The manual control was studied of a vehicle with slowly time-varying dynamics to develop analytic and computer techniques necessary for the study of time-varying systems. The human operator is considered as he controls a time-varying plant in which the changes are neither abrupt nor so slow that the time variations are unimportant. An experiment in which pilots controlled the longitudinal mode of a simulated time-varying aircraft is described. The vehicle changed from a pure double integrator to a damped second order system, either instantaneously or smoothly over time intervals of 30, 75, or 120 seconds. The regulator task consisted of trying to null the error term resulting from injected random disturbances with bandwidths of 0.8, 1.4, and 2.0 radians per second. Each of the twelve experimental conditons was replicated ten times. It is shown that the pilot's performance in the time-varying task is essentially equivalent to his performance in stationary tasks which correspond to various points in the transition. A rudimentary model for the pilot-vehicle-regulator is presented.

The Effect of Varying Teacher Presentation Rates on Responding during Discrete Trial Training for Two Children with Autism

ERIC Educational Resources Information Center

Roxburgh, Carole A.; Carbone, Vincent J.

2013-01-01

Recent research has emphasized the importance of manipulating antecedent variables to reduce interfering behaviors when teaching persons with autism. Few studies have focused on the effects of the rate of teacher-presented instructional demands as an independent variable. In this study, an alternating treatment design was used to evaluate the…

The Interaction of Cognitive Styles with Varying Levels of Feedback in Multimedia Presentation.

ERIC Educational Resources Information Center

Khine, Myint Swe

1996-01-01

Study of 105 Brunei secondary school students investigating interactive effects of feedback levels using aptitude treatment interaction (ATI) approach and cognitive styles (field dependent-independent (FDI) in multimedia presentations found differences between no feedback (NF) and knowledge of results (KOR), NF and elaborated feedback (EF), none…

International Students and "The Presentation of Self" across Cultures

ERIC Educational Resources Information Center

Kamara, Abu

2017-01-01

Findings from this qualitative research study suggest that some international students view social and academic interactions not simply as mediums for absorbing requisite sociocultural and academic norms, and discipline knowledge, but also as stages for expressing their varied identities. As a result, whenever students' ability to present their…

Generalized Projective Synchronization between Two Complex Networks with Time-Varying Coupling Delay

NASA Astrophysics Data System (ADS)

Sun, Mei; Zeng, Chang-Yan; Tian, Li-Xin

2009-01-01

Generalized projective synchronization (GPS) between two complex networks with time-varying coupling delay is investigated. Based on the Lyapunov stability theory, a nonlinear controller and adaptive updated laws are designed. Feasibility of the proposed scheme is proven in theory. Moreover, two numerical examples are presented, using the energy resource system and Lü's system [Physica A 382 (2007) 672] as the nodes of the networks. GPS between two energy resource complex networks with time-varying coupling delay is achieved. This study can widen the application range of the generalized synchronization methods and will be instructive for the demand-supply of energy resource in some regions of China.

Insensitivity of cardiovascular function to low power cm-/mm-microwaves.

PubMed

Kantz, J; Müller, J; Hadeler, K P; Landstorfer, F M; Lang, F

2005-06-01

A previous study failed to disclose an effect of short (15 min) exposure to low level energy microwaves (3 microW/cm2) emitted by a commercially available automobile radar system (77 GHz) for adaptive cruise control (ACC) on cardiovascular function. The present study explored whether a 15 min exposure to higher level energy microwaves of frequencies varying from 5.8 to 110 GHz influences cardiovascular function. To this end heart rate, skin temperature (thermocouple), skin conductance (Ag/AgCl electrodes), systolic and diastolic blood pressure (automatic cuff) were recorded in 50 test persons before, during and after a 15 min exposure to a sequential pattern of microwaves varying from 5.8 to 110 GHz (59.7 microW/cm2). After an equilibration period of 30 min the first group of test persons and after additional 30 min the second group of test persons were exposed. The study has been performed in a strict double blind design. While significant effects on the measured parameters were observed depending on time ("calming" effect), no significant difference was observed between exposure and sham exposure to microwaves. In view of the small scatter of the data the present study rules out physiologically relevant effects of moderate energy (59.7 microW/cm2) microwaves varying from 5.8 to 110 GHz on cardiovascular function.

Cox model with interval-censored covariate in cohort studies.

PubMed

Ahn, Soohyun; Lim, Johan; Paik, Myunghee Cho; Sacco, Ralph L; Elkind, Mitchell S

2018-05-18

In cohort studies the outcome is often time to a particular event, and subjects are followed at regular intervals. Periodic visits may also monitor a secondary irreversible event influencing the event of primary interest, and a significant proportion of subjects develop the secondary event over the period of follow-up. The status of the secondary event serves as a time-varying covariate, but is recorded only at the times of the scheduled visits, generating incomplete time-varying covariates. While information on a typical time-varying covariate is missing for entire follow-up period except the visiting times, the status of the secondary event are unavailable only between visits where the status has changed, thus interval-censored. One may view interval-censored covariate of the secondary event status as missing time-varying covariates, yet missingness is partial since partial information is provided throughout the follow-up period. Current practice of using the latest observed status produces biased estimators, and the existing missing covariate techniques cannot accommodate the special feature of missingness due to interval censoring. To handle interval-censored covariates in the Cox proportional hazards model, we propose an available-data estimator, a doubly robust-type estimator as well as the maximum likelihood estimator via EM algorithm and present their asymptotic properties. We also present practical approaches that are valid. We demonstrate the proposed methods using our motivating example from the Northern Manhattan Study. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessment of teacher interruptions on learners during oral case presentations.

PubMed

Yang, Glen; Chin, Rachel

2007-06-01

Studies have only recently begun to investigate the effects of interruptions on physicians in the emergency department (ED). To determine the frequency and nature of interruptions by the training physician that occur when medical trainees do oral case presentations (OCPs) in the ED. This was an observational study. Learner OCPs to attending emergency physicians were observed in the ED of an urban Level 1 trauma center at a major teaching hospital. A single investigator followed attending physicians blinded to the study objective in a nonrandomized convenience sampling of all ED shifts, recording information regarding teacher interruptions during new patient presentations. Learners completed a brief questionnaire after each OCP. A total of 196 OCPs were observed. The mean (+/-SD) duration of OCPs was 3.30 (+/-1.85) minutes, and the mean (+/-SD) number of interruptions was 0.75 (+/-0.60) per minute and 2.49 (+/-1.95) per OCP. The number of interruptions (per OCP) and duration of OCP varied by learner level of training, with more experienced learners giving shorter presentations and being interrupted less often. Frequency (per minute) of interruptions did not vary by learner level. In 40.3% of OCPs, attending physicians interrupted to give an assessment and/or a plan before the learner had done so, but 8.3% of interrupted learners believed that teacher interruptions were "disruptive" to their OCP. Attending emergency physicians frequently interrupt learners during new patient OCPs, with the number of interruptions varying by learner level of training. Teacher interruptions appear to have minimal, if any, detrimental effect on the perceived effectiveness of OCPs as a learning experience.

Mixed-effects varying-coefficient model with skewed distribution coupled with cause-specific varying-coefficient hazard model with random-effects for longitudinal-competing risks data analysis.

PubMed

Lu, Tao; Wang, Min; Liu, Guangying; Dong, Guang-Hui; Qian, Feng

2016-01-01

It is well known that there is strong relationship between HIV viral load and CD4 cell counts in AIDS studies. However, the relationship between them changes during the course of treatment and may vary among individuals. During treatments, some individuals may experience terminal events such as death. Because the terminal event may be related to the individual's viral load measurements, the terminal mechanism is non-ignorable. Furthermore, there exists competing risks from multiple types of events, such as AIDS-related death and other death. Most joint models for the analysis of longitudinal-survival data developed in literatures have focused on constant coefficients and assume symmetric distribution for the endpoints, which does not meet the needs for investigating the nature of varying relationship between HIV viral load and CD4 cell counts in practice. We develop a mixed-effects varying-coefficient model with skewed distribution coupled with cause-specific varying-coefficient hazard model with random-effects to deal with varying relationship between the two endpoints for longitudinal-competing risks survival data. A fully Bayesian inference procedure is established to estimate parameters in the joint model. The proposed method is applied to a multicenter AIDS cohort study. Various scenarios-based potential models that account for partial data features are compared. Some interesting findings are presented.

Analysis of Memory Codes and Cumulative Rehearsal in Observational Learning

ERIC Educational Resources Information Center

Bandura, Albert; And Others

1974-01-01

The present study examined the influence of memory codes varying in meaningfulness and retrievability and cumulative rehearsal on retention of observationally learned responses over increasing temporal intervals. (Editor)

Mobile Purposive-Extensive-Podcast-Listening versus Mobile Self-Regulated-Podcast-Development: A Critical Framework for Designing Foreign Language Listening

ERIC Educational Resources Information Center

Sendag, Serkan; Caner, Mustafa; Kafes, Hüseyin

2014-01-01

Nowadays mobile technologies are widely employed in almost all fields of education for varying reasons. The present study intends to explore the role of mobile technologies in the development of students' listening skills in a higher education context. The aim of the present study is twofold; while it seeks for the feasibility of mobile…

Varying coefficient function models to explore interactions between maternal nutritional status and prenatal methylmercury toxicity in the Seychelles Child Development Nutrition Study

PubMed Central

Lynch, Miranda L.; Huang, Li-Shan; Cox, Christopher; Strain, J.J.; Myers, Gary J.; Bonham, Maxine P.; Shamlaye, Conrad F.; Stokes-Riner, Abbie; Wallace, Julie M.W.; Duffy, Emeir M.; Clarkson, Thomas W.; Davidson, Philip W.

2010-01-01

Maternal consumption of fish during the gestational period exposes the fetus to both nutrients, especially the long-chain polyunsaturated fatty acids (LCPUFAs), believed to be beneficial for fetal brain development, as well as to the neurotoxicant methylmercury (MeHg). We recently reported that nutrients present in fish may modify MeHg neurotoxicity. Understanding the apparent interaction of MeHg exposure and nutrients present in fish is complicated by the limitations of modeling methods. In this study we fit varying coefficient function models to data from the Seychelles Child Development Nutrition Study (SCDNS) cohort to assess the association of dietary nutrients and children’s development. This cohort of mother-child pairs in the Republic of Seychelles had fish consumption averaging 9 meals per week. Maternal nutritional status was assessed for five different nutritional components known to be present in fish (n-3 LCPUFA, n-6 LCPUFA, iron status, iodine status, and choline) and associated with children’s neurological development. We also included prenatal MeHg exposure (measured in maternal hair). We examined two child neurodevelopmental outcomes (Bayley Scales Infant Development-II (BSID-II) Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI)), each administered at 9 and at 30 months. The varying coefficient models allow the possible interactions between each nutritional component and MeHg to be modeled as a smoothly varying function of MeHg as an effect modifier. Iron, iodine, choline, and n-6 LCPUFA had little or no observable modulation at different MeHg exposures. In contrast the n-3 LCPUFA docosahexaenoic acid (DHA) had beneficial effects on the BSID-II PDI that were reduced or absent at higher MeHg exposures. This study presents a useful modeling method that can be brought to bear on questions involving interactions between covariates, and illustrates the continuing importance of viewing fish consumption during pregnancy as a case of multiple exposures to nutrients and to MeHg. The results encourage more emphasis on a holistic view of the risks and benefits of fish consumption as it relates to infant development. PMID:20961536

Varying coefficient function models to explore interactions between maternal nutritional status and prenatal methylmercury toxicity in the Seychelles Child Development Nutrition Study.

PubMed

Lynch, Miranda L; Huang, Li-Shan; Cox, Christopher; Strain, J J; Myers, Gary J; Bonham, Maxine P; Shamlaye, Conrad F; Stokes-Riner, Abbie; Wallace, Julie M W; Duffy, Emeir M; Clarkson, Thomas W; Davidson, Philip W

2011-01-01

Maternal consumption of fish during the gestational period exposes the fetus to both nutrients, especially the long-chain polyunsaturated fatty acids (LCPUFAs), believed to be beneficial for fetal brain development, as well as to the neurotoxicant methylmercury (MeHg). We recently reported that nutrients present in fish may modify MeHg neurotoxicity. Understanding the apparent interaction of MeHg exposure and nutrients present in fish is complicated by the limitations of modeling methods. In this study we fit varying coefficient function models to data from the Seychelles Child Development Nutrition Study (SCDNS) cohort to assess the association of dietary nutrients and children's development. This cohort of mother-child pairs in the Republic of Seychelles had fish consumption averaging 9 meals per week. Maternal nutritional status was assessed for five different nutritional components known to be present in fish (n-3 LCPUFA, n-6 LCPUFA, iron status, iodine status, and choline) and associated with children's neurological development. We also included prenatal MeHg exposure (measured in maternal hair). We examined two child neurodevelopmental outcomes (Bayley Scales Infant Development-II (BSID-II) Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI)), each administered at 9 and at 30 months. The varying coefficient models allow the possible interactions between each nutritional component and MeHg to be modeled as a smoothly varying function of MeHg as an effect modifier. Iron, iodine, choline, and n-6 LCPUFA had little or no observable modulation at different MeHg exposures. In contrast the n-3 LCPUFA docosahexaenoic acid (DHA) had beneficial effects on the BSID-II PDI that were reduced or absent at higher MeHg exposures. This study presents a useful modeling method that can be brought to bear on questions involving interactions between covariates, and illustrates the continuing importance of viewing fish consumption during pregnancy as a case of multiple exposures to nutrients and to MeHg. The results encourage more emphasis on a holistic view of the risks and benefits of fish consumption as it relates to infant development. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of varying presentation time on long-term recognition memory for scenes: Verbatim and gist representations.

PubMed

Ahmad, Fahad N; Moscovitch, Morris; Hockley, William E

2017-04-01

Konkle, Brady, Alvarez and Oliva (Psychological Science, 21, 1551-1556, 2010) showed that participants have an exceptional long-term memory (LTM) for photographs of scenes. We examined to what extent participants' exceptional LTM for scenes is determined by presentation time during encoding. In addition, at retrieval, we varied the nature of the lures in a forced-choice recognition task so that they resembled the target in gist (i.e., global or categorical) information, but were distinct in verbatim information (e.g., an "old" beach scene and a similar "new" beach scene; exemplar condition) or vice versa (e.g., a beach scene and a new scene from a novel category; novel condition). In Experiment 1, half of the list of scenes was presented for 1 s, whereas the other half was presented for 4 s. We found lower performance for shorter study presentation time in the exemplar test condition and similar performance for both study presentation times in the novel test condition. In Experiment 2, participants showed similar performance in an exemplar test for which the lure was of a different category but a category that was used at study. In Experiment 3, when presentation time was lowered to 500 ms, recognition accuracy was reduced in both novel and exemplar test conditions. A less detailed memorial representation of the studied scene containing more gist (i.e., meaning) than verbatim (i.e., surface or perceptual details) information is retrieved from LTM after a short compared to a long study presentation time. We conclude that our findings support fuzzy-trace theory.

Subjective evaluation of mobile 3D video content: depth range versus compression artifacts

NASA Astrophysics Data System (ADS)

Jumisko-Pyykkö, Satu; Haustola, Tomi; Boev, Atanas; Gotchev, Atanas

2011-02-01

Mobile 3D television is a new form of media experience, which combines the freedom of mobility with the greater realism of presenting visual scenes in 3D. Achieving this combination is a challenging task as greater viewing experience has to be achieved with the limited resources of the mobile delivery channel such as limited bandwidth and power constrained handheld player. This challenge sets need for tight optimization of the overall mobile 3DTV system. Presence of depth and compression artifacts in the played 3D video are two major factors that influence viewer's subjective quality of experience and satisfaction. The primary goal of this study has been to examine the influence of varying depth and compression artifacts on the subjective quality of experience for mobile 3D video content. In addition, the influence of the studied variables on simulator sickness symptoms has been studied and vocabulary-based descriptive quality of experience has been conducted for a sub-set of variables in order to understand the perceptual characteristics in detail. In the experiment, 30 participants have evaluated the overall quality of different 3D video contents with varying depth ranges and compressed with varying quantization parameters. The test video content has been presented on a portable autostereoscopic LCD display with horizontal double density pixel arrangement. The results of the psychometric study indicate that compression artifacts are a dominant factor determining the quality of experience compared to varying depth range. More specifically, contents with strong compression has been rejected by the viewers and deemed unacceptable. The results of descriptive study confirm the dominance of visible spatial artifacts along the added value of depth for artifact-free content. The level of visual discomfort has been determined as not offending.

Influence of Child Factors on Health-Care Professionals' Recognition of Common Childhood Mental-Health Problems.

PubMed

Burke, Delia A; Koot, Hans M; de Wilde, Amber; Begeer, Sander

Early recognition of childhood mental-health problems can help minimise long-term negative outcomes. Recognition of mental-health problems, needed for referral and diagnostic evaluation, is largely dependent on health-care professionals' (HCPs) judgement of symptoms presented by the child. This study aimed to establish whether HCPs recognition of mental-health problems varies as a function of three child-related factors (type of problem, number of symptoms, and demographic characteristics). In an online survey, HCPs ( n  = 431) evaluated a series of vignettes describing children with symptoms of mental-health problems. Vignettes varied by problem type (Attention-Deficit/Hyperactivity Disorder (ADHD), Generalised Anxiety Disorder (GAD), Autism Spectrum Disorder (ASD), Conduct Disorder (CD) and Major Depressive Disorder), number of symptoms presented (few and many), and child demographic characteristics (ethnicity, gender, age and socio-economic status (SES)). Results show that recognition of mental-health problems varies by problem type, with ADHD best recognised and GAD worst. Furthermore, recognition varies by the number of symptoms presented. Unexpectedly, a child's gender, ethnicity and family SES did not influence likelihood of problem recognition. These results are the first to reveal differences in HCPs' recognition of various common childhood mental-health problems. HCPs in practice should be advised about poor recognition of GAD, and superior recognition of ADHD, if recognition of all childhood mental-health problems is to be equal.

Course of Study for Secondary Level Bookkeeping/Accounting. Final Report.

ERIC Educational Resources Information Center

Brower, Edward B.

The present project was designed to continue the preparation of a course of study useful for developing secondary level bookkeeping/accounting instruction. The course of study is intended to (1) derive vocational instruction for students with varying career goals, (2) develop accounting-oriented career exploration units for Introduction to…

Varying the Order in which Positive and Negative Information Is Presented: Effects on Counselors' Judgments of Clients' Mental Health.

ERIC Educational Resources Information Center

Pain, Michelle D.; Sharpley, Christopher F.

1989-01-01

Studied ratings by Australian counseling psychology graduate students (N=38) and practicing counseling psychologists (N=40) of four hypothetical clients' mental health. Presented "good,""bad," and "neutral" information on each client and asked subjects to rate clients' on Global Assessment Scale. Found bad information…

Conjunction Faces Alter Confidence-Accuracy Relations for Old Faces

ERIC Educational Resources Information Center

Reinitz, Mark Tippens; Loftus, Geoffrey R.

2017-01-01

The authors used a state-trace methodology to investigate the informational dimensions used to recognize old and conjunction faces (made by combining parts of separately studied faces). Participants in 3 experiments saw faces presented for 1 s each. They then received a recognition test; faces were presented for varying brief durations and…

A Time Use Diary Study of Adult Everyday Writing Behavior

ERIC Educational Resources Information Center

Cohen, Dale J.; White, Sheida; Cohen, Steffaney B.

2011-01-01

The present study documents everyday adult writing by type of text and medium (computer or paper) in an "in vivo" diary study. The authors compare writing patterns by gender, race/ethnicity, educational attainment, age and working status. The study results reveal that (a) writing time varied with demographic variables for networkers, but…

The effectiveness of physiologically based early warning or track and trigger systems after triage in adult patients presenting to emergency departments: a systematic review.

PubMed

Wuytack, Francesca; Meskell, Pauline; Conway, Aislinn; McDaid, Fiona; Santesso, Nancy; Hickey, Fergal G; Gillespie, Paddy; Raymakers, Adam J N; Smith, Valerie; Devane, Declan

2017-12-06

Changes to physiological parameters precede deterioration of ill patients. Early warning and track and trigger systems (TTS) use routine physiological measurements with pre-specified thresholds to identify deteriorating patients and trigger appropriate and timely escalation of care. Patients presenting to the emergency department (ED) are undiagnosed, undifferentiated and of varying acuity, yet the effectiveness and cost-effectiveness of using early warning systems and TTS in this setting is unclear. We aimed to systematically review the evidence on the use, development/validation, clinical effectiveness and cost-effectiveness of physiologically based early warning systems and TTS for the detection of deterioration in adult patients presenting to EDs. We searched for any study design in scientific databases and grey literature resources up to March 2016. Two reviewers independently screened results and conducted quality assessment. One reviewer extracted data with independent verification of 50% by a second reviewer. Only information available in English was included. Due to the heterogeneity of reporting across studies, results were synthesised narratively and in evidence tables. We identified 6397 citations of which 47 studies and 1 clinical trial registration were included. Although early warning systems are increasingly used in EDs, compliance varies. One non-randomised controlled trial found that using an early warning system in the ED may lead to a change in patient management but may not reduce adverse events; however, this is uncertain, considering the very low quality of evidence. Twenty-eight different early warning systems were developed/validated in 36 studies. There is relatively good evidence on the predictive ability of certain early warning systems on mortality and ICU/hospital admission. No health economic data were identified. Early warning systems seem to predict adverse outcomes in adult patients of varying acuity presenting to the ED but there is a lack of high quality comparative studies to examine the effect of using early warning systems on patient outcomes. Such studies should include health economics assessments.

Varying coefficient function models to explore interactions between maternal nutritional status and prenatal methylmercury toxicity in the Seychelles Child Development Nutrition Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynch, Miranda L., E-mail: Miranda_Lynch@urmc.rochester.edu; Huang, Li-Shan; Cox, Christopher

Maternal consumption of fish during the gestational period exposes the fetus to both nutrients, especially the long-chain polyunsaturated fatty acids (LCPUFAs), believed to be beneficial for fetal brain development, as well as to the neurotoxicant methylmercury (MeHg). We recently reported that nutrients present in fish may modify MeHg neurotoxicity. Understanding the apparent interaction of MeHg exposure and nutrients present in fish is complicated by the limitations of modeling methods. In this study we fit varying coefficient function models to data from the Seychelles Child Development Nutrition Study (SCDNS) cohort to assess the association of dietary nutrients and children's development. Thismore » cohort of mother-child pairs in the Republic of Seychelles had fish consumption averaging 9 meals per week. Maternal nutritional status was assessed for five different nutritional components known to be present in fish (n-3 LCPUFA, n-6 LCPUFA, iron status, iodine status, and choline) and associated with children's neurological development. We also included prenatal MeHg exposure (measured in maternal hair). We examined two child neurodevelopmental outcomes (Bayley Scales Infant Development-II (BSID-II) Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI)), each administered at 9 and at 30 months. The varying coefficient models allow the possible interactions between each nutritional component and MeHg to be modeled as a smoothly varying function of MeHg as an effect modifier. Iron, iodine, choline, and n-6 LCPUFA had little or no observable modulation at different MeHg exposures. In contrast the n-3 LCPUFA docosahexaenoic acid (DHA) had beneficial effects on the BSID-II PDI that were reduced or absent at higher MeHg exposures. This study presents a useful modeling method that can be brought to bear on questions involving interactions between covariates, and illustrates the continuing importance of viewing fish consumption during pregnancy as a case of multiple exposures to nutrients and to MeHg. The results encourage more emphasis on a holistic view of the risks and benefits of fish consumption as it relates to infant development. - Research highlights: {yields}Varying coefficient models are tools for examining interactions in exposure settings Associations between MeHg and fish nutrients and developmental outcomes were examined. {yields} Interactions between MeHg exposure and fish-derived nutrients were modeled using VC. {yields} Models show beneficial association of DHA with outcomes were reduced as MeHg increases. {yields} VC models show other measured nutrients unmodulated by increasing MeHg exposure.« less

Aspects Of 40- to 50-Day Oscillations In LOD And AAM

NASA Technical Reports Server (NTRS)

Dickey, Jean O.; Marcus, Steven L.; Ghil, Michael

1992-01-01

Report presents study of fluctuations in rotation of Earth, focusing on irregular intraseasonal oscillations in length of day (LOD) and atmospheric angular momentum (AAM) with periods varying from 40 to 50 days. Study draws upon and extends results of prior research.

Is attendance at an ovarian cancer screening clinic a worry-reducing event? Findings from pre- to post-screening.

PubMed

Ruberg, Joshua L; Helm, C William; Felleman, Benjamin I; Helm, Jane E; Studts, Jamie L

2017-02-01

Many studies have examined the relationship between worry and cancer screening. Due to methodological inconsistencies, results of these studies have varied and few conclusions can be made when generalizing across studies. The purpose of the current study was to better understand the worry-cancer screening relationship using a prospective research design. 180 women enrolled in an annual ovarian cancer (OC) screening clinic completed surveys at three time points-pre-screening, day of screening, and post-screening-using three measures of cancer-specific worry. OC worry was highest in the weeks prior to screening and mere presentation at a screening clinic was associated with a significant worry decline. Observed elevations in worry following abnormal screening were not universal and varied by the instrument used to measure worry. In contrast to our hypotheses, it appears that mere presentation at a cancer screening clinic may be a worry-reducing event. Receipt of abnormal results was not necessarily associated with increased worry. Published by Elsevier Inc.

Varying coefficient subdistribution regression for left-truncated semi-competing risks data.

PubMed

Li, Ruosha; Peng, Limin

2014-10-01

Semi-competing risks data frequently arise in biomedical studies when time to a disease landmark event is subject to dependent censoring by death, the observation of which however is not precluded by the occurrence of the landmark event. In observational studies, the analysis of such data can be further complicated by left truncation. In this work, we study a varying co-efficient subdistribution regression model for left-truncated semi-competing risks data. Our method appropriately accounts for the specifical truncation and censoring features of the data, and moreover has the flexibility to accommodate potentially varying covariate effects. The proposed method can be easily implemented and the resulting estimators are shown to have nice asymptotic properties. We also present inference, such as Kolmogorov-Smirnov type and Cramér Von-Mises type hypothesis testing procedures for the covariate effects. Simulation studies and an application to the Denmark diabetes registry demonstrate good finite-sample performance and practical utility of the proposed method.

Baclofen-induced reductions in optional food intake depend upon food composition.

PubMed

Wojnicki, F H E; Charny, G; Corwin, R L W

2013-05-01

Baclofen reduces intake of some foods but stimulates intake or has no effect on others. The reasons for these differences are not known. The present study examined effects of baclofen when composition, energy density, preference, presentation and intake of optional foods varied. Semi-solid fat emulsions and sucrose products were presented for brief periods to non-food-deprived rats. In Experiment 1, fat and sucrose composition were varied while controlling energy density. In Experiment 2A, schedule of access and the number of optional foods were varied. In Experiment 2B, the biopolymer (thickener) was examined. Baclofen reduced intake of fat and/or sugar options with different energy densities (1.28-9kcal/g), when presented daily or intermittently, and when intakes were relatively high or low. However, the efficacy of baclofen was affected by the biopolymer used to thicken the options: baclofen had no effect when options were thickened with one biopolymer (3173), but reduced intake when options were thickened with another biopolymer (515). Baclofen failed to reduce intake of a concentrated sugar option (64% sucrose), regardless of biopolymer. Based upon these results, caution is urged when interpreting results obtained with products using different thickening agents. Systematic research is needed when designing products used in rat models of food intake. Copyright © 2013 Elsevier Ltd. All rights reserved.

BACLOFEN-INDUCED REDUCTIONS IN OPTIONAL FOOD INTAKE DEPEND UPON FOOD COMPOSITION

PubMed Central

Wojnicki, F.H.E.; Charny, G.; Corwin, R.L.W

2013-01-01

Baclofen reduces intake of some foods but stimulates intake or has no effect on others. The reasons for these differences are not known. The present study examined effects of baclofen when composition, energy density, preference, presentation and intake of optional foods varied. Semi-solid fat emulsions and sucrose products were presented for brief periods to non-food-deprived rats. In Experiment 1, fat and sucrose composition were varied while controlling energy density. In Experiment 2A, schedule of access and the number of optional foods were varied. In Experiment 2B, the biopolymer (thickener) was examined. Baclofen reduced intake of fat and/or sugar options with different energy densities (1.28-9 kcal/g), when presented daily or intermittently, and when intakes were relatively high or low. However, the efficacy of baclofen was affected by the biopolymer used to thicken the options: baclofen had no effect when options were thickened with one biopolymer (3173), but reduced intake when options were thickened with another biopolymer (515). Baclofen failed to reduce intake of a concentrated sugar option (64% sucrose), regardless of biopolymer. Based upon these results, caution is urged when interpreting results obtained with products using different thickening agents. Systematic research is needed when designing products used in rat models of food intake. PMID:23321345

Dipole moment and polarizability of impurity doped quantum dots under anisotropy, spatially-varying effective mass and dielectric screening function: Interplay with noise

NASA Astrophysics Data System (ADS)

Ghosh, Anuja; Ghosh, Manas

2018-01-01

Present work explores the profiles of polarizability (αp) and electric dipole moment (μ) of impurity doped GaAs quantum dot (QD) under the aegis of spatially-varying effective mass, spatially-varying dielectric constant and anisotropy of the system. Presence of noise has also been invoked to examine how its intervention further tunes αp and μ. Noise term maintains a Gaussian white feature and it has been incorporated to the system through two different roadways; additive and multiplicative. The various facets of influence of spatially-varying effective mass, spatially-varying dielectric constant and anisotropy on αp and μ depend quite delicately on presence/absence of noise and also on the mode through which noise has been administered. The outcomes of the study manifest viable routes to harness the dipole moment and polarizability of doped QD system through the interplay between noise, anisotropy and variable effective mass and dielectric constant of the system.

Opportunistic Capacity-Based Resource Allocation for Chunk-Based Multi-Carrier Cognitive Radio Sensor Networks

PubMed Central

Huang, Jie; Zeng, Xiaoping; Jian, Xin; Tan, Xiaoheng; Zhang, Qi

2017-01-01

The spectrum allocation for cognitive radio sensor networks (CRSNs) has received considerable research attention under the assumption that the spectrum environment is static. However, in practice, the spectrum environment varies over time due to primary user/secondary user (PU/SU) activity and mobility, resulting in time-varied spectrum resources. This paper studies resource allocation for chunk-based multi-carrier CRSNs with time-varied spectrum resources. We present a novel opportunistic capacity model through a continuous time semi-Markov chain (CTSMC) to describe the time-varied spectrum resources of chunks and, based on this, a joint power and chunk allocation model by considering the opportunistically available capacity of chunks is proposed. To reduce the computational complexity, we split this model into two sub-problems and solve them via the Lagrangian dual method. Simulation results illustrate that the proposed opportunistic capacity-based resource allocation algorithm can achieve better performance compared with traditional algorithms when the spectrum environment is time-varied. PMID:28106803

Stability of neutrino parameters and self-complementarity relation with varying SUSY breaking scale

NASA Astrophysics Data System (ADS)

Singh, K. Sashikanta; Roy, Subhankar; Singh, N. Nimai

2018-03-01

The scale at which supersymmetry (SUSY) breaks (ms) is still unknown. The present article, following a top-down approach, endeavors to study the effect of varying ms on the radiative stability of the observational parameters associated with the neutrino mixing. These parameters get additional contributions in the minimal supersymmetric model (MSSM). A variation in ms will influence the bounds for which the Standard Model (SM) and MSSM work and hence, will account for the different radiative contributions received from both sectors, respectively, while running the renormalization group equations (RGE). The present work establishes the invariance of the self complementarity relation among the three mixing angles, θ13+θ12≈θ23 against the radiative evolution. A similar result concerning the mass ratio, m2:m1 is also found to be valid. In addition to varying ms, the work incorporates a range of different seesaw (SS) scales and tries to see how the latter affects the parameters.

Ballistic impact to access the high-rate behaviour of individual silk fibres

NASA Astrophysics Data System (ADS)

Drodge, Daniel R.; Mortimer, Beth; Holland, Chris; Siviour, Clive R.

2012-10-01

A revision of a classic transverse fibre impact technique is presented, as applied to the problem of obtaining the high strain-rate constitutive behaviour of commercial Bombyx mori silk. Medium tenacity nylon was also studied. Two approaches are presented: firstly a fixed pre-stress, varied impact velocity method that derives stress-strain behaviour by inverse fit; and secondly a fixed impact velocity, varied pre-stress approach, assuming basic elastic jump conditions to obtain a locus of post-impact states. The post-impact stress-strain states obtained using the two approaches converge for silk but diverge for nylon. This we attribute to silk's fine structure being able to homogenise energy dissipation at static and dynamic deformation rates. However, the coarser microstructure of nylon results in a different loading path dependence, thus divergence in the two approaches. It was also noted that silk exhibited a comparatively stable level of impact energy absorption under varying pre-stress, when compared to nylon.

Detection of soil erosion within pinyon-juniper woodlands using Thematic Mapper (TM) data

NASA Technical Reports Server (NTRS)

Price, Kevin P.

1993-01-01

Multispectral measurements collected by Landsat Thematic Mapper (TM) were correlated with field measurements, direct soil loss estimates, and Universal Soil Loss Equation (USLE) estimates to determine the sensitivity of TM data to varying degrees of soil erosion in pinyon-juniper woodland in central Utah. TM data were also evaluated as a predictor of the USLE Crop Management C factor for pinyon-juniper woodlands. TM spectral data were consistently better predictors of soil erosion factors than any combination of field factors. TM data were more sensitive to vegetation variations than the USLE C factor. USLE estimates showed low annual rates of erosion which varied little among the study sites. Direct measurements of rate of soil loss using the SEDIMENT (Soil Erosion DIrect measureMENT) technique, indicated high and varying rates of soil loss among the sites since tree establishment. Erosion estimates from the USLE and SEDIMENT methods suggest that erosion rates have been severe in the past, but because significant amounts of soil have already been eroded, and the surface is now armored by rock debris, present erosion rates are lower. Indicators of accelerated erosion were still present on all sites, however, suggesting that the USLE underestimated erosion within the study area.

Research Measures for Dyscalculia: A Validity and Reliability Study.

ERIC Educational Resources Information Center

Geiman, R. M.

1986-01-01

This study sought to evaluate a measure of dyscalculia to determine its validity and reliability. It also tested use of the instrument with seventh graders and ascertained where errors attributed to dyscalculia were also present in an average sample of seventh graders. Results varied. (MNS)

Effects of Variation and Prior Knowledge on Abstract Concept Learning

ERIC Educational Resources Information Center

Braithwaite, David W.; Goldstone, Robert L.

2015-01-01

Learning abstract concepts through concrete examples may promote learning at the cost of inhibiting transfer. The present study investigated one approach to solving this problem: systematically varying superficial features of the examples. Participants learned to solve problems involving a mathematical concept by studying either superficially…

Communication: The Study of Human Interaction.

ERIC Educational Resources Information Center

Mortensen, C. David

Designed to provide a comprehensive and broadly based introduction to the study of human communication, this book presents the concept of communication as interrelated constituent processes that operate at varying levels of complexity and acquire significance only in the context of larger intrapersonal, interpersonal, or socio-cultural systems of…

Caregiver Perceptions of Sexual Abuse and Its Effect on Management after a Disclosure

ERIC Educational Resources Information Center

Walker-Descartes, Ingrid; Sealy, Yvette M.; Laraque, Danielle; Rojas, Mary

2011-01-01

Objective: The aim of the study was to examine caregiver management strategies for child sexual abuse (CSA) when presented with hypothetical scenarios that vary in physical invasiveness. Methods: One hundred fifty three caregivers were given 3 scenarios of CSA with 7 management strategies presented in the 21-item Taking Action Strategies (TAS)…

YF-12 Experiments Symposium, Volume 1

NASA Technical Reports Server (NTRS)

1978-01-01

Papers presented by personnel from the Dryden Flight Research Center, the Lewis Research Center, and the Ames Research Center are presented. Topics cover propulsion system performance, inlet time varying distortion, structures, aircraft controls, propulsion controls, and aerodynamics. The reports were based on analytical studies, laboratory experiments, wind tunnel tests, and extensive flight research with two YF-12 airplanes.

The Development of Pointing Perception in Infancy: Effects of Communicative Signals on Covert Shifts of Attention

ERIC Educational Resources Information Center

Daum, Moritz M.; Ulber, Julia; Gredebäck, Gustaf

2013-01-01

The present study aims to investigate the interplay of verbal and nonverbal communication with respect to infants' perception of pointing gestures. Infants were presented with still images of pointing hands (cue) in combination with an acoustic stimulus. The communicative content of this acoustic stimulus was varied from being human and…

Policymaking as a Multi-Layered Activity. A Case Study from the Higher Education Sector in Norway

ERIC Educational Resources Information Center

Ljosland, Ragnhild

2015-01-01

This paper deals with policymaking in the higher education sector as an activity which happens on many levels, with many and varying interests involved. As the present thematic issue highlights, language is present in higher education policymaking, whether explicitly or implicitly. This special issue's initial claim is that "Policy is what…

Spatially Varying Index of Refraction: An Open Ended Undergraduate Topic.

ERIC Educational Resources Information Center

Krueger, David A.

1980-01-01

Presents an experiment on the bending of light in a medium with a continuously varying index of refraction. Several theoretical approaches for the analysis of this experiment, designed for college physics students, are also presented. (HM)

Holographic cinematography of time-varying reflecting and time-varying phase objects using a Nd:YAG laser.

PubMed

Decker, A J

1982-03-01

The use of a Nd:YAG laser to record holographic motion pictures of time-varying reflecting objects and time-varying phase objects is discussed. Sample frames from both types of holographic motion pictures are presented. The holographic system discussed is intended for three-dimensional flow visualization of the time-varying flows that occur in jet-engine components.

Holographic cinematography of time-varying reflecting and time-varying phase objects using a Nd:YAG laser

NASA Technical Reports Server (NTRS)

Decker, A. J.

1982-01-01

The use of a Nd:YAG laser to record holographic motion pictures of time-varying reflecting objects and time-varying phase objects is discussed. Sample frames from both types of holographic motion pictures are presented. The holographic system discussed is intended for three-dimensional flow visualization of the time-varying flows that occur in jet-engine components.

CFD Analysis of A Starved Four-Pad Tilting-Pad Journal Bearing with An Elastic Support of Pads

NASA Astrophysics Data System (ADS)

Parovay, E. F.; Falaleev, S. V.

2018-01-01

Tilting-pad journal bearings are widely used in technics. Oil starvation operation regime is not common for hydrodynamic bearings. However, correctly designed low-flow journal bearing have to operate efficiently and consistently on high rotor speeds. An elastic support of bearing pads is a set of elastic pins made of steel. Elastic support allows pads to self-align and achieve an optimal operational mode. The article presents the thermohydrodynamic performance of an axial journal bearing. The study deals with 60 mm diameter four-pad tilting-pad journal bearing, submitted to a static load varying from 1000 to 30000 N with a rotating speed varying from 1000 to 10000 rpm. The investigation focuses on numerical studying the characteristics of low-flow tilting-pad journal bearings under oil starvation conditions. Dependencies of the bearing performance on the load, rotational speed of the shaft, and the size of the radial clearance are presented.

The latitudinal gradient of the NO peak density

NASA Technical Reports Server (NTRS)

Fesen, C. G.; Rusch, D. W.; Gerard, J.-C.

1990-01-01

Results are presented from SME observations of the latitudinal gradients of peak NO densities at about 110-km altitude during the solstice and equinox periods from 1982 through 1985. It is shown that the response of the peak NO densities to the declining level of solar activity varies with latitude, with the polar regions exhibiting low sensitivity and the low-latitude regions responding strongly. The SME data also revealed marked asymmetries in the latitudinal structure of the two hemispheres for each season and considerable day-to-day variations in the NO densities. The solar cycle minimum data for June were simulated using a two-dimensional model; results of sensitivity studies performed with varied quenching rate and eddy diffusion coefficient are presented.

Correlation of shear design between AASHTO LRFD bridge design specifications and AASHTO Guide Specifications for the LRFD Seismic Bridge Design.

DOT National Transportation Integrated Search

2017-01-05

This report presents the analytical study of the shear capacity of reinforced concrete columns using both the AASHTO LRFD Bridge Design Specifications and the AASHTO Guide Specifications for the LRFD Seismic Bridge Design. The study investigates vari...

Elementary and Middle School Teacher Perceptions of Attention-Deficit/Hyperactivity Disorder Prevalence

ERIC Educational Resources Information Center

Fabiano, Gregory A.; Pelham, William E., Jr.; Majumdar, Antara; Evans, Steven W.; Manos, Michael J.; Caserta, Donald; Girio-Herrera, Erin L.; Pisecco, Stewart; Hannah, Jane N.; Carter, Randy L.

2013-01-01

Background: Estimates of ADHD diagnosis and stimulant medication use vary across studies. Few studies ascertain the teacher perspective on these rates. Objective: To ascertain teachers' perceptions of ADHD prevalence and medication treatment within their classrooms. Method: The present school survey collected teacher report of identified children…

Negative Interpersonal Interactions in Student Training Settings

ERIC Educational Resources Information Center

Ferris, Patricia A.; Kline, Theresa J. B.

2009-01-01

Studies demonstrate that negative interpersonal interaction(s) (NII) such as bullying are frequent and harmful to individuals in workplace and higher education student settings. Nevertheless, it is unclear whether the degree of perceived severity of NII varies by the status of the actor. The present study explored the moderating effect of actor…

Mirror Image Confusability in Adults.

ERIC Educational Resources Information Center

Wolff, Peter

Several studies have indicated that children have difficulty differentiating mirror-image stimuli. In the present study adults were required to classify pairs of horseshoe stimuli as same or different. Response times were compared for stimulus pairs that varied in orientation (left-right vs up-down) and spatial plane of the pair (horizontal vs.…

A driving simulator study : evaluation of vehicle mounted attenuator markings in work zones during different times of the day.

DOT National Transportation Integrated Search

2010-09-01

This report presents a study of driver perceptions using a driving simulator carried out on the : effectiveness of four markings which vary in striping patterns and color combinations used at the : rear of vehicle mounted attenuators (VMAs) in work z...

Obstacles to Reasoning about Inertia in Different Contexts

ERIC Educational Resources Information Center

Yerdelen-Damar, Sevda

2015-01-01

The present study investigated the underlying reasons for difficulties faced by students when they applied the concept of inertia across varying contexts. The participants of the study included five high school students. Data obtained from interviews were interpreted from the perspectives of the coordination class and epistemological framing…

Connective stability of nonlinear matrix systems

NASA Technical Reports Server (NTRS)

Siljak, D. D.

1974-01-01

Consideration of stability under structural perturbations of free dynamic systems described by the differential equation dx/dt = A(t,x)x, where the matrix A(t,x) has time-varying nonlinear elements. The concept of 'connective stability' is introduced to study the structural properties of competitive-cooperative nonlinear matrix systems. It is shown that stability reliability in such systems is high and that they remain stable despite time-varying (including 'on-off') interaction among individual agents present in the system. The results obtained can be used to study stability aspects of mathematical models arising in as diverse fields as economics, biology, arms races, and transistor circuits.

The centrifuge facility - A life sciences research laboratory for Space Station Freedom

NASA Technical Reports Server (NTRS)

Fuller, Charles A.; Johnson, Catherine C.; Hargens, Alan R.

1991-01-01

The paper describes the centrifugal facility that is presently being developed by NASA for studies aboard the Space Station Freedom on the role of gravity, or its absence, at varying intensities for varying periods of time and with multiple model systems. Special attention is given to the design of the centrifuge system, the habitats designed to hold plants and animals, the glovebox system designed for experimental manipulations of the specimens, and the service unit. Studies planned for the facility will include experiments in the following disciplines: cell and developmental biology, plant biology, regulatory physiology, musculoskeletal physiology, behavior and performance, neurosciences, cardiopulmonary physiology, and environmental health and radiation.

Storage requirement definition study

NASA Technical Reports Server (NTRS)

Stacy, L. E.; Wesling, G. C.; Zimmerman, W. F.

1980-01-01

A dish Stirling solar receiver (DSSR) and a heat pipe solar receiver with TES (HPSR) for a 25 kWe dish Stirling solar power system are described. The thermal performance and cost effectiveness of each are analyzed minute by minute over the equivalent of one year of solar insolation. Existing designs of these two systems were used as a basis for the study; TES concepts for the DSSR and alternative TES concepts for the HPSR are presented. Parametric performance and cost studies were performed to determine the operating and cost characteristics of these systems. Data are reported for systems (1) without TES and with varying amounts of TES, (2) with and without a fossil fuel combustor, (3) with varying solar to fossil power input, and (4) with different system control assumptions. The principal effects of TES duration, collector area, engine efficiency, and fuel cost sensitivity are indicated. Development needs for each of the systems are discussed and the need and nature of possible future TES solar modular experiments are presented and discussed.

A ballistic performance study on multiphase particulate systems impacted by various projectiles

NASA Astrophysics Data System (ADS)

Comtois-Arnaldo, Christian; Petel, Oren

2017-06-01

The present study investigates the complex multiscale dynamic response of particulate composites, in an effort to link the bulk material behavior to strain-rate activated microstructures. These investigations involve multiphase systems containing micron-sized ceramic particles integrated into a siloxane elastomer to create flexible nanocomposites with varying inclusion properties. In particular, the effects of varying particle morphology, strength, volume fraction, and density are under investigation. The experimental focus of the study concerns the ballistic penetration of the nanocomposite targets. The targets are impacted by fragment simulating steel projectiles of constant mass and varying nose shapes (i.e., flat, ogive, and chisel-nose) to identify variations in the penetration mechanics. The projectiles are accelerated in a single-stage gas gun to velocities ranging from 200 m/s to 900 m/s prior to impact. The results for each projectile type are compared to analytical penetration models in order to shed light on the dominant penetration mechanisms and their relationship to the microstructure of the nanocomposites.

Hemolymph drop impact outcomes on surfaces with varying wettability

NASA Astrophysics Data System (ADS)

Milionis, Athanasios; Ghokulla Krishnan, K.; Loth, Eric

2015-08-01

Insect fouling from coagulated hemolymph and exoskeleton parts is a major challenge in the aerospace industry for the next generation of aerodynamic surfaces, which will employ laminar flow that requires extremely smooth surfaces. However, the wetting physics and dynamics of hemolymph (insect blood) on surfaces are not well understood. The present study seeks to gain a fundamental insight on the effect of surface wetting characteristics and dynamics resulting from a hemolymph drop impact, the first such study. In particular, hemolymph drops extracted from Acheta domesticus were dispensed from a range of heights to vary the kinetic impact on surfaces, which had widely varying water wetting behavior (from superhydrophilic to superhydrophobic). The impact dynamics were investigated with high-speed imaging while the dried residues were studied with optical microscopy. It was found that a superhydrophobic surface (based on thermoplastic with silica nano-particles) was able to significantly reduce hemolymph drop spreading, and even provide complete rebound when impacting on inclined surfaces.

The clinical presentation of acute bacterial meningitis varies with age, sex and duration of illness.

PubMed

Johansson Kostenniemi, Urban; Norman, David; Borgström, Malin; Silfverdal, Sven Arne

2015-11-01

This Swedish study reviewed differences in clinical presentation and laboratory findings of acute bacterial meningitis in children aged one month to 17 years in Västerbotten County, Sweden. A register-based study was performed for the period 1986 to 2013 using the Västerbotten County Council's patient registration and laboratory records at the Department of Laboratory Medicine at Umeå University Hospital. The medical records were reviewed to extract data and confirm the diagnosis. We found 103 cases of acute bacterial meningitis, and Haemophilus influenzae was the most common pathogen, causing 40.8% of all cases, followed by Streptococcus pneumoniae at 30.1% and Neisseria meningitidis at 9.7%. Significant differences in clinical presentation and laboratory findings were found. Younger children were more unwell than older ones and had more diffuse symptoms on admission. In addition, important sex-related differences were found that might explain the higher case fatality rates for boys than girls. For example, boys tended to have a higher disturbance in the blood-brain barrier, which is known to be a negative prognostic factor. This study showed that clinical presentation for acute bacterial meningitis varied with age and sex and, to a lesser extent, on the duration of the illness. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Stability Metrics for Simulation and Flight-Software Assessment and Monitoring of Adaptive Control Assist Compensators

NASA Technical Reports Server (NTRS)

Hodel, A. S.; Whorton, Mark; Zhu, J. Jim

2008-01-01

Due to a need for improved reliability and performance in aerospace systems, there is increased interest in the use of adaptive control or other nonlinear, time-varying control designs in aerospace vehicles. While such techniques are built on Lyapunov stability theory, they lack an accompanying set of metrics for the assessment of stability margins such as the classical gain and phase margins used in linear time-invariant systems. Such metrics must both be physically meaningful and permit the user to draw conclusions in a straightforward fashion. We present in this paper a roadmap to the development of metrics appropriate to nonlinear, time-varying systems. We also present two case studies in which frozen-time gain and phase margins incorrectly predict stability or instability. We then present a multi-resolution analysis approach that permits on-line real-time stability assessment of nonlinear systems.

Application of an improved Nelson-Nguyen analysis to eccentric, arbitrary profile liquid annular seals

NASA Technical Reports Server (NTRS)

Padavala, Satyasrinivas; Palazzolo, Alan B.; Vallely, Pat; Ryan, Steve

1994-01-01

An improved dynamic analysis for liquid annular seals with arbitrary profile based on a method, first proposed by Nelson and Nguyen, is presented. An improved first order solution that incorporates a continuous interpolation of perturbed quantities in the circumferential direction, is presented. The original method uses an approximation scheme for circumferential gradients, based on Fast Fourier Transforms (FFT). A simpler scheme based on cubic splines is found to be computationally more efficient with better convergence at higher eccentricities. A new approach of computing dynamic coefficients based on external specified load is introduced. This improved analysis is extended to account for arbitrarily varying seal profile in both axial and circumferential directions. An example case of an elliptical seal with varying degrees of axial curvature is analyzed. A case study based on actual operating clearances of an interstage seal of the Space Shuttle Main Engine High Pressure Oxygen Turbopump is presented.

The effect of varying talker identity and listening conditions on gaze behavior during audiovisual speech perception.

PubMed

Buchan, Julie N; Paré, Martin; Munhall, Kevin G

2008-11-25

During face-to-face conversation the face provides auditory and visual linguistic information, and also conveys information about the identity of the speaker. This study investigated behavioral strategies involved in gathering visual information while watching talking faces. The effects of varying talker identity and varying the intelligibility of speech (by adding acoustic noise) on gaze behavior were measured with an eyetracker. Varying the intelligibility of the speech by adding noise had a noticeable effect on the location and duration of fixations. When noise was present subjects adopted a vantage point that was more centralized on the face by reducing the frequency of the fixations on the eyes and mouth and lengthening the duration of their gaze fixations on the nose and mouth. Varying talker identity resulted in a more modest change in gaze behavior that was modulated by the intelligibility of the speech. Although subjects generally used similar strategies to extract visual information in both talker variability conditions, when noise was absent there were more fixations on the mouth when viewing a different talker every trial as opposed to the same talker every trial. These findings provide a useful baseline for studies examining gaze behavior during audiovisual speech perception and perception of dynamic faces.

The Impact of an Online Tool for Monitoring and Regulating Learning at University: Overconfidence, Learning Strategy, and Personality

ERIC Educational Resources Information Center

de Bruin, Anique B. H.; Kok, Ellen M.; Lobbestael, Jill; de Grip, Andries

2017-01-01

Being overconfident when estimating scores for an upcoming exam is a widespread phenomenon in higher education and presents threats to self-regulated learning and academic performance. The present study sought to investigate how overconfidence and poor monitoring accuracy vary over the length of a college course, and how an intervention consisting…

Varying the Narration Presentation Format and On-Screen Character-Narrator Relationship in an Instructional Science Film.

ERIC Educational Resources Information Center

Sherman, Greg

This study examined how learning, attitudes, and mental efforts are affected by changing the verbal information presentation format and relationship between the narrator and on-screen character in a junior high school-level science film. Twenty seventh-grade science classes (N=441) were randomly assigned to one of five treatment groups. Each class…

Comment on ``Steady-state properties of a totally asymmetric exclusion process with periodic structure''

NASA Astrophysics Data System (ADS)

Jiang, Rui; Hu, Mao-Bin; Wu, Qing-Song

2008-07-01

Lakatos [Phys. Rev. E 71, 011103 (2005)] have studied a totally asymmetric exclusion process that contains periodically varying movement rates. They have presented a cluster mean-field theory for the problem. We show that their cluster mean-field theory leads to redundant equations. We present a mean-field analysis in which there is no redundant equation.

Using Multisite Experiments to Study Cross-Site Variation in Treatment Effects: A Hybrid Approach with Fixed Intercepts and A Random Treatment Coefficient

ERIC Educational Resources Information Center

Bloom, Howard S.; Raudenbush, Stephen W.; Weiss, Michael J.; Porter, Kristin

2017-01-01

The present article considers a fundamental question in evaluation research: "By how much do program effects vary across sites?" The article first presents a theoretical model of cross-site impact variation and a related estimation model with a random treatment coefficient and fixed site-specific intercepts. This approach eliminates…

Evaluation of iconic versus F-map microburst displays

NASA Technical Reports Server (NTRS)

Salzberger, Mark; Hansman, R. John; Wanke, Craig

1994-01-01

Previous studies have shown graphical presentation methods of hazardous wind shear to be superior to textual or audible warnings alone. Positional information and the strength of the hazard were observed to be and were cited by pilots as the most important factors in a display. In this experiment the use of the three different graphical presentations of hazardous wind shear are examined. Airborne predictive detectors of wind shear enable the dissemination of varying levels of information. The effectiveness of iconic and mapping display modes of different complexities are addressed through simulation and analysis. Different positional and time-varying situations are presented in a 'part-task' Boeing 767 simulator using data from actual microburst events. Experienced airline pilots fly approach profiles using both iconic and F-map wind shear alerting displays. Microburst accompanied each event is also shown to the pilot. Mapping display types are expected to be found exceptionally efficient at conveying location comparison information while iconic displays simplify the threat recognition process. Preliminary results from the simulator study are presented. Recommendations concerning the suitability of multilevel iconic and mapping displays are made. Situational problems with current display prototypes are also addressed.

Effect of Instructional Strategies and Individual Differences: A Meta-Analytic Assessment.

ERIC Educational Resources Information Center

Baker, Rose M.; Dwyer, Francis

2005-01-01

This meta-analytic study is unique and significant in that all the 1,341 learners in 11 studies completed the Group Embedded Figures Test (GEFT), interacted with the same instructional module, and completed the same five criterion tests measuring different types of educational objectives. Studies varied in presentation mode and type of independent…

Visual Field Asymmetries in Attention Vary with Self-Reported Attention Deficits

ERIC Educational Resources Information Center

Poynter, William; Ingram, Paul; Minor, Scott

2010-01-01

The purpose of this study was to determine whether an index of self-reported attention deficits predicts the pattern of visual field asymmetries observed in behavioral measures of attention. Studies of "normal" subjects do not present a consistent pattern of asymmetry in attention functions, with some studies showing better left visual field (LVF)…

Wood specific gravity variation among five important hardwood species of Kashmir Himalaya.

PubMed

Wani, Bilal Ahmad; Bodha, R H; Khan, Amina

2014-02-01

Wood Specific Gravity (SG) is a measure of the amount of structural material a tree species allocates to support and strength. In the present study, specific gravity varied among the five different woods at three different sites from 0.40 in Populus nigra at site III (Shopian) to 0.80 in Parrotiopsis jacquemontiana at site II (Surasyar). Among the three different sites, specific gravity varied from 0.73 to 0.80 in Parroptiosis jacquemontiana; in Robinia pseudoacacia it varied from 0.71 to 0.79; in Salix alba, it varied from 0.42 to 0.48; In Populus nigra it varied from 0.40 to 0.48 and in Juglans regia it varied from 0.59 to 0.66. On the basis of the specific gravity variation patterns these woods were categorized as light (Salix alba, Populus nigra) moderately heavy (Juglans regia) and moderately heavy to heavy (Robinia pseudoacacia, Parrotiopsis jacquemontiana) which predicts their properties like strength, dimensional stability with moisture content change, ability to retain paint, fiber yield per unit volume, suitability for making particleboard and related wood composite materials and suitability as a raw material for making paper.

Approximation-based adaptive tracking control of pure-feedback nonlinear systems with multiple unknown time-varying delays.

PubMed

Wang, Min; Ge, Shuzhi Sam; Hong, Keum-Shik

2010-11-01

This paper presents adaptive neural tracking control for a class of non-affine pure-feedback systems with multiple unknown state time-varying delays. To overcome the design difficulty from non-affine structure of pure-feedback system, mean value theorem is exploited to deduce affine appearance of state variables x(i) as virtual controls α(i), and of the actual control u. The separation technique is introduced to decompose unknown functions of all time-varying delayed states into a series of continuous functions of each delayed state. The novel Lyapunov-Krasovskii functionals are employed to compensate for the unknown functions of current delayed state, which is effectively free from any restriction on unknown time-delay functions and overcomes the circular construction of controller caused by the neural approximation of a function of u and [Formula: see text] . Novel continuous functions are introduced to overcome the design difficulty deduced from the use of one adaptive parameter. To achieve uniformly ultimate boundedness of all the signals in the closed-loop system and tracking performance, control gains are effectively modified as a dynamic form with a class of even function, which makes stability analysis be carried out at the present of multiple time-varying delays. Simulation studies are provided to demonstrate the effectiveness of the proposed scheme.

A Study of Turkish High School Students' Burnout and Proficiency Levels in Relation to Their Sex

ERIC Educational Resources Information Center

Yeni Palabiyik, Pinar

2014-01-01

The present study examines high school students' burnout levels. The main aims of the study are to investigate whether their burnout levels vary according to gender and grade levels, and to check the correlation between overall burnout levels and their English language proficiency attained with a specific test. The study followed a quantitative…

The effect of encoding manipulation on word-stem cued recall: an event-related potential study.

PubMed

Fay, Séverine; Isingrini, Michel; Ragot, Richard; Pouthas, Viviane

2005-08-01

The purpose of the present study was to find out whether the neural correlates of explicit retrieval from episodic memory would vary according to conditions at encoding when the words were presented in separate study/test blocks. Event-related potentials (ERPs) were recorded while participants performed a word-stem cued-recall task. Deeply (semantically) studied words were associated with higher levels of recall and faster response times than shallowly (lexically) studied words. Robust ERP old/new effects were observed for each encoding condition. They varied in magnitude, being largest in the semantic condition. As expected, scalp distributions also differed: for deeply studied words, the old/new effect resembled that found in previous ERP studies of word-stem cued-recall tasks (parietal and right frontal effects, between 400-800 and 800-1100 ms post-stimulus), whereas for shallowly studied words, the parietal old/new effect was absent in the latter latency window. These results can be interpreted as reflecting access to different kinds of memory representation depending on the nature of the processing engaged during encoding. Furthermore, differences in the ERPs elicited by new items indicate that subjects adopted different processing strategies in the test blocks following each encoding condition.

An experimental study of dynamic stall on advanced airfoil section. Volume 2: Pressure and force data

NASA Technical Reports Server (NTRS)

Mcalister, K. W.; Pucci, S. L.; Mccroskey, W. J.; Carr, L. W.

1982-01-01

Experimentally derived force and moment data are presented for eight airfoil sections that were tested at fixed and varying incidence in a subsonic two dimensional stream. Airfoil incidence was varied through sinusoidal oscillations in pitch over a wide range of amplitude and frequency. The surface pressure distribution, as well as the lift, drag, and pitching moment derived therefrom, are displayed in a uniform fashion to delineate the static and dynamic characteristics of each airfoil both in and out of stall.

Astronomical site survey report on dust measurement, wind profile, optical turbulence, and their correlation with seeing over IAO-Hanle. Astronomical site survey report over IAO-Hanle

NASA Astrophysics Data System (ADS)

Ningombam, Shantikumar S.; Kathiravan, S.; Parihar, P. S.; L. Larson, E. J.; Mohanan, Sharika; Angchuk, Dorje; Jorphel, Sonam; Rangarajan, K. E.; Prabhu, K.

2017-04-01

The present work discusses astronomical site survey reports on dust content, vertical distribution of atmospheric turbulence, precipitable water vapor (PWV), surface and upper-air data, and their effects on seeing over the Indian Astronomical Observatory (IAO) Hanle. Using Laser Particulate Counter, ambient dust measurements at various sizes (0.3 μm to 25 μm) were performed at various locations at the site during November 2015. Estimated volume concentration for the particle size at 0.5 μm was around 10,000 per cubic foot, which is equivalent to ten thousand class of clean room standard protocol. During the measurement, surface wind speed varied from 0-20 m s -1, while estimated aerosol optical depth (AOD) using Sky radiometer (Prede) varied from 0.02-0.04 at 500 nm, which indicates the site is fairly clean. The two independent measurements of dust content and aerosol concentrations at the site agreed well. The turbulence or wind gust at the site was studied with wind profiles at three different heights above the ground. The strength of the wind gust varies with time and altitude. Nocturnal temperature across seasons varied with a moderate at summer (6-8 ∘C) and lower in winter (4-5 ∘C). However, the contrast between the two is significantly small due to cold and extremely dry typical climatic conditions of the site. The present study also examined the effects of surface and upper-air data along with Planetary Boundary Layer (PBL) dynamics with seeing measurement over the site. Further, a comparative study of such observed parameters was conducted with other high altitude astronomical observatories across the globe.

Quantitative Estimation of Plasma Free Drug Fraction in Patients With Varying Degrees of Hepatic Impairment: A Methodological Evaluation.

PubMed

Li, Guo-Fu; Yu, Guo; Li, Yanfei; Zheng, Yi; Zheng, Qing-Shan; Derendorf, Hartmut

2018-07-01

Quantitative prediction of unbound drug fraction (f u ) is essential for scaling pharmacokinetics through physiologically based approaches. However, few attempts have been made to evaluate the projection of f u values under pathological conditions. The primary objective of this study was to predict f u values (n = 105) of 56 compounds with or without the information of predominant binding protein in patients with varying degrees of hepatic insufficiency by accounting for quantitative changes in molar concentrations of either the major binding protein or albumin plus alpha 1-acid glycoprotein associated with differing levels of hepatic dysfunction. For the purpose of scaling, data pertaining to albumin and α1-acid glycoprotein levels in response to differing degrees of hepatic impairment were systematically collected from 919 adult donors. The results of the present study demonstrate for the first time the feasibility of physiologically based scaling f u in hepatic dysfunction after verifying with experimentally measured data of a wide variety of compounds from individuals with varying degrees of hepatic insufficiency. Furthermore, the high level of predictive accuracy indicates that the inter-relation between the severity of hepatic impairment and these plasma protein levels are physiologically accurate. The present study enhances the confidence in predicting f u in hepatic insufficiency, particularly for albumin-bound drugs. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Breaking the Illiteracy Bonds.

ERIC Educational Resources Information Center

Taylor, Susan Champlin

1988-01-01

Describes current research being done on literacy and discusses reasons behind the varied estimates of adult literacy rates. Presents several case studies of adults who are currently or have been in reading programs, particularly older adults. Describes the work of major literacy education providers. (CH)

Picture-Word Differences in the Acquisition and Retention of Paired Associates

ERIC Educational Resources Information Center

Postman, Leo

1978-01-01

In a study of paired-associate learning and retention, the mode of presentation (pictures versus words) of the stimuli and the responses was varied factorially. Results pose difficulties for current interpretations of picture-word differences. (Editor/RK)

Estimating terrestrial amphibian pesticide body burden through dermal exposure

EPA Science Inventory

Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Our study measured dermal uptake of pesticides of varying hydrophobicity (logKow) in frogs. Amphibians were indirectly exposed to one of five pesticide active...

Mothers' Socialization Goals, Mothers' Emotion Socialization Behaviors, Child Emotion Regulation, and Child Socioemotional Functioning in Urban India

ERIC Educational Resources Information Center

Raval, Vaishali V.; Raval, Pratiksha H.; Deo, Neeraj

2014-01-01

Studies examining the link between parental socialization and child functioning in varying cultural contexts are scarce. Focusing on early adolescents in suburban middle-class families in India, the present study examined interrelations among reports of mothers' socialization goals, socialization behaviors in response to child emotion, child…

Patterns of Adolescents' Participation in Organized Activities: Are Sports Best when Combined with Other Activities?

ERIC Educational Resources Information Center

Linver, Miriam R.; Roth, Jodie L.; Brooks-Gunn, Jeanne

2009-01-01

Although many adolescents participate in sports and other types of organized activities, little extant research explores how youth development outcomes may vary for youth involved in different combinations of activities. The present study uses the Child Development Supplement of the Panel Study of Income Dynamics, a large, nationally…

Shiga toxin-producing Escherichia coli in meat: a preliminary simulation study on detection capabilities for three sampling methods

USDA-ARS?s Scientific Manuscript database

The objective of this simulation study is to determine which sampling method (Cozzini core sampler, core drill shaving, and N-60 surface excision) will better detect Shiga Toxin-producing Escherichia coli (STEC) at varying levels of contamination when present in the meat. 1000 simulated experiments...

Consumer Acceptance of Population-Level Intervention Strategies for Healthy Food Choices: The Role of Perceived Effectiveness and Perceived Fairness.

PubMed

Bos, Colin; Lans, Ivo Van Der; Van Rijnsoever, Frank; Van Trijp, Hans

2015-09-15

The present study investigates acceptance of intervention strategies for low-calorie snack choices that vary regarding the effect they have on consumers' freedom of choice (providing information, guiding choice through (dis)incentives, and restricting choice). We examine the mediating effects of perceived effectiveness and perceived fairness, and the moderating effects of barriers to choose low-calorie snacks and perceived responsibility for food choice. Data was collected through an online survey, involving three waves that were completed over a seven week timespan. Information was collected on barriers and perceived responsibility, and evaluations of a total of 128 intervention strategies with varying levels of intrusiveness that were further systematically varied in terms of source, location, approach/avoidance, type, and severity. A total of 1173 respondents completed all three waves. We found that the effect of intervention intrusiveness on acceptance was mediated by the perceived personal- and societal effectiveness, and the perceived fairness of interventions. For barriers and perceived responsibility, only main effects on intervention-specific beliefs were found. Government interventions were accepted less than interventions by food manufacturers. In conclusion, the present study shows that acceptance of interventions depends on perceptions of personal- and societal effectiveness and fairness, thereby providing novel starting points for increasing acceptance of both existing and new food choice interventions.

Hierarchical Spatio-temporal Visual Analysis of Cluster Evolution in Electrocorticography Data

DOE PAGES

Murugesan, Sugeerth; Bouchard, Kristofer; Chang, Edward; ...

2016-10-02

Here, we present ECoG ClusterFlow, a novel interactive visual analysis tool for the exploration of high-resolution Electrocorticography (ECoG) data. Our system detects and visualizes dynamic high-level structures, such as communities, using the time-varying spatial connectivity network derived from the high-resolution ECoG data. ECoG ClusterFlow provides a multi-scale visualization of the spatio-temporal patterns underlying the time-varying communities using two views: 1) an overview summarizing the evolution of clusters over time and 2) a hierarchical glyph-based technique that uses data aggregation and small multiples techniques to visualize the propagation of clusters in their spatial domain. ECoG ClusterFlow makes it possible 1) tomore » compare the spatio-temporal evolution patterns across various time intervals, 2) to compare the temporal information at varying levels of granularity, and 3) to investigate the evolution of spatial patterns without occluding the spatial context information. Lastly, we present case studies done in collaboration with neuroscientists on our team for both simulated and real epileptic seizure data aimed at evaluating the effectiveness of our approach.« less

Joint optimization of green vehicle scheduling and routing problem with time-varying speeds

PubMed Central

Zhang, Dezhi; Wang, Xin; Ni, Nan; Zhang, Zhuo

2018-01-01

Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO2 emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO2 emissions and the optimal departure time saves on fuel consumption and reduces CO2 emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions. PMID:29466370

Longitudinal Mediation Analysis with Time-varying Mediators and Exposures, with Application to Survival Outcomes

PubMed Central

Zheng, Wenjing; van der Laan, Mark

2017-01-01

In this paper, we study the effect of a time-varying exposure mediated by a time-varying intermediate variable. We consider general longitudinal settings, including survival outcomes. At a given time point, the exposure and mediator of interest are influenced by past covariates, mediators and exposures, and affect future covariates, mediators and exposures. Right censoring, if present, occurs in response to past history. To address the challenges in mediation analysis that are unique to these settings, we propose a formulation in terms of random interventions based on conditional distributions for the mediator. This formulation, in particular, allows for well-defined natural direct and indirect effects in the survival setting, and natural decomposition of the standard total effect. Upon establishing identifiability and the corresponding statistical estimands, we derive the efficient influence curves and establish their robustness properties. Applying Targeted Maximum Likelihood Estimation, we use these efficient influence curves to construct multiply robust and efficient estimators. We also present an inverse probability weighted estimator and a nested non-targeted substitution estimator for these parameters. PMID:29387520

An investigation of messy genetic algorithms

NASA Technical Reports Server (NTRS)

Goldberg, David E.; Deb, Kalyanmoy; Korb, Bradley

1990-01-01

Genetic algorithms (GAs) are search procedures based on the mechanics of natural selection and natural genetics. They combine the use of string codings or artificial chromosomes and populations with the selective and juxtapositional power of reproduction and recombination to motivate a surprisingly powerful search heuristic in many problems. Despite their empirical success, there has been a long standing objection to the use of GAs in arbitrarily difficult problems. A new approach was launched. Results to a 30-bit, order-three-deception problem were obtained using a new type of genetic algorithm called a messy genetic algorithm (mGAs). Messy genetic algorithms combine the use of variable-length strings, a two-phase selection scheme, and messy genetic operators to effect a solution to the fixed-coding problem of standard simple GAs. The results of the study of mGAs in problems with nonuniform subfunction scale and size are presented. The mGA approach is summarized, both its operation and the theory of its use. Experiments on problems of varying scale, varying building-block size, and combined varying scale and size are presented.

Joint optimization of green vehicle scheduling and routing problem with time-varying speeds.

PubMed

Zhang, Dezhi; Wang, Xin; Li, Shuangyan; Ni, Nan; Zhang, Zhuo

2018-01-01

Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO2 emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO2 emissions and the optimal departure time saves on fuel consumption and reduces CO2 emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions.

The role of word order in the interpretation of canonical and non-canonical graphic symbol utterances: A developmental study.

PubMed

Trudeau, Natacha; Morford, Jill P; Sutton, Ann

2010-06-01

Graphic symbols are often used to represent words in Augmentative and Alternative Communication systems. Previous findings suggest that different processes operate when using graphic symbols and when using speech. This study assessed the ability of native speakers of French with no communication disorders from four age groups to interpret graphic-symbol sequences of varying length and canonicity. Results reveal that, as they get older, participants show an increase in their capacity to interpret graphic-symbol sequences. Constituent order played an important role in the interpretation of the sequences. However, the specific word-order strategies used varied depending on the age group and the type of sequence presented.

Modeling information diffusion in time-varying community networks

NASA Astrophysics Data System (ADS)

Cui, Xuelian; Zhao, Narisa

2017-12-01

Social networks are rarely static, and they typically have time-varying network topologies. A great number of studies have modeled temporal networks and explored social contagion processes within these models; however, few of these studies have considered community structure variations. In this paper, we present a study of how the time-varying property of a modular structure influences the information dissemination. First, we propose a continuous-time Markov model of information diffusion where two parameters, mobility rate and community attractiveness, are introduced to address the time-varying nature of the community structure. The basic reproduction number is derived, and the accuracy of this model is evaluated by comparing the simulation and theoretical results. Furthermore, numerical results illustrate that generally both the mobility rate and community attractiveness significantly promote the information diffusion process, especially in the initial outbreak stage. Moreover, the strength of this promotion effect is much stronger when the modularity is higher. Counterintuitively, it is found that when all communities have the same attractiveness, social mobility no longer accelerates the diffusion process. In addition, we show that the local spreading in the advantage group has been greatly enhanced due to the agglomeration effect caused by the social mobility and community attractiveness difference, which thus increases the global spreading.

Effect of Free Stream Turbulence on Flow Past a Circular Cylinder at Low Reynolds Numbers

NASA Astrophysics Data System (ADS)

Kumar, Vinoth; Singh, Mrityunjay; Thangadurai, Murugan; Chatterjee, P. K.

2018-01-01

Circular cylinders experiencing different upstream flow conditions have been studied for low Reynolds numbers using hot-wire anemometry and smoke flow visualizations. The upstream condition of the cylinder in the test section is varied using a wire mesh placed at the entrance of the test section. The Reynolds number is varied by varying the diameter of the cylinder and the mean velocity in the test section. Smooth cylinders of diameter varying from 1.25 to 25 mm are used in the present study. A multi-channel hot-wire anemometry is used for measuring the fluctuating velocities in the test section and the wake behind the cylinder. The sectional views of the wake behind the cylinder are obtained using a 4 MP CCD camera, 200 mJ pulsed laser and a fog generator. The flow quality in the test section is examined using higher order turbulence statistics. The effect of free stream turbulence levels and their frequencies on wake structures and the shedding frequencies of circular cylinders are studied in detail. It has been observed that the alteration in wake structure and the shedding frequency depend strongly on the frequencies and the amplitudes of upstream disturbances besides the diameter of the circular cylinder.

Poster exhibitions at conferences: are we doing it properly?

PubMed

Beamish, Andrew J; Ansell, James; Foster, Jessica J; Foster, Kathryn A; Egan, Richard J

2015-01-01

Literature exploring the educational value and quality of conference poster presentation is scarce. The aim of this study was to identify and describe the variation in poster exhibitions across a spectrum of conferences attended by trainees. Prospective observational assessment of conference posters was carried out across 7 variables at 4 conferences attended by surgical trainees in 2012. Posters were compared by individual variables and according to overall poster score combining all 7 variables examined. The number of authors listed was also compared. Random samples of consecutively numbered posters were examined at the exhibitions of 4 conferences, which included a UK national medical education conference (Association for the Study of Medical Education), a UK international surgical conference (Association of Surgeons of Great Britain and Ireland), a European oncology conference (European Society of Surgical Oncology), and a North American joint medical and surgical conference (Digestive Diseases Week). Significant variation existed between conferences in posters and their presentation. The proportion of presenters failing to display their posters ranged from 3% to 26% (p < 0.0001). Adherence to size guidelines varied from 89% to 100% (p = 0.002). The inclusion of references ranged from 19% to 82% (p < 0.0001). The presence of a presenting author during the allocated session varied widely from 21% to 86% (p < 0.0001). No significant variation was observed in the proportion of posters that were formatted using aims, methods, results, and conclusion sections (81%-93%; p = 0.513) or in the proportion of posters that were identified as difficult to read (24%-28%; p = 0.919). Association for the Study of Medical Education outperformed each of the other exhibitions overall (p < 0.0001). Posters with greater than the median of 4 authors performed significantly better across all areas (p < 0.0001-0.042) except presenter attendance (p = 0.480). Poster exhibitions varied widely, with room for improvement at all 4 conferences. Lessons can be learned by all conferences from each other to improve presenter engagement with and the educational value of poster exhibitions. Copyright © 2014 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Upper Elementary Reading Instruction in the Age of Accountability: Balancing Best Practices with Pressures to Achieve on High-Stakes Tests

ERIC Educational Resources Information Center

Saunders, Christina Henry

2017-01-01

The present study identifies reading instructional practices used in upper elementary classrooms during the age of high-stakes test accountability and compares reading practices among schools of varying accreditation status and socio-economic status (SES). The current study partially replicates and extends a study conducted by Baumann, Hoffman,…

MIXING RATIO INFLUENCES HALOACETIC ACID (HAA) MIXTURE TOXICITY

EPA Science Inventory

Mixtures of the same type (for example, disinfection byproduct mixtures) often contain the same chemicals, but at varying concentrations. The objective of the present study was to examine the influence of mixing ratio (the concentrations of chemicals relative to one another) on ...

Sample size adjustments for varying cluster sizes in cluster randomized trials with binary outcomes analyzed with second-order PQL mixed logistic regression.

PubMed

Candel, Math J J M; Van Breukelen, Gerard J P

2010-06-30

Adjustments of sample size formulas are given for varying cluster sizes in cluster randomized trials with a binary outcome when testing the treatment effect with mixed effects logistic regression using second-order penalized quasi-likelihood estimation (PQL). Starting from first-order marginal quasi-likelihood (MQL) estimation of the treatment effect, the asymptotic relative efficiency of unequal versus equal cluster sizes is derived. A Monte Carlo simulation study shows this asymptotic relative efficiency to be rather accurate for realistic sample sizes, when employing second-order PQL. An approximate, simpler formula is presented to estimate the efficiency loss due to varying cluster sizes when planning a trial. In many cases sampling 14 per cent more clusters is sufficient to repair the efficiency loss due to varying cluster sizes. Since current closed-form formulas for sample size calculation are based on first-order MQL, planning a trial also requires a conversion factor to obtain the variance of the second-order PQL estimator. In a second Monte Carlo study, this conversion factor turned out to be 1.25 at most. (c) 2010 John Wiley & Sons, Ltd.

Modeling the time--varying subjective quality of HTTP video streams with rate adaptations.

PubMed

Chen, Chao; Choi, Lark Kwon; de Veciana, Gustavo; Caramanis, Constantine; Heath, Robert W; Bovik, Alan C

2014-05-01

Newly developed hypertext transfer protocol (HTTP)-based video streaming technologies enable flexible rate-adaptation under varying channel conditions. Accurately predicting the users' quality of experience (QoE) for rate-adaptive HTTP video streams is thus critical to achieve efficiency. An important aspect of understanding and modeling QoE is predicting the up-to-the-moment subjective quality of a video as it is played, which is difficult due to hysteresis effects and nonlinearities in human behavioral responses. This paper presents a Hammerstein-Wiener model for predicting the time-varying subjective quality (TVSQ) of rate-adaptive videos. To collect data for model parameterization and validation, a database of longer duration videos with time-varying distortions was built and the TVSQs of the videos were measured in a large-scale subjective study. The proposed method is able to reliably predict the TVSQ of rate adaptive videos. Since the Hammerstein-Wiener model has a very simple structure, the proposed method is suitable for online TVSQ prediction in HTTP-based streaming.

What Makes for Successful Speaker-Listener Technique? Two Case Studies

ERIC Educational Resources Information Center

Wood, Mary R.

2010-01-01

This article reviews some of the controversy surrounding the use and effectiveness of active listening or the Speaker-Listener Technique (SL) in relational counseling. The purpose and function of SL is described and two case studies are presented to illustrate how SL operates in a therapeutic setting and how the outcomes can vary. These case…

The Effects of Television Advertising on Children. Report No. 2: Second Year Experimental Evidence. Final Report.

ERIC Educational Resources Information Center

Atkin, Charles K.

This report, the second in a series of six reports on television advertising and children, presents the results from a series of experimental studies designed to test children's intentional and incidental learning from television commercials. A total of 400 elementary school students of varying socioeconomic status participated in the study, with…

The Effect of Bullying and Victimization on Cognitive Empathy Development during the Transition to Middle School

ERIC Educational Resources Information Center

Williford, Anne; Boulton, Aaron J.; Forrest-Bank, Shandra S.; Bender, Kimberly A.; Dieterich, William A.; Jenson, Jeffrey M.

2016-01-01

Background: Interventions aimed at reducing bullying behavior commonly target the development of empathy. Yet, few longitudinal studies have investigated how empathy levels vary with bullying and victimization over time, especially during the transition to middle school. Objective: To that end, the purpose of the present study was to: (1) examine…

Applied vs Basic Research: On Maintaining Your Balance with a Foot in Each Camp.

ERIC Educational Resources Information Center

Martin, David W.

The paper discusses a number of issues concerning the practical usefulness of cognitive psychology research, and presents a case study of pilot training methods to illustrate a model of research processes that produces outcomes which contribute to both basic and applied research goals. Research studies are described as varying in the degree to…

Historical Thinking Ability among Talented Math and Science Students: An Exploratory Study.

ERIC Educational Resources Information Center

Fehn, Bruce

This study sought to discern the extent to which a sample of talented math and science students displayed domain-relevant skills possessed by those expertly trained in history. Subjects' experiences varied in terms of their exposure to primary source materials. The students were presented with five different kinds of documents related to the…

Model versus Military Pilot: A Mixed-Methods Study of Adolescents' Attitudes toward Women in Varied Occupations

ERIC Educational Resources Information Center

Daniels, Elizabeth A.; Sherman, Aurora M.

2016-01-01

Using an experimental methodology, the present study investigated adolescents' attitudes toward media images of women in non-appearance-focused (CEO and military pilot) and appearance-focused occupations (model and actor). One hundred adolescent girls and 76 adolescent boys provided ratings of likability, competence, and similarity to self after…

Identifiability and Accessibility in Learning Definite Article Usages: A Quasi-Experimental Study with Japanese Learners of English

ERIC Educational Resources Information Center

Hinenoya, Kimiko; Lyster, Roy

2015-01-01

The present study investigated the effects of instruction on the use of the definite article "the" by Japanese learners of English by implementing two instructional treatments that varied in the extent to which they emphasized identifiability and accessibility. One instructional treatment, referred to as the traditional (TR) treatment,…

Is Overall Oral English Ability Related to Young Latinos' English Reading Growth?

ERIC Educational Resources Information Center

Fitzgerald, Jill; Amendum, Steven J.; Relyea, Jackie Eunjung; Garcia, Sandra G.

2015-01-01

The present study investigated whether young Latino dual-language learners' 2-year English reading growth varied over time according to their initial overall oral English ability. We followed 41 Latino children for 2 years. We tested overall oral English at the beginning of the study and administered multiple curriculum-based reading assessments…

Therapeutic Interpersonal Behavior in the Crisis Situation: An Empirical Study of Coping Responses.

ERIC Educational Resources Information Center

DeWine, Sue; Alderton, Steven

Research in crisis intervention has prescribed how trained but non-professional individuals should and do act in a crisis situation. The present study, however, focused on the types of responses untrained helpers use to respond to the crisis of another individual. Results indicate that types of responses vary significantly, with probing and…

The Investigation of Peer Assessment in Primary School Cooperative Learning Groups with Respect to Gender

ERIC Educational Resources Information Center

Yurdabakan, Irfan

2011-01-01

There are studies especially at higher education level investigating the subsequent responses of students towards reciprocity, tacit agreement and assessment of peers, but research on the effect of gender on peer assessment is limited. The present study focuses on whether peer assessment used in cooperative learning groups varies with respect to…

Can false memories be created through nonconscious processes?

PubMed

Zeelenberg, René; Plomp, Gijs; Raaijmakers, Jeroen G W

2003-09-01

Presentation times of study words presented in the Deese/Roediger and McDermott (DRM) paradigm varied from 20 to 2000 ms per word in an attempt to replicate the false memory effect following extremely short presentations reported by. Both in a within-subjects design (Experiment 1) and in a between-subjects design (Experiment 2) subjects showed memory for studied words as well as a false memory effect for related critical lures in the 2000-ms condition. However, in the conditions with shorter presentation times (20 ms in Experiment 1; 20 and 40 ms in Experiment 2) no memory for studied words, nor a false memory effect was found. We argue that there is at present no strong evidence supporting the claim for a nonconscious basis of the false memory effect.

Education Level of Catholic Hispanic Deacons

ERIC Educational Resources Information Center

Ferrari, Joseph R.

2016-01-01

The present study assessed self-reported religiosity, spirituality, faith-related behaviors, leadership styles, and personality dimensions of 156 Hispanic Catholic deacons, based on varied educational degrees assisting in Hispanic (n = 91) or non-Hispanic (n = 65) parishes. Results found no significant differences on any self-reported variables…

Effects of boron addition on a-Si(90)Ge(10):H films obtained by low frequency plasma enhanced chemical vapour deposition.

PubMed

Pérez, Arllene M; Renero, Francisco J; Zúñiga, Carlos; Torres, Alfonso; Santiago, César

2005-06-29

Optical, structural and electric properties of (a-(Si(90)Ge(10))(1-y)B(y):H) thin film alloys, deposited by low frequency plasma enhanced chemical vapour deposition, are presented. The chemical bonding structure has been studied by IR spectroscopy, while the composition was investigated by Raman spectroscopy. A discussion about boron doping effects, in the composition and bonding of samples, is presented. Transport of carriers has been studied by measurement of the conductivity dependence on temperature, which increases from 10(-3) to 10(1) Ω(-1) cm(-1) when the boron content varies from 0 to 50%. Similarly, the activation energy is between 0.62 and 0.19 eV when the doping increases from 0 to 83%. The optical properties have been determined from the film's optical transmission, using Swanepoel's method. It is shown that the optical gap varies from 1.3 to 0.99 eV.

Measurement of radon exhalation rate in various building materials and soil samples

NASA Astrophysics Data System (ADS)

Bala, Pankaj; Kumar, Vinod; Mehra, Rohit

2017-03-01

Indoor radon is considered as one of the potential dangerous radioactive elements. Common building materials and soil are the major source of this radon gas in the indoor environment. In the present study, the measurement of radon exhalation rate in the soil and building material samples of Una and Hamirpur districts of Himachal Pradesh has been done with solid state alpha track detectors, LR-115 type-II plastic track detectors. The radon exhalation rate for the soil samples varies from 39.1 to 91.2 mBq kg-1 h-1 with a mean value 59.7 mBq kg-1 h-1. Also the radium concentration of the studied area is found and it varies from 30.6 to 51.9 Bq kg-1 with a mean value 41.6 Bq kg-1. The exhalation rate for the building material samples varies from 40.72 (sandstone) to 81.40 mBq kg-1 h-1 (granite) with a mean value of 59.94 mBq kg-1 h-1.

Duration of stimulus presentation and screening for perceptual disabilities.

PubMed

Rohr, M E; Ayers, J B

1975-02-01

This study examined the effects of increasing the stimulus-presentation time of a motion picture test for identifying perceptual disabilities in the performance of Ss in regular first and fourth grade classrooms and on a sample of Ss in special education classes who had been identified as having varying degrees of perceptual deficiencies. The length of stimulus presentation increased the total performance of Ss on the motion picture test but did not add to the value of the instrument as a screening device.

A comparison of time-varying covariates in two smoking cessation interventions for cardiac patients.

PubMed

Prenger, Rilana; Pieterse, Marcel E; Braakman-Jansen, Louise M A; Bolman, Catherine; de Vries, Hein; Wiggers, Loes C W

2013-04-01

The aim of the study was to explore the time-varying contribution of social cognitive determinants of smoking cessation following an intervention on cessation. Secondary analyses were performed on data from two comparable randomized controlled trials on brief smoking cessation interventions for cardiac in- and outpatients. Cox regression with time-varying covariates was applied to examine the predictive cognitions for smoking cessation over time. Both samples showed self-efficacy and intention-to-quit to be strong time-varying indicators of smoking cessation during the full 1-year follow-up period, and during the post-treatment phase in particular. Less consistently, time-varying cons of quitting and social influence were also found to be associated with smoking cessation, depending on the sample and type of intervention. Self-efficacy and intention-to-quit were the major covariates and positively related to smoking cessation over time among cardiac patients, in line with social-cognitive theories. Interestingly, both cognitive constructs appeared to act with some delay. Apparently, smoking cessation is a lengthy process in which the interplay between self-efficacy (and intention indirectly) and quitting behavior will largely determine long-term maintenance of abstinence. The presented time-varying analyses seem a valid and feasible way to underpin trajectories of cognitions in datasets with a limited number of time intervals.

A life cycle cost economics model for automation projects with uniformly varying operating costs. [applied to Deep Space Network and Air Force Systems Command

NASA Technical Reports Server (NTRS)

Remer, D. S.

1977-01-01

The described mathematical model calculates life-cycle costs for projects with operating costs increasing or decreasing linearly with time. The cost factors involved in the life-cycle cost are considered, and the errors resulting from the assumption of constant rather than uniformly varying operating costs are examined. Parameters in the study range from 2 to 30 years, for project life; 0 to 15% per year, for interest rate; and 5 to 90% of the initial operating cost, for the operating cost gradient. A numerical example is presented.

The effects of nuclear magnetic resonance on patients with cardiac pacemakers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavlicek, W.; Geisinger, M.; Castle, L.

1983-04-01

The effect of nuclear magnetic resonance (NMR) imaging on six representative cardiac pacemakers was studied. The results indicate that the threshold for initiating the asynchronous mode of a pacemaker is 17 gauss. Radiofrequency levels are present in an NMR unit and may confuse or possibly inhibit demand pacemakers, although sensing circuitry is normally provided with electromagnetic interference discrimination. Time-varying magnetic fields can generate pulse amplitudes and frequencies to mimic cardiac activity. A serious limitation in the possibility of imaging a patient with a pacemaker would be the alteration of normal pulsing parameters due to time-varying magnetic fields.

Experimental Study of the Influence of Speed and Load on Thermal Behavior of High-Speed Helical Gear Trains

NASA Technical Reports Server (NTRS)

Handschuh, R.; Kilmain, C.

2005-01-01

An experimental effort has been conducted on an aerospace-quality helical gear train to investigate the thermal behavior of the gear system as speed, load, and lubricant flow rate were varied. Temperature test data from a helical gear train at varying speeds and loads (to 5000 hp and 15000 rpm) was collected using thermocouple rakes and axial arrays. The instrumentation was able to capture the radial and axial expelled lubricant-air environment (fling-off lubricant) that is expelled during the gear meshing process. Effects of operational characteristics are presented.

Effects of turbine cooling assumptions on performance and sizing of high-speed civil transport

NASA Technical Reports Server (NTRS)

Senick, Paul F.

1992-01-01

The analytical study presented examines the effects of varying turbine cooling assumptions on the performance of a high speed civil transport propulsion system as well as the sizing sensitivity of this aircraft to these performance variations. The propulsion concept employed in this study was a two spool, variable cycle engine with a sea level thrust of 55,000 lbf. The aircraft used for this study was a 250 passenger vehicle with a cruise Mach number of 2.4 and 5000 nautical mile range. The differences in turbine cooling assumptions were represented by varying the amount of high pressure compressor bleed air used to cool the turbines. It was found that as this cooling amount increased, engine size and weight increased, but specific fuel consumption (SFC) decreased at takeoff and climb only. Because most time is spent at cruise, the SFC advantage of the higher bleed engines seen during subsonic flight was minimized and the lower bleed, lighter engines led to the lowest takeoff gross weight vehicles. Finally, the change in aircraft takeoff gross weight versus turbine cooling level is presented.

Higher Dimensional Meta-State Analysis Reveals Reduced Resting fMRI Connectivity Dynamism in Schizophrenia Patients.

PubMed

Miller, Robyn L; Yaesoubi, Maziar; Turner, Jessica A; Mathalon, Daniel; Preda, Adrian; Pearlson, Godfrey; Adali, Tulay; Calhoun, Vince D

2016-01-01

Resting-state functional brain imaging studies of network connectivity have long assumed that functional connections are stationary on the timescale of a typical scan. Interest in moving beyond this simplifying assumption has emerged only recently. The great hope is that training the right lens on time-varying properties of whole-brain network connectivity will shed additional light on previously concealed brain activation patterns characteristic of serious neurological or psychiatric disorders. We present evidence that multiple explicitly dynamical properties of time-varying whole-brain network connectivity are strongly associated with schizophrenia, a complex mental illness whose symptomatic presentation can vary enormously across subjects. As with so much brain-imaging research, a central challenge for dynamic network connectivity lies in determining transformations of the data that both reduce its dimensionality and expose features that are strongly predictive of important population characteristics. Our paper introduces an elegant, simple method of reducing and organizing data around which a large constellation of mutually informative and intuitive dynamical analyses can be performed. This framework combines a discrete multidimensional data-driven representation of connectivity space with four core dynamism measures computed from large-scale properties of each subject's trajectory, ie., properties not identifiable with any specific moment in time and therefore reasonable to employ in settings lacking inter-subject time-alignment, such as resting-state functional imaging studies. Our analysis exposes pronounced differences between schizophrenia patients (Nsz = 151) and healthy controls (Nhc = 163). Time-varying whole-brain network connectivity patterns are found to be markedly less dynamically active in schizophrenia patients, an effect that is even more pronounced in patients with high levels of hallucinatory behavior. To the best of our knowledge this is the first demonstration that high-level dynamic properties of whole-brain connectivity, generic enough to be commensurable under many decompositions of time-varying connectivity data, exhibit robust and systematic differences between schizophrenia patients and healthy controls.

Higher Dimensional Meta-State Analysis Reveals Reduced Resting fMRI Connectivity Dynamism in Schizophrenia Patients

PubMed Central

Miller, Robyn L.; Yaesoubi, Maziar; Turner, Jessica A.; Mathalon, Daniel; Preda, Adrian; Pearlson, Godfrey; Adali, Tulay; Calhoun, Vince D.

2016-01-01

Resting-state functional brain imaging studies of network connectivity have long assumed that functional connections are stationary on the timescale of a typical scan. Interest in moving beyond this simplifying assumption has emerged only recently. The great hope is that training the right lens on time-varying properties of whole-brain network connectivity will shed additional light on previously concealed brain activation patterns characteristic of serious neurological or psychiatric disorders. We present evidence that multiple explicitly dynamical properties of time-varying whole-brain network connectivity are strongly associated with schizophrenia, a complex mental illness whose symptomatic presentation can vary enormously across subjects. As with so much brain-imaging research, a central challenge for dynamic network connectivity lies in determining transformations of the data that both reduce its dimensionality and expose features that are strongly predictive of important population characteristics. Our paper introduces an elegant, simple method of reducing and organizing data around which a large constellation of mutually informative and intuitive dynamical analyses can be performed. This framework combines a discrete multidimensional data-driven representation of connectivity space with four core dynamism measures computed from large-scale properties of each subject’s trajectory, ie., properties not identifiable with any specific moment in time and therefore reasonable to employ in settings lacking inter-subject time-alignment, such as resting-state functional imaging studies. Our analysis exposes pronounced differences between schizophrenia patients (Nsz = 151) and healthy controls (Nhc = 163). Time-varying whole-brain network connectivity patterns are found to be markedly less dynamically active in schizophrenia patients, an effect that is even more pronounced in patients with high levels of hallucinatory behavior. To the best of our knowledge this is the first demonstration that high-level dynamic properties of whole-brain connectivity, generic enough to be commensurable under many decompositions of time-varying connectivity data, exhibit robust and systematic differences between schizophrenia patients and healthy controls. PMID:26981625

A numerical simulation of finite-length Taylor-Couette flow

NASA Technical Reports Server (NTRS)

Streett, C. L.; Hussaini, M. Y.

1988-01-01

Results from numerical simulations of finite-length Taylor-Couette flow are presented. Included are time-accurate and steady-state studies of the change in the nature of the symmetric two-cell/asymmetric one-cell bifurcation with varying aspect ratio and of the Reynolds number/aspect ratio locus of the two-cell/four-cell bifurcation. Preliminary results from wavy-vortex simulations at low aspect ratios are also presented.

Mind Games: Setting Conditions for Successful Counterinsurgency Military Information Support Operations

DTIC Science & Technology

2010-12-01

conflicts that relied primarily on mass media , the face-to-face communication relied upon to conduct counter-oathing, and thus, pseudo gang operations...has been studied at varying levels by numerous investigators over the decades. While many civilian applications like marketing and mass media have...cultural-drama teams that presented pro-government performances in rural villages.89 This effort not only reinforced mass media appeals presented in

Dynamic behavior of a magnetic bearing supported jet engine rotor with auxiliary bearings

NASA Technical Reports Server (NTRS)

Homaifar, Abdollah (Editor); Kelly, John C., Jr. (Editor); Flowers, G. T.; Xie, H.; Sinha, S. C.

1994-01-01

This paper presents a study of the dynamic behavior of a rotor system supported by auxiliary bearings. The steady-state behavior of a simulation model based upon a production jet engine is explored over a wide range of operating conditions for varying rotor imbalance, support stiffness and damping. Interesting dynamical phenomena, such as chaos, subharmonic responses, and double-valued responses, are presented and discussed.

Dynamic behavior of a magnetic bearing supported jet engine rotor with auxiliary bearings

NASA Technical Reports Server (NTRS)

Flowers, George T.; Xie, Huajun; Sinha, S. C.

1995-01-01

This paper presents a study of the dynamic behavior of a rotor system supported by auxiliary bearings. The steady-state behavior of a simulation model based upon a production jet engine is explored over a wide range of operating conditions for varying rotor imbalance, support stiffness, and damping. Interesting dynamical phenomena, such as chaos, subharmonic responses, and double-valued responses, are presented and discussed.

Nine children over the age of one year with full trisomy 13: a case series describing medical conditions.

PubMed

Bruns, Deborah A; Campbell, Emily

2014-12-01

Trisomy 13 (Patau syndrome), identified by Patau and colleagues [1960; Lancet 1: 790-793] is the third most common autosomal condition. Population studies indicate less than one in 10 children reaches their first birthday. In the face of mixed findings and recommendations for treatment, additional research is needed to further determine what contributes to longevity and implications for treatment for presenting medical conditions. The purpose of the present study is to report on presenting medical conditions and the presence or absence of the specific conditions (age at survey completion). Data on nine survivors (seven female, two male) with trisomy 13 indicated mean gestational age of approximately 36 weeks, birth weight ranging from 1100 to 3290 g and mean length of 45.3 cm. Length of hospital stay after birth varied. The majority of infants presented with well-known physical characteristics. Medical conditions and their treatment varied at birth and at survey completion. Notably, several infants' cardiac anomalies resolved without surgical intervention. Surgeries were provided for a range of conditions including gastrostomy tube placement to address feeding issues and removal of intestinal blockage. There were no reports of holoprosencephaly. Implications and recommendations are provided. © 2014 Wiley Periodicals, Inc.

Varied morphology carbon nanotubes and method for their manufacture

DOEpatents

Li, Wenzhi; Wen, Jian Guo; Ren, Zhi Feng

2007-01-02

The present invention describes the preparation of carbon nanotubes of varied morphology, catalyst materials for their synthesis. The present invention also describes reactor apparatus and methods of optimizing and controlling process parameters for the manufacture carbon nanotubes with pre-determined morphologies in relatively high purity and in high yields. In particular, the present invention provides methods for the preparation of non-aligned carbon nanotubes with controllable morphologies, catalyst materials and methods for their manufacture.

The Timing of Multiple Retrieval Events Can Alter GluR1 Phosphorylation and the Requirement for Protein Synthesis in Fear Memory Reconsolidation

ERIC Educational Resources Information Center

Jarome, Timothy J.; Kwapis, Janine L.; Werner, Craig T.; Parsons, Ryan G.; Gafford, Georgette M.; Helmstetter, Fred J.

2012-01-01

Numerous studies have indicated that maintaining a fear memory after retrieval requires de novo protein synthesis. However, no study to date has examined how the temporal dynamics of repeated retrieval events affect this protein synthesis requirement. The present study varied the timing of a second retrieval of an established auditory fear memory…

Performance Study of Chromium (VI) Removal in Presence of Phenol in a Continuous Packed Bed Reactor by Escherichia coli Isolated from East Calcutta Wetlands

PubMed Central

Chakraborty, Bhaswati; Indra, Suvendu; Hazra, Ditipriya; Betai, Rupal; Ray, Lalitagauri; Basu, Srabanti

2013-01-01

Organic pollutants, like phenol, along with heavy metals, like chromium, are present in various industrial effluents that pose serious health hazard to humans. The present study looked at removal of chromium (VI) in presence of phenol in a counter-current continuous packed bed reactor packed with E. coli cells immobilized on clay chips. The cells removed 85% of 500 mg/L of chromium (VI) from MS media containing glucose. Glucose was then replaced by 500 mg/L phenol. Temperature and pH of the MS media prior to addition of phenol were 30°C and 7, respectively. Hydraulic retention times of phenol- and chromium (VI)-containing synthetic media and air flow rates were varied to study the removal efficiency of the reactor system. Then temperature conditions of the reactor system were varied from 10°C to 50°C, the optimum being 30°C. The pH of the media was varied from pH 1 to pH 12, and the optimum pH was found to be 7. The maximum removal efficiency of 77.7% was achieved for synthetic media containing phenol and chromium (VI) in the continuous reactor system at optimized conditions, namely, hydraulic retention time at 4.44 hr, air flow rate at 2.5 lpm, temperature at 30°C, and pH at 7. PMID:24073400

An Apparatus for Varying Effective Dihedral in Flight with Application to a Study of Tolerable Dihedral on a Conventional Fighter Airplane

NASA Technical Reports Server (NTRS)

Kauffman, William M; Liddell, Charles J , Jr; Smith, Allan; Van Dyke, Rudolph D , Jr

1949-01-01

An apparatus for varying effective dihedral in flight by means of servo actuation of the ailerons in response to sideslip angle is described. The results of brief flight tests of the apparatus on a conventional fighter airplane are presented and discussed. The apparatus is shown to have satisfactory simulated a wide range of effective dihedral under static and dynamic conditions. The effects of a small amount of servo lag are shown to be measurable when the apparatus is simulating small negative values of dihedral. However, these effects were not considered by the pilots to give the airplane an artificial feel. The results of an investigation employing the apparatus to determine the tolerable (safe for normal fighter operation) range of effective dihedral on the test airplane are presented.

Impact of Low-Level Thyroid Hormone Disruption Induced by Propylthiouracil on Brain Development and Function.*

EPA Science Inventory

The critical role of thyroid hormone (TH) in brain development is well established, severe deficiencies leading to significant neurological dysfunction. Much less information is available on more modest perturbations of TH on brain function. The present study induced varying degr...

Regional Disparities in Educational Development: A Controversial Issue.

ERIC Educational Resources Information Center

Carron, Gabriel, Ed.; Chau, Ta Ngoc, Ed.

To complement a volume of case studies, these four papers and an introduction discuss the problem of regional disparities in educational development from several different perspectives. Varying points of view are presented on the relationship between regional educational disparities and socioeconomic, political, and cultural development; the…

Herbicide Dissipation Studies in Southern Forest Ecosystems

Treesearch

Jerry L. Michael; Daniel G. Neary

1993-01-01

Results of research on the movement of bexazinone, imazapyr, picloram, and sulfometuron in first-order watersheds in the southern United States are presented. Herbicides contaminate surface waters to varying degrees, depending on application rate, method of application, product formulation, and site-spezific characteristics. Highest concentrations are observed in...

Environmental Teaching in Higher Education

ERIC Educational Resources Information Center

Tarabula-Fiertak, Marta; Gajus-Lankamer, Ewa; Wojcik, Maria Anna

2004-01-01

The scope, form and task of environmental education in Polish universities varies depending on the course of studies and the specialisation. In this paper, models of environmental education in different types of universities as well as their effect on undergraduates' attitudes and knowledge are presented. The most comprehensive environmental…

Global Perspectives on Multilingualism: Unity in Diversity

ERIC Educational Resources Information Center

Torres-Guzman, Maria E., Ed.; Gomez, Joel, Ed.

2009-01-01

In this timely volume, international scholars examine how multilingual schooling is handled in schools across the world with a series of case studies from South Africa, Nigeria, Germany, Colombia, Slovakia, New Zealand, and Taiwan. Presenting new contributions arising from the varied contexts of multilingualism today, this collection urges…

Sensational Studies in Marine Science.

ERIC Educational Resources Information Center

Keller, E. C., Jr.; Schroyer, Fred C.

1981-01-01

Presents a description of a five-week summer course in marine biology and oceanography offered to college-bound, secondary students with varied physical handicaps. Summarizes insights gained after four summer sessions related to communication problems, physical arrangements for the wheelchair-bound, and handicap-proof maps; evaluates the course's…

Improving work zone safety for freight vehicles : effective design patterns for vehicle mounted attenuators.

DOT National Transportation Integrated Search

2010-12-01

This report presents a study of driver perceptions using a driving simulator carried out on the effectiveness of : four markings which vary in striping patterns and color combinations used at the rear of vehicle mounted : attenuators (VMAs) in work z...

Performance and operational improvements made to the Waukesha AT27-GL engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinbold, E.O.

1996-12-31

This paper presents the results of combustion and engine performance studies performed on the AT27GL lean burn engine. One study was to evaluate the effect of the pre-combustion chamber cup geometry on engine performance under several operating conditions including: Air-Fuel Ratio (AFR), ignition timing, and engine load. The study examined several combustion parameters; including IMEP, coefficient of variation of IMEP, heat release rates, and maximum combustion pressures. The study also examined engine thermal efficiency, and brake specific emissions of Oxides of Nitrogen, Carbon Monoxide, and Total Hydrocarbons (gaseous). Studies were also performed on different spark plug designs, comparing firing voltages,more » and electrode temperatures while operating under conditions of varying AFR, and ignition timing. In addition an Air-Fuel-Ratio controller was recently tested and released on the engine. The controller was tested under conditions of varying fuel quality, along with a detonation control system.« less

EXPERIMENTAL AND ANALYTICAL STUDIES OF REFLECTRO CONTROL FOR THE ADVANCED ENGINEERING TEST REACTOR. PART A. EXPERIMENTAL STUDIES WITH THE REFLECTOR CONTROL SYSTEM MODEL. PART B. ANALYTICAL STUDIES OF REFLECTOR CONTROL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertelson, P.C.; Francis, T.L.

1959-10-21

Studies of reflector control for the Advanced Engineering Test Reactor were made. The performance of various parts of the reflector control system model such as the safety reflector and the water jet educator, boric acid injection, and demineralizer systems is discussed. The experimental methods and results obtained are discussed. Four reflector control schemes were studied. The schemes were a single-region and three-region reflector schemes two separate reflectors, and two connected reflectors. Calculations were made of shim and safety reflector worth for a variety of parameters. Safety reflector thickness was varied from 7.75 to 0 inches, with and without boron. Boricmore » acid concentration was varied from 100 to 2% of saturation in the shim reflectors. Neutron flux plots are presented (C.J.G.)« less

ICASE/LaRC Symposium on Visualizing Time-Varying Data

NASA Technical Reports Server (NTRS)

Banks, D. C. (Editor); Crockett, T. W. (Editor); Stacy, K. (Editor)

1996-01-01

Time-varying datasets present difficult problems for both analysis and visualization. For example, the data may be terabytes in size, distributed across mass storage systems at several sites, with time scales ranging from femtoseconds to eons. In response to these challenges, ICASE and NASA Langley Research Center, in cooperation with ACM SIGGRAPH, organized the first symposium on visualizing time-varying data. The purpose was to bring the producers of time-varying data together with visualization specialists to assess open issues in the field, present new solutions, and encourage collaborative problem-solving. These proceedings contain the peer-reviewed papers which were presented at the symposium. They cover a broad range of topics, from methods for modeling and compressing data to systems for visualizing CFD simulations and World Wide Web traffic. Because the subject matter is inherently dynamic, a paper proceedings cannot adequately convey all aspects of the work. The accompanying video proceedings provide additional context for several of the papers.

The effect of prognostic data presentation format on perceived risk among surrogate decision makers of critically ill patients: a randomized comparative trial.

PubMed

Chapman, Andy R; Litton, Edward; Chamberlain, Jenny; Ho, Kwok M

2015-04-01

The purpose of this study is to determine whether varying the format used to present prognostic data alters the perception of risk among surrogate decision makers in the intensive care unit (ICU). This was a prospective randomized comparative trial conducted in a 23-bed adult tertiary ICU. Enrolled surrogate decision makers were randomized to 1 of 2 questionnaires, which presented hypothetical ICU scenarios, identical other than the format in which prognostic data were presented (eg, frequencies vs percentages). Participants were asked to rate the risk associated with each prognostic statement. We enrolled 141 surrogate decision makers. The perception of risk varied significantly dependent on the presentation format. For "quantitative data," risks were consistently perceived as higher, when presented as frequencies (eg, 1 in 50) compared with equivalent percentages (eg, 2%). Framing "qualitative data" in terms of chance of "death" rather than "survival" led to a statistically significant increase in perceived risks. Framing "quantitative" data in this way did not significantly affect risk perception. Data format had a significant effect on how surrogate decision makers interpreted risk. Qualitative statements are interpreted widely and affected by framing. Where possible, multiple quantitative formats should be used for presenting prognostic information. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Relation of Different Type Love-Shida Numbers Determined with the Use of Time-Varying Incremental Gravitational Potential

NASA Astrophysics Data System (ADS)

Varga, Peter; Grafarend, Erik; Engels, Johannes

2017-03-01

There are different equations to describe relations between different classes of Love-Shida numbers. In this study with the use of the time-varying gravitational potential an integral relation was obtained which connects tidal Love-Shida numbers (h, l, k), load numbers (h', l', k'), potential free Love-Shida numbers generated by normal (h″, l″, k″) and horizontal (h‴, l‴, k‴) stresses. The equations obtained in frame of present study is the only one which - holds for every type of Love-Shida numbers, - describes a relationship not between different, but the same type of Love-Shida numbers, - does not follow from the sixth-order differential equation system of motion usually applied to calculate the Love-Shida numbers.

Extension of Kaplan-Meier methods in observational studies with time-varying treatment.

PubMed

Xu, Stanley; Shetterly, Susan; Powers, David; Raebel, Marsha A; Tsai, Thomas T; Ho, P Michael; Magid, David

2012-01-01

Inverse probability of treatment weighted Kaplan-Meier estimates have been developed to compare two treatments in the presence of confounders in observational studies. Recently, stabilized weights were developed to reduce the influence of extreme inverse probability of treatment-weighted weights in estimating treatment effects. The objective of this research was to use adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests to examine the effect of a treatment that varies over time in an observational study. We proposed stabilized weight adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests when the treatment was time-varying over the follow-up period. We applied these new methods in examining the effect of an anti-platelet agent, clopidogrel, on subsequent events, including bleeding, myocardial infarction, and death after a drug-eluting stent was implanted into a coronary artery. In this population, clopidogrel use may change over time based on a patient's behavior (e.g., nonadherence) and physicians' recommendations (e.g., end of duration of therapy). Consequently, clopidogrel use was treated as a time-varying variable. We demonstrate that 1) the sample sizes at three chosen time points are almost identical in the original and weighted datasets; and 2) the covariates between patients on and off clopidogrel were well balanced after stabilized weights were applied to the original samples. The stabilized weight-adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests are useful in presenting and comparing survival functions for time-varying treatments in observational studies while adjusting for known confounders. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Solution of Radiative Transfer Equation with a Continuous and Stochastic Varying Refractive Index by Legendre Transform Method

PubMed Central

Gantri, M.

2014-01-01

The present paper gives a new computational framework within which radiative transfer in a varying refractive index biological tissue can be studied. In our previous works, Legendre transform was used as an innovative view to handle the angular derivative terms in the case of uniform refractive index spherical medium. In biomedical optics, our analysis can be considered as a forward problem solution in a diffuse optical tomography imaging scheme. We consider a rectangular biological tissue-like domain with spatially varying refractive index submitted to a near infrared continuous light source. Interaction of radiation with the biological material into the medium is handled by a radiative transfer model. In the studied situation, the model displays two angular redistribution terms that are treated with Legendre integral transform. The model is used to study a possible detection of abnormalities in a general biological tissue. The effect of the embedded nonhomogeneous objects on the transmitted signal is studied. Particularly, detection of targets of localized heterogeneous inclusions within the tissue is discussed. Results show that models accounting for variation of refractive index can yield useful predictions about the target and the location of abnormal inclusions within the tissue. PMID:25013454

Study of selected phenotype switching strategies in time varying environment

NASA Astrophysics Data System (ADS)

Horvath, Denis; Brutovsky, Branislav

2016-03-01

Population heterogeneity plays an important role across many research, as well as the real-world, problems. The population heterogeneity relates to the ability of a population to cope with an environment change (or uncertainty) preventing its extinction. However, this ability is not always desirable as can be exemplified by an intratumor heterogeneity which positively correlates with the development of resistance to therapy. Causation of population heterogeneity is therefore in biology and medicine an intensively studied topic. In this paper the evolution of a specific strategy of population diversification, the phenotype switching, is studied at a conceptual level. The presented simulation model studies evolution of a large population of asexual organisms in a time-varying environment represented by a stochastic Markov process. Each organism disposes with a stochastic or nonlinear deterministic switching strategy realized by discrete-time models with evolvable parameters. We demonstrate that under rapidly varying exogenous conditions organisms operate in the vicinity of the bet-hedging strategy, while the deterministic patterns become relevant as the environmental variations are less frequent. Statistical characterization of the steady state regimes of the populations is done using the Hellinger and Kullback-Leibler functional distances and the Hamming distance.

Measuring sexual dimorphism with a race-gender face space.

PubMed

Hopper, William J; Finklea, Kristin M; Winkielman, Piotr; Huber, David E

2014-10-01

Faces are complex visual objects, and faces chosen to vary in 1 regard may unintentionally vary in other ways, particularly if the correlation is a property of the population of faces. Here, we present an example of a correlation that arises from differences in the degree of sexual dimorphism. In Experiment 1, paired similarity ratings were collected for a set of 40 real face images chosen to vary in terms of gender and race (Asian vs. White). Multidimensional scaling (MDS) placed these stimuli in a "face space," with different attributes corresponding to different dimensions. Gender was found to vary more for White faces, resulting in a negative or positive correlation between gender and race when only considering male or only considering female faces. This increased sexual dimorphism for White faces may provide an alternative explanation for differences in face processing between White and Asian faces (e.g., the own-race bias, face attractiveness biases, etc.). Studies of face processing that are unconfounded by this difference in the degree of sexual dimorphism require stimuli that are decorrelated in terms of race and gender. Decorrelated faces were created using a morphing technique, spacing the morphs uniformly around a ring in the 2-dimensional (2D) race-gender plane. In Experiment 2, paired similarity ratings confirmed the 2D positions of the morph faces. In Experiment 3, race and gender category judgments varied uniformly for these decorrelated stimuli. Our results and stimuli should prove useful for studying sexual dimorphism and for the study of face processing more generally.

Diagnostic accuracy of history, physical examination, and bedside ultrasound for diagnosis of extremity fractures in the emergency department: a systematic review.

PubMed

Joshi, Nikita; Lira, Alena; Mehta, Ninfa; Paladino, Lorenzo; Sinert, Richard

2013-01-01

Understanding history, physical examination, and ultrasonography (US) to diagnose extremity fractures compared with radiography has potential benefits of decreasing radiation exposure, costs, and pain and improving emergency department (ED) resource management and triage time. The authors performed two electronic searches using PubMed and EMBASE databases for studies published between 1965 to 2012 using a strategy based on the inclusion of any patient presenting with extremity injuries suspicious for fracture who had history and physical examination and a separate search for US performed by an emergency physician (EP) with subsequent radiography. The primary outcome was operating characteristics of ED history, physical examination, and US in diagnosing radiologically proven extremity fractures. The methodologic quality of the studies was assessed using the quality assessment of studies of diagnostic accuracy tool (QUADAS-2). Nine studies met the inclusion criteria for history and physical examination, while eight studies met the inclusion criteria for US. There was significant heterogeneity in the studies that prevented data pooling. Data were organized into subgroups based on anatomic fracture locations, but heterogeneity within the subgroups also prevented data pooling. The prevalence of fracture varied among the studies from 22% to 70%. Upper extremity physical examination tests have positive likelihood ratios (LRs) ranging from 1.2 to infinity and negative LRs ranging from 0 to 0.8. US sensitivities varied between 85% and 100%, specificities varied between 73% and 100%, positive LRs varied between 3.2 and 56.1, and negative LRs varied between 0 and 0.2. Compared with radiography, EP US is an accurate diagnostic test to rule in or rule out extremity fractures. The diagnostic accuracy for history and physical examination are inconclusive. Future research is needed to understand the accuracy of ED US when combined with history and physical examination for upper and lower extremity fractures. © 2013 by the Society for Academic Emergency Medicine.

Consumer Acceptance of Population-Level Intervention Strategies for Healthy Food Choices: The Role of Perceived Effectiveness and Perceived Fairness

PubMed Central

Bos, Colin; Van Der Lans, Ivo; Van Rijnsoever, Frank; Van Trijp, Hans

2015-01-01

The present study investigates acceptance of intervention strategies for low-calorie snack choices that vary regarding the effect they have on consumers’ freedom of choice (providing information, guiding choice through (dis)incentives, and restricting choice). We examine the mediating effects of perceived effectiveness and perceived fairness, and the moderating effects of barriers to choose low-calorie snacks and perceived responsibility for food choice. Data was collected through an online survey, involving three waves that were completed over a seven week timespan. Information was collected on barriers and perceived responsibility, and evaluations of a total of 128 intervention strategies with varying levels of intrusiveness that were further systematically varied in terms of source, location, approach/avoidance, type, and severity. A total of 1173 respondents completed all three waves. We found that the effect of intervention intrusiveness on acceptance was mediated by the perceived personal- and societal effectiveness, and the perceived fairness of interventions. For barriers and perceived responsibility, only main effects on intervention-specific beliefs were found. Government interventions were accepted less than interventions by food manufacturers. In conclusion, the present study shows that acceptance of interventions depends on perceptions of personal- and societal effectiveness and fairness, thereby providing novel starting points for increasing acceptance of both existing and new food choice interventions. PMID:26389949

The Latent Structure of Spatial Skills and Mathematics: A Replication of the Two-Factor Model

ERIC Educational Resources Information Center

Mix, Kelly S.; Levine, Susan C.; Cheng, Yi-Lang; Young, Christopher J.; Hambrick, David Z.; Konstantopoulos, Spyros

2017-01-01

In a previous study, Mix et al. (2016) reported that spatial skill and mathematics were composed of 2 highly correlated, domain-specific factors, with a few cross-domain loadings. The overall structure was consistent across grade (kindergarten, 3rd grade, 6th grade), but the cross-domain loadings varied with age. The present study sought to…

No Teacher Left Behind: Educating Students with ASD and ADHD in the Inclusion Classroom

ERIC Educational Resources Information Center

Jones, Michaela N.; Weber, Kimberly P.; McLaughlin, T. F.

2013-01-01

The purpose of the present study was to evaluate the effects of a token economy on on-task behaviors by two seventh grade boys with varying disabilities within a public school inclusion classroom setting. At the end of the study, the participant identified with ASD increased his on-task behaviors approximately 52%. The participant identified with…

The Relationship between EFL Teachers' Critical Thinking and Use of Motivational Strategies

ERIC Educational Resources Information Center

Parsi, Gholamreza

2017-01-01

The present study was conducted to investigate the relationship between EFL teachers' critical thinking and use of motivational strategies. The participants of this study were 101 EFL teachers. These teachers were both male and female between 21 to 36 years old, and they taught intermediate and advanced levels and varied in their experience from 3…

A Developmental Study of the Attitudinal Effects of Nonsexist Television Commericals under Varied Conditions of Perceived Reality.

ERIC Educational Resources Information Center

Pingree, Suzanne

To test the proposition that television content can teach sex-typed behaviors and attitudes, this study presented children of two ages (third grade and eighth grade) with one of two sets of television commercials. The first set contained women engaged in nontraditional occupations outside the home. The second set showed traditional women in their…

History Places: A Case Study for Relational Database and Information Retrieval System Design

ERIC Educational Resources Information Center

Hendry, David G.

2007-01-01

This article presents a project-based case study that was developed for students with diverse backgrounds and varied inclinations for engaging technical topics. The project, called History Places, requires that student teams develop a vision for a kind of digital library, propose a conceptual model, and use the model to derive a logical model and…

Do the Kinds of Achievement Errors Made by Students Diagnosed with ADHD Vary as a Function of Their Reading Ability?

ERIC Educational Resources Information Center

Pagirsky, Matthew S.; Koriakin, Taylor A.; Avitia, Maria; Costa, Michael; Marchis, Lavinia; Maykel, Cheryl; Sassu, Kari; Bray, Melissa A.; Pan, Xingyu

2017-01-01

A large body of research has documented the relationship between attention-deficit hyperactivity disorder (ADHD) and reading difficulties in children; however, there have been no studies to date that have examined errors made by students with ADHD and reading difficulties. The present study sought to determine whether the kinds of achievement…

The Crusades from Medieval European and Muslim Perspectives. A Unit of Study for Grades 7-12.

ERIC Educational Resources Information Center

Aghaie, Kamran Scot

This unit of study seeks to supplement the information presented in world history textbooks about the Crusades. The Crusades were instigated by the call for "holy war" against Muslims by Pope Urban II in 1095 and spanned several centuries. The unit notes that usually the depth and breadth of coverage varies substantially, and the…

Does the Direction in Which a Figure Is Looking Influence Whether It Is Visible?

ERIC Educational Resources Information Center

McGuigan, Nicola

2009-01-01

Previous studies have shown that young preschool children are highly sensitive to mutual engagement and struggle to diagnose the visibility of a figure when their facial area is occluded. The present study aimed to explore the specificity of engagement by varying (a) the orientation of a figure relative to an observer and (b) the visible area of…

Binding of Verbal and Spatial Features in Auditory Working Memory

ERIC Educational Resources Information Center

Maybery, Murray T.; Clissa, Peter J.; Parmentier, Fabrice B. R.; Leung, Doris; Harsa, Grefin; Fox, Allison M.; Jones, Dylan M.

2009-01-01

The present study investigated the binding of verbal identity and spatial location in the retention of sequences of spatially distributed acoustic stimuli. Study stimuli varying in verbal content and spatial location (e.g. V[subscript 1]S[subscript 1], V[subscript 2]S[subscript 2], V[subscript 3]S[subscript 3], V[subscript 4]S[subscript 4]) were…

A Study of Al-Mn Transition Edge Sensor Engineering for Stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

George, E. M.; et al.

2013-11-10

The stability of Al-Mn transition edge sensor (TES) bolometers is studied as we vary the engineered TES transition, heat capacity, and/or coupling between the heat capacity and TES. We present thermal structure measurements of each of the 39 designs tested. The data is accurately fit by a two-body bolometer model, which allows us to extract the basic TES parameters that affect device stability. We conclude that parameters affecting device stability can be engineered for optimal device operation, and present the model parameters extracted for the different TES designs.

Visual Complexity in Orthographic Learning: Modeling Learning across Writing System Variations

ERIC Educational Resources Information Center

Chang, Li-Yun; Plaut, David C.; Perfetti, Charles A.

2016-01-01

The visual complexity of orthographies varies across writing systems. Prior research has shown that complexity strongly influences the initial stage of reading development: the perceptual learning of grapheme forms. This study presents a computational simulation that examines the degree to which visual complexity leads to grapheme learning…

Syntactic Predictability in the Recognition of Carefully and Casually Produced Speech

ERIC Educational Resources Information Center

Viebahn, Malte C.; Ernestus, Mirjam; McQueen, James M.

2015-01-01

The present study investigated whether the recognition of spoken words is influenced by how predictable they are given their syntactic context and whether listeners assign more weight to syntactic predictability when acoustic-phonetic information is less reliable. Syntactic predictability was manipulated by varying the word order of past…

Hybrid Air Quality Modeling Approach for use in the Hear-road Exposures to Urban air pollutant Study(NEXUS)

EPA Science Inventory

The paper presents a hybrid air quality modeling approach and its application in NEXUS in order to provide spatial and temporally varying exposure estimates and identification of the mobile source contribution to the total pollutant exposure. Model-based exposure metrics, associa...

Neural Correlates of Affective Influence on Choice

ERIC Educational Resources Information Center

Piech, Richard M.; Lewis, Jade; Parkinson, Caroline H.; Owen, Adrian M.; Roberts, Angela C.; Downing, Paul E.; Parkinson, John A.

2010-01-01

Making the right choice depends crucially on the accurate valuation of the available options in the light of current needs and goals of an individual. Thus, the valuation of identical options can vary considerably with motivational context. The present study investigated the neural structures underlying context dependent evaluation. We instructed…

Parenting Styles, Young Adults' Self-Concepts, and Evaluations of Parents.

ERIC Educational Resources Information Center

Parish, Thomas S.; McCluskey, James J.

1993-01-01

Research shows that parenting style may strongly influence children's and adolescents' development. The present study reexamined this association, using a sample of 123 midwestern college students enrolled in a human development class. Participants' self-concepts varied directly with the perceived level of warmth displayed by both their fathers…

Self-Paced Physics, Segments 37-40.

ERIC Educational Resources Information Center

New York Inst. of Tech., Old Westbury.

Four study segments of the Self-Paced Physics Course materials are presented in this eighth problems and solutions book used as a part of course assignments. The content is related to magnetic induction, Faraday's law, induced currents, Lenz's law, induced electromotive forces, time-varying magnetic fields, self-inductance, inductors,…

Evolving the Concept of Homology

ERIC Educational Resources Information Center

Naples, Virginia L.; Miller, Jon S.

2009-01-01

Understanding homology is fundamental to learning about evolution. The present study shows an exercise that can be varied in complexity, for which students compile research illustrating the fate of homologous fish skull elements, and assemble a mural to serve as a learning aid. The skull of the most primitive living Actinopterygian (bony fish),…

An Exploration of EFL Teachers' Attributions

ERIC Educational Resources Information Center

Ghonsooly, Behzad; Ghanizadeh, Afsaneh; Ghazanfari, Mohammad; Ghabanchi, Zargham

2015-01-01

The present study investigated English as a foreign language (EFL) teachers' attributions of success and failure. It also set out to investigate whether these attributions vary by teachers' age, teaching experience, gender and educational level. To do so, 200 EFL teachers were selected according to convenience sampling among EFL teachers teaching…

Predicting Reasoning from Memory

ERIC Educational Resources Information Center

Heit, Evan; Hayes, Brett K.

2011-01-01

In an effort to assess the relations between reasoning and memory, in 8 experiments, the authors examined how well responses on an inductive reasoning task are predicted from responses on a recognition memory task for the same picture stimuli. Across several experimental manipulations, such as varying study time, presentation frequency, and the…

Inductive Learning: Does Interleaving Exemplars Affect Long-Term Retention?

ERIC Educational Resources Information Center

Zulkiply, Norehan; Burt, Jennifer S.

2013-01-01

Purpose: The present study investigated whether or not the benefits of interleaving of exemplars from several categories vary with retention interval in inductive learning. Methodology: Two experiments were conducted using paintings (Experiment 1) and textual materials (Experiment 2), and the experiments used a mixed factorial design. Forty…

An Analysis of Active Rehearsal in Children's Memory.

ERIC Educational Resources Information Center

Stone, Barbara Prince; And Others

This paper presents a developmental study of the effects of item rehearsal on children's short term memory. Two experiments are discussed. The first, involving second and sixth grade children, concerned the relationship between item retrieval ability and rehearsal strategies in item recall. The design of the experiment involved varying the visual…

Can Family Affectedness Inform Infant Sibling Outcomes of Autism Spectrum Disorders?

ERIC Educational Resources Information Center

Schwichtenberg, A. J.; Young, G. S.; Sigman, M.; Hutman, T.; Ozonoff, S.

2010-01-01

Background: Difficulties in communication and reciprocal social behavior are core features of autism spectrum disorders (ASD) and are often present, to varying degrees, in other family members. This prospective longitudinal infant sibling study examines whether social-communicative features of family members may inform which infants are at…

Technology User Groups and Early Childhood Education: A Preliminary Study

ERIC Educational Resources Information Center

Parette, Howard P.; Hourcade, Jack J.; Blum, Craig; Watts, Emily H.; Stoner, Julia B.; Wojcik, Brian W.; Chrismore, Shannon B.

2013-01-01

This article presents a preliminary examination of the potential of Technology User Groups as a professional development venue for early childhood education professionals in developing operational and functional competence in using hardware and software components of a Technology toolkit. Technology user groups are composed of varying numbers of…

Flexibility in Bilingual Infants' Word Learning

ERIC Educational Resources Information Center

Graf Estes, Katharine; Hay, Jessica F.

2015-01-01

The present experiments tested bilingual infants' developmental narrowing for the interpretation of sounds that form words. These studies addressed how language specialization proceeds when the environment provides varied and divergent input. Experiment 1 (N = 32) demonstrated that bilingual 14- and 19-month-olds learned a pair of object labels…

Perceptions of Preceptors and Students on the Importance of Writing

ERIC Educational Resources Information Center

Fields, Tina T.; Hatala, Jeff J.; Nauert, Richard F.

2014-01-01

Health administration programs vary from other administrative programs based on emphasis in writing. Prior studies about writing skills in professional degree programs show student writing skills are not at a professional level. There is no literature at present that identifies important and essential writing skills related specifically to…

Dual-Function Air Cathode for Metal-Air Batteries with Pulse-Power Capability

DTIC Science & Technology

2013-01-28

surfaces of the nanofoam papers via reaction with aqueous permanganate solutions. [ 16–18 ] Because the deposition is performed under self...The MnO x weight loading can be varied based on exposure time in the permanganate solution; [ 17 ] for the present studies we examined carbon

The Sleep Patterns and Well-Being of Australian Adolescents

ERIC Educational Resources Information Center

Short, Michelle A.; Gradisar, Michael; Lack, Leon C.; Wright, Helen R.; Dohnt, Hayley

2013-01-01

Aim: Adolescent sleep patterns vary between countries, and these differences influence adolescent functioning and well-being. The present study provides data on the sleep and well-being of Australian adolescents. Methods: 385 adolescents aged 13-18 years were recruited from 8 South Australian schools spanning the socio-economic spectrum.…

Teaching Observational Learning to Children Diagnosed with Autism

ERIC Educational Resources Information Center

MacDonald, Jacquelyn

2014-01-01

Observational learning is a critical skill needed for the acquisition of social skills and is likely an important skill for learning within traditional educational settings. Although several varying definitions of observational learning have been posited, for the purpose of the present study, observational learning (OL) was defined as differential…

Impression Management in the Psychiatric Interview: Quality, Style, and Individual Differences

ERIC Educational Resources Information Center

Sherman, Mark; And Others

1975-01-01

The ability of 24 Veterans Administration Day Treatment Center psychiatric outpatients to vary intentionally their degree of apparent psychopathology during structured interviews was studied. Patients defined as sick presenters behaved in a significantly more pathological manner during an interview preceded by "fake sick" instructions than they…

Organizational Culture as a Function of Institutional Type in Higher Education

ERIC Educational Resources Information Center

Kaufman, Jason A.

2013-01-01

The purpose of the present study was to examine whether organizational culture varies as a function of institutional type in higher education, and to identify whether there exists congruence between organizational culture type and leader behavior. Utilizing the Organizational Culture Assessment Instrument (OCAI) developed by Cameron and Quinn…

Effects of Grammatical Categories on Children's Visual Language Processing: Evidence from Event-Related Brain Potentials

ERIC Educational Resources Information Center

Weber-Fox, Christine; Hart, Laura J.; Spruill, John E., III

2006-01-01

This study examined how school-aged children process different grammatical categories. Event-related brain potentials elicited by words in visually presented sentences were analyzed according to seven grammatical categories with naturally varying characteristics of linguistic functions, semantic features, and quantitative attributes of length and…

Perceptions of Life on the Tenure Track.

ERIC Educational Resources Information Center

Verrier, David A.

1994-01-01

The report of a study of 18 junior faculty in varying stages of tenure eligibility at a research university presents the experiences of two, a man and a woman, felt to be representative of faculty experiences and perceptions. Issues addressed include peer relationships, competition, publishing, performance feedback, social expectations, personal…

The Influence of Asynchronous Video Communication on Learner Social Presence: A Narrative Analysis of Four Cases

ERIC Educational Resources Information Center

Borup, Jered; West, Richard E.; Graham, Charles R.

2013-01-01

Online courses are increasingly using asynchronous video communication. However, little is known about how asynchronous video communication influences students' communication patterns. This study presents four narratives of students with varying characteristics who engaged in asynchronous video communication. The extrovert valued the efficiency of…

Language Non-Selective Syntactic Activation in Early Bilinguals: The Role of Verbal Fluency

ERIC Educational Resources Information Center

Sanoudaki, Eirini; Thierry, Guillaume

2015-01-01

Numerous studies have shown that bilinguals presented with words in one of their languages spontaneously and automatically activate lexical representations from their other language. However, such effects, found in varied experimental contexts, both in behavioural and psychophysiological investigations, have been essentially limited to the…

High speed Infrared imaging method for observation of the fast varying temperature phenomena

NASA Astrophysics Data System (ADS)

Moghadam, Reza; Alavi, Kambiz; Yuan, Baohong

With new improvements in high-end commercial R&D camera technologies many challenges have been overcome for exploring the high-speed IR camera imaging. The core benefits of this technology is the ability to capture fast varying phenomena without image blur, acquire enough data to properly characterize dynamic energy, and increase the dynamic range without compromising the number of frames per second. This study presents a noninvasive method for determining the intensity field of a High Intensity Focused Ultrasound Device (HIFU) beam using Infrared imaging. High speed Infrared camera was placed above the tissue-mimicking material that was heated by HIFU with no other sensors present in the HIFU axial beam. A MATLAB simulation code used to perform a finite-element solution to the pressure wave propagation and heat equations within the phantom and temperature rise to the phantom was computed. Three different power levels of HIFU transducers were tested and the predicted temperature increase values were within about 25% of IR measurements. The fundamental theory and methods developed in this research can be used to detect fast varying temperature phenomena in combination with the infrared filters.

Influence of Word Class Proportion on Cerebral Asymmetries for High- And Low-Imagery Words

ERIC Educational Resources Information Center

Chiarello, C.; Shears, C.; Liu, S.; Kacinik, N.A.

2005-01-01

It has been claimed that the typical RVF/LH advantage for word recognition is reduced or eliminated for imageable, as compared to nonimageable, nouns. To determine whether such word-class effects vary depending on the stimulus list context in which the words are presented, we varied the proportion of high- and low-image words presented in a…

Elucidative analysis and sequencing of two respiratory health monitoring methods to study the impact of varying atmospheric composition on human health

NASA Astrophysics Data System (ADS)

Awasthi, Amit; Hothi, Navjot; Kaur, Prabhjot; Singh, Nirankar; Chakraborty, Monojit; Bansal, Sangeeta

2017-12-01

Atmospheric composition of ambient air consists of different gases in definite proportion that affect the earth's climate and its ecological system. Due to varied anthropogenic reasons, this composition is changed, which ultimately have an impact on the health of living beings. For survival, the human respiratory system is one of the sensitive systems, which is easily and closely affected by the change in atmospheric composition of an external environment. Many studies have been conducted to quantify the effects of atmospheric pollution on human health by using different approaches. This article presents different scenario of studies conducted to evaluate the effects on different human groups. Differences between the studies conducted using spirometry and survey methods are presented in this article to extract a better sequence between these two methodologies. Many studies have been conducted to measure the respiratory status by evaluating the respiratory symptoms and hospital admissions. Limited numbers of studies are found with repeated spirometry on the same subjects for long duration to nullify the error arising due to decrease in efforts by the same subjects during manoeuvre of pulmonary function tests. Present study reveals the importance of methodological sequencing in order to obtain more authentic and reliable results. This study suggests that impacts of deteriorating atmospheric composition on human health can be more significantly studied if spirometry is done after survey analysis. The article also proposes that efficiency and authenticity of surveys involving health impacts will increase, if medical data information of patients is saved in hospitals in a proper format.

Vascular plant checklist of the Chimney Spring and Limestone Flats Prescribed Burning Study Areas within ponderosa pine experimental forests in northern Arizona

Treesearch

Catherine Scudieri; James F. Fowler; Carolyn Hull Sieg; Laura Williams; Sally M. Haase

2008-01-01

This paper presents a vascular plant species list for two sites that are part of a long-term study exploring the effects of varying fire intervals on forest characteristics including the abundance and composition of understory vegetation. The Chimney Spring study area is on the Fort Valley Experimental Forest near Flagstaff, AZ, and the Limestone Flats study area is on...

The Effectiveness of Digital Game-Based Vocabulary Learning: A Framework-Based View of Meta-Analysis

ERIC Educational Resources Information Center

Chen, Meng-Hua; Tseng, Wen-Ta; Hsiao, Tsung-Yuan

2018-01-01

This study presents the results of a meta-analytic study about the effects of digital game-based learning (DGBL) on vocabulary. The results of the study showed that the effects of DGBL on vocabulary learning may vary with game design features (Q = 5.857, df = 1, p = 0.016), but not with learners' age (Q = 0.906, df = 1, p = 0.341) or linguistic…

A New Dimension to Relative Age Effects: Constant Year Effects in German Youth Handball

PubMed Central

Schorer, Jörg; Wattie, Nick; Baker, Joseph R.

2013-01-01

In this manuscript we argue for a broader use of the term ‘relative age effect’ due to the influence of varying development policies on the development of sport expertise. Two studies are presented on basis of data from Schorer, et al. [1]. The first showed clear ‘constant year effects’ in the German handball talent development system. A shift in year groupings for the female athletes resulted in a clear shift of birth year patterns. In the second study we investigated whether the constant year effect in the national talent development system carried over to professional handball. No patterns were observable. Together both studies show that a differentiation of varying effects that often happen simultaneously is necessary to understand the secondary mechanisms behind the development of sport expertise. PMID:23637745

A one-dimensional sectional model to simulate multicomponent aerosol dynamics in the marine boundary layer 3. Numerical methods and comparisons with exact solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelbard, F.; Fitzgerald, J.W.; Hoppel, W.A.

1998-07-01

We present the theoretical framework and computational methods that were used by {ital Fitzgerald} {ital et al.} [this issue (a), (b)] describing a one-dimensional sectional model to simulate multicomponent aerosol dynamics in the marine boundary layer. The concepts and limitations of modeling spatially varying multicomponent aerosols are elucidated. New numerical sectional techniques are presented for simulating multicomponent aerosol growth, settling, and eddy transport, coupled to time-dependent and spatially varying condensing vapor concentrations. Comparisons are presented with new exact solutions for settling and particle growth by simultaneous dynamic condensation of one vapor and by instantaneous equilibration with a spatially varying secondmore » vapor. {copyright} 1998 American Geophysical Union« less

Time-Varying Effects of Signs and Symptoms on Pregnancy Loss <20 Weeks: Findings from a Preconception Prospective Cohort Study.

PubMed

Sapra, Katherine J; Buck Louis, Germaine M; Sundaram, Rajeshwari; Joseph, K S; Bates, Lisa M; Galea, Sando; Ananth, Cande V

2018-01-01

Although pregnancy loss affects one-third of pregnancies, the associated signs/symptoms have not been fully described. Given the dynamic nature of maternal physiologic adaptation to early pregnancy, we posited the relationships between signs/symptoms and subsequent loss would vary weekly. In a preconception cohort with daily follow-up, pregnancies were ascertained by self-administered sensitive home pregnancy tests on day of expected menses. We evaluated the effects of weekly time-varying signs/symptoms (including vaginal bleeding, lower abdominal cramping, and nausea and/or vomiting) on pregnancy loss <20 weeks in Cox proportional hazards models and calculated the week-specific probability of loss by the presence/absence of each sign/symptom. Of 341 pregnancies ascertained by home pregnancy test, 95 (28%) ended in loss. Relationships between signs/symptoms and loss varied across time since first positive pregnancy test. In the first week following pregnancy confirmation, when many losses occurred, bleeding [hazard ratio (HR) 8.7, 95% confidence interval (CI) 4.7, 16.0] and cramping (HR 1.8, 95% CI 1.2, 2.7) were associated with loss even when accompanied by nausea and/or vomiting (HR 5.2, 95% CI 2.6, 10.5). After the second week, new relationships emerged with nausea and/or vomiting inversely associated (HR range 0.6-0.3, all 95% CI upper bounds <1.00) and bleeding no longer associated with loss. Probabilities of loss of ranged from 78% (95% CI 59%, 96%) with bleeding present in week 1 to 8% (95% CI 5%, 12%) with nausea/vomiting present in week 5. Relationships between signs/symptoms and pregnancy loss vary in early pregnancy possibly reflecting maternal physiologic response. © 2017 John Wiley & Sons Ltd.

Time-varying coupling functions: Dynamical inference and cause of synchronization transitions

NASA Astrophysics Data System (ADS)

Stankovski, Tomislav

2017-02-01

Interactions in nature can be described by their coupling strength, direction of coupling, and coupling function. The coupling strength and directionality are relatively well understood and studied, at least for two interacting systems; however, there can be a complexity in the interactions uniquely dependent on the coupling functions. Such a special case is studied here: synchronization transition occurs only due to the time variability of the coupling functions, while the net coupling strength is constant throughout the observation time. To motivate the investigation, an example is used to present an analysis of cross-frequency coupling functions between delta and alpha brain waves extracted from the electroencephalography recording of a healthy human subject in a free-running resting state. The results indicate that time-varying coupling functions are a reality for biological interactions. A model of phase oscillators is used to demonstrate and detect the synchronization transition caused by the varying coupling functions during an invariant coupling strength. The ability to detect this phenomenon is discussed with the method of dynamical Bayesian inference, which was able to infer the time-varying coupling functions. The form of the coupling function acts as an additional dimension for the interactions, and it should be taken into account when detecting biological or other interactions from data.

Systematic, Cross-Cortex Variation in Neuron Numbers in Rodents and Primates

PubMed Central

Charvet, Christine J.; Cahalane, Diarmuid J.; Finlay, Barbara L.

2015-01-01

Uniformity, local variability, and systematic variation in neuron numbers per unit of cortical surface area across species and cortical areas have been claimed to characterize the isocortex. Resolving these claims has been difficult, because species, techniques, and cortical areas vary across studies. We present a stereological assessment of neuron numbers in layers II–IV and V–VI per unit of cortical surface area across the isocortex in rodents (hamster, Mesocricetus auratus; agouti, Dasyprocta azarae; paca, Cuniculus paca) and primates (owl monkey, Aotus trivigratus; tamarin, Saguinus midas; capuchin, Cebus apella); these chosen to vary systematically in cortical size. The contributions of species, cortical areas, and techniques (stereology, “isotropic fractionator”) to neuron estimates were assessed. Neurons per unit of cortical surface area increase across the rostro-caudal (RC) axis in primates (varying by a factor of 1.64–2.13 across the rostral and caudal poles) but less in rodents (varying by a factor of 1.15–1.54). Layer II–IV neurons account for most of this variation. When integrated into the context of species variation, and this RC gradient in neuron numbers, conflicts between studies can be accounted for. The RC variation in isocortical neurons in adulthood mirrors the gradients in neurogenesis duration in development. PMID:23960207

Inferring time-varying recharge from inverse analysis of long-term water levels

NASA Astrophysics Data System (ADS)

Dickinson, Jesse E.; Hanson, R. T.; Ferré, T. P. A.; Leake, S. A.

2004-07-01

Water levels in aquifers typically vary in response to time-varying rates of recharge, suggesting the possibility of inferring time-varying recharge rates on the basis of long-term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Niño-Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one-dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long-term water level records using southwest aquifers as the case study. Time-varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.

Inferring time‐varying recharge from inverse analysis of long‐term water levels

USGS Publications Warehouse

Dickinson, Jesse; Hanson, R.T.; Ferré, T.P.A.; Leake, S.A.

2004-01-01

Water levels in aquifers typically vary in response to time‐varying rates of recharge, suggesting the possibility of inferring time‐varying recharge rates on the basis of long‐term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Niño‐Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one‐dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long‐term water level records using southwest aquifers as the case study. Time‐varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.

Analysis of laminated plates under thermal environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iyenger, N.G.R.; Shankara, C.A.

1995-12-31

Use of composites in advanced aircrafts and spacecraft structures calls for a thorough understanding of their behaviour under various types of loads. In the present paper, an attempt has been made to study the effect of thermal loads on the flexural response of composite laminated plates. Most of the studies in this area are either based on Classical Lamination Theory or First Order Shear Deformation Theory. In the present investigation, analysis has been carried out using a Higher Order Shear Deformation Theory, that allows for a parabolic variation of transverse shear stress through the thickness. The displacement model presented bymore » Reddy has been transformed so that only C{degrees} continuous element is required. This, however, increases the Degree of freedom per node from 5 to 7. Nine-noded isoparametric Legrangian elements are used for computing the results. The results were found to be very stable and comparable with those of exact elasticity solutions. The temperature is assumed to remain constant or vary linearly through the thickness. However, it varies sinusoidally in the plane of the plate. Effect of various parameters like material, fiber orientation, number of layers and boundary conditions on the response of the laminate has been investigated. The present study indicates that the flexural behaviour of laminates under thermal loads is very much different from that when subjected only to mechanical loads. Further, the variation of plate deflection with increase in temperature is not linear.« less

Development of biodegradable polymer based tamoxifen citrate loaded nanoparticles and effect of some manufacturing process parameters on them: a physicochemical and in-vitro evaluation.

PubMed

Sahana, Basudev; Santra, Kousik; Basu, Sumit; Mukherjee, Biswajit

2010-09-07

The aim of the present study was to develop nanoparticles of tamoxifen citrate, a non-steroidal antiestrogenic drug used for the treatment of breast cancer. Biodegradable poly (D, L- lactide-co-glycolide)-85:15 (PLGA) was used to develop nanoparticles of tamoxifen citrate by multiple emulsification (w/o/w) and solvent evaporation technique. Drug-polymer ratio, polyvinyl alcohol concentrations, and homogenizing speeds were varied at different stages of preparation to optimize the desired size and release profile of drug. The characterization of particle morphology and shape was performed by field emission scanning electron microscope (FE-SEM) and particle size distribution patterns were studied by direct light scattering method using zeta sizer. In vitro drug release study showed that release profile of tamoxifen from biodegradable nanoparticles varied due to the change in speed of centrifugation for separation. Drug loading efficiency varied from 18.60% to 71.98%. The FE-SEM study showed that biodegradable nanoparticles were smooth and spherical in shape. The stability studies of tamoxifen citrate in the experimental nanoparticles showed the structural integrity of tamoxifen citrate in PLGA nanoparticles up to 60°C in the tested temperatures. Nanoparticles containing tamoxifen citrate could be useful for the controlled delivery of the drug for a prolonged period.

On the correct use of stepped-sine excitations for the measurement of time-varying bioimpedance.

PubMed

Louarroudi, E; Sanchez, B

2017-02-01

When a linear time-varying (LTV) bioimpedance is measured using stepped-sine excitations, a compromise must be made: the temporal distortions affecting the data depend on the experimental time, which in turn sets the data accuracy and limits the temporal bandwidth of the system that needs to be measured. Here, the experimental time required to measure linear time-invariant bioimpedance with a specified accuracy is analyzed for different stepped-sine excitation setups. We provide simple equations that allow the reader to know whether LTV bioimpedance can be measured through repeated time- invariant stepped-sine experiments. Bioimpedance technology is on the rise thanks to a plethora of healthcare monitoring applications. The results presented can help to avoid distortions in the data while measuring accurately non-stationary physiological phenomena. The impact of the work presented is broad, including the potential of enhancing bioimpedance studies and healthcare devices using bioimpedance technology.

Alimentary tract duplications in newborns and children: Diagnostic aspects and the role of laparoscopic treatment

PubMed Central

Patiño Mayer, Jan; Bettolli, Marcos

2014-01-01

Alimentary tract duplications are rare congenital lesions normally diagnosed in newborns and children that can occur anywhere from the mouth to the anus and have a reported incidence of approximately 1 in 4500 life births. Symptoms and clinical presentation vary greatly. The presentation varies according to age and location. The treatment finally is surgical; total resection when possible should be the aim of the intervention. In pediatric surgery minimally invasive surgical procedures became more and more important over the last decades. In consequence the operative procedure on alimentary tract duplications changed in this manner. We review on case reports and clinical reports on minimally invasive surgery in the treatment of alimentary tract duplications, determine the importance of minimally invasive techniques in the treatment of this rare entity and rule out that further studies in the field should be performed. PMID:25339813

The performance of H2O, R134a, SES36, ethanol, and HFE7100 two-phase closed thermosyphons for varying operating parameters and geometry

NASA Astrophysics Data System (ADS)

Andrzejczyk, Rafał; Muszyński, Tomasz

2017-09-01

In this study, the influences of different parameters at performance two-phase closed thermosiphon (TPCT) was presented. It has been confirmed that the working fluid, as well as operating parameters and fill ratio, are very important factors in the performance of TPCT. The article shows characteristics of gravitational tube geometries, as well as the technical characteristic of the most important system components, i.e., the evaporator/condenser. The experiment's plan and the results of it for the two-phase thermosiphon for both evaluated geometries with varying thermal and fluid flow parameters are presented. Experiments were performed for the most perspective working fluids, namely: water, R134a, SES36, ethanol and HFE7100. Obtained research proves the possibility to use TPCT for heat recovery from the industrial waste water.

The growth of oscillating bubbles in an ultrasound field

NASA Astrophysics Data System (ADS)

Yamauchi, Risa; Yamashita, Tatsuya; Ando, Keita

2017-11-01

From our recent experiments to test particle removal by underwater ultrasound, dissolved gas supersaturation is found to play an important role in physical cleaning; cavitation bubble nucleation can be triggered easily by weak ultrasound under the supersaturation and mild motion of the bubbles contributes to efficient cleaning without erosion. The state of gas bubble nuclei in water is critical to the determination of a cavitation inception threshold. Under ultrasound forcing, the size of bubble nuclei is varied by the transfer of dissolved gas (i.e., rectified diffusion); the growth rate will be promoted by the supersaturation and is thus expected to contribute to cavitation activity enhancement. In the present work, we experimentally study rectified diffusion for bubbles attached at glass surfaces in an ultrasound field. We will present the evolution of bubble nuclei sizes with varying parameters such as dissolved oxygen supersaturation, and ultrasound intensity and frequency. the Research Grant of Keio Leading-edge Laboratory of Science & Technology.

The relationship between parenting styles and young adults' self-concepts and evaluations of parents.

PubMed

Parish, T S; McCluskey, J J

1992-01-01

In the present study, 123 college students were surveyed in order to assess their self-concepts, evaluations of parents, and perceptions of their parents' parenting styles. Notably, the students' self-concepts were found to vary directly with perceived level of parental warmth, but did not vary as a function of their parents' level of restrictiveness. Fathers and mothers were found to be rated more highly if they were perceived as being warm and permissive rather than hostile and restrictive. Finally, opposite-sex parents' level of warmth also correlated with how each parent was evaluated. Some explanations for these findings are offered.

An Experimental Study on the Edgewise Compressive Failure of Paper Honeycomb Sandwich Panels with Respect to Various Aspect Ratios

NASA Astrophysics Data System (ADS)

Samad, W. A.; Warsame, A. A.; Khan, A.

2018-04-01

The present work investigates the edgewise compression failure for honeycomb paperboards. Various panels are tested under a fixed loading rate with varying aspect ratios. The influence of the varying properties aspect ratio on yield strength is recorded. The experimental results indicate that the honeycomb paperboards are subject a decrease in yield strength with an increase in aspect ratio towards more slender bodies. Buckling was not observed in any of the tested specimens. All experiments are conducted under the general framework of ASTM C364/C364M -16 with a few noted changes.

Probing temperature-driven flow lines in a gated two-dimensional electron gas with tunable spin-splitting.

PubMed

Wang, Yi-Ting; Kim, Gil-Ho; Huang, C F; Lo, Shun-Tsung; Chen, Wei-Jen; Nicholls, J T; Lin, Li-Hung; Ritchie, D A; Chang, Y H; Liang, C-T; Dolan, B P

2012-10-10

We study the temperature flow of conductivities in a gated GaAs two-dimensional electron gas (2DEG) containing self-assembled InAs dots and compare the results with recent theoretical predictions. By changing the gate voltage, we are able to tune the 2DEG density and thus vary disorder and spin-splitting. Data for both the spin-resolved and spin-degenerate phase transitions are presented, the former collapsing to the latter with decreasing gate voltage and/or decreasing spin-splitting. The experimental results support a recent theory, based on modular symmetry, which predicts how the critical Hall conductivity varies with spin-splitting.

Application of a movable active vibration control system on a floating raft

NASA Astrophysics Data System (ADS)

Wang, Zhen; Mak, Cheuk Ming

2018-02-01

This paper presents a theoretical study of an inertial actuator connected to an accelerometer by a local feedback loop for active vibration control on a floating raft. On the criterion of the minimum power transmission from the vibratory machines to the flexible foundation in the floating raft, the best mounting positions for the inertial actuator on the intermediate mass of the floating raft are investigated. Simulation results indicate that the best mounting positions for the inertial actuator vary with frequency. To control time-varying excitations of vibratory machines on a floating raft effectively, an automatic control system based on real-time measurement of a cost function and automatically searching the best mounting position of the inertial actuator is proposed. To the best of our knowledge, it is the first time that an automatic control system is proposed to move an actuator automatically for controlling a time-varying excitation.

Assessment of the accuracy of portion size reports using computer-based food photographs aids in the development of an automated self-administered 24-hour recall.

PubMed

Subar, Amy F; Crafts, Jennifer; Zimmerman, Thea Palmer; Wilson, Michael; Mittl, Beth; Islam, Noemi G; McNutt, Suzanne; Potischman, Nancy; Buday, Richard; Hull, Stephen G; Baranowski, Tom; Guenther, Patricia M; Willis, Gordon; Tapia, Ramsey; Thompson, Frances E

2010-01-01

To assess the accuracy of portion-size estimates and participant preferences using various presentations of digital images. Two observational feeding studies were conducted. In both, each participant selected and consumed foods for breakfast and lunch, buffet style, serving themselves portions of nine foods representing five forms (eg, amorphous, pieces). Serving containers were weighed unobtrusively before and after selection as was plate waste. The next day, participants used a computer software program to select photographs representing portion sizes of foods consumed the previous day. Preference information was also collected. In Study 1 (n=29), participants were presented with four different types of images (aerial photographs, angled photographs, images of mounds, and household measures) and two types of screen presentations (simultaneous images vs an empty plate that filled with images of food portions when clicked). In Study 2 (n=20), images were presented in two ways that varied by size (large vs small) and number (4 vs 8). Convenience sample of volunteers of varying background in an office setting. Repeated-measures analysis of variance of absolute differences between actual and reported portions sizes by presentation methods. Accuracy results were largely not statistically significant, indicating that no one image type was most accurate. Accuracy results indicated the use of eight vs four images was more accurate. Strong participant preferences supported presenting simultaneous vs sequential images. These findings support the use of aerial photographs in the automated self-administered 24-hour recall. For some food forms, images of mounds or household measures are as accurate as images of food and, therefore, are a cost-effective alternative to photographs of foods. Copyright 2010 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

Assessment of the Accuracy of Portion Size Reports Using Computer-Based Food Photographs Aids in the Development of an Automated Self-Administered 24-Hour Recall

PubMed Central

Subar, Amy F.; Crafts, Jennifer; Zimmerman, Thea Palmer; Wilson, Michael; Mittl, Beth; Islam, Noemi G.; Mcnutt, Suzanne; Potischman, Nancy; Buday, Richard; Hull, Stephen G.; Baranowski, Tom; Guenther, Patricia M.; Willis, Gordon; Tapia, Ramsey; Thompson, Frances E.

2013-01-01

Objective To assess the accuracy of portion-size estimates and participant preferences using various presentations of digital images. Design Two observational feeding studies were conducted. In both, each participant selected and consumed foods for breakfast and lunch, buffet style, serving themselves portions of nine foods representing five forms (eg, amorphous, pieces). Serving containers were weighed unobtrusively before and after selection as was plate waste. The next day, participants used a computer software program to select photographs representing portion sizes of foods consumed the previous day. Preference information was also collected. In Study 1 (n=29), participants were presented with four different types of images (aerial photographs, angled photographs, images of mounds, and household measures) and two types of screen presentations (simultaneous images vs an empty plate that filled with images of food portions when clicked). In Study 2 (n=20), images were presented in two ways that varied by size (large vs small) and number (4 vs 8). Subjects/setting Convenience sample of volunteers of varying background in an office setting. Statistical analyses performed Repeated-measures analysis of variance of absolute differences between actual and reported portions sizes by presentation methods. Results Accuracy results were largely not statistically significant, indicating that no one image type was most accurate. Accuracy results indicated the use of eight vs four images was more accurate. Strong participant preferences supported presenting simultaneous vs sequential images. Conclusions These findings support the use of aerial photographs in the automated self-administered 24-hour recall. For some food forms, images of mounds or household measures are as accurate as images of food and, therefore, are a cost-effective alternative to photographs of foods. PMID:20102828

Genetic contribution for non-syndromic cleft lip with or without cleft palate (NS CL/P) in different regions of Brazil and implications for association studies.

PubMed

Brito, Luciano A; Cruz, Lucas A; Rocha, Kátia M; Barbara, Ligia K; Silva, Camila B F; Bueno, Daniela F; Aguena, Meire; Bertola, Débora R; Franco, Diogo; Costa, André M; Alonso, Nivaldo; Otto, Paulo A; Passos-Bueno, Maria Rita

2011-07-01

Non-syndromic cleft lip with or without cleft palate (NS CL/P) is a complex disease in which heritability estimates vary widely depending on the population studied. To evaluate the importance of genetic contribution to NS CL/P in the Brazilian population, we conducted a study with 1,042 families from five different locations (Santarém, Fortaleza, Barbalha, Maceió, and Rio de Janeiro). We also evaluated the role of consanguinity and ethnic background. The proportion of familial cases varied significantly across locations, with the highest values found in Santarém (44%) and the lowest in Maceió (23%). Heritability estimates showed a higher genetic contribution to NS CL/P in Barbalha (85%), followed by Santarém (71%), Rio de Janeiro (70%), Fortaleza (64%), and Maceió (45%). Ancestry was not correlated with the occurrence of NS CL/P or with the variability in heritability. Only in Rio de Janeiro was the coefficient of inbreeding significantly larger in NS CL/P families than in the local population. Recurrence risk for the total sample was approximately 1.5-1.6%, varying according to the location studied (0.6-0.7% in Maceió to 2.2-2.8% in Barbalha). Our findings show that the degree of genetic contribution to NS CL/P varies according to the geographic region studied, and this difference cannot be attributed to consanguinity or ancestry. These findings suggest that Barbalha is a promising region for genetic studies. The data presented here will be useful in interpreting results from molecular analyses and show that care must be taken when pooling samples from different populations for association studies. Copyright © 2011 Wiley-Liss, Inc.

Approximation-Based Adaptive Neural Tracking Control of Nonlinear MIMO Unknown Time-Varying Delay Systems With Full State Constraints.

PubMed

Li, Da-Peng; Li, Dong-Juan; Liu, Yan-Jun; Tong, Shaocheng; Chen, C L Philip

2017-10-01

This paper deals with the tracking control problem for a class of nonlinear multiple input multiple output unknown time-varying delay systems with full state constraints. To overcome the challenges which cause by the appearances of the unknown time-varying delays and full-state constraints simultaneously in the systems, an adaptive control method is presented for such systems for the first time. The appropriate Lyapunov-Krasovskii functions and a separation technique are employed to eliminate the effect of unknown time-varying delays. The barrier Lyapunov functions are employed to prevent the violation of the full state constraints. The singular problems are dealt with by introducing the signal function. Finally, it is proven that the proposed method can both guarantee the good tracking performance of the systems output, all states are remained in the constrained interval and all the closed-loop signals are bounded in the design process based on choosing appropriate design parameters. The practicability of the proposed control technique is demonstrated by a simulation study in this paper.

Impedance Eduction in Sound Fields With Peripherally Varying Liners and Flow

NASA Technical Reports Server (NTRS)

Watson, W. R.; Jones, M. G.

2015-01-01

A two-dimensional impedance eduction theory is extended to three-dimensional sound fields and peripherally varying duct liners. The approach is to first measure the acoustic pressure field at a series of flush-mounted wall microphones located around the periphery of the flow duct. The numerical solution for the acoustic pressure field at these microphones is also obtained by solving the three-dimensional convected Helmholtz equation using the finite element method. A quadratic objective function based on the difference between the measured and finite element solution is constructed and the unknown impedance function is obtained by minimizing this objective function. Impedance spectra educed for two uniform-structure liners (a wire-mesh and a conventional liner) and a hard-soft-hard peripherally varying liner (for which the soft segment is that of the conventional liner) are presented. Results are presented at three mean flow Mach numbers and fourteen sound source frequencies. The impedance spectra of the uniform-structure liners are also computed using a two-dimensional impedance eduction theory. The primary conclusions of the study are: 1) when measured data is used with the uniform-structure liners, the three-dimensional theory reproduces the same impedance spectra as the two-dimensional theory except for frequencies corresponding to very low or very high liner attenuation; and 2) good agreement between the educed impedance spectra of the uniform structure conventional liner and the soft segment of the peripherally varying liner is obtained.

Improved LTVMPC design for steering control of autonomous vehicle

NASA Astrophysics Data System (ADS)

Velhal, Shridhar; Thomas, Susy

2017-01-01

An improved linear time varying model predictive control for steering control of autonomous vehicle running on slippery road is presented. Control strategy is designed such that the vehicle will follow the predefined trajectory with highest possible entry speed. In linear time varying model predictive control, nonlinear vehicle model is successively linearized at each sampling instant. This linear time varying model is used to design MPC which will predict the future horizon. By incorporating predicted input horizon in each successive linearization the effectiveness of controller has been improved. The tracking performance using steering with front wheel and braking at four wheels are presented to illustrate the effectiveness of the proposed method.

Visual and Cardiac Responses to Animate and Inanimate Faces by Young Term and Preterm Infants.

ERIC Educational Resources Information Center

Field, Tiffany Martini

This paper presents a study of the looking and looking away or gaze alternation behavior of both full term and preterm infants in the presence of varying degrees of facial animation. The faces used in the study included, in increasing order of animation, a Raggedy Ann doll's face, a moving and talking doll's face, a mother's less animated face…

A Psychometric Study of Reading Processes in L2 Acquisition: Deploying Deep Processing to Push Learners' Discourse Towards Syntactic Processing-Based Constructions

ERIC Educational Resources Information Center

Manuel, Carlos J.

2009-01-01

This study assesses reading processes and/or strategies needed to deploy deep processing that could push learners towards syntactic-based constructions in L2 classrooms. Research has found L2 acquisition to present varying degrees of success and/or fossilization (Bley-Vroman 1989, Birdsong 1992 and Sharwood Smith 1994). For example, learners have…

PROJECT TALENT, IDENTIFICATION, DEVELOPMENT, AND UTILIZATION OF HUMAN TALENTS--SELECTED PUPIL AND SCHOOL CHARACTERISTICS IN RELATION TO PERCENTAGE OF NEGROES IN SCHOOL ENROLLMENT. FINAL REPORT.

ERIC Educational Resources Information Center

BURKET, GEORGE R.; FLANAGAN, JOHN C.

CONSISTING MAINLY OF TABLES, THIS REPORT PRESENTS THE FINDINGS OF A STATISTICAL STUDY WHICH EXAMINED THE DIFFERENCES AND SIMILARITIES AMONG 733 PROJECT TALENT SENIOR HIGH SCHOOLS WITH VARYING PROPORTIONS OF NEGRO ENROLLMENT. THE FACTORS STUDIED IN THESE SCHOOLS WERE EDUCATIONAL OUTCOMES, SCHOOL PRACTICES, STUDENT BODY CHARACTERISTICS, AND SCHOOL…

Working Memory Capacity and Recall from Long-Term Memory: Examining the Influences of Encoding Strategies, Study Time Allocation, Search Efficiency, and Monitoring Abilities

ERIC Educational Resources Information Center

Unsworth, Nash

2016-01-01

The relation between working memory capacity (WMC) and recall from long-term memory (LTM) was examined in the current study. Participants performed multiple measures of delayed free recall varying in presentation duration and self-reported their strategy usage after each task. Participants also performed multiple measures of WMC. The results…

Understanding the Factors That Shape Dispositions toward Students with Disabilities: A Case Study of Three General Education Pre-Service Teachers

ERIC Educational Resources Information Center

Bialka, Christa S.

2017-01-01

Presently, there is limited research that explores how the nature of pre-service teachers' prior experience informs their dispositional development, and it has yet to be determined whether the pedagogical needs of these prospective teachers vary based on their level of prior exposure. This qualitative case study examines the dispositions of three…

Water Transformation and Storage in the Mountains and at the Coast: Midwest Students' Disconnected Conceptions of the Hydrologic Cycle

ERIC Educational Resources Information Center

Shepardson, Daniel P.; Wee, Bryan; Priddy, Michelle; Schellenberger, Lauren; Harbor, Jon

2009-01-01

The purpose of the present study was to investigate students' conceptions of the hydrologic cycle and to examine whether these conceptions vary by grade level and community setting. This study was descriptive in nature and reflected a cross-age design involving the collection of qualitative data from 1,298 students from the Midwest, USA. These…

SERS internship Spring 1995 abstracts and research papers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, B.

Presented topics varied over many fields in science and engineering. Botany on grasses in California, real time face recognition technology, thermogravimetric studies on corrosion and finite element modeling of the human pelvis are examples of discussed subjects. Further fields of study are carcinogenics, waste management, radar imaging, automobile accessories, document searching on the internet, and shooting stars. Individual papers are indexed separately on EDB.

On discounting of health gains from human papillomavirus vaccination: effects of different approaches.

PubMed

Westra, Tjalke A; Parouty, Mehraj; Brouwer, Werner B; Beutels, Philippe H; Rogoza, Raina M; Rozenbaum, Mark H; Daemen, Toos; Wilschut, Jan C; Boersma, Cornelis; Postma, Maarten J

2012-05-01

Discounting has long been a matter of controversy in the field of health economic evaluations. How to weigh future health effects has resulted in ongoing discussions. These discussions are imminently relevant for health care interventions with current costs but future benefits. Different approaches to discount health effects have been proposed. In this study, we estimated the impact of different approaches for discounting health benefits of human papillomavirus (HPV) vaccination. An HPV model was used to estimate the impact of different discounting approaches on the present value of health effects. For the constant discount approaches, we varied the discount rate for health effects ranging from 0% to 4%. Next, the impact of relevant alternative discounting approaches was estimated, including hyperbolic, proportional, stepwise, and time-shifted discounting. The present value of health effects gained through HPV vaccination varied strongly when varying discount rates and approaches. The application of the current Dutch guidelines resulted in a present value of health effects that was eight or two times higher than that produced when using the proportional discounting approach or when using the internationally more common 4% discount rate for health effects, respectively. Obviously, such differences translate into large variations in corresponding incremental cost-effectiveness ratios. The exact discount rate and approach chosen in an economic evaluation importantly impact the projected value of health benefits of HPV vaccination. Investigating alternative discounting approaches in health-economic analysis is important, especially for vaccination programs yielding health effects far into the future. Our study underlines the relevance of ongoing discussions on how and at what rates to discount. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Influence of strontium on structure, sintering and biodegradation behaviour of CaO-MgO-SrO-SiO2-P2O5-CaF2 glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goel, Ashutosh; Rajagopal, Raghu R.; Ferreira, Jose M.

The present study investigates the influence of SrO on structure, apatite forming ability, physico-chemical degradation and sintering behaviour of melt-quenched bioactive glasses with composition: mol.% (36.07 – x) CaO – x SrO - 19.24 MgO – 5.61 P2O5 – 38.49 SiO2 – 0.59 CaF2, where x varies between 0 – 10. The detailed structural analysis of glasses has been made by infra red spectroscopy (FTIR) and magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR). Silicon was predominantly present as Q2 (Si) species while phosphorus was found in orthophosphate type environment in all the investigated glasses. The apatite forming ability of glassesmore » was investigated by immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1 h – 7 days. While increasing Sr2+/Ca2+ ratio in glasses did not affect the structure of glasses significantly, their apatite forming ability was decreased considerably. Further, physico-chemical degradation of glasses has been studied in accordance with ISO 10993-14 “Biological evaluation of medical devices – Part 14: Identification and quantification of degradation products from ceramics” in Tris HCl and citric acid buffer and the possible implications of ion release profile from glasses in different solutions has been discussed. The addition of strontium in glasses led to a 7-fold decrease in chemical degradation of glasses in Tris-HCl. The sintering of glass powders rendered glass-ceramics (GCs) with varying degree of crystallinity and good flexural strength (98-131 MPa) where the mechanical properties depend on the nature and amount of crystalline phases present in GCs.« less

Specimen loading list for the varying temperature experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qualls, A.L.; Sitterson, R.G.

1998-09-01

The varying temperature experiment HFIR-RB-13J has been assembled and inserted in the reactor. Approximately 5300 specimens were cleaned, inspected, matched, and loaded into four specimen holders. A listing of each specimen loaded into the steady temperature holder, its position in the capsule, and the identification of the corresponding specimen loaded into the varying temperature holder is presented in this report.

[Major tricuspid insufficiency and absence of systolic valvular coaptation. Echocardiographic study. Apropos of 6 cases].

PubMed

Roudaut, R; Héraudeau, A; Gosse, P; Aouizerate, E; Dequecker, J L; Dallocchio, M

1986-09-01

In a retrospective series of 960 cases of tricuspid regurgitation studied by two-dimensional echocardiography 6 patients presented a systolic defect of valvular coaptation. The origin of this defect varied: one case was due to carcinoid, two to rheumatic cardiopathy, two to papyraceous right ventricle and one to sclerodermia associated with pulmonary arterial hypertension. The mechanism of the lacking coaptation varies according to the etiology: valvular retraction in carcinoid cardiopathy, right-ventricle dilatation, dilatation of the tricuspid ring and altered kinetics of the right ventricle in the other cases. Changed contractility of the right ventricle is the only element allowing to distinguish tricuspid regurgitation with and without a coaptation defect. Clinically this abnormality always points to an advanced stage of severe tricuspid regurgitation.

Degradation of Kresoxim-Methyl in Water: Impact of Varying pH, Temperature, Light and Atmospheric CO2 Level.

PubMed

Khandelwal, Ashish; Gupta, Suman; Gajbhiye, Vijay T; Varghese, Eldho

2016-01-01

In the present investigation, persistence of kresoxim-methyl (a broad spectrum strobilurin fungicide) was studied in water. Results revealed that kresoxim-methyl readily form acid metabolite. Therefore, residues of kresoxim-methyl were quantified on the basis of parent molecule alone and sum total of kresoxim-methyl and its acid metabolite. In water, influence of various abiotic factors like pH, temperature, light and atmospheric carbon dioxide level on dissipation of kresoxim-methyl was studied. The half life value for kresoxim-methyl and total residue varied from 1 to 26.1 and 6.1 to 94.0 days under different conditions. Statistical analysis revealed the significant effect of abiotic factors on the dissipation of kresoxim-methyl from water.

Viscous drop collisions on surfaces of varying wettability

NASA Astrophysics Data System (ADS)

Bolleddula, Daniel; Berchielli, Al; Aliseda, Alberto

2010-11-01

We present an experimental study of increasingly viscous acetone rich and Newtonian equivalent liquid drops colliding on surfaces of varying wettability. This class of liquids applies directly to spray coating processes in pharmaceutical industries. The results from this study will elucidate the physics in a regime where resisting viscous forces and the restoring forces of capillarity are balanced, Oh˜ 1. Early spreading dynamics τ=Ut/D 1 indicate negligible dependence on contact angles while longer times demonstrate deviations from Tanner's law, D˜t^1/10. We will compare our results with recent theory to demonstrate the feasibility of modelling complex rheology spreading characteristics over short and long time scales. Preliminary results indicate an intermediate spreading regime following the inertial phase where the diameter, D˜t^n with 1/7 < n < 1/5.

A comparison of clinicians' access to online knowledge resources using two types of information retrieval applications in an academic hospital setting

PubMed Central

Hunt, Sevgin; Cimino, James J.; Koziol, Deloris E.

2013-01-01

Objective: The research studied whether a clinician's preference for online health knowledge resources varied with the use of two applications that were designed for information retrieval in an academic hospital setting. Methods: The researchers analyzed a year's worth of computer log files to study differences in the ways that four clinician groups (attending physicians, housestaff physicians, nurse practitioners, and nurses) sought information using two types of information retrieval applications (health resource links or Infobutton icons) across nine resources while they reviewed patients' laboratory results. Results: From a set of 14,979 observations, the authors found statistically significant differences among the 4 clinician groups for accessing resources using the health resources application (P<0.001) but not for the Infobuttons application (P = 0.31). For the health resources application, the preferences of the 4 clinical groups varied according to the specific resources examined (all P≤0.02). Conclusion: The information-seeking behavior of clinicians may vary in relation to their role and the way in which the information is presented. Studying these behaviors can provide valuable insights to those tasked with maintaining information retrieval systems' links to appropriate online knowledge resources. PMID:23405044

Dielectric Characterization of Mylar and The Effects of Doping Processes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belcher, Cami Beth

2016-11-01

Mylar® polymer is a bi-axially oriented polyethylene terephthalate (PET) polymer film used widely as a dielectric, specifically in capacitors. The dielectric characteristics of Mylar have been well studied and documented over the years; however, many of the mechanisms responsible for dielectric breakdown and failure are not understood for modified versions of the material. Previous studies on Mylar confirm that factors such as temperature, humidity, and voltage ramp rates can also have a significant effect on the dielectric properties and measurement of the dielectric properties. This study seeks to determine how dielectric properties, including permittivity, dielectric loss, and breakdown strength, aremore » affected by doping of the polymer. To do this, two types of Mylar films, virgin film and film doped with a small-molecule electron-acceptor, are tested. Both types of materials are tested under a variety of environmental and experimental conditions, including testing at elevated temperatures, varying relative humidity, and varying ramp rates in dielectric breakdown testing. Analysis of permittivity, dielectric loss, and breakdown strength will be presented comparing virgin and doped Mylar to gain insight into the effects of doping with electron-acceptor molecules on dielectric properties under these varying environmental and test conditions.« less

A comparison of clinicians' access to online knowledge resources using two types of information retrieval applications in an academic hospital setting.

PubMed

Hunt, Sevgin; Cimino, James J; Koziol, Deloris E

2013-01-01

The research studied whether a clinician's preference for online health knowledge resources varied with the use of two applications that were designed for information retrieval in an academic hospital setting. The researchers analyzed a year's worth of computer log files to study differences in the ways that four clinician groups (attending physicians, housestaff physicians, nurse practitioners, and nurses) sought information using two types of information retrieval applications (health resource links or Infobutton icons) across nine resources while they reviewed patients' laboratory results. From a set of 14,979 observations, the authors found statistically significant differences among the 4 clinician groups for accessing resources using the health resources application (P<0.001) but not for the Infobuttons application (P = 0.31). For the health resources application, the preferences of the 4 clinical groups varied according to the specific resources examined (all P≤0.02). The information-seeking behavior of clinicians may vary in relation to their role and the way in which the information is presented. Studying these behaviors can provide valuable insights to those tasked with maintaining information retrieval systems' links to appropriate online knowledge resources.

REACTIONS TO POSITIVE AND NEGATIVE INFORMATION ABOUT THE SELF AS A FUNCTION OF CERTAIN PERSONALITY CHARACTERISTICS OF THE RECIPIENT.

DTIC Science & Technology

discrepancies are compared for groups at three levels of self - esteem . The research is partly a replication of the studies by Harvey, Kelley, and...subsequent to the present one. In presenting individuals at varying levels of self - esteem with discrepant evaluations of themselves, the intent of this...handled within a theoretical model, there is no attempt to state a more comprehensive theory of self - esteem . (Author)

Effects of monetary reserves and rate of gain on human risky choice under budget constraints.

PubMed

Pietras, Cynthia J; Searcy, Gabriel D; Huitema, Brad E; Brandt, Andrew E

2008-07-01

The energy-budget rule is an optimal foraging model that predicts that choice should be risk averse when net gains plus reserves meet energy requirements (positive energy-budget conditions) and risk prone when net gains plus reserves fall below requirements (negative energy-budget conditions). Studies have shown that the energy-budget rule provides a good description of risky choice in humans when choice is studied under economic conditions (i.e., earnings budgets) that simulate positive and negative energy budgets. In previous human studies, earnings budgets were manipulated by varying earnings requirements, but in most nonhuman studies, energy budgets have been manipulated by varying reserves and/or mean rates of reinforcement. The present study therefore investigated choice in humans between certain and variable monetary outcomes when earnings budgets were manipulated by varying monetary reserves and mean rates of monetary gain. Consistent with the energy-budget rule, choice tended to be risk averse under positive-budget conditions and risk neutral or risk prone under negative-budget conditions. Sequential choices were also well described by a dynamic optimization model, especially when expected earnings for optimal choices were high. These results replicate and extend the results of prior experiments in showing that humans' choices are generally consistent with the predictions of the energy-budget rule when studied under conditions analogous to those used in nonhuman energy-budget studies, and that choice patterns tend to maximize reinforcement.

Survey of otolaryngology services in Ukraine and neighbouring Central and Eastern European countries.

PubMed

Verkerk, M M; Wagner, R; Fishchuk, R; Fagan, J J

2017-11-01

The present humanitarian crisis in Ukraine is putting strains on its healthcare system. This study aimed to assess services and training in otolaryngology, audiology and speech therapy in Ukraine and its geographical neighbours. Survey study of 327 otolaryngologists from 19 countries. Fifty-six otolaryngologists (17 per cent) from 15 countries responded. Numbers of otolaryngologists varied from 3.6 to 12.3 per 100 000 population (Ukraine = 7.8). Numbers of audiologists varied from 0, in Ukraine, to 2.8 per 100 000, in Slovakia, and numbers of speech therapists varied from 0, in Bulgaria, to 4.0 per 100 000, in Slovenia (Ukraine = 0.1). Ukraine lacks newborn and school hearing screening, good availability of otological drills and microscopes, and a cochlear implant programme. There is wide variation in otolaryngology services in Central and Eastern Europe. All countries surveyed had more otolaryngologists per capita than the UK, but availability of audiology and speech and language therapy is poor. Further research on otolaryngology health outcomes in the region will guide service improvement.

Gut microbiomes of Indian children of varying nutritional status.

PubMed

Ghosh, Tarini Shankar; Gupta, Sourav Sen; Bhattacharya, Tanudeep; Yadav, Deepak; Barik, Anamitra; Chowdhury, Abhijit; Das, Bhabatosh; Mande, Sharmila S; Nair, G Balakrish

2014-01-01

Malnutrition is a global health problem affecting more than 300 million pre-school children worldwide. It is one of the major health concerns in India since around 50% of children below the age of two suffer from various forms of malnutrition. The gut microbiome plays an important role in nutrient pre-processing, assimilation and energy harvest from food. Consequently, dysbiosis of the gut microbiota has been implicated in malnutrition. Metagenomics approach was adopted to investigate the gut microbiome sampled from 20 rural Indian children with varying nutritional status. The changes in the abundances of various taxonomic and functional groups were investigated across these gut microbiomes. A core set of 23 genera were observed across samples, with some showing differential abundances with varying nutritional status. One of the findings of the current study is the positive/negative associations of specific taxonomic and functional groups with the nutritional status of the children. Notable alterations in the architecture of the inter-microbial co-occurrence networks were also observed with changes in nutritional status. A key example is the clustering of potentially pathogenic groups into a distinct hub in severely malnourished gut. Our data does not demonstrate causality with the microbiome patterns that we observed, rather a description of some interesting patterns, whose underlying mechanism remains to be uncovered. The present study envisioned interrelationships between the pattern of gut microbiome and the nutritional status of children. The cause of this pattern needs to be explored. However, insights obtained from the present study form the basis for further metagenomic investigations on larger population of children. Results of such studies will be useful in identifying the key microbial groups that can be utilized for targeted therapeutic interventions for managing severe acute malnutrition.

Spontaneous Unfolding-Refolding of Fibronectin Type III Domains Assayed by Thiol Exchange

PubMed Central

Shah, Riddhi; Ohashi, Tomoo; Erickson, Harold P.; Oas, Terrence G.

2017-01-01

Globular proteins are not permanently folded but spontaneously unfold and refold on time scales that can span orders of magnitude for different proteins. A longstanding debate in the protein-folding field is whether unfolding rates or folding rates correlate to the stability of a protein. In the present study, we have determined the unfolding and folding kinetics of 10 FNIII domains. FNIII domains are one of the most common protein folds and are present in 2% of animal proteins. FNIII domains are ideal for this study because they have an identical seven-strand β-sandwich structure, but they vary widely in sequence and thermodynamic stability. We assayed thermodynamic stability of each domain by equilibrium denaturation in urea. We then assayed the kinetics of domain opening and closing by a technique known as thiol exchange. For this we introduced a buried Cys at the identical location in each FNIII domain and measured the kinetics of labeling with DTNB over a range of urea concentrations. A global fit of the kinetics data gave the kinetics of spontaneous unfolding and refolding in zero urea. We found that the folding rates were relatively similar, ∼0.1–1 s−1, for the different domains. The unfolding rates varied widely and correlated with thermodynamic stability. Our study is the first to address this question using a set of domains that are structurally homologous but evolved with widely varying sequence identity and thermodynamic stability. These data add new evidence that thermodynamic stability correlates primarily with unfolding rate rather than folding rate. The study also has implications for the question of whether opening of FNIII domains contributes to the stretching of fibronectin matrix fibrils. PMID:27909052

Gut Microbiomes of Indian Children of Varying Nutritional Status

PubMed Central

Bhattacharya, Tanudeep; Yadav, Deepak; Barik, Anamitra; Chowdhury, Abhijit; Das, Bhabatosh; Mande, Sharmila S.; Nair, G. Balakrish

2014-01-01

Background Malnutrition is a global health problem affecting more than 300 million pre-school children worldwide. It is one of the major health concerns in India since around 50% of children below the age of two suffer from various forms of malnutrition. The gut microbiome plays an important role in nutrient pre-processing, assimilation and energy harvest from food. Consequently, dysbiosis of the gut microbiota has been implicated in malnutrition. Methodology/Principal Findings Metagenomics approach was adopted to investigate the gut microbiome sampled from 20 rural Indian children with varying nutritional status. The changes in the abundances of various taxonomic and functional groups were investigated across these gut microbiomes. A core set of 23 genera were observed across samples, with some showing differential abundances with varying nutritional status. One of the findings of the current study is the positive/negative associations of specific taxonomic and functional groups with the nutritional status of the children. Notable alterations in the architecture of the inter-microbial co-occurrence networks were also observed with changes in nutritional status. A key example is the clustering of potentially pathogenic groups into a distinct hub in severely malnourished gut. Our data does not demonstrate causality with the microbiome patterns that we observed, rather a description of some interesting patterns, whose underlying mechanism remains to be uncovered. Conclusions The present study envisioned interrelationships between the pattern of gut microbiome and the nutritional status of children. The cause of this pattern needs to be explored. However, insights obtained from the present study form the basis for further metagenomic investigations on larger population of children. Results of such studies will be useful in identifying the key microbial groups that can be utilized for targeted therapeutic interventions for managing severe acute malnutrition. PMID:24763225

Vascular plant checklist of the Chimney Spring and Limestone Flats prescribed burning study areas within ponderosa pine experimental forests in northern Arizona (P-53)

Treesearch

Catherine Scudieri; James Fowler; Carolyn Hull Sieg; Laura Williams; Sally Haase

2008-01-01

This paper presents a vascular plant species list for two sites that are part of a long-term study exploring the effects of varying fire intervals on forest characteristics including the abundance and composition of understory vegetation. The Chimney Spring study area is on the Fort Valley Experimental Forest near Flagstaff, AZ and the Limestone Flats study area is on...

Orbitally-Induced, Quasi-Periodic Climate Change on Mars: Modelling Changes in the Global Cycling of Water and Carbon Dioxide

NASA Astrophysics Data System (ADS)

Mischna, M. A.; Richardson, M. I.; Wilson, R. J.

2002-12-01

Mars' orbital parameters (obliquity, eccentricity and argument of perihelion) are thought to have varied substantially on time scales >105 years. Such variations, especially in obliquity, may drastically affect the circulation of the atmosphere and volatile cycling. In this study, we focus on the response of the water and carbon dioxide cycles to changes in these orbital parameters, chiefly obliquity. The study employs the Geophysical Fluid Dynamics Laboratory Mars General Circulation Model, conducting simulations over a range of orbital states to examine changes in the cycling and deposition of these volatiles. This model contains full 3D accounting of atmospheric water and carbon dioxide as well as a basic dust cycle. The present martian obliquity is 25°, though it is believed to have recently varied between 15 and 45 degrees. Our simulations look at present martian conditions, only with obliquity varying between 5 and 60 degrees. Simulations are run out until water and carbon dioxide budgets have reached equilibrium--typically 30-40 years. As expected, volatile cycling on Mars increases with obliquity, as the polar caps are exposed to increased insolation, leading to greater seasonal ice caps and ultimately development of surface water ice in the now thermally favorible low latitudes. By 45°, water ice is stable in a broad band just north of the equator. Such an ice distribution has potential implications for the surface wind pattern through the ice-albedo effect on surface heating. Permanent polar CO2 caps are not stable under present conditions, but we find CO2 cap growth and corresponding atmospheric deflation to be evident at very low obliquities. We find that for most choices of orbital conditions, the northern hemisphere remains the stable pole for water ice, a result of the martian topographic dichotomy. We have begun to look at the impact of desorbed CO2 and H2O ice from the regolith on climatic conditions. Present estimates of the volatile abundance in the regolith vary greatly, but recent Mars Odyssey results hint at large abundances of water ice in the martian high-latitude regolith. The results of this study should better define models of polar volatile evolution, specifically those of layered terrain formation. The radiative feedback effects of increased atmospheric CO2 and H2O from the polar caps and regoliths has yet to be examined. Future plans include more accurate representations of dust injection and radiative transfer to tackle this problem.

Event Structure and Cognitive Control

ERIC Educational Resources Information Center

Reimer, Jason F.; Radvansky, Gabriel A.; Lorsbach, Thomas C.; Armendarez, Joseph J.

2015-01-01

Recently, a great deal of research has demonstrated that although everyday experience is continuous in nature, it is parsed into separate events. The aim of the present study was to examine whether event structure can influence the effectiveness of cognitive control. Across 5 experiments we varied the structure of events within the AX-CPT by…

Microenvironments in swine farrowing rooms: the thermal, lighting and acoustic environments of sows and piglets

USDA-ARS?s Scientific Manuscript database

The present research hypothesized that the thermal, lighting and acoustic environments in commercial swine farrowing rooms vary over time and among crates. The study was conducted in 27 replicates in two commercial farrowing rooms in North Central Indiana, each equipped with 60 farrowing crates. Tem...

Mothers' Socialization of Children's Emotion in India and the USA: A Cross- and within-Culture Comparison

ERIC Educational Resources Information Center

Raval, Vaishali V.; Raval, Pratiksha H.; Salvina, Jennifer M.; Wilson, Stephanie L.; Writer, Sharon

2013-01-01

Parent responses to children's emotions vary within and across cultures. The present study compared mothers' reports of their emotional and behavioral responses in hypothetical situations depicting their children experiencing anger, sadness, or physical pain in two communities in India (traditional old city, "N" = 60; suburban middle…

The Effects of Professors' Race and Gender on Student Evaluations and Performance

ERIC Educational Resources Information Center

Basow, Susan A.; Codos, Stephanie; Martin, Julie L.

2013-01-01

This experimental study examined the effects of professor gender, professor race, and student gender on student ratings of teaching effectiveness and amount learned. After watching a three-minute engineering lecture presented by a computer-animated professor who varied by gender and race (African American, White), female and male undergraduates…

Graduate Medical Education in the European Region. EURO Reports and Studies 77.

ERIC Educational Resources Information Center

World Health Organization, Copenhagen (Denmark). Regional Office for Europe.

Statistics about postgraduate training requirements in the main medical specialties in 26 European countries belonging to the World Health Organization are presented. It is noted that conventions vary widely from country to country concerning the designation of main specialties and subspecialties. These variations are apparent from the lengths of…

Self-Assessed Intelligence: Inter-Ethnic, Rural-Urban, and Sex Differences in Malaysia

ERIC Educational Resources Information Center

Swami, Viren; Furnham, Adrian

2010-01-01

The present study examined inter-ethnic, rural-urban, and sex differences in self-assessed intelligence (SAI) in a Malaysian general population sample. In total, 633 individuals varying in rural or urban location, ethnicity (Malay, Kadazan, and Bajau), and sex (women versus men) provided their self-assessed overall intelligence and ten multiple…

Cyberbully, Cybervictim, and Forgiveness among Indonesian High School Students

ERIC Educational Resources Information Center

Safaria, Triantoro; Tentama, Fatwa; Suyono, Hadi

2016-01-01

Cyberbullying has been commonplace practice among Indonesian teenagers engaging in on-line space. However, this phenomenon has not been extensively researched in the context of Indonesia. This present study aims to examine the extent to which level of forgiveness contribute to varying degrees of cyberbullying. It is a quantitative in which the…

Songs as Ambient Language Input in Phonology Acquisition

ERIC Educational Resources Information Center

Au, Terry Kit-fong

2013-01-01

Children cannot learn to speak a language simply from occasional noninteractive exposure to native speakers' input (e.g., by hearing television dialogues), but can they learn something about its phonology? To answer this question, the present study varied ambient hearing experience for 126 5- to 7-year-old native Cantonese-Chinese speakers…

The Effects of Syntactic Complexity on Processing Sentences in Noise

ERIC Educational Resources Information Center

Carroll, Rebecca; Ruigendijk, Esther

2013-01-01

This paper discusses the influence of stationary (non-fluctuating) noise on processing and understanding of sentences, which vary in their syntactic complexity (with the factors canonicity, embedding, ambiguity). It presents data from two RT-studies with 44 participants testing processing of German sentences in silence and in noise. Results show a…

ASD, a Psychiatric Disorder, or Both? Psychiatric Diagnoses in Adolescents with High-Functioning ASD

ERIC Educational Resources Information Center

Mazefsky, Carla A.; Oswald, Donald P.; Day, Taylor N.; Eack, Shaun M.; Minshew, Nancy J.; Lainhart, Janet E.

2012-01-01

Varied presentations of emotion dysregulation in autism complicate diagnostic decision making and may lead to inaccurate psychiatric diagnoses or delayed autism diagnosis for high-functioning children. This pilot study aimed to determine the concordance between prior psychiatric diagnoses and the results of an autism-specific psychiatric interview…

Sex Differences in Children's Discrepant Perceptions of Peer Acceptance

ERIC Educational Resources Information Center

Smith, Stephanie D.; Van Gessel, Christine A.; David-Ferdon, Corinne; Kistner, Janet A.

2013-01-01

Sex differences in children's play patterns during middle childhood are thought to promote greater awareness of social acceptance among girls compared with boys. The present study posited that girls are more discerning of peer acceptance than are boys; however, these sex differences were predicted to vary depending on how discrepant perceptions…

The Impact of Behavioral Signs of Intoxication on Bartender Service

ERIC Educational Resources Information Center

Goodsite, Billie; Klear, Lacey; Rosenberg, Harold

2008-01-01

Objective: The present study was designed to assess whether the serving practices of a sample of bartenders in an American university town would vary as a function of the number of behavioral cues of intoxication displayed by apparently real patrons (who were actually experimental confederates). Method: We trained two male and three female…

Reasons for Living and Alcohol Use among College Students

ERIC Educational Resources Information Center

Lamis, Dorian A.; Ellis, Jon B.; Chumney, Frances L.; Dula, Chris S.

2009-01-01

Heavy alcohol consumption is prevalent on many college campuses and alcohol use has been linked to suicidal behavior. The present study examined reasons for living in 287 college students with varying levels of risk for alcohol-related problems. With the exception of the moral objections subscale of the Reasons for Living Inventory, significant…

Cowboys and Indians: Perceptions of Western Films among American Indians and Anglos.

ERIC Educational Resources Information Center

Shively, JoEllen

1992-01-01

Presents the results of a study of how minorities participate in and rework the central myths of the dominant culture. The responses of 20 Anglo White males versus 20 American Indian males to a western film showed that the meaning imputed to cultural works varies over social space. (JB)

Awareness and the Effect of Rate Rehearsal on Free Recall

ERIC Educational Resources Information Center

Kestner, Jane; Walter, Donald A.

1977-01-01

The effect of time of awareness of a subsequent test of recall and the relationship of that awareness and rote rehearsal were studied by telling subjects which specific items to encode before the item's presentation (prior instructions) or after its rehearsal (postrehearsal instructions) and by varying rehearsal intervals for individual items.…

Fostering Students' Moderation Competence: The Interplay between Social Relatedness and Perceived Competence

ERIC Educational Resources Information Center

Bürgermeister, Anika; Ringeisen, Tobias; Raufelder, Diana

2016-01-01

Using a longitudinal design, the present study examined whether two teaching concepts that varied in their capacity to foster students' self-determination affected students' sense of social relatedness and their perceived moderation competence, as well as the interplay between these two components and the students' performance during a moderation…

Temporal Dynamics of Awareness for Facial Identity Revealed with ERP

ERIC Educational Resources Information Center

Genetti, Melanie; Khateb, Asaid; Heinzer, Severine; Michel, Christoph M.; Pegna, Alan J.

2009-01-01

In this study, we investigated the scalp recorded event-related potential (ERP) responses related to visual awareness. A backward masking procedure was performed while high-density EEG recordings were carried out. Subjects were asked to detect a familiar face, presented at durations that varied parametrically between 16 and 266 ms. ERPs were…

An Attempt to Compare EMCS with TOXLINE.

ERIC Educational Resources Information Center

Lorent, Jean-Pierre; Schirner, Hedi

1978-01-01

Sixteen queries, performed on the two systems, resulted in 247 unique relevant references from EMCS and 559 from TOXLINE. The overlap varied considerably, from 6 to 50 percent. It is remarkable that TOXLINE, with nine subfiles specially compiled for toxicology, can be supplemented by EMCS, which in the present study delivered 31 percent of all the…

Linguistic and Psychomotor Development in Children with Chromosome 14 Deletions

ERIC Educational Resources Information Center

Zampini, Laura; D'Odorico, Laura; Zanchi, Paola; Zollino, Marcella; Neri, Giovanni

2012-01-01

The present study focussed on a specific type of rare genetic condition: chromosome 14 deletions. Children with this genetic condition often show developmental delays and brain and neurological problems, although the type and severity of symptoms varies depending on the size and location of the deleted genetic material. The specific aim of the…

Psychostimulant Use for Children with ADHD in Australia.

ERIC Educational Resources Information Center

Reid, Robert; Prosser, Brenton

1999-01-01

This study presents data from Australia on psychostimulant production and prescription rates for children with attention-deficit disorders and analyzes data from one city. Results indicate that medication use is increasing at a rate similar to that in the United States and that prescription rates may vary by income and unemployment. (Author/CR)

Profiling Students' Multiple Source Use by Question Type

ERIC Educational Resources Information Center

List, Alexandra; Grossnickle, Emily M.; Alexander, Patricia A.

2016-01-01

The present study examined undergraduate students' multiple source use in response to two different types of academic questions, one discrete and one open-ended. Participants (N = 240) responded to two questions using a library of eight digital sources, varying in source type (e.g., newspaper article) and reliability (e.g., authors' credentials).…

Longitudinal Consistency of Adolescent Ethnic Identification across Varying School Ethnic Contexts

ERIC Educational Resources Information Center

Nishina, Adrienne; Bellmore, Amy; Witkow, Melissa R.; Nylund-Gibson, Karen

2010-01-01

The present study examined consistency and inconsistency in adolescents' ethnic identification (i.e., self-reported ethnicity) across the 6 middle-school semesters. The sample (N = 1,589, of whom 46% were boys and 54% were girls) included African American, Asian/Pacific Islander, Caucasian/White, Latino/Latina, Mexican/Mexican American, and…

Learning from Our Mistakes: Improvements in Spelling Lead to Gains in Reading Speed

ERIC Educational Resources Information Center

Ouellette, Gene; Martin-Chang, Sandra; Rossi, Maya

2017-01-01

The present study tested the hypothesis that underlying orthographic representations vary in completeness within the individual, which is manifested in both spelling accuracy and reading speed. Undergraduate students were trained to improve their spelling of difficult words. Word reading speed was then measured for these same words, allowing for a…

Emergency Presentations to an Inner-City Psychiatric Service for Children and Adolescents

ERIC Educational Resources Information Center

Dil, L. M.; Vuijk, P. J.

2012-01-01

Psychiatric emergency services for children and adolescents vary in process, structure and outcome. There are few systematic studies on the type and prevalence of psychiatric problems encountered, related circumstances or resulting interventions. Evidence in these areas is important in evaluation of the function of mental health services in the…

Using a Chart-table Medium to Focus Students' Attention on Science Concepts.

ERIC Educational Resources Information Center

Holliday, William G.; Benson, Garth D.

A study is presented which utilizes a selective attention model to investigate the learning effects of different questioning strategies under four experimental conditions using a non-prose medium (science textbook chart) containing information of varying established difficulty. A 14-row, 4-column chart describing 14 vitamins was used to present…

A Biosocial View of Population: Fertility Behavior in Animal Groups and Early Human Societies. A Review.

ERIC Educational Resources Information Center

Murphy, Elaine M.

The paper discusses the relationship between social structure and fertility behavior in man. Focusing upon human fertility within the context of varying social groups, the document reviews recent interdisciplinary population studies. Information and interpretations from biology, ethnology, anthropology, history, and sociology are presented in four…

The Effect of Social Dominance Orientation on Perceptions of Corporal Punishment

ERIC Educational Resources Information Center

Hess, Chelsie A.; Gray, Jennifer M.; Nunez, Narina L.

2012-01-01

Previous research has suggested the use of corporal punishment is widely endorsed in our society (Straus, 2000; Straus & Stewart, 1999). Furthermore, perceptions of what constitutes corporal punishment vary. The present study examined social dominance orientation (SDO) and age of child as potential factors that may influence perceptions of what is…

Subspace in Linear Algebra: Investigating Students' Concept Images and Interactions with the Formal Definition

ERIC Educational Resources Information Center

Wawro, Megan; Sweeney, George F.; Rabin, Jeffrey M.

2011-01-01

This paper reports on a study investigating students' ways of conceptualizing key ideas in linear algebra, with the particular results presented here focusing on student interactions with the notion of subspace. In interviews conducted with eight undergraduates, we found students' initial descriptions of subspace often varied substantially from…

School Ethnic Composition and Bullying in Canadian Schools

ERIC Educational Resources Information Center

Vitoroulis, Irene; Brittain, Heather; Vaillancourt, Tracy

2016-01-01

Bullying in ethnically diverse schools varies as a function of the ethnic composition and degree of diversity in schools. Although Canada is highly multicultural, few researchers have focused on the role of context on ethnic majority and minority youths' bullying involvement. In the present study, 11,649 European-Canadian/ethnic majority (77%) and…

Status and Use of African Lingua Francas. Afrika-Studien Nr. 49.

ERIC Educational Resources Information Center

Heine, Bernd

Defining a lingua franca as a "common language which is habitually used as a medium of communication between groups of people whose mother tongues are different, "this book begins by comparing various Africa lingua francas and discussing questions of general relevance to their study, and then presents statements of varying length about…

The Development of Arithmetic Principle Knowledge: How Do We Know What Learners Know?

ERIC Educational Resources Information Center

Prather, Richard W.; Alibali, Martha W.

2009-01-01

This paper reviews research on learners' knowledge of three arithmetic principles: "Commutativity", "Relation to Operands", and "Inversion." Studies of arithmetic principle knowledge vary along several dimensions, including the age of the participants, the context in which the arithmetic is presented, and most importantly, the type of knowledge…

Post-processing method to reduce noise while preserving high time resolution in aethalometer real-time black carbon data

EPA Science Inventory

Real-time aerosol black carbon (BC) data, presented at time resolutions on the order of seconds to minutes, is desirable in field and source characterization studies measuring rapidly varying concentrations of BC. The Optimized Noise-reduction Averaging (ONA) algorithm has been d...

Facework among L2 Speakers: A Close Look at Intercultural Communication

ERIC Educational Resources Information Center

Jwa, Soomin

2017-01-01

Although significant attention has been devoted to the notion of facework and its functions, facework among L2 speakers, whose cultural backgrounds and language proficiencies vary, has remained unexplored. The present study attempts to explore situations of intercultural communication in which facework is used as a way to remedy moments of…

Orienting to Third-Party Conversations

ERIC Educational Resources Information Center

Martinez-Sussmann, Carmen; Akhtar, Nameera; Diesendruck, Gil; Markson, Lori

2011-01-01

Children as young as two years of age are able to learn novel object labels through overhearing, even when distracted by an attractive toy (Akhtar, 2005). The present studies varied the information provided about novel objects and examined which elements (i.e. novel versus neutral information and labels versus facts) toddlers chose to monitor, and…

Opaque for the Reader but Transparent for the Brain: Neural Signatures of Morphological Complexity

ERIC Educational Resources Information Center

Meinzer, Marcus; Lahiri, Aditi; Flaisch, Tobias; Hannemann, Ronny; Eulitz, Carsten

2009-01-01

Within linguistics, words with a complex internal structure are commonly assumed to be decomposed into their constituent morphemes (e.g., un-help-ful). Nevertheless, an ongoing debate concerns the brain structures that subserve this process. Using functional magnetic resonance imaging, the present study varied the internal complexity of derived…

Journalogue: Voicing Student Challenges in Writing through a Classroom Blog

ERIC Educational Resources Information Center

Thomas, Suneeta

2017-01-01

This study qualitatively analyzes the challenges presented by international undergraduate students in a freshman composition course at a large Midwestern university in the US. 15 students were divided into five groups, of three members each, with varying proficiency levels in writing. They were asked to submit reflections as journal/blog posts, on…

Preschool Children's Participation in Representational and Non-Representational Activities

ERIC Educational Resources Information Center

Braswell, Gregory S.

2017-01-01

The present study examined representational and non-representational activities in which children in a Head Start classroom participated. This was an investigation from the perspective of cultural-historical activity theory of how components (e.g. artifacts and division of labour) of classroom activities vary across and within types of activities.…

The Effect of Faculty Self-Promotion on Student Evaluations of Teaching

ERIC Educational Resources Information Center

Farreras, Ingrid G.; Boyle, Robert W.

2012-01-01

This study investigated the effect that varying degrees of faculty self-promotion had on 322 student evaluations. As high student evaluations are correlated with greater student learning, it is imperative that we assess how faculty's presentation style is perceived by students so as to enhance instruction and therefore student learning. Students…

Novel expression patterns of carotenoid pathway-related gene in citrus leaves and maturing fruits

USDA-ARS?s Scientific Manuscript database

Carotenoids are abundant in citrus fruits and vary among cultivars and species. In the present study, HPLC and real-time PCR were used to investigate the expression patterns of 23 carotenoid biosynthesis gene family members and their possible relation with carotenoid accumulation in flavedo, juice s...

A Differential Analysis of Effectiveness in Middle and Low Socioeconomic Status Schools

ERIC Educational Resources Information Center

Teddlie, Charles; Stringfield, Samuel

2017-01-01

A major focus of the Louisiana School Effectiveness Study has been the search for characteristics of exemplary schooling in varied economic contexts. In this paper differential results of analyses of effective, typical, and ineffective schools in middle and low socioeconomic neighborhoods are presented. Implications for practitioners and for…

Anxiety in People Diagnosed with Autism and Intellectual Disability: Recognition and Phenomenology

ERIC Educational Resources Information Center

Helverschou, Sissel Berge; Martinsen, Harald

2011-01-01

Anxiety seems to occur frequently in individuals with autism, but varying prevalence estimates indicate uncertainties in identifying anxiety, especially in those with intellectual disability (ID). The present study explores the recognition of anxiety symptoms and aims to provide suggestions for the assessment of anxiety in individuals with autism…

Studies on heat transfer and pressure drop in turbulent flow of silver - water nanofluids through a circular tube at constant wall heat flux

NASA Astrophysics Data System (ADS)

Iyahraja, S.; Rajadurai, J. Selwin; Rajesh, S.; Pandian, R. Seeni Thangaraj; Kumaran, M. Selva; Selvakumar, G.

2018-07-01

In the present study, performance of convective heat transfer and friction factor of silver-water nanofluids in a horizontal circular pipe under turbulent flow were investigated experimentally under uniform heat flux condition. The volume concentration of silver nanoparticles is varied as 0.01, 0.05 and 0.1%. Heat transfer coefficient and friction factor of nanofluids were measured experimentally by varying the Reynolds number from 3000 to 21,000. It is observed that the addition of even low volume fraction of silver nanoparticles increases both Nusselt number and heat transfer coefficient of the nanofluid significantly. Nusselt number of silver-water nanofluid increases up to 32.6% for 0.1% volume fraction at Reynolds number of 21,000. However, the addition of nanoparticles in the base fluid increases the friction factor slightly. New empirical correlations are also proposed for the estimation of Nusselt number and friction factor of silver-water nanofluid based on the data of present experimental investigation. The proposed correlations of Nusselt number and friction factor show good agreement with their experimental data.

Adaptive fuzzy logic controller with direct action type structures for InnoSAT attitude control system

NASA Astrophysics Data System (ADS)

Bakri, F. A.; Mashor, M. Y.; Sharun, S. M.; Bibi Sarpinah, S. N.; Abu Bakar, Z.

2016-10-01

This study proposes an adaptive fuzzy controller for attitude control system (ACS) of Innovative Satellite (InnoSAT) based on direct action type structure. In order to study new methods used in satellite attitude control, this paper presents three structures of controllers: Fuzzy PI, Fuzzy PD and conventional Fuzzy PID. The objective of this work is to compare the time response and tracking performance among the three different structures of controllers. The parameters of controller were tuned on-line by adjustment mechanism, which was an approach similar to a PID error that could minimize errors between actual and model reference output. This paper also presents a Model References Adaptive Control (MRAC) as a control scheme to control time varying systems where the performance specifications were given in terms of the reference model. All the controllers were tested using InnoSAT system under some operating conditions such as disturbance, varying gain, measurement noise and time delay. In conclusion, among all considered DA-type structures, AFPID controller was observed as the best structure since it outperformed other controllers in most conditions.

Studies on heat transfer and pressure drop in turbulent flow of silver - water nanofluids through a circular tube at constant wall heat flux

NASA Astrophysics Data System (ADS)

Iyahraja, S.; Rajadurai, J. Selwin; Rajesh, S.; Pandian, R. Seeni Thangaraj; Kumaran, M. Selva; Selvakumar, G.

2018-02-01

In the present study, performance of convective heat transfer and friction factor of silver-water nanofluids in a horizontal circular pipe under turbulent flow were investigated experimentally under uniform heat flux condition. The volume concentration of silver nanoparticles is varied as 0.01, 0.05 and 0.1%. Heat transfer coefficient and friction factor of nanofluids were measured experimentally by varying the Reynolds number from 3000 to 21,000. It is observed that the addition of even low volume fraction of silver nanoparticles increases both Nusselt number and heat transfer coefficient of the nanofluid significantly. Nusselt number of silver-water nanofluid increases up to 32.6% for 0.1% volume fraction at Reynolds number of 21,000. However, the addition of nanoparticles in the base fluid increases the friction factor slightly. New empirical correlations are also proposed for the estimation of Nusselt number and friction factor of silver-water nanofluid based on the data of present experimental investigation. The proposed correlations of Nusselt number and friction factor show good agreement with their experimental data.

The effect of path length and display size on memory for spatial information.

PubMed

Guérard, Katherine; Tremblay, Sébastien

2012-01-01

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Spatially varying geometric phase in classically entangled vector beams of light

NASA Astrophysics Data System (ADS)

King-Smith, Andrew; Leary, Cody

We present theoretical results describing a spatially varying geometric (Pancharatnam) phase present in vector modes of light, in which the polarization and transverse spatial mode degrees of freedom exhibit classical entanglement. We propose an experimental setup capable of characterizing this effect, in which a vector mode propagates through a Mach-Zehnder interferometer with a birefringent phase retarder present in one arm. Since the polarization state of a classically entangled light beam exhibits spatial variation across the transverse mode profile, the phase retarder gives rise to a spatially varying geometric phase in the beam propagating through it. When recombined with the reference beam from the other interferometer arm, the presence of the geometric phase is exhibited in the resulting interference pattern. We acknowledge funding from the Research Corporation for Science Advancement by means of a Cottrell College Science Award.

[Gender differences in emotion regulation in response to texts with violent content].

PubMed

Lysenko, N E; Davydov, D M

2012-01-01

We investigated gender differences in emotion regulation depending on the cognitive disclosure of negative emotive content of 3 different texts after their presentations. For the purposes of the study we varied order between (i) completing of special checklists, created for specification of emotive and arousing attributes of the text contents and (ii) readings of autonomic activity. Results suggested that completing of the checklists increased engagement in processing of the most arousing text's content in men, while no effect was found in women, who were proposed to be engaged in content processing already during the text presentation. Results of the present study are discussed in the context of the recent findings on the emotional regulation.

Simulating demand for cigarettes among pregnant women: A Low-Risk method for studying vulnerable populations.

PubMed

Higgins, Stephen T; Reed, Derek D; Redner, Ryan; Skelly, Joan M; Zvorsky, Ivori A; Kurti, Allison N

2017-01-01

A substantive obstacle to experimentally studying cigarette smoking and use of other tobacco products in pregnant women is the risk of adverse effects on mother and fetus from experimenter administration of the product of interest. The purpose of this study is to investigate bypassing that obstacle by using behavioral economic simulation tasks. In the present study we used the Cigarette Purchase Task (CPT) to simulate changes in demand for hypothetical cigarettes as a function of varying cigarette prices. Participants were 95 pregnant women who completed the CPT prior to participation in a smoking-cessation trial. Aggregate and individual participant demand varied as an orderly function of price and those changes were well fitted by an exponential equation. Demand also varied in correspondence to two well-validated predictors of individual differences in smoking cessation among pregnant women (cigarettes smoked per day, pre-pregnancy quit attempts). Moreover, CPT indices were more effective than these two conventional variables in predicting individual differences in whether women made a quit attempt during the current pregnancy. Overall, these results represent a promising step in demonstrating the validity and utility of the CPT for experimentally examining demand for cigarettes, and potentially other tobacco and nicotine delivery products, among pregnant women. © 2016 Society for the Experimental Analysis of Behavior.

SIMULATING DEMAND FOR CIGARETTES AMONG PREGNANT WOMEN: A LOW-RISK METHOD FOR STUDYING VULNERABLE POPULATIONS

PubMed Central

Higgins, Stephen T.; Reed, Derek D.; Redner, Ryan; Skelly, Joan M.; Zvorsky, Ivori A.; Kurti, Allison N.

2016-01-01

A substantive obstacle to experimentally studying cigarette smoking and use of other tobacco products in pregnant women is the risk of adverse effects on mother and fetus from experimenter administration of the product of interest. The purpose of this study is to investigate bypassing that obstacle by using behavioral economic simulation tasks. In the present study we used the Cigarette Purchase Task (CPT) to simulate changes in demand for hypothetical cigarettes as a function of varying cigarette prices. Participants were 95 pregnant women who completed the CPT prior to participation in a smoking-cessation trial. Aggregate and individual participant demand varied as an orderly function of price and those changes were well fitted by an exponential equation. Demand also varied in correspondence to two well-validated predictors of individual differences in smoking cessation among pregnant women (cigarettes smoked per day, pre-pregnancy quit attempts). Moreover, CPT indices were more effective than these two conventional variables in predicting individual differences in whether women made a quit attempt during the current pregnancy. Overall, these results represent a promising step in demonstrating the validity and utility of the CPT for experimentally examining demand for cigarettes, and potentially other tobacco and nicotine delivery products, among pregnant women. PMID:28000917

[Mes differ by positioning: empirical testing of decentralized dynamics of the self].

PubMed

Mizokami, Shinichi

2013-10-01

The present study empirically tested the conceptualization of the decentralized dynamics of the self proposed by Hermans & Kempen (1993), which they developed theoretically and from clinical cases, not from large samples of empirical data. They posited that worldviews and images of the self could vary by positioning even in the same individual, and denied that the ego was an omniscient entity that knew and controlled all aspects of the self (centralized ego). Study 1 tested their conceptualization empirically with 47 university students in an experimental group and 17 as a control group. The results showed that the scores on the Rosenberg's self-esteem scale and images of the Mes in the experimental group significantly varied by positioning, but those in the control group did not. Similar results were found in Study 2 with a sample of 120 university students. These results empirically supported the conceptualization of the decentralized dynamics of the self.

[Continuity and non-continuity from child- to adulthood in psychiatric clinical studies].

PubMed

Kuwabara, Hitoshi; Kawakubo, Yuki; Kano, Yukiko

2014-01-01

It is difficult to conceive of the development of the brain as a single process, especially when we think about continuity and non-continuity from child- to adulthood. Non-continuity may be present when the brain is developing normally or consistently, or during aging, and development may vary across behavioral, structural, functional, and regional units. Clinical studies that consider the developmental process of change as natural and expected may better incorporate the potential variety and non-continuity than clinical studies that do not consider the process of change. It is likely that these complications are exacerbated because the timing of changes appears to vary across units. If we can identify the critical points of plasticity, temporally appropriate interventions can be developed. A focus on the developmental process of changes in the brain may lead to more rational and effective intervention strategies.

Datasets for supplier selection and order allocation with green criteria, all-unit quantity discounts and varying number of suppliers.

PubMed

Hamdan, Sadeque; Cheaitou, Ali

2017-08-01

This data article provides detailed optimization input and output datasets and optimization code for the published research work titled "Dynamic green supplier selection and order allocation with quantity discounts and varying supplier availability" (Hamdan and Cheaitou, 2017, In press) [1]. Researchers may use these datasets as a baseline for future comparison and extensive analysis of the green supplier selection and order allocation problem with all-unit quantity discount and varying number of suppliers. More particularly, the datasets presented in this article allow researchers to generate the exact optimization outputs obtained by the authors of Hamdan and Cheaitou (2017, In press) [1] using the provided optimization code and then to use them for comparison with the outputs of other techniques or methodologies such as heuristic approaches. Moreover, this article includes the randomly generated optimization input data and the related outputs that are used as input data for the statistical analysis presented in Hamdan and Cheaitou (2017 In press) [1] in which two different approaches for ranking potential suppliers are compared. This article also provides the time analysis data used in (Hamdan and Cheaitou (2017, In press) [1] to study the effect of the problem size on the computation time as well as an additional time analysis dataset. The input data for the time study are generated randomly, in which the problem size is changed, and then are used by the optimization problem to obtain the corresponding optimal outputs as well as the corresponding computation time.

3D printing of novel osteochondral scaffolds with graded microstructure

NASA Astrophysics Data System (ADS)

Nowicki, Margaret A.; Castro, Nathan J.; Plesniak, Michael W.; Zhang, Lijie Grace

2016-10-01

Osteochondral tissue has a complex graded structure where biological, physiological, and mechanical properties vary significantly over the full thickness spanning from the subchondral bone region beneath the joint surface to the hyaline cartilage region at the joint surface. This presents a significant challenge for tissue-engineered structures addressing osteochondral defects. Fused deposition modeling (FDM) 3D bioprinters present a unique solution to this problem. The objective of this study is to use FDM-based 3D bioprinting and nanocrystalline hydroxyapatite for improved bone marrow human mesenchymal stem cell (hMSC) adhesion, growth, and osteochondral differentiation. FDM printing parameters can be tuned through computer aided design and computer numerical control software to manipulate scaffold geometries in ways that are beneficial to mechanical performance without hindering cellular behavior. Additionally, the ability to fine-tune 3D printed scaffolds increases further through our investment casting procedure which facilitates the inclusion of nanoparticles with biochemical factors to further elicit desired hMSC differentiation. For this study, FDM was used to print investment-casting molds innovatively designed with varied pore distribution over the full thickness of the scaffold. The mechanical and biological impacts of the varied pore distributions were compared and evaluated to determine the benefits of this physical manipulation. The results indicate that both mechanical properties and cell performance improve in the graded pore structures when compared to homogeneously distributed porous and non-porous structures. Differentiation results indicated successful osteogenic and chondrogenic manipulation in engineered scaffolds.

Study on the Variation of Groundwater Level under Time-varying Recharge

NASA Astrophysics Data System (ADS)

Wu, Ming-Chang; Hsieh, Ping-Cheng

2017-04-01

The slopes of the suburbs come to important areas by focusing on the work of soil and water conservation in recent years. The water table inside the aquifer is affected by rainfall, geology and topography, which will result in the change of groundwater discharge and water level. Currently, the way to obtain water table information is to set up the observation wells; however, owing to that the cost of equipment and the wells excavated is too expensive, we develop a mathematical model instead, which might help us to simulate the groundwater level variation. In this study, we will discuss the groundwater level change in a sloping unconfined aquifer with impermeable bottom under time-varying rainfall events. Referring to Child (1971), we employ the Boussinesq equation as the governing equation, and apply the General Integral Transforms Method (GITM) to analyzing the groundwater level after linearizing the Boussinesq equation. After comparing the solution with Verhoest & Troch (2000) and Bansal & Das (2010), we get satisfactory results. To sum up, we have presented an alternative approach to solve the linearized Boussinesq equation for the response of groundwater level in a sloping unconfined aquifer. The present analytical results combine the effect of bottom slope and the time-varying recharge pattern on the water table fluctuations. Owing to the limitation and difficulty of measuring the groundwater level directly, we develop such a mathematical model that we can predict or simulate the variation of groundwater level affected by any rainfall events in advance.

Truth of Varying Shades: Analyzing Language in Fake News and Political Fact-Checking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rashkin, Hannah J.; Choi, Eunsol; Jang, Jin Yea

We present an analytic study on the language of news media in the context of political fact-checking and fake news detection. We compare the language of real news with that of satire, hoax, and propaganda to find linguistic cues for untruthful text. To probe the feasibility of automatic political fact-checking, we present a case study based on PolitiFact.com using their factuality judgments on a 6-point scale. Experimental results show that while media fact-checking remains to be an open research question, stylistic cues can help determine the truthfulness of text.

Investigation of the influence of groundwater advection on energy extraction rates for sustainable borehole heat exchanger operation

NASA Astrophysics Data System (ADS)

Schelenz, Sophie; Dietrich, Peter; Vienken, Thomas

2016-04-01

A sustainable thermal exploitation of the shallow subsurface requires a precise understanding of all relevant heat transport processes. Currently, planning practice of shallow geothermal systems (especially for systems < 30 kW) focuses on conductive heat transport as the main energy source while the impact of groundwater flow as the driver for advective heat transport is neglected or strongly simplified. The presented study proves that those simplifications of complex geological and hydrogeological subsurface characteristics are insufficient for a precise evaluation of site-specific energy extraction rates. Based on synthetic model scenarios with varying subsurface conditions (groundwater flow velocity and aquifer thickness) the impact of advection on induced long term temperature changes in 5 and 10 m distance of the borehole heat exchanger is presented. Extending known investigations, this study enhances the evaluation of shallow geothermal energy extraction rates by considering conductive and advective heat transport under varying aquifer thicknesses. Further, it evaluates the impact of advection on installation lengths of the borehole heat exchanger to optimize the initial financial investment. Finally, an evaluation approach is presented that classifies relevant heat transport processes according to their Péclet number to enable a first quantitative assessment of the subsurface energy regime and recommend further investigation and planning procedures.

A new theoretical model for transmembrane potential and ion currents induced in a spherical cell under low frequency electromagnetic field.

PubMed

Zheng, Yu; Gao, Yang; Chen, Ruijuan; Wang, Huiquan; Dong, Lei; Dou, Junrong

2016-10-01

Time-varying electromagnetic fields (EMF) can induce some physiological effects in neuronal tissues, which have been explored in many applications such as transcranial magnetic stimulation. Although transmembrane potentials and induced currents have already been the subjects of many theoretical studies, most previous works about this topic are mainly completed by utilizing Maxwell's equations, often by solving a Laplace equation. In previous studies, cells were often considered to be three-compartment models with different electroconductivities in different regions (three compartments are often intracellular regions, membrane, and extracellular regions). However, models like that did not take dynamic ion channels into consideration. Therefore, one cannot obtain concrete ionic current changes such as potassium current change or sodium current change by these models. The aim of the present work is to present a new and more detailed model for calculating transmembrane potentials and ionic currents induced by time-varying EMF. Equations used in the present paper originate from Nernst-Plank equations, which are ionic current-related equations. The main work is to calculate ionic current changes induced by EMF exposure, and then transmembrane potential changes are calculated with Hodgkin-Huxley model. Bioelectromagnetics. 37:481-492, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A Hydrological Tomography Collocated with Time-varying Gravimetry for Hydrogeology -An Example in Yun-Lin Alluvial Plain and Ming-Ju Basin in Taiwan

NASA Astrophysics Data System (ADS)

Chen, K. H.; Cheng, C. C.; Hwang, C.

2016-12-01

A new inversion technique featured by the collocation of hydrological modeling and gravimetry observation is presented in this report. Initially this study started from a project attempting to build a sequence of hydrodynamic models of ground water system, which was applied to identify the supplement areas of alluvial plains and basins along the west coast of Taiwan. To calibrate the decent hydro-geological parameters for the modeling, geological evolution were carefully investigated and absolute gravity observations, along with other on-site hydrological monitoring data were specially introduced. It was discovered in the data processing that the time-varying gravimetrical data are highly sensitive to certain boundary conditions in the hydrodynamic model, which are correspondent with respective geological features. A new inversion technique coined by the term "hydrological tomography" is therefore developed by reversing the boundary condition into the unknowns to be solved. An example of accurate estimate for water storage and precipitation infiltration of a costal alluvial plain Yun-Lin is presented. In the mean time, the study of an anticline structure of the upstream basin Ming-Ju is also presented to demonstrate how a geological formation is outlined when the gravimetrical data and hydrodynamic model are re-directed into an inversion.

Heterogeneity of proteins expressed by Brazilian Sporothrix schenckii isolates.

PubMed

Fernandes, Geisa Ferreira; Do Amaral, Cristiane Candida; Sasaki, Alexandre; Godoy, Patrício Martinez; De Camargo, Zoilo Pires

2009-12-01

The profiles of proteins present in the exoantigens of Brazilian Sporothrix schenckii isolates were studied and compared by electrophoresis (SDS-PAGE). Thirteen isolates from five different regions of Brazil (1,000 to 2,000 km apart) and ten from a more limited region (200 to 400 km apart within the state of São Paulo) were cultured in Sabouraud, M199 and minimum (MM) media. Qualitative and quantitative differences in the expression of proteins, which varied according to the medium and the isolate, were observed. Fractions with the same MW but varying in intensity were detected, as well as fractions present in 1 isolate but absent in others. Dendrograms were constructed and isolates grouped based on the fractions obtained, irrespective of the intensity. The results showed that Brazilian S. schenckii isolates express different protein profiles, a feature also present in isolates from a more restricted region. The exoantigens were found to have a maximum of 15 protein fractions, ranging in MW from 19-220 KDaltons depending on the medium used for the cultures. These data show the great heterogeneity of Brazilian S. schenckii protein expression.

The Interaction of Temporal and Spectral Acoustic Information with Word Predictability on Speech Intelligibility

NASA Astrophysics Data System (ADS)

Shahsavarani, Somayeh Bahar

High-level, top-down information such as linguistic knowledge is a salient cortical resource that influences speech perception under most listening conditions. But, are all listeners able to exploit these resources for speech facilitation to the same extent? It was found that children with cochlear implants showed different patterns of benefit from contextual information in speech perception compared with their normal-haring peers. Previous studies have discussed the role of non-acoustic factors such as linguistic and cognitive capabilities to account for this discrepancy. Given the fact that the amount of acoustic information encoded and processed by auditory nerves of listeners with cochlear implants differs from normal-hearing listeners and even varies across individuals with cochlear implants, it is important to study the interaction of specific acoustic properties of the speech signal with contextual cues. This relationship has been mostly neglected in previous research. In this dissertation, we aimed to explore how different acoustic dimensions interact to affect listeners' abilities to combine top-down information with bottom-up information in speech perception beyond the known effects of linguistic and cognitive capacities shown previously. Specifically, the present study investigated whether there were any distinct context effects based on the resolution of spectral versus slowly-varying temporal information in perception of spectrally impoverished speech. To that end, two experiments were conducted. In both experiments, a noise-vocoded technique was adopted to generate spectrally-degraded speech to approximate acoustic cues delivered to listeners with cochlear implants. The frequency resolution was manipulated by varying the number of frequency channels. The temporal resolution was manipulated by low-pass filtering of amplitude envelope with varying low-pass cutoff frequencies. The stimuli were presented to normal-hearing native speakers of American English. Our results revealed a significant interaction effect between spectral, temporal, and contextual information in the perception of spectrally-degraded speech. This suggests that specific types and degradation of bottom-up information combine differently to utilize contextual resources. These findings emphasize the importance of taking the listener's specific auditory abilities into consideration while studying context effects. These results also introduce a novel perspective for designing interventions for listeners with cochlear implants or other auditory prostheses.

Survival analysis with error-prone time-varying covariates: a risk set calibration approach

PubMed Central

Liao, Xiaomei; Zucker, David M.; Li, Yi; Spiegelman, Donna

2010-01-01

Summary Occupational, environmental, and nutritional epidemiologists are often interested in estimating the prospective effect of time-varying exposure variables such as cumulative exposure or cumulative updated average exposure, in relation to chronic disease endpoints such as cancer incidence and mortality. From exposure validation studies, it is apparent that many of the variables of interest are measured with moderate to substantial error. Although the ordinary regression calibration approach is approximately valid and efficient for measurement error correction of relative risk estimates from the Cox model with time-independent point exposures when the disease is rare, it is not adaptable for use with time-varying exposures. By re-calibrating the measurement error model within each risk set, a risk set regression calibration method is proposed for this setting. An algorithm for a bias-corrected point estimate of the relative risk using an RRC approach is presented, followed by the derivation of an estimate of its variance, resulting in a sandwich estimator. Emphasis is on methods applicable to the main study/external validation study design, which arises in important applications. Simulation studies under several assumptions about the error model were carried out, which demonstrated the validity and efficiency of the method in finite samples. The method was applied to a study of diet and cancer from Harvard’s Health Professionals Follow-up Study (HPFS). PMID:20486928

Temporal Discounting and Inter-Temporal Choice in Rhesus Monkeys

PubMed Central

Hwang, Jaewon; Kim, Soyoun; Lee, Daeyeol

2009-01-01

Humans and animals are more likely to take an action leading to an immediate reward than actions with delayed rewards of similar magnitudes. Although such devaluation of delayed rewards has been almost universally described by hyperbolic discount functions, the rate of this temporal discounting varies substantially among different animal species. This might be in part due to the differences in how the information about reward is presented to decision makers. In previous animal studies, reward delays or magnitudes were gradually adjusted across trials, so the animals learned the properties of future rewards from the rewards they waited for and consumed previously. In contrast, verbal cues have been used commonly in human studies. In the present study, rhesus monkeys were trained in a novel inter-temporal choice task in which the magnitude and delay of reward were indicated symbolically using visual cues and varied randomly across trials. We found that monkeys could extract the information about reward delays from visual symbols regardless of the number of symbols used to indicate the delay. The rate of temporal discounting observed in the present study was comparable to the previous estimates in other mammals, and the animal's choice behavior was largely consistent with hyperbolic discounting. Our results also suggest that the rate of temporal discounting might be influenced by contextual factors, such as the novelty of the task. The flexibility furnished by this new inter-temporal choice task might be useful for future neurobiological investigations on inter-temporal choice in non-human primates. PMID:19562091

Neural correlates of differential retrieval orientation: Sustained and item-related components.

PubMed

Woodruff, C Chad; Uncapher, Melina R; Rugg, Michael D

2006-01-01

Retrieval orientation refers to a cognitive state that biases processing of retrieval cues in service of a specific goal. The present study used a mixed fMRI design to investigate whether adoption of different retrieval orientations - as indexed by differences in the activity elicited by retrieval cues corresponding to unstudied items - is associated with differences in the state-related activity sustained across a block of test trials sharing a common retrieval goal. Subjects studied mixed lists comprising visually presented words and pictures. They then undertook a series of short test blocks in which all test items were visually presented words. The blocks varied according to whether the test items were used to cue retrieval of studied words or studied pictures. In several regions, neural activity elicited by correctly classified new items differed according to whether words or pictures were the targeted material. The loci of these effects suggest that one factor driving differential cue processing is modulation of the degree of overlap between cue and targeted memory representations. In addition to these item-related effects, neural activity sustained throughout the test blocks also differed according to the nature of the targeted material. These findings indicate that the adoption of different retrieval orientations is associated with distinct neural states. The loci of these sustained effects were distinct from those where new item activity varied, suggesting that the effects may play a role in biasing retrieval cue processing in favor of the current retrieval goal.

Prevalence of low back pain in emergency settings: a systematic review and meta-analysis.

PubMed

Edwards, Jordan; Hayden, Jill; Asbridge, Mark; Gregoire, Bruce; Magee, Kirk

2017-04-04

Low back pain may be having a significant impact on emergency departments around the world. Research suggests low back pain is one of the leading causes of emergency department visits. However, in the peer-reviewed literature, there has been limited focus on the prevalence and management of back pain in the emergency department setting. The aim of the systematic review was to synthesize evidence about the prevalence of low back pain in emergency settings and explore the impact of study characteristics including type of emergency setting and how the study defined low back pain. Studies were identified from PubMed and EMBASE, grey literature search, and other sources. We selected studies that presented prevalence data for adults presenting to an emergency setting with low back pain. Critical appraisal was conducted using a modified tool developed to assess prevalence studies. Meta-analyses and a meta-regression explored the influence of study-level characteristics on prevalence. We screened 1187 citations and included 21 studies, reported between 2000 and 2016 presenting prevalence data from 12 countries. The pooled prevalence estimate from studies of standard emergency settings was 4.39% (95% CI: 3.67-5.18). Prevalence estimates of the included studies ranged from 0.9% to 17.1% and varied with study definition of low back pain and the type of emergency setting. The overall quality of the evidence was judged to be moderate as there was limited generalizability and high heterogeneity in the results. This is the first systematic review to examine the prevalence of low back pain in emergency settings. Our results indicate that low back pain is consistently a top presenting complaint and that the prevalence of low back pain varies with definition of low back pain and emergency setting. Clinicians and policy decisions makers should be aware of the potential impact of low back pain in their emergency settings.

Varying Herbivore Population Structure Correlates with Lack of Local Adaptation in a Geographic Variable Plant-Herbivore Interaction

PubMed Central

Cogni, Rodrigo; Trigo, José R.; Futuyma, Douglas J.

2011-01-01

Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries) vary at the regional scale, while other traits (trichomes and nitrogen content) just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation. PMID:22220208

The Impact of Attention on Judgments of Frequency and Duration

PubMed Central

Winkler, Isabell; Glauer, Madlen; Betsch, Tilmann; Sedlmeier, Peter

2015-01-01

Previous studies that examined human judgments of frequency and duration found an asymmetrical relationship: While frequency judgments were quite accurate and independent of stimulus duration, duration judgments were highly dependent upon stimulus frequency. A potential explanation for these findings is that the asymmetry is moderated by the amount of attention directed to the stimuli. In the current experiment, participants' attention was manipulated in two ways: (a) intrinsically, by varying the type and arousal potential of the stimuli (names, low-arousal and high-arousal pictures), and (b) extrinsically, by varying the physical effort participants expended during the stimulus presentation (by lifting a dumbbell vs. relaxing the arm). Participants processed stimuli with varying presentation frequencies and durations and were subsequently asked to estimate the frequency and duration of each stimulus. Sensitivity to duration increased for pictures in general, especially when processed under physical effort. A large effect of stimulus frequency on duration judgments was obtained for all experimental conditions, but a similar large effect of presentation duration on frequency judgments emerged only in the conditions that could be expected to draw high amounts of attention to the stimuli: when pictures were judged under high physical effort. Almost no difference in the mutual impact of frequency and duration was obtained for low-arousal or high-arousal pictures. The mechanisms underlying the simultaneous processing of frequency and duration are discussed with respect to existing models derived from animal research. Options for the extension of such models to human processing of frequency and duration are suggested. PMID:26000712

The impact of attention on judgments of frequency and duration.

PubMed

Winkler, Isabell; Glauer, Madlen; Betsch, Tilmann; Sedlmeier, Peter

2015-01-01

Previous studies that examined human judgments of frequency and duration found an asymmetrical relationship: While frequency judgments were quite accurate and independent of stimulus duration, duration judgments were highly dependent upon stimulus frequency. A potential explanation for these findings is that the asymmetry is moderated by the amount of attention directed to the stimuli. In the current experiment, participants' attention was manipulated in two ways: (a) intrinsically, by varying the type and arousal potential of the stimuli (names, low-arousal and high-arousal pictures), and (b) extrinsically, by varying the physical effort participants expended during the stimulus presentation (by lifting a dumbbell vs. relaxing the arm). Participants processed stimuli with varying presentation frequencies and durations and were subsequently asked to estimate the frequency and duration of each stimulus. Sensitivity to duration increased for pictures in general, especially when processed under physical effort. A large effect of stimulus frequency on duration judgments was obtained for all experimental conditions, but a similar large effect of presentation duration on frequency judgments emerged only in the conditions that could be expected to draw high amounts of attention to the stimuli: when pictures were judged under high physical effort. Almost no difference in the mutual impact of frequency and duration was obtained for low-arousal or high-arousal pictures. The mechanisms underlying the simultaneous processing of frequency and duration are discussed with respect to existing models derived from animal research. Options for the extension of such models to human processing of frequency and duration are suggested.

Efficient kinetic Monte Carlo method for reaction-diffusion problems with spatially varying annihilation rates

NASA Astrophysics Data System (ADS)

Schwarz, Karsten; Rieger, Heiko

2013-03-01

We present an efficient Monte Carlo method to simulate reaction-diffusion processes with spatially varying particle annihilation or transformation rates as it occurs for instance in the context of motor-driven intracellular transport. Like Green's function reaction dynamics and first-passage time methods, our algorithm avoids small diffusive hops by propagating sufficiently distant particles in large hops to the boundaries of protective domains. Since for spatially varying annihilation or transformation rates the single particle diffusion propagator is not known analytically, we present an algorithm that generates efficiently either particle displacements or annihilations with the correct statistics, as we prove rigorously. The numerical efficiency of the algorithm is demonstrated with an illustrative example.

Fatal Liver Cyst Rupture Due to Anabolic Steroid Use: A Case Presentation.

PubMed

Hansma, Patrick; Diaz, Francisco J; Njiwaji, Chantel

2016-03-01

Liver cysts are commonly found incidentally from imaging scans or at autopsy. These benign neoplasms vary in size and represent a heterogeneous group of disorders, for which the demographics, risk factors, apparent inciting event, clinical presentation, and outcome are varied. Complications that can develop from a liver cyst include development of spontaneous hemorrhage, infection, and/or obstruction. Although the etiology of liver cysts varies, fatal rupture of a hemorrhagic liver cyst due to anabolic steroid use is a rare occurrence. In fact, there are few reported cases in journal literature. We report a case of a fatal liver cyst rupture with resultant hemoperitoneum in the presence of anabolic steroid (stanozolol) use.

Study and Characterization of Subharmonic Emissions by Using Shaped Ultrasonic Driving Pulse

NASA Astrophysics Data System (ADS)

Masotti, L.; Biagi, E.; Breschi, L.; Vannacci, E.

Subharmonic emissions from Ultrasound Contrast Agents (UCAs) were studied by a Pulse Inversion method in order to assess the feasibility of implementation of this technique to subharmonic imaging. Interesting results concerning the dependence of the subharmonic emission with respect to initial pulse shape are presented. The experimentation was performed also by varying the acoustic pressure and concentration of the contrast agent (SonoVue®)

An Exploration of the Use of Mobile Applications to Support the Learning of Chinese Characters Employed by Students of Chinese as a Foreign Language

ERIC Educational Resources Information Center

Mason, Amanda; Wenxin, Zhang

2017-01-01

At present, there are few studies which explore the learning strategies employed by students of Chinese as a Foreign Language (CFL) and even fewer that focus specifically on mobile application use. This study provides insights into how adult learners at varying levels of proficiency employ mobile apps to support their Chinese character learning.…

Face Recognition across Varying Poses in 7- and 9-Month-Old Infants: The Role of Facial Expression

ERIC Educational Resources Information Center

Gross, Cornelia; Schwarzer, Gudrun

2010-01-01

Three studies were conducted to determine whether 7- and 9-month-old infants generalize face identity to a novel pose of the same face when only internal face sections with and without an emotional expression were presented. In Study 1, 7- and 9-month-old infants were habituated to a full frontal or three-quarter pose of a face with neutral facial…

Development of Subjective Well-Being Increasing Strategies Scale for Children (1-5 Ages) Their Mothers Use

ERIC Educational Resources Information Center

Eryilmaz, Ali; Sapsaglam, Özkan

2018-01-01

Subjective well-being is a sign of positive mental health of children. The aim of the present study is to develop subjective well-being increasing strategies scale for children whose mothers' uses are varied 1 to 5. In this study, there were 195 mothers whose mean ages were 31, 49 and standard deviation were 4,71. Satisfaction with life, positive…

SLIDE PRESENTATION--PHARMACEUTICALS AS ENVIRONMENTAL CONTAMINANTS: AN OVERVIEW OF THE SCIENCE

EPA Science Inventory

While pharmaceuticals are ubiquitous trace contaminants in the environment, thetypes, concentrations, and relative abundances of individual residues will vary depending on thegeographic locale and time of year, primarily a reflection of differing and varying prescribing andconsum...

Visualization of leading edge vortices on a series of flat plate delta wings

NASA Technical Reports Server (NTRS)

Payne, Francis M.; Ng, T. Terry; Nelson, Robert C.

1991-01-01

A summary of flow visualization data obtained as part of NASA Grant NAG2-258 is presented. During the course of this study, many still and high speed motion pictures were taken of the leading edge vortices on a series of flat plate delta wings at varying angles of attack. The purpose is to present a systematic collection of photographs showing the state of vortices as a function of the angle of attack for the four models tested.

The effect of presentation rate on foreign-language vocabulary learning.

PubMed

Zeelenberg, René; de Jonge, Mario; Tabbers, Huib K; Pecher, Diane

2015-01-01

The present study examined the effect of presentation rate on foreign-language vocabulary learning. Experiment 1 varied presentation rates from 1 s to 16 s per pair while keeping the total study time per pair constant. Speakers of English studied Dutch-English translation pairs (e.g., kikker-frog) for 16 × 1 s, 8 × 2 s, 4 × 4 s, 2 × 8 s, or 1 × 16 s. The results showed a nonmonotonic relationship between presentation rate and recall performance for both translation directions (Dutch → English and English → Dutch). Performance was best for intermediate presentation rates and dropped off for short (1 s) or long (16 s) presentation rates. Experiment 2 showed that the nonmonotonic relationship between presentation rate and recall performance was still present after a 1-day retention interval for both translation directions. Our results suggest that a presentation rate in the order of 4 s results in optimal learning of foreign-language vocabulary.

Varied Presentation of Congenital Segmental Dilatation of the Intestine in Neonates: Report of Three Cases

PubMed Central

Rai, Binod Kumar; Mirza, Bilal; Hashim, Imran; Saleem, Muhammad

2016-01-01

Congenital segmental dilatation (CSD) of the intestine is a rare developmental anomaly characterized by sharply demarcated dilatation of a gastrointestinal segment and may present with intestinal obstruction. We report three cases of CSD of the intestine in neonates with varied presentation. First patient was mistaken as pneumoperitoneum on abdominal radiograph, which led to initial abdominal drain placement. The 2nd patient was a case of anorectal malformation associated with congenital pouch colon (CPC) and CSD of ileum; and the third case presented as neonatal intestinal obstruction and found to have CSD of ileum. All the patients were successfully managed in our department. PMID:27896163

Characterization of children's decision making: sensitivity to punishment frequency, not task complexity.

PubMed

Crone, Eveline A; Bunge, Silvia A; Latenstein, Heleen; van der Molen, Maurits W

2005-06-01

On a gambling task that models real-life decision making, children between ages 7 and 12 perform like patients with bilateral lesions of the ventromedial prefrontal cortex (VMPFC), opting for choices that yield high immediate gains in spite of higher future losses (Crone & Van der Molen, 2004). The current study set out to characterize developmental changes in decision making by varying task complexity and punishment frequency. Three age groups (7-9 years, 10-12 years, 13-15 years) performed two versions of a computerized variant of the original Iowa gambling task. Task complexity was manipulated by varying the number of choices participants could make. Punishment frequency was manipulated by varying the frequency of delayed punishment. Results showed a developmental increase in the sensitivity to future consequences, which was present only when the punishment was presented infrequently. These results could not be explained by differential sensitivity to task complexity, hypersensitivity to reward, or failure to switch response set after receiving punishment. There was a general pattern of boys outperforming girls by making more advantageous choices over the course of the task. In conclusion, 7-12-year-old children--like VMPFC patients--appear myopic about the future except when the potential for future punishment is high.

Mittag-Leffler synchronization of fractional neural networks with time-varying delays and reaction-diffusion terms using impulsive and linear controllers.

PubMed

Stamova, Ivanka; Stamov, Gani

2017-12-01

In this paper, we propose a fractional-order neural network system with time-varying delays and reaction-diffusion terms. We first develop a new Mittag-Leffler synchronization strategy for the controlled nodes via impulsive controllers. Using the fractional Lyapunov method sufficient conditions are given. We also study the global Mittag-Leffler synchronization of two identical fractional impulsive reaction-diffusion neural networks using linear controllers, which was an open problem even for integer-order models. Since the Mittag-Leffler stability notion is a generalization of the exponential stability concept for fractional-order systems, our results extend and improve the exponential impulsive control theory of neural network system with time-varying delays and reaction-diffusion terms to the fractional-order case. The fractional-order derivatives allow us to model the long-term memory in the neural networks, and thus the present research provides with a conceptually straightforward mathematical representation of rather complex processes. Illustrative examples are presented to show the validity of the obtained results. We show that by means of appropriate impulsive controllers we can realize the stability goal and to control the qualitative behavior of the states. An image encryption scheme is extended using fractional derivatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Advancing HIV/AIDS prevention among American Indians through capacity building and the community readiness model.

PubMed

Thurman, Pamela Jumper; Vernon, Irene S; Plested, Barbara

2007-01-01

Although HIV/AIDS prevention has presented challenges over the past 25 years, prevention does work! To be most effective, however, prevention must be specific to the culture and the nature of the community. Building the capacity of a community for prevention efforts is not an easy process. If capacity is to be sustained, it must be practical and utilize the resources that already exist in the community. Attitudes vary across communities; resources vary, political climates are constantly varied and changing. Communities are fluid-always changing, adapting, growing. They are "ready" for different things at different times. Readiness is a key issue! This article presents a model that has experienced a high level of success in building community capacity for effective prevention/intervention for HIV/AIDS and offers case studies for review. The Community Readiness Model provides both quantitative and qualitative information in a user-friendly structure that guides a community through the process of understanding the importance of the measure of readiness. The model identifies readiness- appropriate strategies, provides readiness scores for evaluation, and most important, involves community stakeholders in the process. The article will demonstrate the importance of developing strategies consistent with readiness levels for more cost-effective and successful prevention efforts.

Pinning synchronization of memristor-based neural networks with time-varying delays.

PubMed

Yang, Zhanyu; Luo, Biao; Liu, Derong; Li, Yueheng

2017-09-01

In this paper, the synchronization of memristor-based neural networks with time-varying delays via pinning control is investigated. A novel pinning method is introduced to synchronize two memristor-based neural networks which denote drive system and response system, respectively. The dynamics are studied by theories of differential inclusions and nonsmooth analysis. In addition, some sufficient conditions are derived to guarantee asymptotic synchronization and exponential synchronization of memristor-based neural networks via the presented pinning control. Furthermore, some improvements about the proposed control method are also discussed in this paper. Finally, the effectiveness of the obtained results is demonstrated by numerical simulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hamiltonian models for the propagation of irrotational surface gravity waves over a variable bottom

NASA Astrophysics Data System (ADS)

Compelli, A.; Ivanov, R.; Todorov, M.

2017-12-01

A single incompressible, inviscid, irrotational fluid medium bounded by a free surface and varying bottom is considered. The Hamiltonian of the system is expressed in terms of the so-called Dirichlet-Neumann operators. The equations for the surface waves are presented in Hamiltonian form. Specific scaling of the variables is selected which leads to approximations of Boussinesq and Korteweg-de Vries (KdV) types, taking into account the effect of the slowly varying bottom. The arising KdV equation with variable coefficients is studied numerically when the initial condition is in the form of the one-soliton solution for the initial depth. This article is part of the theme issue 'Nonlinear water waves'.

Time-varying Concurrent Risk of Extreme Droughts and Heatwaves in California

NASA Astrophysics Data System (ADS)

Sarhadi, A.; Diffenbaugh, N. S.; Ausin, M. C.

2016-12-01

Anthropogenic global warming has changed the nature and the risk of extreme climate phenomena such as droughts and heatwaves. The concurrent of these nature-changing climatic extremes may result in intensifying undesirable consequences in terms of human health and destructive effects in water resources. The present study assesses the risk of concurrent extreme droughts and heatwaves under dynamic nonstationary conditions arising from climate change in California. For doing so, a generalized fully Bayesian time-varying multivariate risk framework is proposed evolving through time under dynamic human-induced environment. In this methodology, an extreme, Bayesian, dynamic copula (Gumbel) is developed to model the time-varying dependence structure between the two different climate extremes. The time-varying extreme marginals are previously modeled using a Generalized Extreme Value (GEV) distribution. Bayesian Markov Chain Monte Carlo (MCMC) inference is integrated to estimate parameters of the nonstationary marginals and copula using a Gibbs sampling method. Modelled marginals and copula are then used to develop a fully Bayesian, time-varying joint return period concept for the estimation of concurrent risk. Here we argue that climate change has increased the chance of concurrent droughts and heatwaves over decades in California. It is also demonstrated that a time-varying multivariate perspective should be incorporated to assess realistic concurrent risk of the extremes for water resources planning and management in a changing climate in this area. The proposed generalized methodology can be applied for other stochastic nature-changing compound climate extremes that are under the influence of climate change.

Some Student Conceptions of Electromagnetic Induction

NASA Astrophysics Data System (ADS)

Thong, Wai Meng; Gunstone, Richard

2008-01-01

Introductory electromagnetism is a central part of undergraduate physics. Although there has been some research into student conceptions of electromagnetism, studies have been sparse and separated. This study sought to explore second year physics students’ conceptions of electromagnetism, to investigate to what extent the results from the present study are similar to these results from other studies, and to uncover any new forms of alternative conceptions. Data for this study came from 15 in-depth interviews. Three previously unreported alternative conceptions were identified in the study: 1) induced current varies proportionately with current in solenoid; 2) there must be contact between magnetic flux and the external coil in order for any emf to be induced in the coil; 3) coulombic or electrostatic potential difference is present in an induced electric field. These alternative conceptions were manifested in these students’ explanations of electromagnetic phenomena presented to them during the interviews.

Study of indoor radon and thoron progeny levels in surrounding areas of Nalbari, Assam, India

NASA Astrophysics Data System (ADS)

Deka, P. C.; Sarma, H.; Sarkar, Subir; Goswami, T. D.; Sarma, B. K.

2009-07-01

With the growing understanding of the role of radon and its daughter products as major sources of radiation exposure, the importance of large number of estimation of radon concentration in various parts of the country is realized. Inhalation of radon, thoron and their decay products is the major source of the total radioactive dose received by the human population from natural radiation. The indoor radon and thoron progeny levels in Nalbari area of Assam are studied by using the LR-115 (type II) Solid State Nuclear Track Detector in Plastic Twin Chamber dosimeter. Radon and thoron progeny levels in different types of dwellings for one full calendar year are presented in this paper. For Assam Type (A.T.) houses, indoor radon progeny concentrations vary from 0.17 to 0.64 mWL with an annual geometric mean of 0.27 mWL and that for Reinforced Cement Concrete (R.C.C.) houses vary from 0.22 mWL to 0.60 mWL with the annual geometric mean of 0.37 mWL. The thoron progeny levels in A.T. houses also vary from 0.01 to of 0.05 mWL with an annual geometric mean of 0.02 mWL and that for R.C.C. houses vary from 0.02 to 0.08 mWL with the annual geometric mean of 0.04 mWL.

Systematic, cross-cortex variation in neuron numbers in rodents and primates.

PubMed

Charvet, Christine J; Cahalane, Diarmuid J; Finlay, Barbara L

2015-01-01

Uniformity, local variability, and systematic variation in neuron numbers per unit of cortical surface area across species and cortical areas have been claimed to characterize the isocortex. Resolving these claims has been difficult, because species, techniques, and cortical areas vary across studies. We present a stereological assessment of neuron numbers in layers II-IV and V-VI per unit of cortical surface area across the isocortex in rodents (hamster, Mesocricetus auratus; agouti, Dasyprocta azarae; paca, Cuniculus paca) and primates (owl monkey, Aotus trivigratus; tamarin, Saguinus midas; capuchin, Cebus apella); these chosen to vary systematically in cortical size. The contributions of species, cortical areas, and techniques (stereology, "isotropic fractionator") to neuron estimates were assessed. Neurons per unit of cortical surface area increase across the rostro-caudal (RC) axis in primates (varying by a factor of 1.64-2.13 across the rostral and caudal poles) but less in rodents (varying by a factor of 1.15-1.54). Layer II-IV neurons account for most of this variation. When integrated into the context of species variation, and this RC gradient in neuron numbers, conflicts between studies can be accounted for. The RC variation in isocortical neurons in adulthood mirrors the gradients in neurogenesis duration in development. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Carbon Dioxide Enrichment: Data on the Response of Cotton to Varying CO2 Irrigation, and Nitrogen (NDP-037)

DOE Data Explorer

Kimball, B. A. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Mauney, J. R. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); La Morte, R. L. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Guinn, G. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Nakayama, F. S. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Radin, J. W. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Lakatos, E. A. [University of Arizona, Tucson, AZ (United States); Mitchell, S. T. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Parker, L. L. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Peresta, G. J. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Nixon III, P. E. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Savoy, B. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Harris, S. M. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); MacDonald, R. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Pros, H. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Martinez, J. [US Dept. of Agriculture (USDA)., Agricultural Research Service, Phoenix, AZ (United States); Sepanski, R. J. [Univ. of Tennessee, Knoxville, TN (United States)

1992-01-01

This NDP presents data on the effects of continuous CO2 enrichment of cotton during five consecutive growing seasons, 1983 to 1987, under both optimal and limiting levels of water and nitrogen. Unlike many prior CO2-enrichment experiments in growth chambers or greenhouses, these studies were conducted on field-planted cotton at close to natural conditions with open-top chambers. Measurements were made on a variety of crop-response variables during the growing season and upon crop harvest. The initial experiment examined the effects of varying CO2 concentration only. During the following two seasons, the interactive effects of CO2 concentration and water availability were studied. During the final two seasons, the interactions among CO2 concentration, water availability, and nitrogen fertility were investigated.

Investigation of Global Citizenship Levels of Pre-Service Physical Education Teachers

ERIC Educational Resources Information Center

Kayisoglu, Numan Bahadir

2016-01-01

The purpose of the present research is to define global citizenship levels of pre-service physical education teachers and investigate whether their global citizenship levels vary by various variables. A total of 485 pre-service teachers, studying at 3rd and 4th grades of undergraduate programs of physical education teaching at thirteen different…

The Effect of Illumination on Gray Color

ERIC Educational Resources Information Center

Da Pos, Osvaldo; Baratella, Linda; Sperandio, Gabriele

2010-01-01

The present study explored the perceptual process of integration of luminance information in the production of the gray color of an object placed in an environment viewed from a window. The mean luminance of the object was varied for each mean luminance of the environment. Participants matched the gray color of the object with that of Munsell…

Effects of Interspersed versus Summary Feedback on the Quality of Students' Case Report Revisions

ERIC Educational Resources Information Center

Phillips, Fred; Wolcott, Susan

2014-01-01

This study examines whether students show greater improvement in written case analyses when given feedback that is either interspersed throughout their written case analyses or presented only as a summary, and whether the benefits of these placements vary across differing levels of student performance in the course. Results from an exploratory…

Student Multimedia Autobiographies: The Roles of Technology, Personal Narrative, and Signifying Practices

ERIC Educational Resources Information Center

Keane, Julie Thompson

2010-01-01

In 2009, the Parsons StoryCorps qualitative case study was designed to closely observe the complexity of youth engagement with digital media for self-presentation in an afterschool digital storytelling project designed to provide students with rich, varied uses of technology in a urban middle school in North Carolina. Several frameworks were…

Social Relationships, Prosocial Behaviour, and Perceived Social Support in Students from Boarding Schools

ERIC Educational Resources Information Center

Pfeiffer, Jens P.; Pinquart, Martin; Krick, Kathrin

2016-01-01

Social development may vary depending on contextual factors, such as attending a day school or a boarding school. The present study compares students from these school types with regard to the achievement of specific social goals, perceived social support, and reported prosocial behaviour. A sample of 701 students was examined. Students from…

Who is a Migrant Farm Worker? Quien Es Un Trabajador Agricola Migrante?

ERIC Educational Resources Information Center

Escamilla, Manuel

Concerned with varying definitions of migrants given by Federal agencies helping them, the 2 objectives of this study were to present migrant definitions utilized by these agencies and to initiate discussion on one standard definition of a migrant worker. Using standards of the Office of Economic Opportunity, the Department of Labor, the…

Word-Related N170 Responses to Implicit and Explicit Reading Tasks in Neoliterate Adults

ERIC Educational Resources Information Center

Sánchez-Vincitore, Laura V.; Avery, Trey; Froud, Karen

2018-01-01

The present study addresses word recognition automaticity in Spanish-speaking adults who are neoliterate by assessing the event-related potential N170 for word stimuli. Participants engaged in two reading conditions that vary the degree of attention required for linguistic components of reading: (a) an implicit reading task, in which they detected…

Providing Information to Parents of Children with Mental Health Problems: A Discrete Choice Conjoint Analysis of Professional Preferences

ERIC Educational Resources Information Center

Cunningham, Charles E.; Deal, Ken; Rimas, Heather; Chen, Yvonne; Buchanan, Don H.; Sdao-Jarvie, Kathie

2009-01-01

We used discrete choice conjoint analysis to model the ways 645 children's mental health (CMH) professionals preferred to provide information to parents seeking CMH services. Participants completed 20 choice tasks presenting experimentally varied combinations of the study's 14 4-level CMH information transfer attributes. Latent class analysis…

Vowel Identification by Listeners with Hearing Impairment in Response to Variation in Formant Frequencies

ERIC Educational Resources Information Center

Molis, Michelle R.; Leek, Marjorie R.

2011-01-01

Purpose: This study examined the influence of presentation level and mild-to-moderate hearing loss on the identification of a set of vowel tokens systematically varying in the frequency locations of their second and third formants. Method: Five listeners with normal hearing (NH listeners) and five listeners with hearing impairment (HI listeners)…

Disability in Full-Length Feature Films: Frequency and Quality of Films over an 11 Year Span.

ERIC Educational Resources Information Center

Byrd, E. Keith; Elliot, Timothy R.

1988-01-01

This study assessed the presentation of disabling conditions in feature films and the general quality of these films (as judged by professional film critics' reviews and movie-goer ratings). Psychiatric disorder was the disability most frequently depicted. Films varied in quality with critics markedly more negative in their reviews than movie…

Versatility, Openness to Experience, and Topical Diversity in Creative Products: An Exploratory Historiometric Analysis of Scientists, Philosophers, and Writers

ERIC Educational Resources Information Center

Cassandro, Vincent J.; Simonton, Dean Keith

2010-01-01

Creative individuals are considered "versatile" when their achievements extend beyond their most commonly cited domain, thus indicating remarkable and varied interests and abilities. The present study examined the association between versatility and (a) the personalities of eminent creators and (b) the topical diversity of their creative products.…

The desert moss Pterygoneurum lamellatum (Pottiaceae) exhibits an inducible ecological strategy of desiccation tolerance: effects of rate of drying on shoot damage and regeneration

USDA-ARS?s Scientific Manuscript database

Premise of the study: Bryophytes are regarded as a clade incorporating constitutive desiccation tolerance, especially terrestrial species. Here we test the hypothesis that the opposing ecological strategy of desiccation tolerance, inducibility, is present in a desert moss, and addressed by varying r...

False Belief Understanding: The Influence of Person, Grammatical Mood, Counterfactual Reasoning and Working Memory

ERIC Educational Resources Information Center

Muller, Ulrich; Miller, Michael R.; Michalczyk, Kurt; Karapinka, Aaron

2007-01-01

The present study had two major goals. The first goal was to assess the relative difficulty among different versions of the unexpected contents task by systematically varying the dimensions of grammatical mood (indicative vs. subjunctive) and person (self vs. other), and to examine the correlational pattern between these different versions of the…

Application of SWAT to assess the effects of land use change in the Murchison Bay catchment in Uganda

USDA-ARS?s Scientific Manuscript database

The Soil and Water Assessment Tool (SWAT) is a versatile model presently used worldwide to evaluate water quality and hydrological concerns under varying land use and environmental conditions. In this study, SWAT was used to simulate streamflow and to estimate sediment yield and nutrients loss from ...

Understory response following varying levels of overstory removal in mixed conifer stands

Treesearch

Fabian C.C. Uzoh; Leroy K. Dolph; John R. Anstead

1997-01-01

Diameter growth rates of understory trees were measured for periods both before and after overstory removal on six study areas in northern California. All the species responded with increased diameter growth after adjusting to their new environments. Linear regression equations that predict post treatment diameter growth increment of the residual trees are presented...

Racing toward the Finish Line

ERIC Educational Resources Information Center

Sternberg, Robert J.; Grigorenko, Elena L.; Kidd, Kenneth K.

2006-01-01

This article presents replies to published comments on the authors' original article (R. L. Sternberg, E. L. Grigorenko, and K. K. Kidd. G. Carey cited in his response to their article a study by Tang et al. (2005) showing that "of 3,636 subjects of varying race/ethnicity, only 5 (0.14%) showed genetic cluster membership different from their…

Understanding a Basic Biological Process: Expert and Novice Models of Meiosis.

ERIC Educational Resources Information Center

Kindfield, Ann C. H.

The results of a study of the meiosis models utilized by individuals at varying levels of expertise while reasoning about the process of meiosis are presented. Based on these results, the issues of sources of misconceptions/difficulties and the construction of a sound understanding of meiosis are discussed. Five individuals from each of three…

The Effect of Observation Length and Presentation Order on the Reliability and Validity of an Observational Measure of Teaching Quality

ERIC Educational Resources Information Center

Mashburn, Andrew J.; Meyer, J. Patrick; Allen, Joseph P.; Pianta, Robert C.

2014-01-01

Observational methods are increasingly being used in classrooms to evaluate the quality of teaching. Operational procedures for observing teachers are somewhat arbitrary in existing measures and vary across different instruments. To study the effect of different observation procedures on score reliability and validity, we conducted an experimental…

Making the Most of Obesity Research: Developing Research and Policy Objectives through Evidence Triangulation

ERIC Educational Resources Information Center

Oliver, Kathryn; Aicken, Catherine; Arai, Lisa

2013-01-01

Drawing lessons from research can help policy makers make better decisions. If a large and methodologically varied body of research exists, as with childhood obesity, this is challenging. We present new research and policy objectives for child obesity developed by triangulating user involvement data with a mapping study of interventions aimed at…

The Impact of Five Missing Data Treatments on a Cross-Classified Random Effects Model

ERIC Educational Resources Information Center

Hoelzle, Braden R.

2012-01-01

The present study compared the performance of five missing data treatment methods within a Cross-Classified Random Effects Model environment under various levels and patterns of missing data given a specified sample size. Prior research has shown the varying effect of missing data treatment options within the context of numerous statistical…

Disease dynamics and persistence of Musca domestica salivary gland hypertropy virus infections in laboratory house fly (Musca domestica) populations.

USDA-ARS?s Scientific Manuscript database

Past surveys of feral house fly populations have shown that Musca domestica salivary gland hypertrophy virus (MdSGHV) has a world-wide distribution with an average prevalence varying between 0.5% and 10%. How this adult-specific virus persists in nature is unknown. In the present study, experiments ...

Judged Similarity of Aptitude and Achievement Tests in Mathematics.

ERIC Educational Resources Information Center

Donlon, Thomas F.

This study attempts to establish the ability of a panel of five judges with varied mathematics background to distinguish between two types of mathematical tests by separating their component items when they are presented in a mixed pool of aptitude and achievement tests. Typically, the two tests show high correlation. The judges showed about 70%…

Graduate Student Teaching Development: Evaluating the Effectiveness of Training in Relation to Graduate Student Characteristics

ERIC Educational Resources Information Center

Boman, Jennifer S.

2013-01-01

In recent years, much attention has been given to the need for more empirical research to evaluate training programs that help prepare graduate students for their current and future teaching responsibilities. The present study investigated the effectiveness of a training workshop for graduate students who had varying levels of experience and…

Suitability of sphagnum moss, coir, and douglas fir bark as soilless substrates for container production of highbush blueberry

USDA-ARS?s Scientific Manuscript database

The purpose of the present study was to investigate the suitability of different soilless substrates for container production of highbush blueberry (Vaccinium sp.). Young plants of ‘Snowchaser’ blueberry were grown in 4.4-liter pots filled with media containing 10% perlite and varying proportions of...

Thwarted Belongingness and Perceived Burdensomeness: Construct Validity and Psychometric Properties of the Interpersonal Needs Questionnaire

ERIC Educational Resources Information Center

Van Orden, Kimberly A.; Cukrowicz, Kelly C.; Witte, Tracy K.; Joiner, Thomas E., Jr.

2012-01-01

The present study examined the psychometric properties and construct validity of scores derived from the Interpersonal Needs Questionnaire (INQ) using latent variable modeling with 5 independent samples varying in age and level of psychopathology. The INQ was derived from the interpersonal theory of suicide and was developed to measure thwarted…

An Exact Solvable Model of Rocket Dynamics in Atmosphere

ERIC Educational Resources Information Center

Rodrigues, H.; Pinho, M. O.; Portes, D., Jr.; Santiago, A.

2009-01-01

In basic physics courses at undergraduate level, the dynamics of self-propelled bodies is presented as an example of momentum conservation law applied to systems with time-varying mass. However, is often studied the simple situation of free motion or the motion under the action of a constant gravitational field. In this work, we investigate the…

Postural Adaptations to a Suprapostural Memory Task among Children with and without Developmental Coordination Disorder

ERIC Educational Resources Information Center

Chen, Fu-Chen; Tsai, Chia-Liang; Stoffregen, Thomas A.; Chang, Chihu-Hui; Wade, Michael G.

2012-01-01

Aim: The present study investigated the effects of varying the cognitive demands of a memory task (a suprapostural task) while recording postural motion on two groups of children, one diagnosed with developmental coordination disorder (DCD) and an age-matched group of typically developing children. Method: Two groups, each comprising 38 child…

Effects of Age, Gender, and Causality on Perceptions of Persons with Mental Retardation

ERIC Educational Resources Information Center

Panek, Paul E.; Jungers, Melissa K.

2008-01-01

The present study examined the effects of age, gender, and causality on the perceptions of persons with mental retardation. Participants rated individuals with mental retardation using a semantic differential scale with three factors: activity, evaluation, and potency. Target individuals in each scenario varied on the variables of age (8, 20, 45),…

Assessing ADHD Symptomatic Behaviors and Functional Impairment in School Settings: Impact of Student and Teacher Characteristics

ERIC Educational Resources Information Center

DuPaul, George J.; Reid, Robert; Anastopoulos, Arthur D.; Power, Thomas J.

2014-01-01

The purpose of the present study was to examine (a) the teacher-reported prevalence of attention-deficit/hyperactivity disorder (ADHD) symptoms and associated impairment in a nationally representative sample of children and adolescents and (b) the degree to which prevalence varied as a function of student and teacher characteristics.…

Predictors of Verbal Working Memory in Children with Cerebral Palsy

ERIC Educational Resources Information Center

Peeters, Marieke; Verhoeven, Ludo; de Moor, Jan

2009-01-01

The goal of the present study was to examine the precursors of verbal working memory in 52 children with cerebral palsy with varying degrees of speech impairments in the first grade of special education. Following Baddeley's model of working memory, children's verbal working memory was measured by means of a forced-recognition task. As precursors…

Size scale effect in cavitation erosion

NASA Technical Reports Server (NTRS)

Rao, P. V.; Rao, B. C.; Buckley, D. H.

1982-01-01

An overview and data analyses pertaining to cavitation erosion size scale effects are presented. The exponents n in the power law relationship are found to vary from 1.7 to 4.9 for venturi and rotating disk devices supporting the values reported in the literature. Suggestions for future studies were made to arrive at further true scale effects.

Does Accessibility of Positive and Negative Schema Vary by Child Physical Abuse Risk?

ERIC Educational Resources Information Center

Crouch, Julie L.; Risser, Heather J.; Skowronski, John J.; Milner, Joel S.; Farc, Magdalena M.; Irwin, Lauren M.

2010-01-01

Objective: To examine differences in accessibility of positive and negative schema in parents with high and low risk for child physical abuse (CPA). Methods: This study combined picture priming and lexical decision making methods to assess the accessibility of positive and negative words following presentation of child and adult faces. The child…

Vowel Bias in Danish Word-Learning: Processing Biases Are Language-Specific

ERIC Educational Resources Information Center

Højen, Anders; Nazzi, Thierry

2016-01-01

The present study explored whether the phonological bias favoring consonants found in French-learning infants and children when learning new words (Havy & Nazzi, 2009; Nazzi, 2005) is language-general, as proposed by Nespor, Peña and Mehler (2003), or varies across languages, perhaps as a function of the phonological or lexical properties of…

Serving-Maids and Literacy: An Approach to Teaching Literacy through History and Music.

ERIC Educational Resources Information Center

Turner-Bisset, R.

2001-01-01

Presents a case study of an integrated approach to teaching history, literacy and music, in a Year 6 class. Suggests success was due to use of varied teaching approaches including storytelling, drama, singing and discussion. Emphasizes links between genuine historical tasks, and activities in the National Literacy Strategy. Suggests how music…

Data-Based Decision Making: The Impact of Data Variability, Training, and Context

ERIC Educational Resources Information Center

Vanselow, Nicholas R.; Thompson, Rachel; Karsina, Allen

2011-01-01

The current study examines agreement among individuals with varying expertise in behavior analysis about the length of baseline when data were presented point by point. Participants were asked to respond to baseline data and to indicate when to terminate the baseline phase. When only minimal information was provided about the data set, experts and…

The Role of Postural Support in Young Adults' Control of Stationary Kicking

ERIC Educational Resources Information Center

Sidaway, Ben; Bouchard, Matthew; Chasse, Julie; Dunn, Jonathan; Govoni, Andrea; McPherson, Breanne; Roy, Katherine; Anderson, David I.

2017-01-01

Purpose: The requirement for postural stability during the performance of motor skills has been clearly demonstrated in infants, but the necessity for such a postural substrate is not well documented in adults. The present study investigated the role of postural stability during a ballistic ball-kicking task in adults by providing varying degrees…

The Discourse Organization of Filipino Homilies and Indian Homilies: An Intercultural Rhetoric Approach

ERIC Educational Resources Information Center

Alamis, Ma. Melvyn P.

2013-01-01

The study examined the discourse structure of homily as a genre. It investigated homilies delivered by Filipino and Indian priests that represent varied types of Englishes in the Outer Circle. It described the organizational moves present in the two sets of homilies. The data which consisted of sixty orally delivered homilies transcribed into…

Impact of Inclusion of Varying Percentages of Repeaters on Equating

ERIC Educational Resources Information Center

Rogers, W. Todd; Radwan, Nizam

2015-01-01

Restricted equating samples are often used to equate test results. Previously eligible students may be excluded because this group of students is not stable from year to year and their inclusion may bias the results. The present study evaluated the impact of including previously eligible students in the equating samples, where the percentage of…

Creation of a Web-Based Lecture Series for Psychiatry Clerkship Students: Initial Findings

ERIC Educational Resources Information Center

Martin, Vicki L.; Bennett, David S.

2004-01-01

Objective: In recent years, the trend in medical education has been to utilize clerkship settings outside the medical school. Subsequently, students rotate at distant sites from the main campus and have lectures of varying quantity and quality. The objective of the present study was to standardize the core didactic experience for students in the…

The Role of Relational and Instructional Classroom Supports in the Language Development of At-Risk Preschoolers

ERIC Educational Resources Information Center

Gosse, Carolyn S.; McGinty, Anita S.; Mashburn, Andrew J.; Hoffman, LaVae M.; Pianta, Robert C.

2014-01-01

The present study examined the extent to which preschool classroom supports--relational support (RS) and instructional support (IS)--are associated with children's language development and whether these associations vary as a function of children's language ability. The language skills of 360 children within 95 classrooms were assessed using an…

Retrieval of Sentence Relations: Semantic vs. Syntactic Deep Structure.

ERIC Educational Resources Information Center

Perfetti, Charles A.

Two experiments on unaided and cued recall of sentences presented in context to college students are reported in this study. Key nouns in the sentences were arranged to have uniform surface functions, but to vary independently in deep syntactic category and semantic function. Cued recall for sentences in which the semantic function of actor and…

Women Principals in Small Schools in South Africa

ERIC Educational Resources Information Center

Lumby, Jacky; Azaola, Cristina

2011-01-01

South Africa presents a distinctive and varied context in which to explore the experience of women principals. The article draws on a larger data set to explore the interplay of gender and school size in seven schools with 200 students or fewer. From this study, we conclude that gender remains a potent influence on the career and experience of…

Stories of Three Editors: A Qualitative Study of Editing in the Workplace.

ERIC Educational Resources Information Center

Thompson, Isabelle K.; Rothschild, Joyce M.

1995-01-01

Presents generalizations about the editing process in a governmental agency. Suggests that editing is a complex, meaning-making process. Notes that the three vary greatly in their readiness to use their personal authority in interpreting the audience's needs. Suggests that editors gain authority by assuming the role of language specialists and by…

A Relationship with a Purpose: Accreditation Facilitation Projects and Early Childhood Programs.

ERIC Educational Resources Information Center

Flis, Deborah

2002-01-01

Describes use of accreditation facilitation projects (AFP) begun in the 1990s to provide varying levels and types of support to early childhood programs engaged in the self-study process for accreditation with the National Association for the Education of Young Children. Presents insights about the early childhood program/AFP relationship related…

Virtual Learning Environments for Students with Disabilities: A Review and Analysis of the Empirical Literature and Two Case Studies

ERIC Educational Resources Information Center

Vasquez, Eleazar, III; Nagendran, Arjun; Welch, Gregory F.; Marino, Matthew T.; Hughes, Darin E.; Koch, Aaron; Delisio, Lauren

2015-01-01

Students with autism spectrum disorder (ASD) show varying levels of impairment in social skills situations. Interventions have been developed utilizing virtual environments (VEs) to teach and improve social skills. This article presents a systematic literature review of peer-reviewed journal articles focusing on social interventions in VEs…

Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present

PubMed Central

Schweitzer, Mary Higby; Wittmeyer, Jennifer L; Horner, John R

2006-01-01

Soft tissues and cell-like microstructures derived from skeletal elements of a well-preserved Tyrannosaurus rex (MOR 1125) were represented by four components in fragments of demineralized cortical and/or medullary bone: flexible and fibrous bone matrix; transparent, hollow and pliable blood vessels; intravascular material, including in some cases, structures morphologically reminiscent of vertebrate red blood cells; and osteocytes with intracellular contents and flexible filipodia. The present study attempts to trace the occurrence of these four components in bone from specimens spanning multiple geological time periods and varied depositional environments. At least three of the four components persist in some skeletal elements of specimens dating to the Campanian. Fibrous bone matrix is more altered over time in morphology and less likely to persist than vessels and/or osteocytes. Vessels vary greatly in preservation, even within the same specimen, with some regions retaining pliability and other regions almost crystalline. Osteocytes also vary, with some retaining long filipodia and transparency, while others present with short and stubby filipodia and deeply pigmented nuclei, or are pigmented throughout with no nucleus visible. Alternative hypotheses are considered to explain the origin/source of observed materials. Finally, a two-part mechanism, involving first cross-linking of molecular components and subsequent mineralization, is proposed to explain the surprising presence of still-soft elements in fossil bone. These results suggest that present models of fossilization processes may be incomplete and that soft tissue elements may be more commonly preserved, even in older specimens, than previously thought. Additionally, in many cases, osteocytes with defined nuclei are preserved, and may represent an important source for informative molecular data. PMID:17148248

Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present.

PubMed

Schweitzer, Mary Higby; Wittmeyer, Jennifer L; Horner, John R

2007-01-22

Soft tissues and cell-like microstructures derived from skeletal elements of a well-preserved Tyrannosaurus rex (MOR 1125) were represented by four components in fragments of demineralized cortical and/or medullary bone: flexible and fibrous bone matrix; transparent, hollow and pliable blood vessels; intravascular material, including in some cases, structures morphologically reminiscent of vertebrate red blood cells; and osteocytes with intracellular contents and flexible filipodia. The present study attempts to trace the occurrence of these four components in bone from specimens spanning multiple geological time periods and varied depositional environments. At least three of the four components persist in some skeletal elements of specimens dating to the Campanian. Fibrous bone matrix is more altered over time in morphology and less likely to persist than vessels and/or osteocytes. Vessels vary greatly in preservation, even within the same specimen, with some regions retaining pliability and other regions almost crystalline. Osteocytes also vary, with some retaining long filipodia and transparency, while others present with short and stubby filipodia and deeply pigmented nuclei, or are pigmented throughout with no nucleus visible. Alternative hypotheses are considered to explain the origin/source of observed materials. Finally, a two-part mechanism, involving first cross-linking of molecular components and subsequent mineralization, is proposed to explain the surprising presence of still-soft elements in fossil bone. These results suggest that present models of fossilization processes may be incomplete and that soft tissue elements may be more commonly preserved, even in older specimens, than previously thought. Additionally, in many cases, osteocytes with defined nuclei are preserved, and may represent an important source for informative molecular data.

Do effects of common case-mix adjusters on patient experiences vary across patient groups?

PubMed

de Boer, Dolf; van der Hoek, Lucas; Rademakers, Jany; Delnoij, Diana; van den Berg, Michael

2017-11-22

Many survey studies in health care adjust for demographic characteristics such as age, gender, educational attainment and general health when performing statistical analyses. Whether the effects of these demographic characteristics are consistent between patient groups remains to be determined. This is important as the rationale for adjustment is often that demographic sub-groups differ in their so-called 'response tendency'. This rationale may be less convincing if the effects of response tendencies vary across patient groups. The present paper examines whether the impact of these characteristics on patients' global rating of care varies across patient groups. Secondary analyses using multi-level regression models were performed on a dataset including 32 different patient groups and 145,578 observations. For each demographic variable, the 95% expected range of case-mix coefficients across patient groups is presented. In addition, we report whether the variance of coefficients for demographic variables across patient groups is significant. Overall, men, elderly, lower educated people and people in good health tend to give higher global ratings. However, these effects varied significantly across patient groups and included the possibility of no effect or an opposite effect in some patient groups. The response tendency attributed to demographic characteristics - such as older respondents being milder, or higher educated respondents being more critical - is not general or universal. As such, the mechanism linking demographic characteristics to survey results on patient experiences with quality of care is more complicated than a general response tendency. It is possible that the response tendency interacts with patient group, but it is also possible that other mechanisms are at play.

Colony differences in response to trapping in roseate terns

USGS Publications Warehouse

Burger, J.; Nisbet, I.C.T.; Zingo, James M.; Spendelow, J.A.; Safina, C.; Gochfeld, M.

1995-01-01

Both members of seabird pairs are normally required to fledge young. Seabirds that nest in sites accessible to predators usually have one parent in attendance during the egg/chick phase. Time devoted to foraging can vary with individual skill and age, prey availability and abundance (Seamy 1978), and distance to foraging grounds (Safina 1990). Although average skill of similar-aged individuals should not vary from colony to colony (Ryder 1980), prey availability and abundance, and spatial distribution of foraging grounds may vary. Thus, the percent of time both members of a pair are present at the nest site may vary in different colonies. In this paper, we examine parental behavior in response to trapping in Roseate Terns (Sterna dougallii) nesting in three of the six major colonies in the northeastern United States: Cedar Beach, New York, Falkner Island, Connecticut; and Bird Island, Massachusetts. Roseate Terns were listed on the United States? Endangered Species List in 1987. We were interested in differences among colonies in how often both parents were present, how soon a mate returned to the nest if one parent was temporarily removed, how soon a trapped bird returned to the nest after release, and the time during which the nest was left unguarded. We feel it is important to recognize and make management decisions based on colony differences where they exist. Our study follows directly from earlier work at Cedar Beach on trapping vulnerability of Common Terns (Sterna hirundo) and Roseate Terns. Nisbet reported that Roseate Terns at Bird Island required about three hours to return to the nest after trapping.

The effect of study time distribution on learning and retention: a Goldilocks principle for presentation rate.

PubMed

de Jonge, Mario; Tabbers, Huib K; Pecher, Diane; Zeelenberg, René

2012-03-01

In 2 experiments, we investigated the effect of presentation rate on both immediate (5 min) and delayed (2 days) cued recall of paired associates. Word pairs were presented for a total of 16 s per pair, with presentation duration of individual presentations varying from 1 to 16 s. In Experiment 1, participants studied word pairs with presentation rates of 16 × 1 s, 8 × 2 s, 4 × 4 s, 2 × 8 s, or 1 × 16 s. A nonmonotonic relationship was found between presentation rate and cued recall performance. Both short (e.g., 1 s) and long (e.g., 16 s) presentation durations resulted in poor immediate and delayed recall, compared with intermediate presentation durations. In Experiment 2, we replicated these general findings. Moreover, we showed that the 4 s condition resulted in less proportional forgetting than the 1 s and the 16 s conditions. 2012 APA, all rights reserved

One process is not enough! A speed-accuracy tradeoff study of recognition memory.

PubMed

Boldini, Angela; Russo, Riccardo; Avons, S E

2004-04-01

Speed-accuracy tradeoff (SAT) methods have been used to contrast single- and dual-process accounts of recognition memory. In these procedures, subjects are presented with individual test items and are required to make recognition decisions under various time constraints. In this experiment, we presented word lists under incidental learning conditions, varying the modality of presentation and level of processing. At test, we manipulated the interval between each visually presented test item and a response signal, thus controlling the amount of time available to retrieve target information. Study-test modality match had a beneficial effect on recognition accuracy at short response-signal delays (< or =300 msec). Conversely, recognition accuracy benefited more from deep than from shallow processing at study only at relatively long response-signal delays (> or =300 msec). The results are congruent with views suggesting that both fast familiarity and slower recollection processes contribute to recognition memory.

Arrogant or self-confident? The use of contextual knowledge to differentiate hubristic and authentic pride from a single nonverbal expression.

PubMed

Tracy, Jessica L; Prehn, Christine

2012-01-01

Two studies tested whether observers could differentiate between two facets of pride-authentic and hubristic-on the basis of a single prototypical pride nonverbal expression combined with relevant contextual information. In Study 1, participants viewed targets displaying posed pride expressions in response to success, while causal attributions for the success (target's effort vs. ability) and the source of this information (target vs. omniscient narrator conveying objective fact) were varied. Study 2 used a similar method, but attribution information came from both the target and an omniscient narrator; the congruence of these attributions was varied. Across studies, participants tended to label expressions as authentic pride, but were relatively more likely to label them as hubristic pride when (a) contextual information indicated that targets were arrogant and (b) no mitigating information about the target's potential value as a hard-working group member (i.e., that success was actually due to effort) was presented.

Comparison of data used for setting occupational exposure limits.

PubMed

Schenk, Linda

2010-01-01

It has previously been shown that occupational exposure limits (OELs) for the same substance can vary significantly between different standard-setters. The work presented in this paper identifies the steps in the process towards establishing an OEL and how variations in those processes could account for these differences. This study selects for further scrutiny substances for which the level of OELs vary by a factor of 100, focussing on 45 documents concerning 14 substances from eight standard-setters. Several of the OELs studied were more than 20 years old and based on outdated knowledge. Furthermore, different standard-setters sometimes based their OELs on different sets of data, and data availability alone could not explain all differences in the selection of data sets used by standard-setters. While the interpretation of key studies did not differ significantly in standard-setters' documentations, the evaluations of the key studies' quality did. Also, differences concerning the critical effect coincided with differences in the level of OELs for half of the substances.

Wing optimization for space shuttle orbiter vehicles

NASA Technical Reports Server (NTRS)

Surber, T. E.; Bornemann, W. E.; Miller, W. D.

1972-01-01

The results were presented of a parametric study performed to determine the optimum wing geometry for a proposed space shuttle orbiter. The results of the study establish the minimum weight wing for a series of wing-fuselage combinations subject to constraints on aerodynamic heating, wing trailing edge sweep, and wing over-hang. The study consists of a generalized design evaluation which has the flexibility of arbitrarily varying those wing parameters which influence the vehicle system design and its performance. The study is structured to allow inputs of aerodynamic, weight, aerothermal, structural and material data in a general form so that the influence of these parameters on the design optimization process can be isolated and identified. This procedure displays the sensitivity of the system design of variations in wing geometry. The parameters of interest are varied in a prescribed fashion on a selected fuselage and the effect on the total vehicle weight is determined. The primary variables investigated are: wing loading, aspect ratio, leading edge sweep, thickness ratio, and taper ratio.

Robust linear parameter-varying control of blood pressure using vasoactive drugs

NASA Astrophysics Data System (ADS)

Luspay, Tamas; Grigoriadis, Karolos

2015-10-01

Resuscitation of emergency care patients requires fast restoration of blood pressure to a target value to achieve hemodynamic stability and vital organ perfusion. A robust control design methodology is presented in this paper for regulating the blood pressure of hypotensive patients by means of the closed-loop administration of vasoactive drugs. To this end, a dynamic first-order delay model is utilised to describe the vasoactive drug response with varying parameters that represent intra-patient and inter-patient variability. The proposed framework consists of two components: first, an online model parameter estimation is carried out using a multiple-model extended Kalman-filter. Second, the estimated model parameters are used for continuously scheduling a robust linear parameter-varying (LPV) controller. The closed-loop behaviour is characterised by parameter-varying dynamic weights designed to regulate the mean arterial pressure to a target value. Experimental data of blood pressure response of anesthetised pigs to phenylephrine injection are used for validating the LPV blood pressure models. Simulation studies are provided to validate the online model estimation and the LPV blood pressure control using phenylephrine drug injection models representing patients showing sensitive, nominal and insensitive response to the drug.

Multimodal Pilot Behavior in Multi-Axis Tracking Tasks with Time-Varying Motion Cueing Gains

NASA Technical Reports Server (NTRS)

Zaal, P. M. T; Pool, D. M.

2014-01-01

In a large number of motion-base simulators, adaptive motion filters are utilized to maximize the use of the available motion envelope of the motion system. However, not much is known about how the time-varying characteristics of such adaptive filters affect pilots when performing manual aircraft control. This paper presents the results of a study investigating the effects of time-varying motion filter gains on pilot control behavior and performance. An experiment was performed in a motion-base simulator where participants performed a simultaneous roll and pitch tracking task, while the roll and/or pitch motion filter gains changed over time. Results indicate that performance increases over time with increasing motion gains. This increase is a result of a time-varying adaptation of pilots' equalization dynamics, characterized by increased visual and motion response gains and decreased visual lead time constants. Opposite trends are found for decreasing motion filter gains. Even though the trends in both controlled axes are found to be largely the same, effects are less significant in roll. In addition, results indicate minor cross-coupling effects between pitch and roll, where a cueing variation in one axis affects the behavior adopted in the other axis.

VARiD: a variation detection framework for color-space and letter-space platforms.

PubMed

Dalca, Adrian V; Rumble, Stephen M; Levy, Samuel; Brudno, Michael

2010-06-15

High-throughput sequencing (HTS) technologies are transforming the study of genomic variation. The various HTS technologies have different sequencing biases and error rates, and while most HTS technologies sequence the residues of the genome directly, generating base calls for each position, the Applied Biosystem's SOLiD platform generates dibase-coded (color space) sequences. While combining data from the various platforms should increase the accuracy of variation detection, to date there are only a few tools that can identify variants from color space data, and none that can analyze color space and regular (letter space) data together. We present VARiD--a probabilistic method for variation detection from both letter- and color-space reads simultaneously. VARiD is based on a hidden Markov model and uses the forward-backward algorithm to accurately identify heterozygous, homozygous and tri-allelic SNPs, as well as micro-indels. Our analysis shows that VARiD performs better than the AB SOLiD toolset at detecting variants from color-space data alone, and improves the calls dramatically when letter- and color-space reads are combined. The toolset is freely available at http://compbio.cs.utoronto.ca/varid.

Western hemlock as a veneer resource.

Treesearch

Thomas D. Fahey; Jr. Woodfin

1982-01-01

Presents recovery of veneer grade and volume from western hemlock from Oregon and Washington. Veneer grade recovery varied by grade and size of logs. Veneer volume recovered was about 45 percent of the cubic volume of the log and varied somewhat with log diameter.

Multiple-orifice liquid injection into hypersonic airstreams and applications to ram C-3 flight

NASA Technical Reports Server (NTRS)

Weaver, W. L.

1972-01-01

Experimental data are presented for the oblique injection of water and three electrophilic liquids (fluorocarbon compounds) through multiple-orifice nozzles from a flat plate and the sides of a hemisphere-cone (0.375 scale of RAM C spacecraft) into hypersonic airstreams. The nozzle patterns included single and multiple orifices, single rows of nozzles, and duplicates of the RAM C-III nozzles. The flat-plate tests were made at Mach 8. Total pressure was varied from 3.45 MN/m2 to 10.34 MN/m2, Reynolds number was varied form 9,840,000 per meter to 19,700,000 per meter, and liquid injection pressure was varied from 0.69 MN/m2 to 3.5 MN/m2. The hemisphere-cone tests were made at Mach 7.3. Total pressure was varied from 1.38 MN/m2, to 6.89 MN/m2, Reynolds number was varied from 3,540,000 per meter to 17,700,000 per meter, and liquid-injection pressure was varied from 0.34 MN/m2 to 4.14 MN/m2. Photographs of the tests and plots of liquid-penetration and spray cross-section area are presented. Maximum penetration was found to vary as the square root of the dynamic-pressure ratio and the square root of the total injection nozzle area. Spray cross-section area was linear with maximum penetration. The test results are used to compute injection parameters for the RAM C-3 flight injection experiment.

Safety management of complex research operators

NASA Technical Reports Server (NTRS)

Brown, W. J.

1981-01-01

Complex research and technology operations present varied potential hazards which are addressed in a disciplined, independent safety review and approval process. Potential hazards vary from high energy fuels to hydrocarbon fuels, high pressure systems to high voltage systems, toxic chemicals to radioactive materials and high speed rotating machinery to high powered lasers. A Safety Permit System presently covers about 600 potentially hazardous operations. The Safety Management Program described is believed to be a major factor in maintaining an excellent safety record.

CMOS-based Stochastically Spiking Neural Network for Optimization under Uncertainties

DTIC Science & Technology

2017-03-01

inverse tangent characteristics at varying input voltage (VIN) [Fig. 3], thereby it is suitable for Kernel function implementation. By varying bias...cost function/constraint variables are generated based on inverse transform on CDF. In Fig. 5, F-1(u) for uniformly distributed random number u [0, 1...extracts random samples of x varying with CDF of F(x). In Fig. 6, we present a successive approximation (SA) circuit to evaluate inverse

Chapter 18: Variable Frequency Drive Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romberger, Jeff

An adjustable-speed drive (ASD) includes all devices that vary the speed of a rotating load, including those that vary the motor speed and linkage devices that allow constant motor speed while varying the load speed. The Variable Frequency Drive Evaluation Protocol presented here addresses evaluation issues for variable-frequency drives (VFDs) installed on commercial and industrial motor-driven centrifugal fans and pumps for which torque varies with speed. Constant torque load applications, such as those for positive displacement pumps, are not covered by this protocol.

The Effects of Varying Contextual Demands on Age-related Positive Gaze Preferences

PubMed Central

Noh, Soo Rim; Isaacowitz, Derek M.

2015-01-01

Despite many studies on the age-related positivity effect and its role in visual attention, discrepancies remain regarding whether one’s full attention is required for age-related differences to emerge. The present study took a new approach to this question by varying the contextual demands of emotion processing. This was done by adding perceptual distractions, such as visual and auditory noise, that could disrupt attentional control. Younger and older participants viewed pairs of happy–neutral and fearful–neutral faces while their eye movements were recorded. Facial stimuli were shown either without noise, embedded in a background of visual noise (low, medium, or high), or with simultaneous auditory babble. Older adults showed positive gaze preferences, looking toward happy faces and away from fearful faces; however, their gaze preferences tended to be influenced by the level of visual noise. Specifically, the tendency to look away from fearful faces was not present in conditions with low and medium levels of visual noise, but was present where there were high levels of visual noise. It is important to note, however, that in the high-visual-noise condition, external cues were present to facilitate the processing of emotional information. In addition, older adults’ positive gaze preferences disappeared or were reduced when they first viewed emotional faces within a distracting context. The current results indicate that positive gaze preferences may be less likely to occur in distracting contexts that disrupt control of visual attention. PMID:26030774

The effects of varying contextual demands on age-related positive gaze preferences.

PubMed

Noh, Soo Rim; Isaacowitz, Derek M

2015-06-01

Despite many studies on the age-related positivity effect and its role in visual attention, discrepancies remain regarding whether full attention is required for age-related differences to emerge. The present study took a new approach to this question by varying the contextual demands of emotion processing. This was done by adding perceptual distractions, such as visual and auditory noise, that could disrupt attentional control. Younger and older participants viewed pairs of happy-neutral and fearful-neutral faces while their eye movements were recorded. Facial stimuli were shown either without noise, embedded in a background of visual noise (low, medium, or high), or with simultaneous auditory babble. Older adults showed positive gaze preferences, looking toward happy faces and away from fearful faces; however, their gaze preferences tended to be influenced by the level of visual noise. Specifically, the tendency to look away from fearful faces was not present in conditions with low and medium levels of visual noise but was present when there were high levels of visual noise. It is important to note, however, that in the high-visual-noise condition, external cues were present to facilitate the processing of emotional information. In addition, older adults' positive gaze preferences disappeared or were reduced when they first viewed emotional faces within a distracting context. The current results indicate that positive gaze preferences may be less likely to occur in distracting contexts that disrupt control of visual attention. (c) 2015 APA, all rights reserved.

Stochastic bio-economic modeling of mastitis in Ethiopian dairy farms.

PubMed

Getaneh, Abraham Mekibeb; Mekonnen, Sefinew Alemu; Hogeveen, Henk

2017-03-01

Mastitis is an inflammation of the mammary gland that is considered to be one of the most frequent and costly diseases in the dairy industry. Also in Ethiopia, bovine mastitis is one of the most frequently encountered diseases of dairy cows. However, there was no study, so far, regarding the costs of clinical mastitis and only two studies were reported on costs of subclinical mastitis. Presenting an appropriate and complete study of the costs of mastitis will help farmers in making management decisions for mastitis control. The objective of this study was to estimate the economic effects of mastitis on Ethiopian market-oriented dairy farms. Market-oriented dairy farming is driven by making profits through selling milk in the market on a regular basis. A dynamic stochastic Monte-Carlo simulation model (bio-economic model) was developed taking into account both clinical and subclinical mastitis. Production losses, culling, veterinarian costs, treatment, discarded milk, and labour were the main cost factors which were modeled in this study. The annual incidence of clinical mastitis varied from 0 to 50% with a mean annual incidence of 21.6%, whereas the mean annual incidence of subclinical mastitis was 36.2% which varied between 0 and 75%. The total costs due to mastitis for a default farm size of 8 lactating cows were 6,709 ETB per year (838 ETB per cow per year). The costs varied considerably, with 5th and 95th percentiles of 109 ETB and 22,009 ETB, respectively. The factor most contributing to the total annual cost of mastitis was culling. On average a clinical case costs 3,631 ETB, varying from 0 to 12,401, whereas a sub clinical case costs 147 ETB, varying from 0 to 412. The sensitivity analysis showed that the total costs at the farm level were most sensitive for variation in the probability of occurrence of clinical mastitis and the probability of culling. This study helps farmers to raise awareness about the actual costs of mastitis and motivate them to timely treat and/or take preventive measures. As a results, the dairy industry will improve. Copyright © 2017 Elsevier B.V. All rights reserved.

Blended-Wing-Body Structural Technology Study

NASA Technical Reports Server (NTRS)

Starnes, James H.

1998-01-01

In most studies of stability of plates, the axial stress has been taken as uniform compression throughout flat rectangular plates. Buckling of isotropic plates under a compressive stress that varies linearly from one loaded edge to the other has been studied by Libove et al. Cases of practical interest exist, however, in which the axial stress is not uniform but varies from tension at both loaded edges to compression in the middle. An example is the stability of the crown of the hat stiffened panel, a candidate configuration of the upper and lower skin of the Blended Wing Body (BWB) Aircraft. The BWB Aircraft is an advanced long-range ultra-high-capacity airliner with the principal feature being the pressurized wide double-deck body which is blended into the wing. In the present research, analytical methods are used to investigate the local stability of the crown in order to minimize its weight while optimizing its buckling strength. The crown is modeled as a rectangular laminated composite plate subjected to a second degree parabolic variation of axial stresses in the longitudinal direction. A varying tension-compression- tension axial stresses are induced in the crown of the stiffeners due to bending. The change in axial stresses is equilibrated by nonuniform shear stresses along the plate edges and transverse normal stresses.

Study of resonant processes in plasmonic nanostructures for sensor applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pirunčík, Jiří; Kwiecien, Pavel; Fiala, Jan; Richter, Ivan

2017-05-01

This contribution is focused on the numerical studies of resonant processes in individual plasmonic nanostructures, with the attention particularly given to rectangular nanoparticles and concominant localized surface plasmon resonance processes. Relevant models for the description and anylysis of localized surface plasmon resonance are introduced, in particular: quasistatic approximation, Mie theory and in particular, a generalized (quasi)analytical approach for treating rectangularly shaped nanostructures. The parameters influencing resonant behavior of nanoparticles are analyzed with special interest in morphology and sensor applications. Results acquired with Lumerical FDTD Solutions software, using finite-difference time-domain simulation method, are shown and discussed. Simulations were mostly performed for selected nanostructures composed of finite rectangular nanowires with square cross-sections. Systematic analysis is made for single nanowires with varying length, parallel couple of nanowires with varying gap (cut -wires) and selected dolmen structures with varying gap between one nanowire transversely located with respect to parallel couple of nanowires (in both in-plane and -out-of-plane arrangements). The dependence of resonant peaks of cross-section spectral behavior (absorption, scattering, extinction) and their tunability via suitable structuring and morphology changes are primarily researched. These studies are then followed with an analysis of the effect of periodic arrangements. The results can be usable with respect to possible sensor applications.

Exploring Biomolecular Recognition by Modeling and Simulation

NASA Astrophysics Data System (ADS)

Wade, Rebecca

2007-12-01

Biomolecular recognition is complex. The balance between the different molecular properties that contribute to molecular recognition, such as shape, electrostatics, dynamics and entropy, varies from case to case. This, along with the extent of experimental characterization, influences the choice of appropriate computational approaches to study biomolecular interactions. I will present computational studies in which we aim to make concerted use of bioinformatics, biochemical network modeling and molecular simulation techniques to study protein-protein and protein-small molecule interactions and to facilitate computer-aided drug design.

Human Mars Transportation Applications Using Solar Electric Propulsion

NASA Technical Reports Server (NTRS)

Donahue, Benjamin B.; Martin, Jim; Potter, Seth; Henley, Mark; Carrington, Connie (Technical Monitor)

2000-01-01

Advanced solar electric power systems and electric propulsion technology constitute viable elements for conducting human Mars transfer missions that are roughly comparable in performance to similar missions utilizing alternative high thrust systems, with the one exception being their inability to achieve short Earth-Mars trip times. A modest solar electric propulsion human Mars scenario is presented that features the use of conjunction class trajectories in concert with pre-emplacement of surface assets that can be used in a series of visits to Mars. Major elements of the Mars solar electric transfer vehicle can be direct derivatives of present state-of-the-art Solar array and electric thruster systems. During the study, several elements affecting system performance were evaluated, including varying Earth orbit altitude for departure, recapturing the transfer stage at Earth for reuse, varying power system mass-to-power ratio, and assessing solar array degradation on performance induced by Van Allen belt passage. Comparisons are made to chemical propulsion and nuclear thermal propulsion Mars vehicles carrying similar payloads.

Methanol Droplet Extinction in Oxygen/Carbon-dioxide/Nitrogen Mixtures in Microgravity: Results from the International Space Station Experiments

NASA Technical Reports Server (NTRS)

Nayagam, Vedha; Dietrich, Daniel L.; Ferkul, Paul V.; Hicks, Michael C.; Williams, Forman A.

2012-01-01

Motivated by the need to understand the flammability limits of condensed-phase fuels in microgravity, isolated single droplet combustion experiments were carried out in the Combustion Integrated Rack Facility onboard the International Space Station. Experimental observations of methanol droplet combustion and extinction in oxygen/carbon-dioxide/nitrogen mixtures at 0.7 and 1 atmospheric pressure in quiescent microgravity environment are reported for initial droplet diameters varying between 2 mm to 4 mm in this study.The ambient oxygen concentration was systematically lowered from test to test so as to approach the limiting oxygen index (LOI) at fixed ambient pressure. At one atmosphere pressure, ignition and some burning were observed for an oxygen concentration of 13% with the rest being nitrogen. In addition, measured droplet burning rates, flame stand-off ratios, and extinction diameters are presented for varying concentrations of oxygen and diluents. Simplified theoretical models are presented to explain the observed variations in extinction diameter and flame stand-off ratios.

Disease scoring systems for oral lichen planus; a critical appraisal

PubMed Central

Wang, Jing

2015-01-01

The aim of the present study has been to critically review 22 disease scoring systems (DSSs) on oral lichen planus (OLP) that have been reported in the literature during the past decades. Although the presently available DSSs may all have some merit, particularly for research purposes, the diversity of both the objective and subjective parameters used in these systems and the lack of acceptance of one of these systems for uniform use, there is a need for an international, authorized consensus meeting on this subject. Because of the natural course of OLP characterized by remissions and exacerbations and also due to the varying distribution pattern and the varying clinical types, e.g. reticular and erosive, the relevance of a DSS based on morphologic parameters is somewhat questionable. Instead, one may consider to only look for a quality of life scoring system adapted for use in OLP patients. Key words:Oral lichen planus, disease scoring system, classification. PMID:25681372

Detonation propagation in a high loss configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, Scott I; Shepherd, Joseph E

2009-01-01

This work presents an experimental study of detonation wave propagation in tubes with inner diameters (ID) comparable to the mixture cell size. Propane-oxygen mixtures were used in two test section tubes with inner diameters of 1.27 mm and 6.35 mm. For both test sections, the initial pressure of stoichiometric mixtures was varied to determine the effect on detonation propagation. For the 6.35 mm tube, the equivalence ratio {phi} (where the mixture was {phi} C{sub 3}H{sub 8} + 50{sub 2}) was also varied. Detonations were found to propagate in mixtures with cell sizes as large as five times the diameter ofmore » the tube. However, under these conditions, significant losses were observed, resulting in wave propagation velocities as slow as 40% of the CJ velocity U{sub CJ}. A review of relevant literature is presented, followed by experimental details and data. Observed velocity deficits are predicted using models that account for boundary layer growth inside detonation waves.« less

Absolute detection efficiencies of low energy H, H -, H +, H 2+ and H 3+ incident on a multichannel plate detector

NASA Astrophysics Data System (ADS)

Peko, B. L.; Stephen, T. M.

2000-12-01

Measured absolute detection efficiencies are presented for H, H - and H n+ ( n=1,2,3) impacting a commercially available, dual multichannel plate (MCP) electron multiplier at kinetic energies ranging from 30 to 1000 eV. Measurements involving isotopic substitutions (D, D -, D n+) and Ar + are also presented. In addition, atomic hydrogen detection efficiencies relative to those of H + and H - are given, as they may have a more universal application. For the three charge states, H, H + and H -, the absolute detection efficiencies are markedly different at low energies and converge to a nearly uniform value of ˜70% with increasing projectile energy. The energy dependence is strongest for H +, varying nearly three orders of magnitude over the energy range studied, and weakest for H -, varying by less than one order of magnitude. In general, for the low energy positive ions at a given energy, the lighter the incident particle mass, the greater the probability of its detection.

A study of methods to estimate debris flow velocity

USGS Publications Warehouse

Prochaska, A.B.; Santi, P.M.; Higgins, J.D.; Cannon, S.H.

2008-01-01

Debris flow velocities are commonly back-calculated from superelevation events which require subjective estimates of radii of curvature of bends in the debris flow channel or predicted using flow equations that require the selection of appropriate rheological models and material property inputs. This research investigated difficulties associated with the use of these conventional velocity estimation methods. Radii of curvature estimates were found to vary with the extent of the channel investigated and with the scale of the media used, and back-calculated velocities varied among different investigated locations along a channel. Distinct populations of Bingham properties were found to exist between those measured by laboratory tests and those back-calculated from field data; thus, laboratory-obtained values would not be representative of field-scale debris flow behavior. To avoid these difficulties with conventional methods, a new preliminary velocity estimation method is presented that statistically relates flow velocity to the channel slope and the flow depth. This method presents ranges of reasonable velocity predictions based on 30 previously measured velocities. ?? 2008 Springer-Verlag.

Characterizing multivariate decoding models based on correlated EEG spectral features

PubMed Central

McFarland, Dennis J.

2013-01-01

Objective Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Methods Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). Results The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Conclusions Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. Significance While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. PMID:23466267

The effect of dam construction on the movement of dwarf caimans, Paleosuchus trigonatus and Paleosuchus palpebrosus, in Brazilian Amazonia.

PubMed

Campos, Zilca; Mourão, Guilherme; Magnusson, William E

2017-01-01

Run-of-the-river hydroelectric dams cause changes in seasonal inundation of the floodplains, and this may cause displacement of semi-aquatic vertebrates present before dam construction. This study evaluated the movement of crocodilians before and after the filling of the Santo Antônio hydroelectric reservoir on the Madeira River in the Brazilian Amazon, which occurred in November 2011. We radio-tracked four adult male Paleosuchus palpebrosus and four adult male Paleosuchus trigonatus before and after the formation of the reservoir between 2011 and 2013. The home ranges of the P. palpebrosus varied from < 1 km2 to 91 km2 and the home ranges of the P. trigonatus varied from < 1km2 to 5 km2. The species responded differently to time since filling and water level in weekly movement and home range. However, overall the dam appears to have had little effect on the use of space by the individuals that were present before dam construction.

Tuning of electronic properties and dynamical stability of graphene oxide with different functional groups

NASA Astrophysics Data System (ADS)

Dabhi, Shweta D.; Jha, Prafulla K.

2017-09-01

The structural, electronic and vibrational properties of graphene oxide (GO) with varying proportion of epoxy and hydroxyl functional groups have been studied using density functional theory. The functional groups and oxygen density have an obvious influence on the electronic and vibrational properties. The dependence of band gap on associated functional groups and oxygen density shows a possibility of tuning the band gap of graphene by varying the functional groups as well as oxidation level. The absorption of high oxygen content in graphene leads to the gap opening and resulting in a transition from semimetal to semiconductor. Phonon dispersion curves show no imaginary frequency or no softening of any phonon mode throughout the Brillouin zone which confirms the dynamical stability of all considered GO models. Different groups and different oxygen density result into the varying characteristics of phonon modes. The computed results show good agreement with the experimental observations. Our results present interesting possibilities for engineering the electronic properties of graphene and GO and impact the fabrication of new electronics.

Study of VTOL in ground-effect flow field including temperature effect

NASA Technical Reports Server (NTRS)

Hill, W. G.; Jenkins, R. C.; Kalemaris, S. G.; Siclari, M. J.

1982-01-01

Detailed pressure, temperature, and velocity data were obtained for twin-fan configurations in-ground-effect and flow models to aid in predicting pressures and upwash forces on aircraft surfaces were developed. For the basic experiments, 49.5 mm-diameter jets were used, oriented normal to a simulated round plane, with pressurized, heated air providing a jet. The experimental data consisted of: (1) the effect of jet height and temperature on the ground, model, and upwash pressures, and temperatures, (2) the effect of simulated aircraft surfaces on the isolated flow field, (3) the jet-induced forces on a three-dimensional body with various strakes, (4) the effects of non-uniform coannular jets. For the uniform circular jets, temperature was varied from room temperature (24 C) to 232 C. Jet total pressure was varied between 9,300 Pascals and 31,500 Pascals. For the coannular jets, intended to represent turbofan engines, fan temperature was maintained at room temperature while core temperature was varied from room temperature to 437 C. Results are presented.

Assessment of a surface-layer parameterization scheme in an atmospheric model for varying meteorological conditions

NASA Astrophysics Data System (ADS)

Anurose, T. J.; Bala Subrahamanyam, D.

2014-06-01

The performance of a surface-layer parameterization scheme in a high-resolution regional model (HRM) is carried out by comparing the model-simulated sensible heat flux (H) with the concurrent in situ measurements recorded at Thiruvananthapuram (8.5° N, 76.9° E), a coastal station in India. With a view to examining the role of atmospheric stability in conjunction with the roughness lengths in the determination of heat exchange coefficient (CH) and H for varying meteorological conditions, the model simulations are repeated by assigning different values to the ratio of momentum and thermal roughness lengths (i.e. z0m/z0h) in three distinct configurations of the surface-layer scheme designed for the present study. These three configurations resulted in differential behaviour for the varying meteorological conditions, which is attributed to the sensitivity of CH to the bulk Richardson number (RiB) under extremely unstable, near-neutral and stable stratification of the atmosphere.

Environmental surfaces and the compression of perceived visual space

PubMed Central

Bian, Zheng; Andersen, George J.

2011-01-01

The present study examined whether the compression of perceived visual space varies according to the type of environmental surface being viewed. To examine this issue, observers made exocentric distance judgments when viewing simulated 3D scenes. In 4 experiments, observers viewed ground and ceiling surfaces and performed either an L-shaped matching task (Experiments 1, 3, and 4) or a bisection task (Experiment 2). Overall, we found considerable compression of perceived exocentric distance on both ground and ceiling surfaces. However, the perceived exocentric distance was less compressed on a ground surface than on a ceiling surface. In addition, this ground surface advantage did not vary systematically as a function of the distance in the scene. These results suggest that the perceived visual space when viewing a ground surface is less compressed than the perceived visual space when viewing a ceiling surface and that the perceived layout of a surface varies as a function of the type of the surface. PMID:21669858

Elastic and viscoelastic calculations of stresses in sedimentary basins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warpinski, N.R.

This study presents a method for estimating the stress state within reservoirs at depth using a time-history approach for both elastic and viscoelastic rock behavior. Two features of this model are particularly significant for stress calculations. The first is the time-history approach, where we assume that the present in situ stress is a result of the entire history of the rock mass, rather than due only to the present conditions. The model can incorporate: (1) changes in pore pressure due to gas generation; (2) temperature gradients and local thermal episodes; (3) consolidation and diagenesis through time-varying material properties; and (4)more » varying tectonic episodes. The second feature is the use of a new viscoelastic model. Rather than assume a form of the relaxation function, a complete viscoelastic solution is obtained from the elastic solution through the viscoelastic correspondence principal. Simple rate models are then applied to obtain the final rock behavior. Example calculations for some simple cases are presented that show the contribution of individual stress or strain components. Finally, a complete example of the stress history of rocks in the Piceance basin is attempted. This calculation compares favorably with present-day stress data in this location. This model serves as a predictor for natural fracture genesis and expected rock fracturing from the model is compared with actual fractures observed in this region. These results show that most current estimates of in situ stress at depth do not incorporate all of the important mechanisms and a more complete formulation, such as this study, is required for acceptable stress calculations. The method presented here is general and is applicable to any basin having a relatively simple geologic history. 25 refs., 18 figs.« less

Hydrologic flow path development varies by aspect during spring snowmelt in complex subalpine terrain

NASA Astrophysics Data System (ADS)

Webb, Ryan W.; Fassnacht, Steven R.; Gooseff, Michael N.

2018-01-01

In many mountainous regions around the world, snow and soil moisture are key components of the hydrologic cycle. Preferential flow paths of snowmelt water through snow have been known to occur for years with few studies observing the effect on soil moisture. In this study, statistical analysis of the topographical and hydrological controls on the spatiotemporal variability of snow water equivalent (SWE) and soil moisture during snowmelt was undertaken at a subalpine forested setting with north, south, and flat aspects as a seasonally persistent snowpack melts. We investigated if evidence of preferential flow paths in snow can be observed and the effect on soil moisture through measurements of snow water equivalent and near-surface soil moisture, observing how SWE and near-surface soil moisture vary on hillslopes relative to the toes of hillslopes and flat areas. We then compared snowmelt infiltration beyond the near-surface soil between flat and sloping terrain during the entire snowmelt season using soil moisture sensor profiles. This study was conducted during varying snowmelt seasons representing above-normal, relatively normal, and below-normal snow seasons in northern Colorado. Evidence is presented of preferential meltwater flow paths at the snow-soil interface on the north-facing slope causing increases in SWE downslope and less infiltration into the soil at 20 cm depth; less association is observed in the near-surface soil moisture (top 7 cm). We present a conceptualization of the meltwater flow paths that develop based on slope aspect and soil properties. The resulting flow paths are shown to divert at least 4 % of snowmelt laterally, accumulating along the length of the slope, to increase the snow water equivalent by as much as 170 % at the base of a north-facing hillslope. Results from this study show that snow acts as an extension of the vadose zone during spring snowmelt and future hydrologic investigations will benefit from studying the snow and soil together.

Simulation of preburner sprays, volumes 1 and 2

NASA Technical Reports Server (NTRS)

Hardalupas, Y.; Whitelaw, J. H.

1993-01-01

The present study considered characteristics of sprays under a variety of conditions. Control of these sprays is important as the spray details can control both rocket combustion stability and efficiency. Under the present study Imperial College considered the following: (1) Measurement of the size and rate of spread of the sprays produced by single coaxial airblast nozzles with axial gaseous stream. The local size, velocity, and flux characteristics for a wide range of gas and liquid flowrates were measured, and the results were correlated with the conditions of the spray at the nozzle exit. (2) Examination of the effect of the geometry of single coaxial airblast atomizers on spray characteristics. The gas and liquid tube diameters were varied over a range of values, the liquid tube recess was varied, and the shape of the exit of the gaseous jet was varied from straight to converging. (3) Quantification of the effect of swirl in the gaseous stream on the spray characteristics produced by single coaxial airblast nozzles. (4) Quantification of the effect of reatomization by impingement of the spray on a flat disc positioned around 200 mm from the nozzle exit. This models spray impingement on the turbopump dome during the startup process of the preburner of the SSME. (5) Study of the interaction between multiple sprays without and with swirl in their gaseous stream. The spray characteristics of single nozzles were compared with that of three identical nozzles with their axis at a small distance from each other. This study simulates the sprays in the preburner of the SSME, where there are around 260 elements on the faceplate of the combustion chamber. (6) Design an experimental facility to study the characteristics of sprays at high pressure conditions and at supercritical pressure and temperature for the gas but supercritical pressure and subcritical temperature for the liquid.

Cu2ZnGeS4 thin films deposited by thermal evaporation: the impact of Ge concentration on physical properties

NASA Astrophysics Data System (ADS)

Courel, Maykel; Sanchez, T. G.; Mathews, N. R.; Mathew, X.

2018-03-01

In this work, the processing of Cu2ZnGeS4 (CZGS) thin films by a thermal evaporation technique starting from CuS, GeS and ZnS precursors, and post-deposition thermal processing, is discussed. Batches of films with GeS layers of varying thicknesses are deposited in order to study the role of Ge concentration on the structural, morphological, optical and electrical properties of CZGS films. The formation of the CZGS compound with a tetragonal phase and a kesterite structure is confirmed for all samples using XRD and Raman studies. An improvement in crystallite size for Ge-poor films is also observed in the XRD analysis, which is in good agreement with the grain size observed in the cross section SEM image. Furthermore, it is found that the band-gap of CZGS film can be tailored in the range of 2.0-2.23 eV by varying Ge concentration. A comprehensive electrical characterization is also performed which demonstrates that slightly Ge-poor samples are described by the lowest grain boundary defect densities and the highest photosensitivity and mobility values. A study of the work function of CZGS samples with different Ge concentrations is also presented. Finally, a theoretical evaluation is presented, considering, under ideal conditions, the possible impact of these films on device performance. Based on the characterization results, it is concluded that Ge-poor CZGS samples deposited by thermal evaporation present better physical properties for device applications.

Exposure of cultured human proximal tubular cells to cadmium, mercury, zinc and bismuth: toxicity and metallothionein induction.

PubMed

Rodilla, V; Miles, A T; Jenner, W; Hawksworth, G M

1998-08-14

The kidney, in particular the proximal convoluted tubule, is a major target site for the toxic effects of various metals. However, little is known about the early effects of these metals after acute exposure in man. In the present study we have evaluated the toxicity of several inorganic metal compounds (CdCl2, HgCl2, ZnCl2, and Bi(NO3)3) and the induction of metallothionein by these compounds in cultured human proximal tubular (HPT) cells for up to 4 days. The results showed that bismuth was not toxic even at the highest dose (100 microM) used, while zinc, cadmium and mercury exhibited varying degrees of toxicity, zinc being the least toxic and mercury the most potent. A significant degree of interindividual variation between the different isolates used in these experiments was also observed. All metals used in the present study induced MT, as revealed by immunocytochemistry. All metals showed maximal induction between 1 and 3 days after treatment. Although a certain amount of constitutive MT was present in the cultures, the intensity of the staining varied with time in culture and between the different isolates studied. No correlation could be made between the intensity of the staining in control cultures (indicating total amount of constitutive MT) and the susceptibility of a given isolate to metal toxicity. Furthermore, no correlation could be made between metal-induced MT and the susceptibility of a given isolate to that particular metal.

Early Verb Learning: How Do Children Learn How to Compare Events?

PubMed Central

Childers, Jane B.; Parrish, Rebecca; Olson, Christina V.; Burch, Clare; Fung, Gavin; McIntyre, Kevin

2015-01-01

An important problem verb learners must solve is how to extend verbs. Children could use cross-situational information to guide their extensions, however comparing events is difficult. Two studies test whether children benefit from initially seeing a pair of similar events (‘progressive alignment’) while learning new verbs, and whether this influence changes with age. In Study 1, 2 ½- and 3 ½-year-old children participated in an interactive task. Children who saw a pair of similar events and then varied events were able to extend verbs at test, differing from a control group; children who saw two pairs of varied events did not differ from the control group. In Study 2, events were presented on a monitor. Following the initial pair of events that varied by condition, a Tobii x120 eye tracker recorded 2 ½-, 3 ½- and 4 ½-year-olds’ fixations to specific elements of events (AOIs) during the second pair of events, which were the same across conditions. After seeing the pair of events that were highly similar, 2 ½-year-olds showed significantly longer fixation durations to agents and to affected objects as compared to the all varied condition. At test, 3 ½-year-olds were able to extend the verb, but only in the progressive alignment condition. These results are important because they show children’s visual attention to relevant elements in dynamic events is influenced by their prior comparison experience, and they show that young children benefit from seeing similar events as they learn to compare events to each other. PMID:27092030

Frozen-wave instability in near-critical hydrogen subjected to horizontal vibration under various gravity fields.

PubMed

Gandikota, G; Chatain, D; Amiroudine, S; Lyubimova, T; Beysens, D

2014-01-01

The frozen-wave instability which appears at a liquid-vapor interface when a harmonic vibration is applied in a direction tangential to it has been less studied until now. The present paper reports experiments on hydrogen (H2) in order to study this instability when the temperature is varied near its critical point for various gravity levels. Close to the critical point, a liquid-vapor density difference and surface tension can be continuously varied with temperature in a scaled, universal way. The effect of gravity on the height of the frozen waves at the interface is studied by performing the experiments in a magnetic facility where effective gravity that results from the coupling of the Earth's gravity and magnetic forces can be varied. The stability diagram of the instability is obtained. The experiments show a good agreement with an inviscid model [Fluid Dyn. 21 849 (1987)], irrespective of the gravity level. It is observed in the experiments that the height of the frozen waves varies weakly with temperature and increases with a decrease in the gravity level, according to a power law with an exponent of 0.7. It is concluded that the wave height becomes of the order of the cell size as the gravity level is asymptotically decreased to zero. The interface pattern thus appears as a bandlike pattern of alternate liquid and vapor phases, a puzzling phenomenon that was observed with CO2 and H2 near their critical point in weightlessness [Acta Astron. 61 1002 (2007); Europhys. Lett. 86 16003 (2009)].

Polling the effective neighborhoods of spoken words with the verbal transformation effect.

PubMed

Bashford, James A; Warren, Richard M; Lenz, Peter W

2006-04-01

Studies of the effects of lexical neighbors upon the recognition of spoken words have generally assumed that the most salient competitors differ by a single phoneme. The present study employs a procedure that induces the listeners to perceive and call out the salient competitors. By presenting a recording of a monosyllable repeated over and over, perceptual adaptation is produced, and perception of the stimulus is replaced by perception of a competitor. Reports from groups of subjects were obtained for monosyllables that vary in their frequency-weighted neighborhood density. The findings are compared with predictions based upon the neighborhood activation model.

ELECTRO-DEPOSITION OF NICKEL ALLOYS FROM THE PYROPHOSPHATE BATH: NICKEL- ZINC AND NICKEL-MOLYBDENUM ALLOYS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panikkar, S.K.; Char, T.L.R.

1958-02-01

Results of studies on the electrodeposition of nickel-zinc and nickel-- molybdenum alloys in a pyrophosphate bath using platinium electrodes are presented. The fects of varying current density and metal contents of the electrolyte on alloy deposit composition, cathode efficiency, and cathode potential are presented in tabular form. (J.R.D.) l2432 A study was made of the effect of homogenization on the mechanical properties of solution-treated and aged aluminum and the quantitative effects of several variables on hardness. The effect of alloying elements on the increase in hardness of aluminum is shown. (J.E.D.)

Thermal Images of Seeds Obtained at Different Depths by Photoacoustic Microscopy (PAM)

NASA Astrophysics Data System (ADS)

Domínguez-Pacheco, A.; Hernández-Aguilar, C.; Cruz-Orea, A.

2015-06-01

The objective of the present study was to obtain thermal images of a broccoli seed ( Brassica oleracea) by photoacoustic microscopy, at different modulation frequencies of the incident light beam ((0.5, 1, 5, and 20) Hz). The thermal images obtained in the amplitude of the photoacoustic signal vary with each applied frequency. In the lowest light frequency modulation, there is greater thermal wave penetration in the sample. Likewise, the photoacoustic signal is modified according to the structural characteristics of the sample and the modulation frequency of the incident light. Different structural components could be seen by photothermal techniques, as shown in the present study.

Nonlinear dynamics of coiling, and mounding in viscoelastic jets

NASA Astrophysics Data System (ADS)

Majmudar, Trushant; Ober, Thomas; McKinley, Gareth

2009-11-01

Free surface continuous jets of non-Newtonian fluids, although relevant for many industrial processes like bottle filling, remain poorly understood in terms of fundamental fluid dynamics. Here we present a systematic study of the effect of viscoelasticity on the dynamics of continuous jets of worm-like micellar surfactant solutions of varying viscosities and elasticities, and model yield-stress fluids. We systematically vary the height of the drop and the flow rate in order to study the effects of varying geometric and kinematic parameters. We observe that for fluids with higher elastic relaxation times, folding is the preferred mode. In contrast, for low elasticity fluids we observe complex nonlinear dynamics consisting of coiling, folding, and irregular meandering as the height of the fall increases. Beyond this regime, the jet dynamics smoothly crosses over to exhibit the ``leaping shampoo" or the Kaye effect. Upon increasing the flow rate to very high values, the ``leaping shampoo" state disappears and is replaced by a pronounced mounding or ``heaping". A subsequent increase in the flow rate results in finger-like protrusions to emerge out of the mound and climb up towards the nozzle. This novel transition is currently under investigation and remains a theoretical challenge.

An adaptive bit synchronization algorithm under time-varying environment.

NASA Technical Reports Server (NTRS)

Chow, L. R.; Owen, H. A., Jr.; Wang, P. P.

1973-01-01

This paper presents an adaptive estimation algorithm for bit synchronization, assuming that the parameters of the incoming data process are time-varying. Experiment results have proved that this synchronizer is workable either judged by the amount of data required or the speed of convergence.

Detecting facial emotion recognition deficits in schizophrenia using dynamic stimuli of varying intensities.

PubMed

Hargreaves, A; Mothersill, O; Anderson, M; Lawless, S; Corvin, A; Donohoe, G

2016-10-28

Deficits in facial emotion recognition have been associated with functional impairments in patients with Schizophrenia (SZ). Whilst a strong ecological argument has been made for the use of both dynamic facial expressions and varied emotion intensities in research, SZ emotion recognition studies to date have primarily used static stimuli of a singular, 100%, intensity of emotion. To address this issue, the present study aimed to investigate accuracy of emotion recognition amongst patients with SZ and healthy subjects using dynamic facial emotion stimuli of varying intensities. To this end an emotion recognition task (ERT) designed by Montagne (2007) was adapted and employed. 47 patients with a DSM-IV diagnosis of SZ and 51 healthy participants were assessed for emotion recognition. Results of the ERT were tested for correlation with performance in areas of cognitive ability typically found to be impaired in psychosis, including IQ, memory, attention and social cognition. Patients were found to perform less well than healthy participants at recognising each of the 6 emotions analysed. Surprisingly, however, groups did not differ in terms of impact of emotion intensity on recognition accuracy; for both groups higher intensity levels predicted greater accuracy, but no significant interaction between diagnosis and emotional intensity was found for any of the 6 emotions. Accuracy of emotion recognition was, however, more strongly correlated with cognition in the patient cohort. Whilst this study demonstrates the feasibility of using ecologically valid dynamic stimuli in the study of emotion recognition accuracy, varying the intensity of the emotion displayed was not demonstrated to impact patients and healthy participants differentially, and thus may not be a necessary variable to include in emotion recognition research. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

What causes IOR? Attention or perception? - manipulating cue and target luminance in either blocked or mixed condition.

PubMed

Zhao, Yuanyuan; Heinke, Dietmar

2014-12-01

Inhibition of return (IOR) refers to the performance disadvantage when detecting a target presented at a previously cued location. The current paper contributes to the long-standing debate whether IOR is caused by attentional processing or perceptual processing. We present a series of four experiments which varied the cue luminance in mixed and blocked conditions. We hypothesised that if inhibition was initialized by an attentional process the size of IOR should not vary in the blocked condition as participants should be able to adapt to the level of cue luminance. However, if a perceptual process triggers inhibition both experimental manipulations should lead to varying levels of IOR. Indeed, we found evidence for the latter hypothesis. In addition, we also varied the target luminance in blocked and mixed condition. Both manipulations, cue luminance and target luminance, affected IOR in an additive fashion suggesting that the two stimuli affect human behaviour on different processing stages. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of EPA and DHA in the viscera of marine fish using gas chromatography.

PubMed

Zhang, De-Yong; Xu, Xiao-Lu; Shen, Xiu-Ying; Mei, Yu; Xu, Hui-Ying

2016-03-01

The viscera of 10 kinds of marine fishes were collected for fish oil extraction and detection of DHA and EPA, two most important polyunsaturated fatty acids. The fish oil extraction ratio for the evaluated fishes varied from 0.95% to 10.18% (wt%). Pseudosciaena crocea presented the highest fish oil yield, followed by Mustelus manazo, Hippoglossus and Sciaenopsocellatus. A gas chromatography method was then established for analysis of EPA/DHA. The EPA concentration (in methyl ester form) in the fish oil varied from 1.39 to 10.65(mg/g). Epinephelus awoara presented the highest EPA concentration (p<0.05), followed by Epinephelussp, Sciaenopsocellatus and Hippoglossus. The DHA concentration (in methyl ester form) in the fish oil varied from 0.58 to 37.02 (mg/g). Epinephelus awoara presented the highest DHA concentration (p<0.05), followed by Sciaenopsocellatus, Pseudosciaena crocea and Hippoglossus. No strict positive correlation between the EPA/DHA concentration and the sea depth where the fish live was observed. The fishes living in middle depth presented highest EPA/DHA concentration.

Tribological Behavior of Electroless Ni-P Coatings in Various Corrosive Environments

NASA Astrophysics Data System (ADS)

Panja, Bikash; Das, Suman Kalyan; Sahoo, Prasanta

2016-04-01

The present paper deals with the study of tribological characteristics, viz. friction and wear, of electroless Ni-P coating in corrosive environments (brine, acidic and alkaline) by varying different coating process parameters as well as varying the tribological testing parameters, viz. applied load and speed. The optimized results of coating process parameters for minimum friction and wear performance of the coating are presented. Moreover, a detailed study of the tribological behavior of the coating is undertaken individually for the three corrosive environments. The results obtained are compared among each other and also with the dry condition test of the coating. It is found that the friction coefficient of Ni-P coating decreases with increase in load for all environments. In case of wear, the wear rate of Ni-P coating gradually increases with increase in load for all mediums but the same decreases after 40N in brine and alkaline mediums. However, for acidic solution, the wear rate shows a continuous increasing trend. It is observed that alkaline and brine environments are favorable from friction and wear point of view of the coating, respectively. Microstructure study of the coatings is also performed and the coating is found to be of cauliflower-like morphology. The coating also exhibits amorphous structure in as-deposited condition, which gradually turns crystalline with heat treatment.

Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity.

PubMed

Spitzer, M W; Semple, M N

1998-12-01

Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity. J. Neurophysiol. 80: 3062-3076, 1998. Previous studies demonstrated that tuning of inferior colliculus (IC) neurons to interaural phase disparity (IPD) is often profoundly influenced by temporal variation of IPD, which simulates the binaural cue produced by a moving sound source. To determine whether sensitivity to simulated motion arises in IC or at an earlier stage of binaural processing we compared responses in IC with those of two major IPD-sensitive neuronal classes in the superior olivary complex (SOC), neurons whose discharges were phase locked (PL) to tonal stimuli and those that were nonphase locked (NPL). Time-varying IPD stimuli consisted of binaural beats, generated by presenting tones of slightly different frequencies to the two ears, and interaural phase modulation (IPM), generated by presenting a pure tone to one ear and a phase modulated tone to the other. IC neurons and NPL-SOC neurons were more sharply tuned to time-varying than to static IPD, whereas PL-SOC neurons were essentially uninfluenced by the mode of stimulus presentation. Preferred IPD was generally similar in responses to static and time-varying IPD for all unit populations. A few IC neurons were highly influenced by the direction and rate of simulated motion, but the major effect for most IC neurons and all SOC neurons was a linear shift of preferred IPD at high rates-attributable to response latency. Most IC and NPL-SOC neurons were strongly influenced by IPM stimuli simulating motion through restricted ranges of azimuth; simulated motion through partially overlapping azimuthal ranges elicited discharge profiles that were highly discontiguous, indicating that the response associated with a particular IPD is dependent on preceding portions of the stimulus. In contrast, PL-SOC responses tracked instantaneous IPD throughout the trajectory of simulated motion, resulting in highly contiguous discharge profiles for overlapping stimuli. This finding indicates that responses of PL-SOC units to time-varying IPD reflect only instantaneous IPD with no additional influence of dynamic stimulus attributes. Thus the neuronal representation of auditory spatial information undergoes a major transformation as interaural delay is initially processed in the SOC and subsequently reprocessed in IC. The finding that motion sensitivity in IC emerges from motion-insensitive input suggests that information about change of position is crucial to spatial processing at higher levels of the auditory system.

Short-term variability in amplitude and motor topography of whole-body involuntary movements in Parkinson's disease dyskinesias and in Huntington's chorea.

PubMed

Fenney, Alison; Jog, Mandar S; Duval, Christian

2008-02-01

Clinical observations have noted variability in amplitude of levodopa-induced dyskinesias (LID) in Parkinson's disease (PD) and chorea in Huntington's disease (HD) during the day. However, no studies have examined whether both the amplitude and body location (motor topography) of whole-body involuntary movement (WBIM) varied over short periods of time (seconds or minutes), which may have a distinct and significant effect on how disruptive these WBIM may be. The present study quantified the variability of WBIM amplitude and motor topography in patients with PD having LID and in patients with HD having chorea. WBIM was quantified using the MotionMonitor magnetic motion tracker system. Five patients in each group were tested in two conditions: sitting and standing. WBIM increased from sitting to standing, more so in choreic patients. WBIM varied from 17% to 102% of total WBIM amplitude. Chorea tended to present with greater variability than LID in absolute terms in the standing condition, but not when the mean WBIM amplitude was taken into consideration. Motor topography of WBIM also varied more in the HD group, but mostly in the seated condition where more limbs were free to move. Neither group expressed any laterality of involuntary movement, with amplitude being equally distributed on both sides of the body. Results show significant short-term variability in amplitude of chorea and LID, as well as, variability in location of these involuntary movements, illustrating the complexity of the adaptations required to live and be active with involuntary movements such as HD chorea or PD dyskinesias.

Extension of the simulated drinking game procedure to multiple drinking games.

PubMed

Cameron, Jennifer M; Leon, Matthew R; Correia, Christopher J

2011-08-01

The present study extended the Simulated Drinking Game Procedure (SDGP) to obtain information about different types of drinking games. Phase I participants (N = 545) completed online screening questionnaires assessing substance use and drinking game participation. Participants who met the selection criteria for Phase II (N = 92) participated in laboratory sessions that consisted of three different periods of drinking game play. Sixty-two percent (N = 57) of the sample was female. Data from these sessions was used to estimate the peak Blood Alcohol Concentration (BAC) a participant would achieve if they consumed alcohol while participating in the SDGP. Total consumption and estimated BAC varied as a function of game type. The total consumption and estimated BAC obtained while playing Beer Pong and Memory varied significantly as a function of group. Total ounces consumed while playing Three Man varied significantly as a function of group; however, the variation in estimated BAC obtained while playing Three Man was not significant. Results indicated that estimated BACs were higher for female participants across game type. Previous experience playing the three drinking games had no impact on total drink consumption or estimated BAC obtained while participating in the SDGP. The present study demonstrated that the SDGP can be used to generate estimates of how much alcohol is consumed and the associated obtained BAC during multiple types of drinking games. In order to fully examine whether previous experience factors in to overall alcohol consumption and BAC, future research should extend the SDGP to incorporate laboratory administration of alcohol during drinking game participation. (c) 2011 APA, all rights reserved.

Diagnostics for Confounding of Time-varying and Other Joint Exposures.

PubMed

Jackson, John W

2016-11-01

The effects of joint exposures (or exposure regimes) include those of adhering to assigned treatment versus placebo in a randomized controlled trial, duration of exposure in a cohort study, interactions between exposures, and direct effects of exposure, among others. Unlike the setting of a single point exposure (e.g., propensity score matching), there are few tools to describe confounding for joint exposures or how well a method resolves it. Investigators need tools that describe confounding in ways that are conceptually grounded and intuitive for those who read, review, and use applied research to guide policy. We revisit the implications of exchangeability conditions that hold in sequentially randomized trials, and the bias structure that motivates the use of g-methods, such as marginal structural models. From these, we develop covariate balance diagnostics for joint exposures that can (1) describe time-varying confounding, (2) assess whether covariates are predicted by prior exposures given their past, the indication for g-methods, and (3) describe residual confounding after inverse probability weighting. For each diagnostic, we present time-specific metrics that encompass a wide class of joint exposures, including regimes of multivariate time-varying exposures in censored data, with multivariate point exposures as a special case. We outline how to estimate these directly or with regression and how to average them over person-time. Using a simulated example, we show how these metrics can be presented graphically. This conceptually grounded framework can potentially aid the transparent design, analysis, and reporting of studies that examine joint exposures. We provide easy-to-use tools to implement it.

Optimal color temperature adjustment for mobile devices under varying illuminants

NASA Astrophysics Data System (ADS)

Choi, Kyungah; Suk, Hyeon-Jeong

2014-01-01

With the wide use of mobile devices, display color reproduction has become extremely important. The purpose of this study is to investigate the optimal color temperature for mobile displays under varying illuminants. The effect of the color temperature and the illuminance of ambient lighting on user preferences were observed. For a visual examination, a total of 19 nuanced whites were examined under 20 illuminants. A total of 19 display stimuli with different color temperatures (2,500 K ~ 19,600 K) were presented on an iPad3 (New iPad). The ambient illuminants ranged in color temperature from 2,500 K to 19,800 K and from 0 lx to 3,000 lx in illuminance. Supporting previous studies of color reproduction, there was found to be a positive correlation between the color temperature of illuminants and that of optimal whites. However, the relationship was not linear. Based on assessments by 56 subjects, a regression equation was derived to predict the optimal color temperature adjustment under varying illuminants, as follows: [Display Tcp = 5138.93 log(Illuminant Tcp) - 11956.59, p<.001, R2=0.94]. Moreover, the influence of an illuminant was positively correlated with the illuminance level, confirming the findings of previous studies. It is expected that the findings of this study can be used as the theoretical basis when designing a color strategy for mobile display devices.

Obesity screening in the pediatric emergency department.

PubMed

Vaughn, Lisa M; Nabors, Laura; Pelley, Terri J; Hampton, Rebecca R; Jacquez, Farrah; Mahabee-Gittens, E Melinda

2012-06-01

The purposes of this study were (1) to examine parental perception of childhood obesity and race with measured body mass index (BMI), (2) to determine if parents are receptive to obesity screening in the pediatric emergency department and if receptivity varies by race or weight status, and (3) to determine eating habits that are predictors of obesity. This study is a cross-sectional study, with a convenience sample of 213 patients (aged 4-16 years accompanied by a parent/legal guardian to a pediatric emergency department). Weight and height were obtained, and parents were asked to complete a survey about perception of their child's weight, nutrition, and exercise habits. The current study found that parent perception of weight status was fairly accurate, and perception was predictive of BMI. Race, however, was not predictive of BMI. Parents were generally receptive of weight screening in the pediatric emergency department, and this did not vary as a function of weight status; however, receptivity did vary based on ethnicity, with African American parents being more receptive than white parents. Large portion sizes and the number of times a child eats fast food per week were found to be predictive of obesity. Greater than half of the children presenting to our pediatric emergency department were overweight or obese. Parents were generally accurate in their perception of their child's weight but were still receptive to obesity prevention and screening in the pediatric emergency department.

Two-thirds of methodological research remained unpublished after presentation at Cochrane Colloquia: an empirical analysis.

PubMed

Chapman, Sarah; Eisinga, Anne; Hopewell, Sally; Clarke, Mike

2012-05-01

To determine the extent to which abstracts of methodology research, initially presented at annual meetings of The Cochrane Collaboration, have been published as full reports and over what period of time. A secondary aim was to explore whether full publication varied in different methodological subject areas. The Cochrane Methodology Register (CMR) was searched for all abstracts reporting methodology research, presented at the 11 Cochrane Colloquia from 1997 to 2007. EMBASE, PubMed, and CMR were searched for full publications of the same research. We identified 908 eligible conference abstracts and found full publications for 312 (34.4%) of these, almost half of which (47.1%) had appeared by the end of the first year after the relevant Colloquium. The proportion of abstracts that had not been published by 3 years was 69.7%, falling to 66.2% at 5 years. Publication varied considerably between different methodological areas. Approximately two-thirds of methodological research studies presented at Cochrane Colloquia remain unpublished as full papers at least 5 years later. This highlights the importance of searching conference abstracts if one wishes to find as comprehensive and complete a sample of methodological research as possible. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

The Effects of Conflict, Quality and Time on Small Group Information Use and Behavior in Evaluative Decision-Making Situations.

ERIC Educational Resources Information Center

Pflum, Glenn D.; Brown, Robert D.

This study investigated information needs and use by groups in decision-making processes. Problem contexts were varied by conflict, quality, and time conditions and presented to 89 graduate level education students who simulated school board members making decisions about educational programs. The research hypotheses were: (1) there are no…

A Review of Psychometric Assessment and Reporting Practices: An Examination of Measurement-Oriented versus Non-Measurement-Oriented Domains

ERIC Educational Resources Information Center

Slaney, Kathleen L.; Tkatchouk, Masha; Gabriel, Stephanie M.; Ferguson, Leona P.; Knudsen, Jared R. S.; Legere, Julien C.

2010-01-01

The primary aim of the present study is to determine whether the psychometric evaluation practices and test-analytic rationales of researchers publishing in journals with a measurement focus differ from those of researchers publishing in journals with varying substantive research foci. Several components of two different samples of articles were…

Individual Differences in Late Bilinguals' L2 Phonological Processes: From Acoustic-Phonetic Analysis to Lexical Access

ERIC Educational Resources Information Center

Diaz, Begona; Mitterer, Holger; Broersma, Mirjam; Sebastian-Galles, Nuria

2012-01-01

The extent to which the phonetic system of a second language is mastered varies across individuals. The present study evaluates the pattern of individual differences in late bilinguals across different phonological processes. Fifty-five late Dutch-English bilinguals were tested on their ability to perceive a difficult L2 speech contrast (the…

Is Silence Golden? Elementary School Teachers' Strategies and Beliefs regarding Hypothetical Shy/Quiet and Exuberant/Talkative Children

ERIC Educational Resources Information Center

Coplan, Robert J.; Hughes, Kathleen; Bosacki, Sandra; Rose-Krasnor, Linda

2011-01-01

The primary goal of the present study was to examine elementary teachers' strategies, attitudes, and beliefs regarding hypothetical shy (i.e., quiet), exuberant (i.e., overly talkative), and average (i.e., typical) children. We explored whether these strategies and beliefs varied as a function of the gender of the hypothetical child as well as…

Asian Americans: A Status Report. Fact Sheet for the Chairman, Select Committee on Hunger, House of Representatives.

ERIC Educational Resources Information Center

General Accounting Office, Washington, DC. Div. of Human Resources.

This fact sheet presents information on the status of Asians in the United States. The following sections are included: (1) "Introduction," which includes Asian American population statistics, and the objectives, scope, and methodology of the study; (2) "Overall Income and Employment Status Comparable With U.S. Population, But Varies Widely Among…

Adaptive Training of Manual Control: 1. Comparison of Three Adaptive Variables and Two Logic Schemes.

ERIC Educational Resources Information Center

Norman, D. A.; And Others

"Machine controlled adaptive training is a promising concept. In adaptive training the task presented to the trainee varies as a function of how well he performs. In machine controlled training, adaptive logic performs a function analogous to that performed by a skilled operator." This study looks at the ways in which gain-effective time…

A Study of the Characteristics, Costs, and Magnitude of Interlibrary Loans in Academic Libraries.

ERIC Educational Resources Information Center

Palmour, Vernon E., Comp.; And Others

A national probability sample was made to survey the costs, the characteristics of materials loaned and borrowed, and the present and future magnitude of interlibrary loans for academic libraries. From a sample of 80 libraries it was found that the cost of a filled loan request varied between two and seven dollars and that lending cost per…

DCS: A global satellite environmental data collection system study

NASA Technical Reports Server (NTRS)

1973-01-01

Cost analysis and technical feasibility data are presented on five medium orbiting and six geosynchronous satellite data collection systems with varying degrees of spacecraft and local user terminal complexity. Data are also provided on system approaches, user requirements, and user classes. Systems considered include orbiting ERTS and EOS type satellites and geosynchronous SmS and SEOS type data collectors.

Boys Might Catch Up, Family Influences Continue: Influences on Behavioral Self-Regulation in Children from an Affluent Region in Germany before School Entry

ERIC Educational Resources Information Center

Gunzenhauser, Catherine; von Suchodoletz, Antje

2015-01-01

Research Findings: Behavioral self-regulation is crucial for school success. Although behavioral self-regulation typically grows rapidly during the preschool period, children in this age group vary widely in their behavioral self-regulation capacities. The present study investigated 3 potential determinants of growth rates in behavioral…

Value of Defect Information in Automated Hardwood Edger and Trimmer Systems

Treesearch

Carmen Regalado; D. Earl Kline; Philip A. Araman

1992-01-01

Due to the limited capability of board defect scanners, not all defect information required to make the best edging and trimming decision can be scanned for use in an automated system. The objective of the study presented in this paper was to evaluate the lumber value obtainable from edging and trimming optimization using varying levels of defect information as input....

Locus of Word Frequency Effects in Spelling to Dictation: Still at the Orthographic Level!

ERIC Educational Resources Information Center

Bonin, Patrick; Laroche, Betty; Perret, Cyril

2016-01-01

The present study was aimed at testing the locus of word frequency effects in spelling to dictation: Are they located at the level of spoken word recognition (Chua & Rickard Liow, 2014) or at the level of the orthographic output lexicon (Delattre, Bonin, & Barry, 2006)? Words that varied on objective word frequency and on phonological…

Exploring Factors Affecting Learner's Perception of Learning Information and Communication Technology: A HLM Analysis of a National Farmers' Training Program in Taiwan

ERIC Educational Resources Information Center

Yueh, Hsiu-Ping; Chen, Tzy-Ling; Chiu, Li-An; Lin, Wei-Chien

2013-01-01

The present study, pertaining to a national information literacy training program for both farmers and rural communities in Taiwan, explores factors that affect learners' perception of learning information and communication technology (ICT). It further analyzes effects of individual characteristics and varied training designs on learners'…

Analyzing Student Confidence in Classroom Voting with Multiple Choice Questions

ERIC Educational Resources Information Center

Stewart, Ann; Storm, Christopher; VonEpps, Lahna

2013-01-01

The purpose of this paper is to present results of a recent study in which students voted on multiple choice questions in mathematics courses of varying levels. Students used clickers to select the best answer among the choices given; in addition, they were also asked whether they were confident in their answer. In this paper we analyze data…

An Empirical Test of the Modified C Index and SII, O*NET, and DHOC Occupational Code Classifications

ERIC Educational Resources Information Center

Dik, Bryan J.; Hu, Ryan S. C.; Hansen, Jo-Ida C.

2007-01-01

The present study investigated new approaches for assessing Holland's congruence hypothesis by (a) developing and applying four sets of decision rules for assigning Holland codes of varying lengths for purposes of computing Eggerth and Andrew's modified C index; (b) testing the modified C index computed using these four approaches against Brown…

Carer Reports of Health Status among Adults with Intellectual/Developmental Disabilities in Taiwan Living at Home and in Institutions

ERIC Educational Resources Information Center

Wang, K.-Y.; Hsieh, K.; Heller, T.; Davidson, P. W.; Janicki, M. P.

2007-01-01

Background: The aim of the present study was to assess the health status of a cohort of adults with intellectual/developmental disabilities (I/DD) residing in family homes or institutions in Taiwan and to examine whether morbidity varied with age, sex, existing diagnosis [Down syndrome (DS), seizures, cerebral palsy (CP), intellectual disability…

Magnet Fall inside a Conductive Pipe: Motion and the Role of the Pipe Wall Thickness

ERIC Educational Resources Information Center

Donoso, G.; Ladera, C. L.; Martin, P.

2009-01-01

Theoretical models and experimental results are presented for the retarded fall of a strong magnet inside a vertical conductive non-magnetic tube. Predictions and experimental results are in good agreement modelling the magnet as a simple magnetic dipole. The effect of varying the pipe wall thickness on the retarding magnetic drag is studied for…

First Graders' Responses to School-Taught Mathematics as a Function of Their Spontaneous Conceptions of Basic Algebraic Relationships.

ERIC Educational Resources Information Center

Kaplan, Rochelle Goldberg

The rationale of this study is based on the premise that the outcomes of children's learning are specifically shaped by the interaction of their individual cognitive structures with the presentations of curricular content in the classroom. Therefore, since the interpretive tools that children apply to instructional content may vary substantially,…

On the Origin and Meaning of Bibliometric Indicators: Journals in the Social Sciences, 1886-1985.

ERIC Educational Resources Information Center

Pierce, Sydney J.

1992-01-01

This study examined the use of footnotes and visuals in 8,634 research articles published in core journals in sociology, political science, and economics between 1886 and 1985. It was found that use of footnotes and visuals within a discipline vary over time and that agreement on presentational standards increases as the discipline matures. (61…

Familial Predictors of Sibling and Romantic-Partner Conflict Resolution: Comparing Late Adolescents from Intact and Divorced Families

ERIC Educational Resources Information Center

Reese-Weber, M.; Kahn, J.H.

2005-01-01

The present study examined whether predictors of romantic-partner conflict may vary as a function of family structure. Using a cross-sectional design, we tested a mediation model of conflict resolution behaviours among late adolescents from intact (n=185) and divorced (n=87) families. Adolescents rated conflict resolution behaviours in five dyadic…

Why Do People Disagree? Explaining and Endorsing the Possibility of Partiality in Judgments

ERIC Educational Resources Information Center

Mills, Candice M.; Al-Jabari, Rawya M.; Archacki, Melinda A.

2012-01-01

The current study examines developing changes in children's intuitions about why disagreements about decisions might occur, focusing on what children understand about partiality and how it may vary depending on the context. Eighty children ages 6 to 13 years old and 20 adults were presented with stories in which there was a disagreement with the…

Cross-Cultural Differences in the Development of Behavior Problems: Contributions of Infant Temperament in Russia and U.S.

ERIC Educational Resources Information Center

Maria A. Gartstein,; Slobodskaya, Helena R.; Kirchhoff, Cornelia; Putnam, Samuel P.

2013-01-01

The present study was designed to examine cross-cultural differences in longitudinal links between infant temperament toddler behavior problems in the U.S. (N= 250) and Russia (N= 129). Profiles of risk/protective temperament factors varied across the two countries, with fewer significant temperament effects observed for the Russian, relative to…

Distortion Representation of Forecast Errors for Model Skill Assessment and Objective Analysis

NASA Technical Reports Server (NTRS)

Hoffman, Ross N.; Nehrkorn, Thomas; Grassotti, Christopher

1996-01-01

We study a novel characterization of errors for numerical weather predictions. In its simplest form we decompose the error into a part attributable to phase errors and a remainder. The phase error is represented in the same fashion as a velocity field and will be required to vary slowly and smoothly with position. A general distortion representation allows for the displacement and a bias correction of forecast anomalies. In brief, the distortion is determined by minimizing the objective function by varying the displacement and bias correction fields. In the present project we use a global or hemispheric domain, and spherical harmonics to represent these fields. In this project we are initially focusing on the assessment application, restricted to a realistic but univariate 2-dimensional situation. Specifically we study the forecast errors of the 500 hPa geopotential height field for forecasts of the short and medium range. The forecasts are those of the Goddard Earth Observing System data assimilation system. Results presented show that the methodology works, that a large part of the total error may be explained by a distortion limited to triangular truncation at wavenumber 10, and that the remaining residual error contains mostly small spatial scales.

Dosage effects of a preventive social-emotional learning intervention on achievement loss associated with middle school transition.

PubMed

Rosenblatt, Jennifer L; Elias, Maurice J

2008-11-01

A number of studies have documented a normative decline in academic achievement across the transition from elementary school to middle or junior high school. The current study examined the effectiveness of varying levels of a social-emotional learning intervention, Talking with TJ, in limiting achievement loss across transition. Data were gathered on 154 students during their fifth and sixth grade years in an urban, low socio-economic school district. Students participated in the Talking with TJ program over their fifth grade years, and curriculum fidelity in individual classrooms was evaluated. Changes in grade point average were assessed across the middle school transition. Overall, students showed a significant decline in GPA across the transition. Students in classrooms where higher dosages of intervention were delivered showed significantly smaller drops in GPA across transition than did students in lower dosage classrooms. Data on differential program effectiveness among demographic groups and along varying levels of baseline emotional intelligence also are presented. Editors' Strategic Implications: The authors present promising findings for a school transition program, link dosage to effects, and raise interesting theoretical questions about the relationships between social-emotional learning and academic growth and achievement.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandoval-Paz, M.G., E-mail: myrnasandoval@udec.cl; Rodríguez, C.A.; Porcile-Saavedra, P.F.

Copper (I) selenide thin films with orthorhombic and cubic structure were deposited on glass substrates by using the chemical bath deposition technique. The effects of the solution pH on the films growth and subsequently the structural, optical and electrical properties of the films were studied. Films with orthorhombic structure were obtained from baths wherein both metal complex and hydroxide coexist; while films with cubic structure were obtained from baths where the metal hydroxide there is no present. The structural modifications are accompanied by changes in bandgap energy, morphology and electrical resistivity of the films. - Graphical abstract: “Study of themore » crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution” by M. G. Sandoval-Paz, C. A. Rodríguez, P. F. Porcile-Saavedra, C. Trejo-Cruz. Display Omitted - Highlights: • Copper (I) selenide thin films were obtained by chemical bath deposition. • Orthorhombic to cubic phase change was induced by varying the reaction solution pH. • Orthorhombic phase is obtained mainly from a hydroxides cluster mechanism. • Cubic phase is obtained mainly from an ion by ion mechanism. • Structural, optical and electrical properties are presented as a function of pH.« less

Framework and algorithms for illustrative visualizations of time-varying flows on unstructured meshes

DOE PAGES

Rattner, Alexander S.; Guillen, Donna Post; Joshi, Alark; ...

2016-03-17

Photo- and physically realistic techniques are often insufficient for visualization of fluid flow simulations, especially for 3D and time-varying studies. Substantial research effort has been dedicated to the development of non-photorealistic and illustration-inspired visualization techniques for compact and intuitive presentation of such complex datasets. However, a great deal of work has been reproduced in this field, as many research groups have developed specialized visualization software. Additionally, interoperability between illustrative visualization software is limited due to diverse processing and rendering architectures employed in different studies. In this investigation, a framework for illustrative visualization is proposed, and implemented in MarmotViz, a ParaViewmore » plug-in, enabling its use on a variety of computing platforms with various data file formats and mesh geometries. Region-of-interest identification and feature-tracking algorithms incorporated into this tool are described. Implementations of multiple illustrative effect algorithms are also presented to demonstrate the use and flexibility of this framework. Here, by providing an integrated framework for illustrative visualization of CFD data, MarmotViz can serve as a valuable asset for the interpretation of simulations of ever-growing scale.« less

Measurement of gender inequality in neighbourhoods of Québec, Canada

PubMed Central

2011-01-01

Introduction Few studies have measured gender inequality at levels lower than the country. We sought to develop neighbourhood indicators of gender inequality, and assess their ability to capture variability in gender inequality across Québec, Canada. Methods Aggregate 2001 census data for 11,564 neighbourhoods were obtained for men and women. Twelve indicators of gender inequality representing demographic/household characteristics, education, income, work/leisure, and political participation were selected. Neighbourhood-level gender inequality scores were computed for each indicator, and examined across parts of Québec (metropolitan areas, mid-sized cities, rural areas). Monte Carlo simulations were used to assess the ability of indicators to capture heterogeneity in gender inequality across neighbourhoods. Results Male-dominant neighbourhood-level gender inequality tended to be present for average employment income, labour force participation, employment rate, and employment in managerial positions. Female-dominant gender inequality tended to be present for divorce, single-headed households, and participation in unpaid housework, child and elderly care. Neighbourhood-level gender inequality tended to vary across metropolitan areas, mid-sized cities, and rural areas. Gender inequality scores also varied within these geographic areas. For example, there was greater income-related gender inequality in high than low income neighbourhoods. Monte Carlo simulations suggested that the variation in gender inequality across neighbourhoods was greater than expected with chance alone. Conclusion Neighbourhood-level gender inequality tended to be present in Québec, and varied across parts of the province. Greater awareness of and research on neighbourhood-level gender inequality may be warranted to inform gender policies in Québec and other nations. PMID:22087586

Measurement of gender inequality in neighbourhoods of Québec, Canada.

PubMed

Tamambang, Lum; Auger, Nathalie; Lo, Ernest; Raynault, Marie-France

2011-11-16

Few studies have measured gender inequality at levels lower than the country. We sought to develop neighbourhood indicators of gender inequality, and assess their ability to capture variability in gender inequality across Québec, Canada. Aggregate 2001 census data for 11,564 neighbourhoods were obtained for men and women. Twelve indicators of gender inequality representing demographic/household characteristics, education, income, work/leisure, and political participation were selected. Neighbourhood-level gender inequality scores were computed for each indicator, and examined across parts of Québec (metropolitan areas, mid-sized cities, rural areas). Monte Carlo simulations were used to assess the ability of indicators to capture heterogeneity in gender inequality across neighbourhoods. Male-dominant neighbourhood-level gender inequality tended to be present for average employment income, labour force participation, employment rate, and employment in managerial positions. Female-dominant gender inequality tended to be present for divorce, single-headed households, and participation in unpaid housework, child and elderly care. Neighbourhood-level gender inequality tended to vary across metropolitan areas, mid-sized cities, and rural areas. Gender inequality scores also varied within these geographic areas. For example, there was greater income-related gender inequality in high than low income neighbourhoods. Monte Carlo simulations suggested that the variation in gender inequality across neighbourhoods was greater than expected with chance alone. Neighbourhood-level gender inequality tended to be present in Québec, and varied across parts of the province. Greater awareness of and research on neighbourhood-level gender inequality may be warranted to inform gender policies in Québec and other nations.

Integrated communication and control systems. I - Analysis

NASA Technical Reports Server (NTRS)

Halevi, Yoram; Ray, Asok

1988-01-01

The paper presents the results of an ICCS analysis focusing on discrete-time control systems subject to time-varying delays. The present analytical technique is applicable to integrated dynamic systems such as those encountered in advanced aircraft, spacecraft, and the real-time control of robots and machine tools via a high-speed network within an autonomous manufacturing environment. The significance of data latency and missynchronization between individual system components in ICCS networks is discussed in view of the time-varying delays.

How sensitive is the deltoid moment arm to humeral offset changes with reverse total shoulder arthroplasty?

PubMed

Walker, David R; Kinney, Allison L; Wright, Thomas W; Banks, Scott A

2016-06-01

Reverse total shoulder arthroplasty commonly treats cuff-deficient or osteoarthritic shoulders not amenable to rotator cuff repair. This study investigates deltoid moment arm sensitivity to variations in the joint center and humeral offset of 3 representative reverse total shoulder arthroplasty subjects. We hypothesized that a superior joint implant placement may exist, indicated by muscle moment arms, compared with the current actual surgical implant configuration. Moment arms for the anterior, lateral, and posterior aspects of the deltoid muscle were determined for 1521 perturbations of the humeral offset location away from the surgical placement in a subject-specific musculoskeletal model with motion defined by subject-specific in vivo abduction kinematics. The humeral offset was varied from its surgical position ±4 mm in the anterior/posterior direction, ±12 mm in the medial/lateral direction, and -10 to 14 mm in the superior/inferior direction. The anterior deltoid moment arm varied in humeral offset and center of rotation up to 20 mm, primarily in the medial/lateral and superior/inferior directions. The lateral deltoid moment arm varied in humeral offset up to 20 mm, primarily in the medial/lateral and anterior/posterior directions. The posterior deltoid moment arm varied up to 15 mm, primarily in early abduction, and was most sensitive to humeral offset changes in the superior/inferior direction. High variations in muscle moment arms were found for all 3 deltoid components, presenting an opportunity to dramatically change the deltoid moment arms through surgical placement of the reverse shoulder components and by varying the overall offset of the humerus. Basic Science Study; Computer Modeling. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Re-evaluation of constant versus varied punishers using empirically derived consequences.

PubMed

Toole, Lisa M; DeLeon, Iser G; Kahng, SungWoo; Ruffin, Geri E; Pletcher, Carrie A; Bowman, Lynn G

2004-01-01

Charlop, Burgio, Iwata, and Ivancic [J. Appl. Behav. Anal. 21 (1988) 89] demonstrated that varied punishment procedures produced greater or more consistent reductions of problem behavior than a constant punishment procedure. More recently, Fisher and colleagues [Res. Dev. Disabil. 15 (1994) 133; J. Appl. Behav. Anal. 27 (1994) 447] developed a systematic methodology for predicting the efficacy of various punishment procedures. Their procedure identified reinforcers and punishers (termed "empirically derived consequences" or EDC) that, when used in combination, reduced the destructive behavior of individuals with developmental disabilities who displayed automatically maintained destructive behavior. The current investigation combines these two lines of research by comparing the effects of constant versus varied punishers on the self-injury of two individuals with developmental disabilities. The punishing stimuli were selected via the procedures described by Fisher et al. and were predicted to be at varying levels of effectiveness. The varied presentation of punishers resulted in enhanced suppressive effects over the constant presentation of a punisher for one of two individuals, but only in comparison to a single stimulus predicted to be minimally effective. Even then, the differences were small. These results suggest that the additive effects of varied punishment are negligible if clinicians use stimuli predicted to be effective and are discussed in terms of the conditions under which stimulus variation could potentially enhance the effects of punishers.

Analysis of vegetation changes in Cidanau watershed, Indonesia

NASA Astrophysics Data System (ADS)

Khairiah, R. N.; Kunihiko, Y.; Prasetyo, L. B.; Setiawan, Y.

2018-05-01

Vegetation change detection is needed for conserve of quality and water cycle in Cidanau watershed. The NDVI was applied to quantify the vegetation changes of Cidanau watershed for three different years 1989, 2001, and 2015. Using NDVI we mapped the reflectance from chlorophyll and distinguished varying amounts of vegetation at the pixel level by index. In the present study, as a preliminary study, we proposed a vegetation change detection analysis based on the NDVI from 1989 through 2015. Multi-temporal satellite data i.e. Landsat imagery with 30 m spatial resolution are used in the present study. It is reported that agroforestry land exhibited the greatest reductions in highly dense vegetation class in 1989-2001 and also moderate vegetation class in 2001-2015. It’s mean that amount of vegetation present in agroforestry land is getting lower year by year.

Transient Optical Sky survey

NASA Astrophysics Data System (ADS)

Hadjiyska, Elena Ivanova

2009-06-01

Optical transients have been studied in isolated cases, but never mapped into a comprehensive data base in the past. These events vary in duration and signature, yet they are united under the umbrella of time varying observables and represent a significant portion of the dynamical processes in the universe. The Transient Optical Sky Survey (TOSS) System is a dedicated, ground-based system of small optical telescopes, observing nightly at fixed Declination while gathering 90 sec exposures and thus creating a repeated partial map of the sky. Presented here is a brief overview of some of the signatures of transient events and a description of the TOSS system along with the data acquired during the 2008-2009 observing campaign, potentially producing over 100,000 light curves.

High Reynolds Number tests of the NASA SC(2)-0012 airfoil in the Langley 0.3-meter transonic cryogenic tunnel

NASA Technical Reports Server (NTRS)

Mineck, Raymond E.; Lawing, Pierce L.

1987-01-01

A wind-tunnel investigation of the NASA SC(2)-0012 airfoil has been conducted in the Langley 0.3-Meter Transonic Cryogenic Tunnel. This investigation supplements the two-dimensional airfoil studies of the Advanced Technology Airfoil Test Program. The Mach number was varied from 0.60 to 0.84. The stagnation temperature and pressure were varied to provide a Reynolds number range from 6 to 40 x 10 to the 6th power based on a 6.0-in. (15.24-cm) airfoil chord. No corrections for wind-tunnel wall interference have been made to the data. The aerodynamic results are presented as integrated force and moment coefficients and pressure distributions without any analysis.

Absolute calibration of a multichannel plate detector for low energy O, O-, and O+

NASA Astrophysics Data System (ADS)

Stephen, T. M.; Peko, B. L.

2000-03-01

Absolute detection efficiencies of a commercial multichannel plate detector have been measured for O, O+, and O-, impacting at normal incidence for energies ranging from 30-1000 eV. In addition, the detection efficiencies for O relative to its ions are presented, as they may have a more universal application. The absolute detection efficiencies are strongly energy dependent and significant differences are observed for the various charge states at lower energies. The detection efficiencies for the different charge states appear to converge at higher energies. The strongest energy dependence is for O+; the detection efficiency varies by three orders of magnitude across the energy range studied. The weakest dependence is for O-, which varies less than one order of magnitude.

Hamiltonian models for the propagation of irrotational surface gravity waves over a variable bottom.

PubMed

Compelli, A; Ivanov, R; Todorov, M

2018-01-28

A single incompressible, inviscid, irrotational fluid medium bounded by a free surface and varying bottom is considered. The Hamiltonian of the system is expressed in terms of the so-called Dirichlet-Neumann operators. The equations for the surface waves are presented in Hamiltonian form. Specific scaling of the variables is selected which leads to approximations of Boussinesq and Korteweg-de Vries (KdV) types, taking into account the effect of the slowly varying bottom. The arising KdV equation with variable coefficients is studied numerically when the initial condition is in the form of the one-soliton solution for the initial depth.This article is part of the theme issue 'Nonlinear water waves'. © 2017 The Author(s).

Using video modeling with substitutable loops to teach varied play to children with autism.

PubMed

Dupere, Sally; MacDonald, Rebecca P F; Ahearn, William H

2013-01-01

Children with autism often engage in repetitive play with little variation in the actions performed or items used. This study examined the use of video modeling with scripted substitutable loops on children's pretend play with trained and untrained characters. Three young children with autism were shown a video model of scripted toy play that included a substitutable loop that allowed various characters to perform the same actions and vocalizations. Three characters were modeled with the substitutable loop during training sessions, and 3 additional characters were present in the video but never modeled. Following video modeling, all the participants incorporated untrained characters into their play, but the extent to which they did so varied. © Society for the Experimental Analysis of Behavior.

Evaluation of the importance of time-frequency contributions to speech intelligibility in noise

PubMed Central

Yu, Chengzhu; Wójcicki, Kamil K.; Loizou, Philipos C.; Hansen, John H. L.; Johnson, Michael T.

2014-01-01

Recent studies on binary masking techniques make the assumption that each time-frequency (T-F) unit contributes an equal amount to the overall intelligibility of speech. The present study demonstrated that the importance of each T-F unit to speech intelligibility varies in accordance with speech content. Specifically, T-F units are categorized into two classes, speech-present T-F units and speech-absent T-F units. Results indicate that the importance of each speech-present T-F unit to speech intelligibility is highly related to the loudness of its target component, while the importance of each speech-absent T-F unit varies according to the loudness of its masker component. Two types of mask errors are also considered, which include miss and false alarm errors. Consistent with previous work, false alarm errors are shown to be more harmful to speech intelligibility than miss errors when the mixture signal-to-noise ratio (SNR) is below 0 dB. However, the relative importance between the two types of error is conditioned on the SNR level of the input speech signal. Based on these observations, a mask-based objective measure, the loudness weighted hit-false, is proposed for predicting speech intelligibility. The proposed objective measure shows significantly higher correlation with intelligibility compared to two existing mask-based objective measures. PMID:24815280

The role of periodically varying discharge on river plume structure and transport

NASA Astrophysics Data System (ADS)

Yuan, Yeping; Horner-Devine, Alexander R.; Avener, Margaret; Bevan, Shaun

2018-04-01

We present results from laboratory experiments that simulate the effects of periodically varying discharge on buoyant coastal plumes. Freshwater is discharged into a two meter diameter tank filled with saltwater on a rotating table. The mean inflow rate, tank rotation period and density of the ambient salt water are varied to simulate a range of inflow Froude and Rossby numbers. The amplitude and the period of the inflow modulation are varied across a range that simulates variability due to tides and storms. Using the optical thickness method, we measure the width and depth of the plume, plume volume and freshwater retention rate in the plume. With constant discharge, freshwater is retained in a growing anticyclonic bulge circulation near the river mouth, as observed in previous studies. When the discharge is varied, the bulge geometry oscillates between a circular plume structure that extends mainly in the offshore direction, and a compressed plume structure that extends mainly in the alongshore direction. The oscillations result in periodic variations in the width and depth of the bulge and the incidence angle formed where the bulge flow re-attaches with the coastal wall. The oscillations are more pronounced for longer modulation periods, but are relatively insensitive to the modulation amplitude. A phase difference between the time varying transport within the bulge and bulge geometry determines the fraction of the bulge flow discharged into the coastal current. As a result, the modulation period determines the variations in amount of freshwater that returns to the bulge. Freshwater retention in the bulge is increased in longer modulation periods and more pronounced for larger modulation amplitudes.