ERIC Educational Resources Information Center
Scharfenberg, Franz-Josef; Bogner, Franz X.
2011-01-01
Emphasis on improving higher level biology education continues. A new two-step approach to the experimental phases within an outreach gene technology lab, derived from cognitive load theory, is presented. We compared our approach using a quasi-experimental design with the conventional one-step mode. The difference consisted of additional focused…
Combined Teaching Method: An Experimental Study
ERIC Educational Resources Information Center
Kolesnikova, Iryna V.
2016-01-01
The search for the best approach to business education has led educators and researchers to seek many different teaching strategies, ranging from the traditional teaching methods to various experimental approaches such as active learning techniques. The aim of this experimental study was to compare the effects of the traditional and combined…
Effectiveness of Constructivist Approach on Academic Achievement in Science at Secondary Level
ERIC Educational Resources Information Center
Adak, Samaresh
2017-01-01
The present study investigated the effectiveness of constructivist approach on academic achievement in science at secondary level using pre-test, post-test, experimental and control group design, with 58 samples grouped as experimental group (29) and control group (29) on the basis of matching by intelligence test. The investigators conducted this…
NASA Astrophysics Data System (ADS)
Furlong, Cosme; Pryputniewicz, Ryszard J.
1998-05-01
Increased demands on the performance and efficiency of mechanical components impose challenges on their engineering design and optimization, especially when new and more demanding applications must be developed in relatively short periods of time while satisfying design objectives, as well as cost and manufacturability. In addition, reliability and durability must be taken into consideration. As a consequence, effective quantitative methodologies, computational and experimental, should be applied in the study and optimization of mechanical components. Computational investigations enable parametric studies and the determination of critical engineering design conditions, while experimental investigations, especially those using optical techniques, provide qualitative and quantitative information on the actual response of the structure of interest to the applied load and boundary conditions. We discuss a hybrid experimental and computational approach for investigation and optimization of mechanical components. The approach is based on analytical, computational, and experimental resolutions methodologies in the form of computational, noninvasive optical techniques, and fringe prediction analysis tools. Practical application of the hybrid approach is illustrated with representative examples that demonstrate the viability of the approach as an effective engineering tool for analysis and optimization.
Impact of Thematic Approach on Communication Skill in Preschool
ERIC Educational Resources Information Center
Ashokan, Varun; Venugopal, Kalpana
2016-01-01
The study investigated the effects of thematic approach on communication skills for preschool children. The study was a quasi experimental non-equivalent pretest-post-test control group design whereby 5-6 year old preschool children (n = 49) were randomly assigned to an experimental and a control group. The experimental group students were exposed…
Nonlinear Stochastic PDEs: Analysis and Approximations
2016-05-23
numerical performance. Main theoretical and experimental advances include: 1.Introduction of a number of effective approaches to numerical analysis of...Stokes and Euler SPDEs, quasi -geostrophic SPDE, Ginzburg-Landau SPDE and Duffing oscillator REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT...compare their numerical performance. Main theoretical and experimental advances include: 1.Introduction of a number of effective approaches to
Wiers, Reinout W; Eberl, Carolin; Rinck, Mike; Becker, Eni S; Lindenmeyer, Johannes
2011-04-01
This study tested the effects of a new cognitive-bias modification (CBM) intervention that targeted an approach bias for alcohol in 214 alcoholic inpatients. Patients were assigned to one of two experimental conditions, in which they were explicitly or implicitly trained to make avoidance movements (pushing a joystick) in response to alcohol pictures, or to one of two control conditions, in which they received no training or sham training. Four brief sessions of experimental CBM preceded regular inpatient treatment. In the experimental conditions only, patients' approach bias changed into an avoidance bias for alcohol. This effect generalized to untrained pictures in the task used in the CBM and to an Implicit Association Test, in which alcohol and soft-drink words were categorized with approach and avoidance words. Patients in the experimental conditions showed better treatment outcomes a year later. These findings indicate that a short intervention can change alcoholics' automatic approach bias for alcohol and may improve treatment outcome.
NASA Astrophysics Data System (ADS)
Scharfenberg, Franz-Josef; Bogner, Franz X.
2011-08-01
Emphasis on improving higher level biology education continues. A new two-step approach to the experimental phases within an outreach gene technology lab, derived from cognitive load theory, is presented. We compared our approach using a quasi-experimental design with the conventional one-step mode. The difference consisted of additional focused discussions combined with students writing down their ideas (step one) prior to starting any experimental procedure (step two). We monitored students' activities during the experimental phases by continuously videotaping 20 work groups within each approach ( N = 131). Subsequent classification of students' activities yielded 10 categories (with well-fitting intra- and inter-observer scores with respect to reliability). Based on the students' individual time budgets, we evaluated students' roles during experimentation from their prevalent activities (by independently using two cluster analysis methods). Independently of the approach, two common clusters emerged, which we labeled as `all-rounders' and as `passive students', and two clusters specific to each approach: `observers' as well as `high-experimenters' were identified only within the one-step approach whereas under the two-step conditions `managers' and `scribes' were identified. Potential changes in group-leadership style during experimentation are discussed, and conclusions for optimizing science teaching are drawn.
NASA Astrophysics Data System (ADS)
Henry, Christine; Kramb, Victoria; Welter, John T.; Wertz, John N.; Lindgren, Eric A.; Aldrin, John C.; Zainey, David
2018-04-01
Advances in NDE method development are greatly improved through model-guided experimentation. In the case of ultrasonic inspections, models which provide insight into complex mode conversion processes and sound propagation paths are essential for understanding the experimental data and inverting the experimental data into relevant information. However, models must also be verified using experimental data obtained under well-documented and understood conditions. Ideally, researchers would utilize the model simulations and experimental approach to efficiently converge on the optimal solution. However, variability in experimental parameters introduce extraneous signals that are difficult to differentiate from the anticipated response. This paper discusses the results of an ultrasonic experiment designed to evaluate the effect of controllable variables on the anticipated signal, and the effect of unaccounted for experimental variables on the uncertainty in those results. Controlled experimental parameters include the transducer frequency, incidence beam angle and focal depth.
ERIC Educational Resources Information Center
Arulselvi, Evangelin
2013-01-01
The present study aims at finding out the effectiveness of Mutual learning approach over the conventional method in learning English optional II among B.Ed students. The randomized pre-test, post test, control group and experimental group design was employed. The B.Ed students of the same college formed the control and experimental groups. Each…
NASA Astrophysics Data System (ADS)
Tommasino, F.
2016-03-01
This review will summarize results obtained in the recent years applying the Local Effect Model (LEM) approach to the study of basic radiobiological aspects, as for instance DNA damage induction and repair, and charged particle track structure. The promising results obtained using different experimental techniques and looking at different biological end points, support the relevance of the LEM approach for the description of radiation effects induced by both low- and high-LET radiation. Furthermore, they suggest that nowadays the appropriate combination of experimental and modelling tools can lead to advances in the understanding of several open issues in the field of radiation biology.
Ding, Yongxia; Zhang, Peili
2018-06-12
Problem-based learning (PBL) is an effective and highly efficient teaching approach that is extensively applied in education systems across a variety of countries. This study aimed to investigate the effectiveness of web-based PBL teaching pedagogies in large classes. The cluster sampling method was used to separate two college-level nursing student classes (graduating class of 2013) into two groups. The experimental group (n = 162) was taught using a web-based PBL teaching approach, while the control group (n = 166) was taught using conventional teaching methods. We subsequently assessed the satisfaction of the experimental group in relation to the web-based PBL teaching mode. This assessment was performed following comparison of teaching activity outcomes pertaining to exams and self-learning capacity between the two groups. When compared with the control group, the examination scores and self-learning capabilities were significantly higher in the experimental group (P < 0.01) compared with the control group. In addition, 92.6% of students in the experimental group expressed satisfaction with the new web-based PBL teaching approach. In a large class-size teaching environment, the web-based PBL teaching approach appears to be more optimal than traditional teaching methods. These results demonstrate the effectiveness of web-based teaching technologies in problem-based learning. Copyright © 2018. Published by Elsevier Ltd.
NASA Astrophysics Data System (ADS)
Samsudin, Syafiza Saila; Ujang, Suriyati; Sahlan, Nor Fasiha
2016-06-01
This study was conducted on students in Year 3 at Sekolah Kebangsaan Air Putih, Kuantan. The study used a constructivism approach in simplest fraction topic in Mathematics. Students were divided into 2 groups; the control group and the experimental group. Experimental group was taught using Constructivist Approach whereas the control group student was taught using the Traditional Approach. This study aimed to determine the effectiveness of constructivist learning approach the topic of Simplest Fraction. It also aimed to compare the student's achievement between the constructivist approach and traditional approach. This study used the instrument in pre-test, post-test, questionnaires and observation. The data were analyzed with SPSS 15.0 for window. The finding shows there is a significant difference between the pre-test and post-test for experimental group after using constructivism approach in learning process. The mean scores (76.39) of the post-test is higher than the mean scores (60.28) for pre-test. It is proved that constructivist approach is more efficient and suitable for teaching and learning in simplest fraction topic in the classroom compared to traditional approaches. The findings also showed interest and the positive perception of this approach.
Learning Effects of an Experimental EFL Program in Second Life
ERIC Educational Resources Information Center
Wang, Charles Xiaoxue; Calandra, Brendan; Hibbard, Susan T.; McDowell Lefaiver, Mary L.
2012-01-01
This paper reports on the effects an experimental English as a Foreign Language (EFL) program in Second Life (SL) had on Chinese student EFL learning. The study took an evaluative approach using quasi-experimental design with participants from one Chinese university and one American university in the southeastern United States. Results indicated…
Using Blended Learning in Developing Student Teachers Teaching Skills
ERIC Educational Resources Information Center
Isman, Aytekin; Abanmy, Fahad AbdulAziz; Hussein, Hisham Barakat; Al Saadany, Mohammed Abdelrahman
2012-01-01
The research aims to determine the effectiveness of using blended learning Approach in developing student teachers teaching skills, and defining teaching skills that confront students of teachers college at King Saud University need it. The research uses the Quasi- Experimental approach, with four experimental groups (Mathematics (21)--Science…
ERIC Educational Resources Information Center
Kaya, Osman Nafiz; Dogan, Alev; Gokcek, Nur; Kilic, Ziya; Kilic, Esma
2007-01-01
The purpose of this study was to investigate the effects of multiple intelligences (MI) teaching approach on 8th Grade students' achievement in and attitudes toward science. This study used a pretest-posttest control group experimental design. While the experimental group (n=30) was taught a unit on acids and bases using MI teaching approach, the…
Flexoelectricity in Nanostructures: Theory, Nanofabrication and Characterization
2017-09-13
public release; distribution is unlimited. Major Goals: The objective of this project is to investigate, theoretically and experimentally , the... experimental approach. Accomplishments: In this report, we investigated the thermal polarization effect where the temperature- dependent dielectric...through an analytical model, which was experimentally verified. Secondly, based on the existence of the converse flexoelectric effect in materials, BST
Implementing Reading Strategies Based on Collaborative Learning Approach in an English Class
ERIC Educational Resources Information Center
Suwantharathip, Ornprapat
2015-01-01
The present study investigated the effects of reading strategies based on collaborative learning approach on students' reading comprehension and reading strategy use. The quasi-experimental research study was performed with two groups of students. While the control group was taught in the traditional way, the experimental group received reading…
Ahn, Si-Nae; Yoo, Eun-Young; Jung, Min-Ye; Park, Hae-Yean; Lee, Ji-Yeon; Choi, Yoo-Im
2017-01-01
Cognitive Orientation to daily Occupational Performance (CO-OP) approach based on cognitive strategy in occupational therapy. To investigate the effects of CO-OP approach on occupational performance in individuals with hemiparetic stroke. This study was designed as a 5-week, randomized, single-blind. Forty-three participants who had a diagnosis of first stroke were enrolled in this study. The participants were randomly assigned to the experimental group (n = 20) or the control group (n = 23). The experimental group conducted CO-OP approach while the control group conducted conventional occupational therapy based on occupational performance components. This study measured Canadian Occupational Performance Measure (COPM) and Performance Quality Rating Scale (PQRS). Outcome measurements were performed at baseline and post-intervention. After training, the scores of COPM and PQRS in trained task were significantly higher for the score in the experimental group than the control group. In addition, the non-trained task was significantly higher for the score in the experimental group than the control group in COPM and the PQRS. This study suggests that the CO-OP approach is beneficial effects on the occupational performance to improvement in individuals with hemiparetic stroke, and have positive effects on generalization and transfer of acquired skills.
Desynchronization of stochastically synchronized chemical oscillators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Snari, Razan; Tinsley, Mark R., E-mail: mark.tinsley@mail.wvu.edu, E-mail: kshowalt@wvu.edu; Faramarzi, Sadegh
Experimental and theoretical studies are presented on the design of perturbations that enhance desynchronization in populations of oscillators that are synchronized by periodic entrainment. A phase reduction approach is used to determine optimal perturbation timing based upon experimentally measured phase response curves. The effectiveness of the perturbation waveforms is tested experimentally in populations of periodically and stochastically synchronized chemical oscillators. The relevance of the approach to therapeutic methods for disrupting phase coherence in groups of stochastically synchronized neuronal oscillators is discussed.
Synthesis of Single-Case Experimental Data: A Comparison of Alternative Multilevel Approaches
ERIC Educational Resources Information Center
Ferron, John; Van den Noortgate, Wim; Beretvas, Tasha; Moeyaert, Mariola; Ugille, Maaike; Petit-Bois, Merlande; Baek, Eun Kyeng
2013-01-01
Single-case or single-subject experimental designs (SSED) are used to evaluate the effect of one or more treatments on a single case. Although SSED studies are growing in popularity, the results are in theory case-specific. One systematic and statistical approach for combining single-case data within and across studies is multilevel modeling. The…
Speaking to Read: Meta-Analysis of Peer-Mediated Learning for English Language Learners
ERIC Educational Resources Information Center
Cole, Mikel W.
2014-01-01
This meta-analysis examines the effectiveness of a group of instructional approaches (i.e., cooperative, collaborative, and peer tutoring) at improving literacy outcomes for English language learners. Main effects analyses of a sample of 28 experimental and quasi-experimental studies reveal that peer-mediation is more effective for ELLs than…
Calculations on the half-lives of Cluster decay in two-potential approach
NASA Astrophysics Data System (ADS)
Soylu, A.
The half-lives of the cluster decay (CD) from the isotopes having the known experimental values, the half-lives of the α-decay (AD) of same nuclei and also the branching ratios are obtained, within the framework of two-potential approach with cosh potential including with and without the isospin effects. Using two-potential approach and taking into account the isospin effects in the calculations decrease the rms values and they improve the results. The obtained branching ratios are in good agreement with the experimental ones for some isotopes. It is obtained that the isospin-dependent potentials have an influence on the half-lives of the cluster decays of nuclei. Present calculations would be important for predicting the experimental half-lives and branching ratios for the cluster decays of different types of isotopes.
Effects of Guilt and Approachability of Examiner upon Associative Sexual Responses
ERIC Educational Resources Information Center
Janda, Louis H.; And Others
1976-01-01
The effects of guilt and approachability of a female examiner upon the associative sexual responses of 48 men and 48 women were examined. It was found that low-guilt males made more sexual responses when tested by an approachable examiner than unapproachable examiner. Subjects' perceptions of the experimenters were also examined. (Author)
A statistical approach to EMI - Theory and experiment
NASA Astrophysics Data System (ADS)
Weiner, Donald; Capraro, Gerard
A probabilistic approach to electromagnetic interference (EMI) is presented. The approach is illustrated by analyzing an experimental circuit in which EMI occurs. Both random and weakly nonlinear effects are accounted for in the analysis.
ERIC Educational Resources Information Center
Theuns, P.; Verresen, N.; Mairesse, O.; Goossens, R.; Michiels, L.; Peeters, E.; Wastiau, M.
2010-01-01
Personal relations constitute an important life domain and satisfaction therein affects happiness in people. In an experimental approach with a 3x3x3 vignettes study in which 103 first year psychology students participated, the contribution of the quality of relationships with parents, friends, and a partner are studied. It is found that the…
Staying on Task: Can a Thinking Skills Approach Support a Productive Pedagogy for Inclusion?
ERIC Educational Resources Information Center
Baumfield, Vivienne; Devlin, Niall
2005-01-01
This study investigates the effects of a thinking skills approach on the on task rates of pupils with Special Educational Needs (SEN). There were three situations: two experimental and one controlled. The experimental situations compared on task rates of 19 primary-aged pupils with SEN in thinking skills (TS) and non-thinking skills (XTS) lessons.…
NASA Technical Reports Server (NTRS)
Gartner, W. B.; Baldwin, K. M.
1973-01-01
A study of the display requirements for final approach management of the space shuttle orbiter vehicle is presented. An experimental display concept, providing a more direct, pictorial representation of the vehicle's movement relative to the selected approach path and aiming points, was developed and assessed as an aid to manual flight path control. Both head-up, windshield projections and head-down, panel mounted presentations of the experimental display were evaluated in a series of simulated orbiter approach sequence. Data obtained indicate that the experimental display would enable orbiter pilots to exercise greater flexibility in implementing alternative final approach control strategies. Touchdown position and airspeed dispersion criteria were satisfied on 91 percent of the approach sequences, representing various profile and wind effect conditions. Flight path control and airspeed management satisfied operationally-relevant criteria for the two-segment, power-off orbiter approach and were consistently more accurate and less variable when the full set of experimental display elements was available to the pilot. Approach control tended to be more precise when the head-up display was used; however, the data also indicate that the head-down display would provide adequate support for the manual control task.
ERIC Educational Resources Information Center
Ugille, Maaike; Moeyaert, Mariola; Beretvas, S. Natasha; Ferron, John M.; Van den Noortgate, Wim
2014-01-01
A multilevel meta-analysis can combine the results of several single-subject experimental design studies. However, the estimated effects are biased if the effect sizes are standardized and the number of measurement occasions is small. In this study, the authors investigated 4 approaches to correct for this bias. First, the standardized effect…
ERIC Educational Resources Information Center
Adeniyi, Folakemi O.; Lawal, R. Adebayo
2012-01-01
The purpose of this study was to find out the relative effects of three instructional Approaches i.e. Multisensory, Metacognitive, and a combination of Multisensory and Metacognitive Instructional Approaches on the Vocabulary achievement of underachieving Secondary School Students. The study adopted the quasi-experimental design in which a…
ERIC Educational Resources Information Center
Shaw, Donita Massengill
2011-01-01
The purpose of this study was to evaluate the effect of two handwriting approaches, D'Nealian and Sunform, on kindergartners' letter formations. Forty-one participants received D'Nealian handwriting instruction as the control group; 133 kindergartners were instructed in Sunform as the experimental approach. Pre-post tests at the beginning and end…
Experimental design matters for statistical analysis: how to handle blocking.
Jensen, Signe M; Schaarschmidt, Frank; Onofri, Andrea; Ritz, Christian
2018-03-01
Nowadays, evaluation of the effects of pesticides often relies on experimental designs that involve multiple concentrations of the pesticide of interest or multiple pesticides at specific comparable concentrations and, possibly, secondary factors of interest. Unfortunately, the experimental design is often more or less neglected when analysing data. Two data examples were analysed using different modelling strategies. First, in a randomized complete block design, mean heights of maize treated with a herbicide and one of several adjuvants were compared. Second, translocation of an insecticide applied to maize as a seed treatment was evaluated using incomplete data from an unbalanced design with several layers of hierarchical sampling. Extensive simulations were carried out to further substantiate the effects of different modelling strategies. It was shown that results from suboptimal approaches (two-sample t-tests and ordinary ANOVA assuming independent observations) may be both quantitatively and qualitatively different from the results obtained using an appropriate linear mixed model. The simulations demonstrated that the different approaches may lead to differences in coverage percentages of confidence intervals and type 1 error rates, confirming that misleading conclusions can easily happen when an inappropriate statistical approach is chosen. To ensure that experimental data are summarized appropriately, avoiding misleading conclusions, the experimental design should duly be reflected in the choice of statistical approaches and models. We recommend that author guidelines should explicitly point out that authors need to indicate how the statistical analysis reflects the experimental design. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
Relaxation and Distraction in Experimental Desensitization.
ERIC Educational Resources Information Center
Weir, R. O.; Marshall, W. L.
1980-01-01
Compared experimental desensitization with a procedure that replaced relaxation with a distraction task and with an approach that combined both relaxation and distraction. Desensitization generally was more effective than the other two procedures. (Author)
Fong, Kenneth N K; Howie, Dorothy R
2009-01-01
We investigated the effects of an explicit problem-solving skills training program using a metacomponential approach with 33 outpatients with moderate acquired brain injury, in the Hong Kong context. We compared an experimental training intervention with this explicit problem-solving approach, which taught metacomponential strategies, with a conventional cognitive training approach that did not have this explicit metacognitive training. We found significant advantages for the experimental group on the Metacomponential Interview measure in association with the explicit metacomponential training, but transfer to the real-life problem-solving measures was not evidenced in statistically significant findings. Small sample size, limited time of intervention, and some limitations with these tools may have been contributing factors to these results. The training program was demonstrated to have a significantly greater effect than the conventional training approach on metacomponential functioning and the component of problem representation. However, these benefits were not transferable to real-life situations.
Elmendorf, Sarah C; Henry, Gregory H R; Hollister, Robert D; Fosaa, Anna Maria; Gould, William A; Hermanutz, Luise; Hofgaard, Annika; Jónsdóttir, Ingibjörg S; Jónsdóttir, Ingibjörg I; Jorgenson, Janet C; Lévesque, Esther; Magnusson, Borgþór; Molau, Ulf; Myers-Smith, Isla H; Oberbauer, Steven F; Rixen, Christian; Tweedie, Craig E; Walker, Marilyn D; Walker, Marilyn
2015-01-13
Inference about future climate change impacts typically relies on one of three approaches: manipulative experiments, historical comparisons (broadly defined to include monitoring the response to ambient climate fluctuations using repeat sampling of plots, dendroecology, and paleoecology techniques), and space-for-time substitutions derived from sampling along environmental gradients. Potential limitations of all three approaches are recognized. Here we address the congruence among these three main approaches by comparing the degree to which tundra plant community composition changes (i) in response to in situ experimental warming, (ii) with interannual variability in summer temperature within sites, and (iii) over spatial gradients in summer temperature. We analyzed changes in plant community composition from repeat sampling (85 plant communities in 28 regions) and experimental warming studies (28 experiments in 14 regions) throughout arctic and alpine North America and Europe. Increases in the relative abundance of species with a warmer thermal niche were observed in response to warmer summer temperatures using all three methods; however, effect sizes were greater over broad-scale spatial gradients relative to either temporal variability in summer temperature within a site or summer temperature increases induced by experimental warming. The effect sizes for change over time within a site and with experimental warming were nearly identical. These results support the view that inferences based on space-for-time substitution overestimate the magnitude of responses to contemporary climate warming, because spatial gradients reflect long-term processes. In contrast, in situ experimental warming and monitoring approaches yield consistent estimates of the magnitude of response of plant communities to climate warming.
ERIC Educational Resources Information Center
Kamarova, Sviatlana; Chatzisarantis, Nikos L. D.; Hagger, Martin S.; Lintunen, Taru; Hassandra, Mary; Papaioannou, Athanasios
2017-01-01
Background: Previous prospective studies have documented that mastery-approach goals are adaptive because they facilitate less negative psychological responses to unfavourable social comparisons than performance-approach goals. Aims: This study aimed to confirm this so-called "mastery goal advantage" effect experimentally. Methods: A…
Evaluating the Effectiveness of Remedial Reading Courses at Community Colleges: A Quantitative Study
ERIC Educational Resources Information Center
Lavonier, Nicole
2014-01-01
The present study evaluated the effectiveness of two instructional approaches for remedial reading courses at a community college. The instructional approaches were strategic reading and traditional, textbook-based instruction. The two research questions that guided the quantitative, quasi-experimental study were: (a) what is the effect of…
USDA-ARS?s Scientific Manuscript database
A number of recent soil biota studies have deviated from the standard experimental approach of generating a distinct data value for each experimental unit (e.g. Yang et al., 2013; Gundale et al., 2014). Instead, these studies have mixed together soils from multiple experimental units (i.e. sites wi...
NASA Technical Reports Server (NTRS)
Satyanarayana, Arunkumar; Bogert, Philip B.; Chunchu, Prasad B.
2007-01-01
The influence of delamination on the progressing damage path and initial failure load in composite laminates is investigated. Results are presented from a numerical and an experimental study of center-notched tensile-loaded coupons. The numerical study includes two approaches. The first approach considers only intralaminar (fiber breakage and matrix cracking) damage modes in calculating the progression of the damage path. In the second approach, the model is extended to consider the effect of interlaminar (delamination) damage modes in addition to the intralaminar damage modes. The intralaminar damage is modeled using progressive damage analysis (PDA) methodology implemented with the VUMAT subroutine in the ABAQUS finite element code. The interlaminar damage mode has been simulated using cohesive elements in ABAQUS. In the experimental study, 2-3 specimens each of two different stacking sequences of center-notched laminates are tensile loaded. The numerical results from the two different modeling approaches are compared with each other and the experimentally observed results for both laminate types. The comparisons reveal that the second modeling approach, where the delamination damage mode is included together with the intralaminar damage modes, better simulates the experimentally observed damage modes and damage paths, which were characterized by splitting failures perpendicular to the notch tips in one or more layers. Additionally, the inclusion of the delamination mode resulted in a better prediction of the loads at which the failure took place, which were higher than those predicted by the first modeling approach which did not include delaminations.
A Structured Career Intervention Program for Academically Challenged Students
ERIC Educational Resources Information Center
Salleh, Amla; Abdullah, Syed Mohamad; Mahmud, Zuria; Ghavifekr, Simin; Ishak, Noriah
2013-01-01
A study was carried out to test the effects of a 2-week structured intervention program on academically challenged students' career development. A quasi-experimental study was designed using pre-tests, post-tests, and a control group approach to examine the effects of the intervention program. Data were collected from both the experimental and…
ERIC Educational Resources Information Center
Selden, Sally; Sherrier, Tom; Wooters, Robert
2012-01-01
The purpose of this study is to examine the effects of a new approach to performance appraisal training. Motivated by split-brain theory and existing studies of cognitive information processing and performance appraisals, this exploratory study examined the effects of a whole-brain approach to training managers for implementing performance…
Numerical and Experimental Investigations of Humping Phenomena in Laser Micro Welding
NASA Astrophysics Data System (ADS)
Otto, Andreas; Patschger, Andreas; Seiler, Michael
The Humping effect is a phenomenon which is observed approximately since 50 years in various welding procedures and is characterized by droplets due to a pile-up of the melt pool. It occurs within a broad range of process parameters. Particularly during micro welding, humping effect is critical due to typically high feed rates. In the past, essentially two approaches (fluid-dynamic approach of streaming melt within the molten pool and the Plateau-Rayleigh instability of a liquid jet) were discussed in order to explain the occurrence of the humping effect. But none of both can fully explain all observed effects. For this reason, experimental studies in micro welding of thin metal foils were performed in order to determine the influence of process parameters on the occurrence of humping effects. The experimental observations were compared with results from numerical multi-physical simulations (incorporating beam propagation, incoupling, heat transfer, fluid dynamics etc.) to provide a deeper understanding of the causes for hump formation.
The Use of Analog Track Angle Error Display for Improving Simulated GPS Approach Performance
DOT National Transportation Integrated Search
1995-08-01
The effect of adding track angle error (TAE) information to general aviation aircraft cockpit displays used for GPS : nonprecision instrument approaches was studied experimentally. Six pilots flew 120 approaches in a Frasca 242 light : twin aircraft ...
Baldwin, David S; Hou, Ruihua; Gordon, Robert; Huneke, Nathan T M; Garner, Matthew
2017-04-01
Many pharmacological and psychological approaches have been found efficacious in patients with generalized anxiety disorder (GAD), but many treatment-seeking patients will not respond and others will relapse despite continuing with interventions that initially had beneficial effects. Other patients will respond but then stop treatment early because of untoward effects such as sexual dysfunction, drowsiness, and weight gain. There is much scope for the development of novel approaches that could have greater overall effectiveness or acceptability than currently available interventions or that have particular effectiveness in specific clinical subgroups. 'Experimental medicine' studies in healthy volunteers model disease states and represent a proof-of-concept approach for the development of novel therapeutic interventions: they determine whether to proceed to pivotal efficacy studies and so can reduce delays in translating innovations into clinical practice. Investigations in healthy volunteers challenged with the inhalation of air 'enriched' with 7.5% carbon dioxide (CO 2 ) indicate this technique provides a validated and robust experimental medicine model, mirroring the subjective, autonomic, and cognitive features of GAD. The anxiety response during CO 2 challenge probably involves both central noradrenergic neurotransmission and effects on acid-base sensitive receptors and so may stimulate development of novel agents targeted at central chemosensors. Increasing awareness of the potential role of altered cytokine balance in anxiety and the interplay of cytokines with monoaminergic mechanisms may also encourage the investigation of novel agents with modulating effects on immunological profiles. Although seemingly disparate, these two approaches to treatment development may pivot on a shared mechanism in exerting anxiolytic-like effects through pharmacological effects on acid-sensing ion channels.
NASA Technical Reports Server (NTRS)
Cater, Christopher; Xiao, Xinran; Goldberg, Robert K.; Kohlman, Lee W.
2015-01-01
A combined experimental and analytical approach was performed for characterizing and modeling triaxially braided composites with a modified subcell modeling strategy. Tensile coupon tests were conducted on a [0deg/60deg/-60deg] braided composite at angles of 0deg, 30deg, 45deg, 60deg and 90deg relative to the axial tow of the braid. It was found that measured coupon strength varied significantly with the angle of the applied load and each coupon direction exhibited unique final failures. The subcell modeling approach implemented into the finite element software LS-DYNA was used to simulate the various tensile coupon test angles. The modeling approach was successful in predicting both the coupon strength and reported failure mode for the 0deg, 30deg and 60deg loading directions. The model over-predicted the strength in the 90deg direction; however, the experimental results show a strong influence of free edge effects on damage initiation and failure. In the absence of these local free edge effects, the subcell modeling approach showed promise as a viable and computationally efficient analysis tool for triaxially braided composite structures. Future work will focus on validation of the approach for predicting the impact response of the braided composite against flat panel impact tests.
NASA Technical Reports Server (NTRS)
Cater, Christopher; Xiao, Xinran; Goldberg, Robert K.; Kohlman, Lee W.
2015-01-01
A combined experimental and analytical approach was performed for characterizing and modeling triaxially braided composites with a modified subcell modeling strategy. Tensile coupon tests were conducted on a [0deg/60deg/-60deg] braided composite at angles [0deg, 30deg, 45deg, 60deg and 90deg] relative to the axial tow of the braid. It was found that measured coupon strength varied significantly with the angle of the applied load and each coupon direction exhibited unique final failures. The subcell modeling approach implemented into the finite element software LS-DYNA was used to simulate the various tensile coupon test angles. The modeling approach was successful in predicting both the coupon strength and reported failure mode for the 0deg, 30deg and 60deg loading directions. The model over-predicted the strength in the 90deg direction; however, the experimental results show a strong influence of free edge effects on damage initiation and failure. In the absence of these local free edge effects, the subcell modeling approach showed promise as a viable and computationally efficient analysis tool for triaxially braided composite structures. Future work will focus on validation of the approach for predicting the impact response of the braided composite against flat panel impact tests.
Bajard, Agathe; Chabaud, Sylvie; Cornu, Catherine; Castellan, Anne-Charlotte; Malik, Salma; Kurbatova, Polina; Volpert, Vitaly; Eymard, Nathalie; Kassai, Behrouz; Nony, Patrice
2016-01-01
The main objective of our work was to compare different randomized clinical trial (RCT) experimental designs in terms of power, accuracy of the estimation of treatment effect, and number of patients receiving active treatment using in silico simulations. A virtual population of patients was simulated and randomized in potential clinical trials. Treatment effect was modeled using a dose-effect relation for quantitative or qualitative outcomes. Different experimental designs were considered, and performances between designs were compared. One thousand clinical trials were simulated for each design based on an example of modeled disease. According to simulation results, the number of patients needed to reach 80% power was 50 for crossover, 60 for parallel or randomized withdrawal, 65 for drop the loser (DL), and 70 for early escape or play the winner (PW). For a given sample size, each design had its own advantage: low duration (parallel, early escape), high statistical power and precision (crossover), and higher number of patients receiving the active treatment (PW and DL). Our approach can help to identify the best experimental design, population, and outcome for future RCTs. This may be particularly useful for drug development in rare diseases, theragnostic approaches, or personalized medicine. Copyright © 2016 Elsevier Inc. All rights reserved.
Promotion of Literacy and Numeracy in Pyramid Classrooms in Germany
ERIC Educational Resources Information Center
Kammermeyer, Gisela; Stuck, Andrea; Roux, Susanna
2016-01-01
Students' school success in literacy and numeracy is often hampered by limited prerequisites in these domains, yet the effectiveness of different approaches to support students is unclear. Using professional training programmes for kindergarten teachers, we tested the effects of three kindergarten approaches in a quasi-experimental pre- and…
Variogram-based feature extraction for neural network recognition of logos
NASA Astrophysics Data System (ADS)
Pham, Tuan D.
2003-03-01
This paper presents a new approach for extracting spatial features of images based on the theory of regionalized variables. These features can be effectively used for automatic recognition of logo images using neural networks. Experimental results on a public-domain logo database show the effectiveness of the proposed approach.
Fatigue crack growth in unidirectional metal matrix composite
NASA Technical Reports Server (NTRS)
Ghosn, Louis J.; Telesman, Jack; Kantzos, Peter
1990-01-01
The weight function method was used to determine the effective stress intensity factor and the crack opening profile for a fatigue tested composite which exhibited fiber bridging. The bridging mechanism was modeled using two approaches; the crack closure approach and the shear lag approach. The numerically determined stress intensity factor values from both methods were compared and correlated with the experimentally obtained crack growth rates for SiC/Ti-15-3 (0)(sub 8) oriented composites. The near crack tip opening profile was also determined for both methods and compared with the experimentally obtained measurements.
NASA Astrophysics Data System (ADS)
Koksal, Ela Ayse; Berberoglu, Giray
2014-01-01
The purpose of this study is to investigate the effectiveness of guided-inquiry approach in science classes over existing science and technology curriculum in developing content-based science achievement, science process skills, and attitude toward science of grade level 6 students in Turkey. Non-equivalent control group quasi-experimental design was used to investigate the treatment effect. There were 162 students in the experimental group and 142 students in the control group. Both the experimental and control group students took the Achievement Test in Reproduction, Development, and Growth in Living Things (RDGLT), Science Process Skills Test, and Attitudes Toward Science Questionnaire, as pre-test and post-test. Repeated analysis of variance design was used in analyzing the data. Both the experimental and control group students were taught in RDGLT units for 22 class hours. The results indicated the positive effect of guided-inquiry approach on the Turkish students' cognitive as well as affective characteristics. The guided inquiry enhanced the experimental group students' understandings of the science concepts as well as the inquiry skills more than the control group students. Similarly, the experimental group students improved their attitudes toward science more than the control group students as a result of treatment. The guided inquiry seems a transition between traditional teaching method and student-centred activities in the Turkish schools.
A comparative analysis of experimental selection on the stickleback pelvis.
Miller, S E; Barrueto, M; Schluter, D
2017-06-01
Mechanisms of natural selection can be identified using experimental approaches. However, such experiments often yield nonsignificant effects and imprecise estimates of selection due to low power and small sample sizes. Combining results from multiple experimental studies might produce an aggregate estimate of selection that is more revealing than individual studies. For example, bony pelvic armour varies conspicuously among stickleback populations, and predation by vertebrate and insect predators has been hypothesized to be the main driver of this variation. Yet experimental selection studies testing these hypotheses frequently fail to find a significant effect. We experimentally manipulated length of threespine stickleback (Gasterosteus aculeatus) pelvic spines in a mesocosm experiment to test whether prickly sculpin (Cottus asper), an intraguild predator of stickleback, favours longer spines. The probability of survival was greater for stickleback with unclipped pelvic spines, but this effect was noisy and not significant. We used meta-analysis to combine the results of our mesocosm experiment with previously published experimental studies of selection on pelvic armour. We found evidence that fish predation indeed favours increased pelvic armour, with a moderate effect size. The same approach found little evidence that insect predation favours reduced pelvic armour. The causes of reduced pelvic armour in many stickleback populations remain uncertain. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.
Dimensional Comparisons: An Experimental Approach to the Internal/External Frame of Reference Model.
ERIC Educational Resources Information Center
Moller, Jens; Koller, Olaf
2001-01-01
Three experimental studies investigated psychological processes underlying the effects of achievement in one domain and on self-perceived competence in another. In Study 1, high achievement in one domain led to lower self-perceived competence in the other. Study 2 showed inverse effects on self-perceived competence based on achievement feedback.…
In-Store Experimental Approach to Pricing and Consumer Behavior
ERIC Educational Resources Information Center
Sigurdsson, Valdimar; Foxall, Gordon; Saevarsson, Hugi
2010-01-01
This study assessed how, and to what extent, it is possible to use behavioral experimentation and relative sales analysis to study the effects of price on consumers' brand choices in the store environment. An in-store experiment was performed in four stores to investigate the effects of different prices of a target brand on consumers' relative…
Experimental measurements of motion cue effects on STOL approach tasks
NASA Technical Reports Server (NTRS)
Ringland, R. F.; Stapleford, R. L.
1972-01-01
An experimental program to investigate the effects of motion cues on STOL approach is presented. The simulator used was the Six-Degrees-of-Freedom Motion Simulator (S.01) at Ames Research Center of NASA which has ?2.7 m travel longitudinally and laterally and ?2.5 m travel vertically. Three major experiments, characterized as tracking tasks, were conducted under fixed and moving base conditions: (1) A simulated IFR approach of the Augmentor Wing Jet STOL Research Aircraft (AWJSRA), (2) a simulated VFR task with the same aircraft, and (3) a single-axis task having only linear acceleration as the motion cue. Tracking performance was measured in terms of the variances of several motion variables, pilot vehicle describing functions, and pilot commentary.
Experimental and AI-based numerical modeling of contaminant transport in porous media
NASA Astrophysics Data System (ADS)
Nourani, Vahid; Mousavi, Shahram; Sadikoglu, Fahreddin; Singh, Vijay P.
2017-10-01
This study developed a new hybrid artificial intelligence (AI)-meshless approach for modeling contaminant transport in porous media. The key innovation of the proposed approach is that both black box and physically-based models are combined for modeling contaminant transport. The effectiveness of the approach was evaluated using experimental and real world data. Artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) were calibrated to predict temporal contaminant concentrations (CCs), and the effect of noisy and de-noised data on the model performance was evaluated. Then, considering the predicted CCs at test points (TPs, in experimental study) and piezometers (in Myandoab plain) as interior conditions, the multiquadric radial basis function (MQ-RBF), as a meshless approach which solves partial differential equation (PDE) of contaminant transport in porous media, was employed to estimate the CC values at any point within the study area where there was no TP or piezometer. Optimal values of the dispersion coefficient in the advection-dispersion PDE and shape coefficient of MQ-RBF were determined using the imperialist competitive algorithm. In temporal contaminant transport modeling, de-noised data enhanced the performance of ANN and ANFIS methods in terms of the determination coefficient, up to 6 and 5%, respectively, in the experimental study and up to 39 and 18%, respectively, in the field study. Results showed that the efficiency of ANFIS-meshless model was more than ANN-meshless model up to 2 and 13% in the experimental and field studies, respectively.
The Need for Governance by Experimentation: The Case of Biofuels.
Asveld, Lotte
2016-06-01
The policies of the European Union concerning the development of biofuels can be termed a lock-in. Biofuels were initially hailed as a green, sustainability technology. However evidence to the contrary quickly emerged. The European Commission proposed to alter its policies to accommodate for these effects but met with fierce resistance from a considerable number of member states who have an economic interest in these first generation biofuels. In this paper I argue that such a lock-in might have been avoided if an experimental approach to governance had been adopted. Existing approaches such as anticipation and niche management either do not reduce uncertainty sufficiently or fail to explicitly address conflicts between values motivating political and economic support for new technologies. In this paper, I suggest to apply an experimental framework to the development of sustainable biobased technologies. Such an approach builds on insights from adaptive management and transition management in that it has the stimulation of learning effects at its core. I argue that these learning effects should occur on the actual impacts of new technologies, on the institutionalisation of new technologies and most specifically on the norms and values that underly policies supporting new technologies. This approach can be relevant for other emerging technologies.
NASA Astrophysics Data System (ADS)
Celli, Paolo; Gonella, Stefano
2015-08-01
In this letter, we discuss a versatile, fully reconfigurable experimental platform for the investigation of phononic phenomena in metamaterial architectures. The approach revolves around the use of 3D laser vibrometry to reconstruct global and local wavefield features in specimens obtained through simple arrangements of LEGO® bricks on a thin baseplate. The agility by which it is possible to reconfigure the brick patterns into a nearly endless spectrum of topologies makes this an effective approach for rapid experimental proof of concept, as well as a powerful didactic tool, in the arena of phononic crystals and metamaterials engineering. We use our platform to provide a compelling visual illustration of important spatial wave manipulation effects (waveguiding and seismic isolation), and to elucidate fundamental dichotomies between Bragg-based and locally resonant bandgap mechanisms.
NASA Astrophysics Data System (ADS)
Prabawanto, S.
2018-05-01
This research aims to investigate the enhancement of students’ mathematical self- efficacy through teaching with metacognitive scaffolding approach. This research used a quasi- experimental design with pre-post respon control. The subjects were pre-service elementary school teachers in a state university in Bandung. In this study, there were two groups: experimental and control groups. The experimental group consists of 60 students who acquire teaching mathematics under metacognitive approach, while the control group consists of 58 students who acquire teaching mathematics under direct approach. Students were classified into three categories based on the mathematical prior ability, namely high, middle, and low. Data collection instruments consist of mathematical self-efficacy instruments. By using mean difference test, two conclusions of the research: (1) there is a significant difference in the enhancement of mathematical self-efficacy between the students who attended the course under metacognitive scaffolding approach and students who attended the course under direct approach, and (2) there is no significant interaction effect of teaching approaches and ability level based on the mathematical prior ability toward enhancement of students’ mathematical self-efficacy.
NASA Astrophysics Data System (ADS)
Prabawanto, Sufyani
2017-05-01
This research aims to investigate the enhancement of students' mathematical problem solving through teaching with metacognitive scaffolding approach. This research used a quasi-experimental design with pretest-posttest control. The subjects were pre-service elementary school teachers in a state university in Bandung. In this study, there were two groups: experimental and control groups. The experimental group consists of 60 studentswho acquire teaching mathematicsunder metacognitive scaffolding approach, while the control group consists of 58 studentswho acquire teaching mathematicsunder direct approach. Students were classified into three categories based on the mathematical prior ability, namely high, middle, and low. Data collection instruments consist of mathematical problem solving test instruments. By usingmean difference test, two conclusions of the research:(1) there is a significant difference in the enhancement of mathematical problem solving between the students who attended the course under metacognitive scaffolding approach and students who attended the course under direct approach, and(2) thereis no significant interaction effect of teaching approaches and ability level based on the mathematical prior ability toward enhancement of students' mathematical problem solving.
ERIC Educational Resources Information Center
Adolphus, Telima; Omeodu, Doris
2016-01-01
The study investigates the effect of gender and collaborative learning approach on students' conceptual understanding of electromagnetic induction in Secondary Schools in Nigeria. Three research questions and 2 hypotheses were formulated to guide the research. The research design adopted for this study is the quasi-experimental design. In…
Estimating Unbiased Treatment Effects in Education Using a Regression Discontinuity Design
ERIC Educational Resources Information Center
Smith, William C.
2014-01-01
The ability of regression discontinuity (RD) designs to provide an unbiased treatment effect while overcoming the ethical concerns plagued by Random Control Trials (RCTs) make it a valuable and useful approach in education evaluation. RD is the only explicitly recognized quasi-experimental approach identified by the Institute of Education…
1981-08-01
electro - optic effect is investigated both theoretically and experimentally. The theoretical approach is based upon W.A. Harrison’s ’Bond-Orbital Model’. The separate electronic and lattice contributions to the second-order, electro - optic susceptibility are examined within the context of this model and formulae which can accommodate any crystal structure are presented. In addition, a method for estimating the lattice response to a low frequency (dc) electric field is outlined. Finally, experimental measurements of the electro -
First steps in experimental cancer evolution
Taylor, Tiffany B; Johnson, Louise J; Jackson, Robert W; Brockhurst, Michael A; Dash, Philip R
2013-01-01
Evolutionary processes play a central role in the development, progression and response to treatment of cancers. The current challenge facing researchers is to harness evolutionary theory to further our understanding of the clinical progression of cancers. Central to this endeavour will be the development of experimental systems and approaches by which theories of cancer evolution can be effectively tested. We argue here that the experimental evolution approach – whereby evolution is observed in real time and which has typically employed microorganisms – can be usefully applied to cancer. This approach allows us to disentangle the ecological causes of natural selection, identify the genetic basis of evolutionary changes and determine their repeatability. Cell cultures used in cancer research share many of the desirable traits that make microorganisms ideal for studying evolution. As such, experimental cancer evolution is feasible and likely to give great insight into the selective pressures driving the evolution of clinically destructive cancer traits. We highlight three areas of evolutionary theory with importance to cancer biology that are amenable to experimental evolution: drug resistance, social evolution and resource competition. Understanding the diversity, persistence and evolution of cancers is vital for treatment and drug development, and an experimental evolution approach could provide strategic directions and focus for future research. PMID:23745144
Evaluation of Test Methods for Triaxially Braided Composites using a Meso-Scale Finite Element Model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Chao
The characterization of triaxially braided composite is complicate due to the nonuniformity of deformation within the unit cell as well as the possibility of the freeedge effect related to the large size of the unit cell. Extensive experimental investigation has been conducted to develop more accurate test approaches in characterizing the actual mechanical properties of the material we are studying. In this work, a meso-scale finite element model is utilized to simulate two complex specimens: notched tensile specimen and tube tensile specimen, which are designed to avoid the free-edge effect and free-edge effect induced premature edge damage. The full fieldmore » strain data is predicted numerically and compared with experimental data obtained by Digit Image Correlation. The numerically predicted tensile strength values are compared with experimentally measured results. The discrepancy between numerically predicted and experimentally measured data, the capability of different test approaches are analyzed and discussed. The presented numerical model could serve as assistance to the evaluation of different test methods, and is especially useful in identifying potential local damage events.« less
Handwriting Without Tears(®): General Education Effectiveness Through a Consultative Approach.
Donica, Denise K
2015-01-01
This study explores the effectiveness of the Handwriting Without Tears(®) (HWT) kindergarten printing curriculum in general education through a consultative approach with occupational therapy. One cohort of students was the control (n = 19), whereas two other cohorts were experimental groups learning printing through the HWT curriculum (n = 20 each). The Test of Handwriting Skills-Revised (THS-R) was used to collect end-of-year legibility scores for all cohorts. Both experimental groups individually and both experimental groups combined into one group outperformed the control group on all 10 of the THS-R subtests-scoring significantly higher (p < .05 using analysis of covariance controlling for age and gender) on 6 of the subtests for the former and 7 for the latter-and on overall score. Large treatment effects were found for the standard score for each experimental group (d = 0.81, 1.03, and 1.00). This study supports the consultative role of occupational therapy with teachers in general education for handwriting curriculum implementation and the success of HWT for printing instruction. Copyright © 2015 by the American Occupational Therapy Association, Inc.
ERIC Educational Resources Information Center
Lin, Yu-Tzu; Chang, Chia-Hu; Hou, Huei-Tse; Wu, Ke-Chou
2016-01-01
This study investigated the effectiveness of using Google Docs in collaborative concept mapping (CCM) by comparing it with a paper-and-pencil approach. A quasi-experimental study was conducted in a physics course. The control group drew concept maps using the paper-and-pencil method and face-to-face discussion, whereas the experimental group…
Simulation, Gaming, and Conventional Instruction: An Experimental Comparison.
ERIC Educational Resources Information Center
Fennessey, Gail M.; And Others
An environmental problems unit was organized to be taught with three approaches. One approach contained two simulation exercises, one contained a simulation game and a simulation exercise, and one contained no simulations. These approaches were compared for their effectiveness for teaching facts and relationships and for producing favorable…
Aquatic effects assessment: needs and tools.
Marchini, Silvia
2002-01-01
In the assessment of the adverse effects pollutants can produce on exposed ecosystems, different approaches can be followed depending on the quality and quantity of information available, whose advantages and limits are discussed with reference to the aquatic compartment. When experimental data are lacking, a predictive approach can be pursued by making use of validated quantitative structure-activity relationships (QSARs), which provide reliable ecotoxicity estimates only if appropriate models are applied. The experimental approach is central to any environmental hazard assessment procedure, although many uncertainties underlying the extrapolation from a limited set of single species laboratory data to the complexity of the ecosystem (e.g., the limitations of common summary statistics, the variability of species sensitivity, the need to consider alterations at higher level of integration) make the task difficult. When adequate toxicity information are available, the statistical extrapolation approach can be used to predict environmental compatible concentrations.
Integrative Systems Biology for Data Driven Knowledge Discovery
Greene, Casey S.; Troyanskaya, Olga G.
2015-01-01
Integrative systems biology is an approach that brings together diverse high throughput experiments and databases to gain new insights into biological processes or systems at molecular through physiological levels. These approaches rely on diverse high-throughput experimental techniques that generate heterogeneous data by assaying varying aspects of complex biological processes. Computational approaches are necessary to provide an integrative view of these experimental results and enable data-driven knowledge discovery. Hypotheses generated from these approaches can direct definitive molecular experiments in a cost effective manner. Using integrative systems biology approaches, we can leverage existing biological knowledge and large-scale data to improve our understanding of yet unknown components of a system of interest and how its malfunction leads to disease. PMID:21044756
Adaptive identification of vessel's added moments of inertia with program motion
NASA Astrophysics Data System (ADS)
Alyshev, A. S.; Melnikov, V. G.
2018-05-01
In this paper, we propose a new experimental method for determining the moments of inertia of the ship model. The paper gives a brief review of existing methods, a description of the proposed method and experimental stand, test procedures and calculation formulas and experimental results. The proposed method is based on the energy approach with special program motions. The ship model is fixed in a special rack consisting of a torsion element and a set of additional servo drives with flywheels (reactive wheels), which correct the motion. The servo drives with an adaptive controller provide the symmetry of the motion, which is necessary for the proposed identification procedure. The effectiveness of the proposed approach is confirmed by experimental results.
Mary Beth Adams; Pamela J. Edwards; W. Mark Ford; Joshua B. Johnson; Thomas M. Schuler; Melissa Thomas-Van Gundy; Frederica Wood
2011-01-01
Development of a natural gas well and pipeline on the Fernow Experimental Forest, WV, raised concerns about the effects on the natural and scientifi c resources of the Fernow, set aside in 1934 for long-term research. A case study approach was used to evaluate effects of the development. This report includes results of monitoring projects as well as observations...
Design approaches to experimental mediation☆
Pirlott, Angela G.; MacKinnon, David P.
2016-01-01
Identifying causal mechanisms has become a cornerstone of experimental social psychology, and editors in top social psychology journals champion the use of mediation methods, particularly innovative ones when possible (e.g. Halberstadt, 2010, Smith, 2012). Commonly, studies in experimental social psychology randomly assign participants to levels of the independent variable and measure the mediating and dependent variables, and the mediator is assumed to causally affect the dependent variable. However, participants are not randomly assigned to levels of the mediating variable(s), i.e., the relationship between the mediating and dependent variables is correlational. Although researchers likely know that correlational studies pose a risk of confounding, this problem seems forgotten when thinking about experimental designs randomly assigning participants to levels of the independent variable and measuring the mediator (i.e., “measurement-of-mediation” designs). Experimentally manipulating the mediator provides an approach to solving these problems, yet these methods contain their own set of challenges (e.g., Bullock, Green, & Ha, 2010). We describe types of experimental manipulations targeting the mediator (manipulations demonstrating a causal effect of the mediator on the dependent variable and manipulations targeting the strength of the causal effect of the mediator) and types of experimental designs (double randomization, concurrent double randomization, and parallel), provide published examples of the designs, and discuss the strengths and challenges of each design. Therefore, the goals of this paper include providing a practical guide to manipulation-of-mediator designs in light of their challenges and encouraging researchers to use more rigorous approaches to mediation because manipulation-of-mediator designs strengthen the ability to infer causality of the mediating variable on the dependent variable. PMID:27570259
Design approaches to experimental mediation.
Pirlott, Angela G; MacKinnon, David P
2016-09-01
Identifying causal mechanisms has become a cornerstone of experimental social psychology, and editors in top social psychology journals champion the use of mediation methods, particularly innovative ones when possible (e.g. Halberstadt, 2010, Smith, 2012). Commonly, studies in experimental social psychology randomly assign participants to levels of the independent variable and measure the mediating and dependent variables, and the mediator is assumed to causally affect the dependent variable. However, participants are not randomly assigned to levels of the mediating variable(s), i.e., the relationship between the mediating and dependent variables is correlational. Although researchers likely know that correlational studies pose a risk of confounding, this problem seems forgotten when thinking about experimental designs randomly assigning participants to levels of the independent variable and measuring the mediator (i.e., "measurement-of-mediation" designs). Experimentally manipulating the mediator provides an approach to solving these problems, yet these methods contain their own set of challenges (e.g., Bullock, Green, & Ha, 2010). We describe types of experimental manipulations targeting the mediator (manipulations demonstrating a causal effect of the mediator on the dependent variable and manipulations targeting the strength of the causal effect of the mediator) and types of experimental designs (double randomization, concurrent double randomization, and parallel), provide published examples of the designs, and discuss the strengths and challenges of each design. Therefore, the goals of this paper include providing a practical guide to manipulation-of-mediator designs in light of their challenges and encouraging researchers to use more rigorous approaches to mediation because manipulation-of-mediator designs strengthen the ability to infer causality of the mediating variable on the dependent variable.
Influence of Joyful Learning on Elementary School Students’ Attitudes Toward Science
NASA Astrophysics Data System (ADS)
Anggoro, S.; Sopandi, W.; Sholehuddin, M.
2017-02-01
This study investigated the effects of joyful learning approach on elementary school students’ attitudes toward science. The method used is quasy experiment with the participants were divided into two groups. Thirty three of 4th grade students volunteered as an experimental group, and the other forty two act as a control group. The data was collected by questionnaire that are given before and after the lesson, observation sheet, and interview. The effect of joyful learning on students’ attitude was obtained by determining the n-gain and independent t-test. Observation and interview results were used to triangulate and support the quantitative findings. The data showed that the gain scores of the experimental group students’ attitudes toward science were significantly higher than the gain scores of control group. In addition, the experimental group made significantly greater progress in their cognitive, affective and conative experiences. Interviews and observations indicated that their attitude toward science changed over the intervention. This indicated that joyful learning approach can enhance the elementary school students’ attitudes toward science. According to these findings, it can be concluded that joyful learning approach can be used as an alternative approach to improve student’s attitude toward science.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Celli, Paolo, E-mail: pcelli@umn.edu; Gonella, Stefano, E-mail: sgonella@umn.edu
2015-08-24
In this letter, we discuss a versatile, fully reconfigurable experimental platform for the investigation of phononic phenomena in metamaterial architectures. The approach revolves around the use of 3D laser vibrometry to reconstruct global and local wavefield features in specimens obtained through simple arrangements of LEGO{sup ®} bricks on a thin baseplate. The agility by which it is possible to reconfigure the brick patterns into a nearly endless spectrum of topologies makes this an effective approach for rapid experimental proof of concept, as well as a powerful didactic tool, in the arena of phononic crystals and metamaterials engineering. We use ourmore » platform to provide a compelling visual illustration of important spatial wave manipulation effects (waveguiding and seismic isolation), and to elucidate fundamental dichotomies between Bragg-based and locally resonant bandgap mechanisms.« less
ERIC Educational Resources Information Center
Al-Madani, Feras Mohammed
2015-01-01
This study aims at investigating the effect of Blended Learning approach compared to the traditional learning approach on fifth grade students' achievement in My Beautiful Language Textbook and the development of their verbal creative thinking. The study consisted of 49 students among which 25 are males in the Experimental Group and 24 females in…
ERIC Educational Resources Information Center
Eze, Nneka Justina
2015-01-01
This study assessed the effects of cloze instructional approach on senior secondary school students' achievement in Igbo language reading comprehension. The study utilized a quasi experimental research design of the pretest posttest non-equivalent control group design. The study was conducted in Abakaliki education zone of Ebonyi State of Nigeria.…
Effects of Mastery Learning Approach on Secondary School Students' Physics Achievement
ERIC Educational Resources Information Center
Wambugu, Patriciah W.; Changeiywo, Johnson M.
2008-01-01
This study aimed at finding out the effects of Mastery Learning Approach (MLA) on students' achievement in Physics. The study was Quasi-experimental and Solomon Four Non-equivalent Control Group Design was used. The target population comprised of secondary school students in Kieni East Division of Nyeri District. The accessible population was Form…
The Effects of Performance Assessment Approach on Democratic Attitude of Students
ERIC Educational Resources Information Center
Yalcinkaya, Elvan
2013-01-01
The aim of the research is to analyze the effects of performance assessment approach on democratic attitude of students. The research model is an experimental design with pretest-posttest control groups. Both quantitative and qualitative techniques are used for gathering of data in this research. 46 students participated in this research, with 23…
ERIC Educational Resources Information Center
Chiu, Thomas K. F.; Churchill, Daniel
2016-01-01
Literature suggests using multimedia learning principles in the design of instructional material. However, these principles may not be sufficient for the design of learning objects for concept learning in mathematics. This paper reports on an experimental study that investigated the effects of an instructional approach, which includes two teaching…
Using Natural Experiments to Study the Impact of Media on the Family
ERIC Educational Resources Information Center
Price, Joseph; Dahl, Gordon B.
2012-01-01
The randomized trial is the gold standard in scientific research and is used by several fields to study the effects of media. Although useful for studying the immediate response to media exposure, the experimental approach is not well suited to studying long-term effects or behavior outside the laboratory. The "natural experiment" approach, a…
Experimental and AI-based numerical modeling of contaminant transport in porous media.
Nourani, Vahid; Mousavi, Shahram; Sadikoglu, Fahreddin; Singh, Vijay P
2017-10-01
This study developed a new hybrid artificial intelligence (AI)-meshless approach for modeling contaminant transport in porous media. The key innovation of the proposed approach is that both black box and physically-based models are combined for modeling contaminant transport. The effectiveness of the approach was evaluated using experimental and real world data. Artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) were calibrated to predict temporal contaminant concentrations (CCs), and the effect of noisy and de-noised data on the model performance was evaluated. Then, considering the predicted CCs at test points (TPs, in experimental study) and piezometers (in Myandoab plain) as interior conditions, the multiquadric radial basis function (MQ-RBF), as a meshless approach which solves partial differential equation (PDE) of contaminant transport in porous media, was employed to estimate the CC values at any point within the study area where there was no TP or piezometer. Optimal values of the dispersion coefficient in the advection-dispersion PDE and shape coefficient of MQ-RBF were determined using the imperialist competitive algorithm. In temporal contaminant transport modeling, de-noised data enhanced the performance of ANN and ANFIS methods in terms of the determination coefficient, up to 6 and 5%, respectively, in the experimental study and up to 39 and 18%, respectively, in the field study. Results showed that the efficiency of ANFIS-meshless model was more than ANN-meshless model up to 2 and 13% in the experimental and field studies, respectively. Copyright © 2017. Published by Elsevier B.V.
Tao, Yunwen; Zou, Wenli; Cremer, Dieter; Kraka, Elfi
2017-10-26
A novel approach is presented to assess chemical similarity based the local vibrational mode analysis developed by Konkoli and Cremer. The local mode frequency shifts are introduced as similarity descriptors that are sensitive to any electronic structure change. In this work, 59 different monosubstituted benzenes are compared. For a subset of 43 compounds, for which experimental data was available, the ortho-/para- and meta-directing effect in electrophilic aromatic substitution reactions could be correctly reproduced, proving the robustness of the new similarity index. For the remaining 16 compounds, the directing effect was predicted. The new approach is broadly applicable to all compounds for which either experimental or calculated vibrational frequency information is available.
Monitoring is not enough: on the need for a model-based approach to migratory bird management
Nichols, J.D.; Bonney, Rick; Pashley, David N.; Cooper, Robert; Niles, Larry
2000-01-01
Informed management requires information about system state and about effects of potential management actions on system state. Population monitoring can provide the needed information about system state, as well as information that can be used to investigate effects of management actions. Three methods for investigating effects of management on bird populations are (1) retrospective analysis, (2) formal experimentation and constrained-design studies, and (3) adaptive management. Retrospective analyses provide weak inferences, regardless of the quality of the monitoring data. The active use of monitoring data in experimental or constrained-design studies or in adaptive management is recommended. Under both approaches, learning occurs via the comparison of estimates from the monitoring program with predictions from competing management models.
ERIC Educational Resources Information Center
Rattanavich, Saowalak
2017-01-01
This experimental study aims to investigate the effects of three vocational English classes, each one academic semester in duration, and using the concentrated language encounter approach and reciprocal peer teaching strategies. This study employed a time-series design with one pre-experiment and two post-experiments. Discourse and frequency…
ERIC Educational Resources Information Center
ERICKSEN, GERALD L.; RYAN, JAMES J.
A REPORT IS GIVEN OF THE FIRST 3 YEARS OF A FIELD STUDY CONDUCTED TO DETERMINE THE EFFECTIVENESS OF SEVERAL PROTOTYPE, SECONDARY MATHEMATICS PROGRAMS THAT WERE PRODUCED BY DIFFERENT CURRICULUM DEVELOPMENT GROUPS. MATHEMATICS TEACHERS WHO HAD NO PREVIOUS EXPERIENCE WITH "MODERN" OR EXPERIMENTAL APPROACHES TO MATHEMATICS TAUGHT A SELECTED…
Savaşan, Ayşegül; Çam, Olcay
2017-06-01
People with alcohol dependency have lower self-esteem than controls and when their alcohol use increases, their self-esteem decreases. Coping skills in alcohol related issues are predicted to reduce vulnerability to relapse. It is important to adapt care to individual needs so as to prevent a return to the cycle of alcohol use. The Tidal Model focuses on providing support and services to people who need to live a constructive life. The aim of the randomized study was to determine the effect of the psychiatric nursing approach based on the Tidal Model on coping and self-esteem in people with alcohol dependency. The study was semi-experimental in design with a control group, and was conducted on 36 individuals (18 experimental, 18 control). An experimental and a control group were formed by assigning persons to each group using the stratified randomization technique in the order in which they were admitted to hospital. The Coping Inventory (COPE) and the Coopersmith Self-Esteem Inventory (CSEI) were used as measurement instruments. The measurement instruments were applied before the application and three months after the application. In addition to routine treatment and follow-up, the psychiatric nursing approach based on the Tidal Model was applied to the experimental group in the One-to-One Sessions. The psychiatric nursing approach based on the Tidal Model is an approach which is effective in increasing the scores of people with alcohol dependency in positive reinterpretation and growth, active coping, restraint, emotional social support and planning and reducing their scores in behavioral disengagement. It was seen that self-esteem rose, but the difference from the control group did not reach significance. The psychiatric nursing approach based on the Tidal Model has an effect on people with alcohol dependency in maintaining their abstinence. The results of the study may provide practices on a theoretical basis for improving coping behaviors and self-esteem and facilitating the recovery process of alcohol dependents with implications for mental health nursing. Copyright © 2017 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Zhu, Meng-Hua; Liu, Liang-Gang; You, Zhong; Xu, Ao-Ao
2009-03-01
In this paper, a heuristic approach based on Slavic's peak searching method has been employed to estimate the width of peak regions for background removing. Synthetic and experimental data are used to test this method. With the estimated peak regions using the proposed method in the whole spectrum, we find it is simple and effective enough to be used together with the Statistics-sensitive Nonlinear Iterative Peak-Clipping method.
Glauber-theory approach for molecular vibrational excitations
NASA Technical Reports Server (NTRS)
Chang, T. N.; Poe, R. T.; Ray, P.
1973-01-01
Molecular vibrational excitations by charged-particle impact are investigated within the Glauber-theory approach. Theoretical results for electron-H2 scattering give good agreement with experimental data. We study the physical effects responsible for the structures in the differential cross section.
An Application of Brief Experimental Analysis with Early Writing
ERIC Educational Resources Information Center
Parker, David C.; Dickey, Bradley N.; Burns, Matthew K.; McMaster, Kristen L.
2012-01-01
Students' poor performance on national assessments of writing suggests that educators need effective approaches to assess and intervene with writing problems. Brief experimental analysis (BEA) has supporting evidence for identifying interventions in reading, but little research has investigated BEA with writing. Early writing is an especially…
Researching in Classrooms: Getting beyond "What Works"
ERIC Educational Resources Information Center
Dudley-Marling, Curt
2011-01-01
The dominant approach to research in learning disabilities utilizes experimental and quasi-experimental designs to identify the most effective instructional strategies for students with learning disabilities. Research is always undertaken from a point of view, yet the discourse on "what works?" is generally silent on how theoretical frameworks…
Use of the dynamic stiffness method to interpret experimental data from a nonlinear system
NASA Astrophysics Data System (ADS)
Tang, Bin; Brennan, M. J.; Gatti, G.
2018-05-01
The interpretation of experimental data from nonlinear structures is challenging, primarily because of dependency on types and levels of excitation, and coupling issues with test equipment. In this paper, the use of the dynamic stiffness method, which is commonly used in the analysis of linear systems, is used to interpret the data from a vibration test of a controllable compressed beam structure coupled to a test shaker. For a single mode of the system, this method facilitates the separation of mass, stiffness and damping effects, including nonlinear stiffness effects. It also allows the separation of the dynamics of the shaker from the structure under test. The approach needs to be used with care, and is only suitable if the nonlinear system has a response that is predominantly at the excitation frequency. For the structure under test, the raw experimental data revealed little about the underlying causes of the dynamic behaviour. However, the dynamic stiffness approach allowed the effects due to the nonlinear stiffness to be easily determined.
Benmarhnia, Tarik; Bailey, Zinzi; Kaiser, David; Auger, Nathalie; King, Nicholas; Kaufman, Jay S
2016-11-01
The impact of heat waves on mortality and health inequalities is well documented. Very few studies have assessed the effectiveness of heat action plans (HAPs) on health, and none has used quasi-experimental methods to estimate causal effects of such programs. We developed a quasi-experimental method to estimate the causal effects associated with HAPs that allows the identification of heterogeneity across subpopulations, and to apply this method specifically to the case of the Montreal (Quebec, Canada) HAP. A difference-in-differences approach was undertaken using Montreal death registry data for the summers of 2000-2007 to assess the effectiveness of the Montreal HAP, implemented in 2004, on mortality. To study equity in the effect of HAP implementation, we assessed whether the program effects were heterogeneous across sex (male vs. female), age (≥ 65 years vs. < 65 years), and neighborhood education levels (first vs. third tertile). We conducted sensitivity analyses to assess the validity of the estimated causal effect of the HAP program. We found evidence that the HAP contributed to reducing mortality on hot days, and that the mortality reduction attributable to the program was greater for elderly people and people living in low-education neighborhoods. These findings show promise for programs aimed at reducing the impact of extreme temperatures and health inequities. We propose a new quasi-experimental approach that can be easily applied to evaluate the impact of any program or intervention triggered when daily thresholds are reached. Citation: Benmarhnia T, Bailey Z, Kaiser D, Auger N, King N, Kaufman J. 2016. A difference-in-differences approach to assess the effect of a heat action plan on heat-related mortality, and differences in effectiveness according to sex, age, and socioeconomic status (Montreal, Quebec). Environ Health Perspect 124:1694-1699; http://dx.doi.org/10.1289/EHP203.
Pavone, Michele; Cimino, Paola; De Angelis, Filippo; Barone, Vincenzo
2006-04-05
The nitrogen isotropic hyperfine coupling constant (hcc) and the g tensor of a prototypical spin probe (di-tert-butyl nitroxide, DTBN) in aqueous solution have been investigated by means of an integrated computational approach including Car-Parrinello molecular dynamics and quantum mechanical calculations involving a discrete-continuum embedding. The quantitative agreement between computed and experimental parameters fully validates our integrated approach. Decoupling of the structural, dynamical, and environmental contributions acting onto the spectral observables allows an unbiased judgment of the role played by different effects in determining the overall experimental observables and highlights the importance of finite-temperature vibrational averaging. Together with their intrinsic interest, our results pave the route toward more reliable interpretations of EPR parameters of complex systems of biological and technological relevance.
ERIC Educational Resources Information Center
Keraro, Fred Nyabuti; Wachanga, Samuel W.; Orora, William
2007-01-01
This study investigated the effects of using the cooperative concept mapping (CCM) teaching approach on secondary school students' motivation in biology. A non equivalent control group design under the quasi-experimental research was used in which a random sample of four co-educational secondary schools was used. The four schools were randomly…
ERIC Educational Resources Information Center
Uyanik, Gökhan
2016-01-01
The purpose of this study was to examine the effect of learning cycle approach-based teaching on academic achievement, attitude, motivation and retention at primary school 4th grade science lesson. It was conducted pretest-posttest quasi-experimental design in this study. The study was conducted on a total of 65 students studying in two different…
ERIC Educational Resources Information Center
Achor, Emmanuel E.; Imoko, Benjamin I.; Uloko, Emmanuel S.
2009-01-01
This study determined the effectiveness of ethnomathematics teaching approach, ETA on students' achievement and retention in Locus. The study was carried out in education zone B of Benue State of Nigeria using a sample size of 253 Senior Secondary 2 (SS 2) students. It was a non equivalent quasi-experimental study which was guided by two research…
ERIC Educational Resources Information Center
Nwafor, Chika E.; Obodo, Abigail Chikaodinaka; Okafor, Gabriel
2015-01-01
This study explored the effect of self-regulated learning approach on junior secondary school students' achievement in basic science. Quasi-experimental design was used for the study.Two co-educational schools were drawn for the study through simple random sampling technique. One school was assigned to the treatment group while the other was…
Li, S; Oreffo, ROC; Sengers, BG; Tare, RS
2014-01-01
Significant oxygen gradients occur within tissue engineered cartilaginous constructs. Although oxygen tension is an important limiting parameter in the development of new cartilage matrix, its precise role in matrix formation by chondrocytes remains controversial, primarily due to discrepancies in the experimental setup applied in different studies. In this study, the specific effects of oxygen tension on the synthesis of cartilaginous matrix by human articular chondrocytes were studied using a combined experimental-computational approach in a “scaffold-free” 3D pellet culture model. Key parameters including cellular oxygen uptake rate were determined experimentally and used in conjunction with a mathematical model to estimate oxygen tension profiles in 21-day cartilaginous pellets. A threshold oxygen tension (pO2 ≈ 8% atmospheric pressure) for human articular chondrocytes was estimated from these inferred oxygen profiles and histological analysis of pellet sections. Human articular chondrocytes that experienced oxygen tension below this threshold demonstrated enhanced proteoglycan deposition. Conversely, oxygen tension higher than the threshold favored collagen synthesis. This study has demonstrated a close relationship between oxygen tension and matrix synthesis by human articular chondrocytes in a “scaffold-free” 3D pellet culture model, providing valuable insight into the understanding and optimization of cartilage bioengineering approaches. Biotechnol. Bioeng. 2014;111: 1876–1885. PMID:24668194
Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-12
... that can demonstrate impact through other methodological approaches such as a quasi-experimental design... definition of ``relevant outcome.'' Lastly, quasi-experimental designs are already included in the definition... paragraph (b) of this definition, provided they are rigorous and comparable across schools. (b) For non...
Brief Experimental Analyses of Academic Performance: Introduction to the Special Series
ERIC Educational Resources Information Center
McComas, Jennifer J.; Burns, Matthew K.
2009-01-01
Academic skills are frequent concerns in K-12 schools that could benefit from the application of applied behavior analysis (ABA). Brief experimental analysis (BEA) of academic performance is perhaps the most promising approach to apply ABA to student learning. Although research has consistently demonstrated the effectiveness of academic…
Vulnerable subjects? The case of nonhuman animals in experimentation.
Johnson, Jane
2013-12-01
The concept of vulnerability is deployed in bioethics to, amongst other things, identify and remedy harms to participants in research, yet although nonhuman animals in experimentation seem intuitively to be vulnerable, this concept and its attendant protections are rarely applied to research animals. I want to argue, however, that this concept is applicable to nonhuman animals and that a new taxonomy of vulnerability developed in the context of human bioethics can be applied to research animals. This taxonomy does useful explanatory work, helping to pinpoint the limitations of the 3Rs/welfare approach currently adopted in the context of animal experimentation. On this account, the 3Rs/welfare approach fails to deliver for nonhuman animals in experimentation because it effectively addresses only one element of their vulnerability (inherent) and paradoxically through the institution of Animal Ethics Committees intended to protect experimental animals in fact generates new vulnerabilities that exacerbate their already precarious situation.
ERIC Educational Resources Information Center
Elshirbini Abdel-fattah Al-Ashrii, Ismail Ibrahim
2011-01-01
This study aimed to examine the effectiveness of using a suggested program based on integrating the direct and indirect approaches on developing Strategic Competence skills of EFL secondary school students. The study adopted the experimental design. One group was an experimental group (using the suggested program) and another group worked as the…
Experimental diode laser-assisted microvascular anastomosis.
Reali, U M; Gelli, R; Giannotti, V; Gori, F; Pratesi, R; Pini, R
1993-05-01
An experimental study to evaluate a diode-laser approach to microvascular end-to-end anastomoses is reported. Studies were carried out on the femoral arteries and veins of Wistar rats, and effective welding of vessel tissue was obtained at low laser power, by enhancing laser absorption with indocyanine green (Cardio-green) solution. The histologic and surgical effects of this laser technique were examined and compared with those of conventional microvascular sutured anastomoses.
ERIC Educational Resources Information Center
Dresel, Markus; Rindermann, Heiner
2011-01-01
Counseling instructors using evaluations made by their students has shown to be a fruitful approach to enhancing teaching quality. However, prior experimental studies are questionable in terms of external validity. Therefore, we conducted a non-experimental intervention study in which all of the courses offered by a specific department at a German…
Sosedova, L M
2014-01-01
In the materials there are presented features of methodological approaches in the performing of experimental studies concerning of the investigation of the impacts of environmental factors on the human body. There were shown the results of our experiments performed at the Institute, in the modeling of biological effects of antimicrobial nanobiocomposites with nanosilver particles, toxic encephalopathy, in the study of the combined effect of the factors of biological and chemical nature. There was proved the importance of intracellular of proteomics in the assessment of the effects of the action of nanoparticles and nanomaterials on the body. There were revealed key parts of progredient course of mercury poisoning in the long-term. The special section is presented by the study of long-term effects of anthropogenic environmental factors on subsequent generations. There are presented results witnessing to a deterioration of the functional state of the central nervous system in rats in the first and second generations, whose parents were exposed to neurotoxicants. There was proved the aggravating role of prenatal hypoxia in the development of toxicity in rats in sexually mature age. Experimental biomodeling is aimed at sighting of pathogenetically substantiated treatment and preventive measures: initially, in experimental conditions, and in the future in the rehabilitation of sick or injured patients.
The use of clinical trials in comparative effectiveness research on mental health
Blanco, Carlos; Rafful, Claudia; Olfson, Mark
2013-01-01
Objectives A large body of research on comparative effectiveness research (CER) focuses on the use of observational and quasi-experimental approaches. We sought to examine the use of clinical trials as a tool for CER, particularly in mental health. Study Design and Setting Examination of three ongoing randomized clinical trials in psychiatry that address issues which would pose difficulties for non-experimental CER methods. Results Existing statistical approaches to non-experimental data appear insufficient to compensate for biases that may arise when the pattern of missing data cannot be properly modeled such as when there are no standards for treatment, when affected populations have limited access to treatment, or when there are high rates of treatment dropout. Conclusions Clinical trials should retain an important role in CER, particularly in cases of high disorder prevalence, large expected effect sizes, difficult to reach populations or when examining sequential treatments or stepped-care algorithms. Progress in CER in mental health will require careful consideration of appropriate selection between clinical trials and non-experimental designs and on allocation of research resources to optimally inform key treatment decisions for each individual patient. PMID:23849150
Letizia, M C; Cornaglia, M; Tranchida, G; Trouillon, R; Gijs, M A M
2018-01-22
When studying the drug effectiveness towards a target model, one should distinguish the effects of the drug itself and of all the other factors that could influence the screening outcome. This comprehensive knowledge is crucial, especially when model organisms are used to study the drug effect at a systemic level, as a higher number of factors can influence the drug-testing outcome. Covering the entire experimental domain and studying the effect of the simultaneous change in several factors would require numerous experiments, which are costly and time-consuming. Therefore, a design of experiment (DoE) approach in drug-testing is emerging as a robust and efficient method to reduce the use of resources, while maximizing the knowledge of the process. Here, we used a 3-factor-Doehlert DoE to characterize the concentration-dependent effect of the drug doxycycline on the development duration of the nematode Caenorhabditis elegans. To cover the experimental space, 13 experiments were designed and performed, where different doxycycline concentrations were tested, while also varying the temperature and the food amount, which are known to influence the duration of C. elegans development. A microfluidic platform was designed to isolate and culture C. elegans larvae, while testing the doxycycline effect with full control of temperature and feeding over the entire development. Our approach allowed predicting the doxycycline effect on C. elegans development in the complete drug concentration/temperature/feeding experimental space, maximizing the understanding of the effect of this antibiotic on the C. elegans development and paving the way towards a standardized and optimized drug-testing process.
The mnemonic mover: nostalgia regulates avoidance and approach motivation.
Stephan, Elena; Wildschut, Tim; Sedikides, Constantine; Zhou, Xinyue; He, Wuming; Routledge, Clay; Cheung, Wing-Yee; Vingerhoets, Ad J J M
2014-06-01
In light of its role in maintaining psychological equanimity, we proposed that nostalgia--a self-relevant, social, and predominantly positive emotion--regulates avoidance and approach motivation. We advanced a model in which (a) avoidance motivation triggers nostalgia and (b) nostalgia, in turn, increases approach motivation. As a result, nostalgia counteracts the negative impact of avoidance motivation on approach motivation. Five methodologically diverse studies supported this regulatory model. Study 1 used a cross-sectional design and showed that avoidance motivation was positively associated with nostalgia. Nostalgia, in turn, was positively associated with approach motivation. In Study 2, an experimental induction of avoidance motivation increased nostalgia. Nostalgia then predicted increased approach motivation. Studies 3-5 tested the causal effect of nostalgia on approach motivation and behavior. These studies demonstrated that experimental nostalgia inductions strengthened approach motivation (Study 3) and approach behavior as manifested in reduced seating distance (Study 4) and increased helping (Study 5). The findings shed light on nostalgia's role in regulating the human motivation system.
ERIC Educational Resources Information Center
Dunn, Lloyd M.; And Others
The Cooperative Reading Project's purpose was to examine the relative effectiveness of three approaches to the teaching of beginning reading and the effectiveness of oral stimulation. This monograph reports the results of the last year of the project. The experimental reading treatments were: (1) the Initial Teaching Alphabet (ITA), (2) the Words…
Teaching Motivational Interviewing to Undergraduates: Evaluation of Three Approaches
ERIC Educational Resources Information Center
Madson, Michael B.; Schumacher, Julie A.; Noble, Jeremy J.; Bonnell, Melissa A.
2013-01-01
Many undergraduate psychology students assume positions as mental health paraprofessionals during or after college. The present study was a quasi-experimental evaluation of the effectiveness of teaching motivational interviewing (MI), a counseling approach that applies to many paraprofessional occupations. Results from 83 undergraduates indicated…
NASA Astrophysics Data System (ADS)
Zubainur, Cut Morina; Veloo, Arsaythamby; Khalid, Rozalina
2015-05-01
This study aims to determine the effects of the Indonesian Realistic Mathematics Education (PMRI) in Aceh primary schools, Indonesia. Although a plethora of research evidence highlights significant outcomes of the incorporation PMRI in mathematics, its use in the teaching and learning process is limited. Total of 50 standard five students from public primary school participated in this study; 25 students in the experimental group and 25 in the control group. The teaching approaches varied between the groups. While the experimental group experienced the PMRI approach, the control group encountered the conventional teaching approach of chalk and talk. Data was collected at two points namely the pre-test and post-test that lasted for five weeks. The results showed significant differences in mathematics achievement among primary students. In addition, PMRI also creates an active learning environment in solving exercises, and discussions among students and teachers. This study provides evidence that learning mathematics with PMRI benefits primary school students.
Testing quantum gravity through dumb holes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pourhassan, Behnam, E-mail: b.pourhassan@du.ac.ir; Faizal, Mir, E-mail: f2mir@uwaterloo.ca; Irving K. Barber School of Arts and Sciences, University of British Columbia - Okanagan, Kelowna, BC V1V 1V7
We propose a method to test the effects of quantum fluctuations on black holes by analyzing the effects of thermal fluctuations on dumb holes, the analogs for black holes. The proposal is based on the Jacobson formalism, where the Einstein field equations are viewed as thermodynamical relations, and so the quantum fluctuations are generated from the thermal fluctuations. It is well known that all approaches to quantum gravity generate logarithmic corrections to the entropy of a black hole and the coefficient of this term varies according to the different approaches to the quantum gravity. It is possible to demonstrate thatmore » such logarithmic terms are also generated from thermal fluctuations in dumb holes. In this paper, we claim that it is possible to experimentally test such corrections for dumb holes, and also obtain the correct coefficient for them. This fact can then be used to predict the effects of quantum fluctuations on realistic black holes, and so it can also be used, in principle, to experimentally test the different approaches to quantum gravity.« less
Seo, M; Kang, H S; Lee, Y J; Chae, S M
2015-08-01
Narrative therapy is a useful approach in the treatment of depression that allows that person to 're-author' his/her life stories by focusing on positive interpretations, and such focus on positive emotions is a crucial component of treatment for depression. This paper evaluates narrative therapy with an emotional approach (NTEA) as a therapeutic modality that could be used by nurses for persons with depression. A nurse-administered NTEA intervention for people with depression appears effective in increasing cognitive-emotional outcomes, such as hope, positive emotions and decreasing symptoms of depression. Thus, NTEA can be a useful nursing intervention strategy for people with depression. Narrative therapy, which allows a person to 're-author' his/her life stories by focusing on positive interpretations, and emotion-focused therapy, which enables the person to realize his/her emotions, are useful approaches in the treatment of depression. Narrative therapy with an emotional approach (NTEA) aims to create new positive life narratives that focus on alternative stories instead of negative stories. The purpose of this study was to evaluate the effects of the NTEA programme on people with depression utilizing a quasi-experimental design. A total of 50 patients (experimental 24, control 26) participated in the study. The experimental group completed eight sessions of the NTEA programme. The effects of the programme were measured using a self-awareness scale, the Nowotny Hope Scale, the Positive Affect and Negative Affect Scale, and the Center for Epidemiological Studies-Depression Scale. The two groups were homogeneous. There were significant differences in hope, positive and negative emotions, and depression between the experimental and control group. The results established that NTEA can be a useful nursing intervention strategy for people with depression by focusing on positive experiences and by helping depressed patients develop a positive identity through authoring affirmative life stories. © 2015 John Wiley & Sons Ltd.
ERIC Educational Resources Information Center
Jack, Gladys Uzezi
2017-01-01
This study investigated the effect of learning cycle constructivist-based approach on secondary schools students' academic achievement and their attitude towards chemistry. The design used was a pre-test, post-test non randomized control group quasi experimental research design. The design consisted of two instructional groups (learning cycle…
ERIC Educational Resources Information Center
Kroflic, Robi; Smrtnik Vitulic, Helena
2015-01-01
The aim of the present study was to ascertain the effects of the five-month implementation of the comprehensive inductive educational approach on the social behaviour of kindergarten children. The sample consisted of 52 children in the experimental group and 48 children in the control group, aged from 2.6 to 6.0 years. The kindergarten teachers…
ERIC Educational Resources Information Center
Suleman, Qaiser; Hussain, Ishtiaq
2016-01-01
The purpose of the research paper was to investigate the effect of eclectic learning approach on the academic achievement and retention of students in English at elementary level. A sample of forty students of 8th grade randomly selected from Government Boys High School Khurram District Karak was used. It was an experimental study and that's why…
ERIC Educational Resources Information Center
Demircioglu, Hülya; Ayas, Alipasa; Demircioglu, Gökhan; Özmen, Haluk
2015-01-01
In this study, the effect of the context-based approach on pre-service primary school teachers' understanding of matter and its states and their attitude towards chemistry was investigated. Using a simple experimental design, the study was conducted with 35 pre-service primary school teachers who were exposed to context-based material with…
ERIC Educational Resources Information Center
Kalkan, Melek; Ersanli, Ercumend
2008-01-01
The aim of this study is to investigate the effects of the marriage enrichment program based on the cognitive-behavioral approach on levels of marital adjustment of individuals. The experimental and control group of this research was totally composed of 30 individuals. A pre-test post-test research model with control group was used in this…
Animal experimentation in Japan: regulatory processes and application for microbiological studies.
Takahashi-Omoe, H; Omoe, K
2007-07-01
We have conducted animal experimentation as a highly effective technique in biological studies. Also in microbiological studies, we have used experimentation to prevent and treat many infectious diseases in humans and animals. In Japan, the 'Law for the Humane Treatment and Management of Animals', which covers the consideration of the three R principles, refinement, replacement and reduction for an international humane approach to animal experimentation came into effect in June 2006. Looking towards the straightforward operation of the law in animal experimentation, three government ministries established new basic guidelines for experimentation performed in their jurisdictional research and testing facilities. For future microbiological studies involving animals in Japan, we need to perform animal experiments according to the basic guidelines in association with overseas management systems. In this report, we discussed essential actions for the management of animal experimentation in microbiological studies in Japan.
NASA Technical Reports Server (NTRS)
Neudeck, Philip G.; Spry, David J.; Chen, Liangyu
2015-01-01
This work reports a theoretical and experimental study of 4H-SiC JFET threshold voltage as a function of substrate body bias, device position on the wafer, and temperature from 25 C (298K) to 500 C (773K). Based on these results, an alternative approach to SPICE circuit simulation of body effect for SiC JFETs is proposed.
Modeling changes in biomass composition during microwave-based alkali pretreatment of switchgrass.
Keshwani, Deepak R; Cheng, Jay J
2010-01-01
This study used two different approaches to model changes in biomass composition during microwave-based pretreatment of switchgrass: kinetic modeling using a time-dependent rate coefficient, and a Mamdani-type fuzzy inference system. In both modeling approaches, the dielectric loss tangent of the alkali reagent and pretreatment time were used as predictors for changes in amounts of lignin, cellulose, and xylan during the pretreatment. Training and testing data sets for development and validation of the models were obtained from pretreatment experiments conducted using 1-3% w/v NaOH (sodium hydroxide) and pretreatment times ranging from 5 to 20 min. The kinetic modeling approach for lignin and xylan gave comparable results for training and testing data sets, and the differences between the predictions and experimental values were within 2%. The kinetic modeling approach for cellulose was not as effective, and the differences were within 5-7%. The time-dependent rate coefficients of the kinetic models estimated from experimental data were consistent with the heterogeneity of individual biomass components. The Mamdani-type fuzzy inference was shown to be an effective approach to model the pretreatment process and yielded predictions with less than 2% deviation from the experimental values for lignin and with less than 3% deviation from the experimental values for cellulose and xylan. The entropies of the fuzzy outputs from the Mamdani-type fuzzy inference system were calculated to quantify the uncertainty associated with the predictions. Results indicate that there is no significant difference between the entropies associated with the predictions for lignin, cellulose, and xylan. It is anticipated that these models could be used in process simulations of bioethanol production from lignocellulosic materials.
Sexual Violence Prevention through Bystander Education: An Experimental Evaluation
ERIC Educational Resources Information Center
Banyard, Victoria L.; Moynihan, Mary M.; Plante, Elizabethe G.
2007-01-01
The current study used an experimental design to evaluate a sexual violence prevention program based on a community of responsibility model that teaches women and men how to intervene safely and effectively in cases of sexual violence before, during, and after incidents with strangers, acquaintances, or friends. It approaches both women and men as…
Problem-Based Learning in the English Language Classroom
ERIC Educational Resources Information Center
Othman, Normala; Shah, Mohamed Ismail Ahamad
2013-01-01
The purpose of this study was to investigate the effects of the problem-based learning approach (PBL) on students in language classes in two areas: course content and language development. The study was conducted on 128 students, grouped into the experimental and control groups, and employed an experimental research design. The syllabus, textbook,…
ERIC Educational Resources Information Center
Hsieh, Bi-Jen
2015-01-01
This study explored whether guided reflection using predetermined prompts can enhance preservice teachers' development of technology integration self-efficacy (TISE) beliefs. A quantitative approach and a quasi-experimental, pre- and posttest design with two experimental groups and a control group were used. Two types of guided reflection prompts…
Development of Managers' Emotional Competencies: Mind-Body Training Implication
ERIC Educational Resources Information Center
Gruicic, Dusan; Benton, Stephen
2015-01-01
Purpose: This paper aims to research about the effect of mind-body training on the development of emotional competencies of managers. Design/methodology/approach: Quasi-experimental design, i.e. before and after (test-retest). Findings: Results showed that the experimental group, after training, achieved around 15 per cent higher scores compared…
NASA Astrophysics Data System (ADS)
Taher, M.; Hamidah, I.; Suwarma, I. R.
2017-09-01
This paper outlined the results of an experimental study on the effects of multi-representation approach in learning Archimedes Law on students’ mental model improvement. The multi-representation techniques implemented in the study were verbal, pictorial, mathematical, and graphical representations. Students’ mental model was classified into three levels, i.e. scientific, synthetic, and initial levels, based on the students’ level of understanding. The present study employed the pre-experimental methodology, using one group pretest-posttest design. The subject of the study was 32 eleventh grade students in a Public Senior High School in Riau Province. The research instrument included model mental test on hydrostatic pressure concept, in the form of essay test judged by experts. The findings showed that there was positive change in students’ mental model, indicating that multi-representation approach was effective to improve students’ mental model.
Sauer, J; Darioly, A; Mast, M Schmid; Schmid, P C; Bischof, N
2010-11-01
The article proposes a multi-level approach for evaluating communication skills training (CST) as an important element of crew resource management (CRM) training. Within this methodological framework, the present work examined the effectiveness of CST in matching or mismatching team compositions with regard to hierarchical status and competence. There is little experimental research that evaluated the effectiveness of CRM training at multiple levels (i.e. reaction, learning, behaviour) and in teams composed of members of different status and competence. An experiment with a two (CST: with vs. without) by two (competence/hierarchical status: congruent vs. incongruent) design was carried out. A total of 64 participants were trained for 2.5 h on a simulated process control environment, with the experimental group being given 45 min of training on receptiveness and influencing skills. Prior to the 1-h experimental session, participants were assigned to two-person teams. The results showed overall support for the use of such a multi-level approach of training evaluation. Stronger positive effects of CST were found for subjective measures than for objective performance measures. STATEMENT OF RELEVANCE: This work provides some guidance for the use of a multi-level evaluation of CRM training. It also emphasises the need to collect objective performance data for training evaluation in addition to subjective measures with a view to gain a more accurate picture of the benefits of such training approaches.
Experimental characterization of composites. [load test methods
NASA Technical Reports Server (NTRS)
Bert, C. W.
1975-01-01
The experimental characterization for composite materials is generally more complicated than for ordinary homogeneous, isotropic materials because composites behave in a much more complex fashion, due to macroscopic anisotropic effects and lamination effects. Problems concerning the static uniaxial tension test for composite materials are considered along with approaches for conducting static uniaxial compression tests and static uniaxial bending tests. Studies of static shear properties are discussed, taking into account in-plane shear, twisting shear, and thickness shear. Attention is given to static multiaxial loading, systematized experimental programs for the complete characterization of static properties, and dynamic properties.
The quantum Hall effects: Philosophical approach
NASA Astrophysics Data System (ADS)
Lederer, P.
2015-05-01
The Quantum Hall Effects offer a rich variety of theoretical and experimental advances. They provide interesting insights on such topics as gauge invariance, strong interactions in Condensed Matter physics, emergence of new paradigms. This paper focuses on some related philosophical questions. Various brands of positivism or agnosticism are confronted with the physics of the Quantum Hall Effects. Hacking's views on Scientific Realism, Chalmers' on Non-Figurative Realism are discussed. It is argued that the difficulties with those versions of realism may be resolved within a dialectical materialist approach. The latter is argued to provide a rational approach to the phenomena, theory and ontology of the Quantum Hall Effects.
Kliegl, Reinhold; Wei, Ping; Dambacher, Michael; Yan, Ming; Zhou, Xiaolin
2011-01-01
Linear mixed models (LMMs) provide a still underused methodological perspective on combining experimental and individual-differences research. Here we illustrate this approach with two-rectangle cueing in visual attention (Egly et al., 1994). We replicated previous experimental cue-validity effects relating to a spatial shift of attention within an object (spatial effect), to attention switch between objects (object effect), and to the attraction of attention toward the display centroid (attraction effect), also taking into account the design-inherent imbalance of valid and other trials. We simultaneously estimated variance/covariance components of subject-related random effects for these spatial, object, and attraction effects in addition to their mean reaction times (RTs). The spatial effect showed a strong positive correlation with mean RT and a strong negative correlation with the attraction effect. The analysis of individual differences suggests that slow subjects engage attention more strongly at the cued location than fast subjects. We compare this joint LMM analysis of experimental effects and associated subject-related variances and correlations with two frequently used alternative statistical procedures. PMID:21833292
The Effect of Visual Information on the Manual Approach and Landing
NASA Technical Reports Server (NTRS)
Wewerinke, P. H.
1982-01-01
The effect of visual information in combination with basic display information on the approach performance. A pre-experimental model analysis was performed in terms of the optimal control model. The resulting aircraft approach performance predictions were compared with the results of a moving base simulator program. The results illustrate that the model provides a meaningful description of the visual (scene) perception process involved in the complex (multi-variable, time varying) manual approach task with a useful predictive capability. The theoretical framework was shown to allow a straight-forward investigation of the complex interaction of a variety of task variables.
Experimental study designs to improve the evaluation of road mitigation measures for wildlife.
Rytwinski, Trina; van der Ree, Rodney; Cunnington, Glenn M; Fahrig, Lenore; Findlay, C Scott; Houlahan, Jeff; Jaeger, Jochen A G; Soanes, Kylie; van der Grift, Edgar A
2015-05-01
An experimental approach to road mitigation that maximizes inferential power is essential to ensure that mitigation is both ecologically-effective and cost-effective. Here, we set out the need for and standards of using an experimental approach to road mitigation, in order to improve knowledge of the influence of mitigation measures on wildlife populations. We point out two key areas that need to be considered when conducting mitigation experiments. First, researchers need to get involved at the earliest stage of the road or mitigation project to ensure the necessary planning and funds are available for conducting a high quality experiment. Second, experimentation will generate new knowledge about the parameters that influence mitigation effectiveness, which ultimately allows better prediction for future road mitigation projects. We identify seven key questions about mitigation structures (i.e., wildlife crossing structures and fencing) that remain largely or entirely unanswered at the population-level: (1) Does a given crossing structure work? What type and size of crossing structures should we use? (2) How many crossing structures should we build? (3) Is it more effective to install a small number of large-sized crossing structures or a large number of small-sized crossing structures? (4) How much barrier fencing is needed for a given length of road? (5) Do we need funnel fencing to lead animals to crossing structures, and how long does such fencing have to be? (6) How should we manage/manipulate the environment in the area around the crossing structures and fencing? (7) Where should we place crossing structures and barrier fencing? We provide experimental approaches to answering each of them using example Before-After-Control-Impact (BACI) study designs for two stages in the road/mitigation project where researchers may become involved: (1) at the beginning of a road/mitigation project, and (2) after the mitigation has been constructed; highlighting real case studies when available. Copyright © 2015 Elsevier Ltd. All rights reserved.
Tau-U: A Quantitative Approach for Analysis of Single-Case Experimental Data in Aphasia.
Lee, Jaime B; Cherney, Leora R
2018-03-01
Tau-U is a quantitative approach for analyzing single-case experimental design (SCED) data. It combines nonoverlap between phases with intervention phase trend and can correct for a baseline trend (Parker, Vannest, & Davis, 2011). We demonstrate the utility of Tau-U by comparing it with the standardized mean difference approach (Busk & Serlin, 1992) that is widely reported within the aphasia SCED literature. Repeated writing measures from 3 participants with chronic aphasia who received computer-based writing treatment are analyzed visually and quantitatively using both Tau-U and the standardized mean difference approach. Visual analysis alone was insufficient for determining an effect between the intervention and writing improvement. The standardized mean difference yielded effect sizes ranging from 4.18 to 26.72 for trained items and 1.25 to 3.20 for untrained items. Tau-U yielded significant (p < .05) effect sizes for 2 of 3 participants for trained probes and 1 of 3 participants for untrained probes. A baseline trend correction was applied to data from 2 of 3 participants. Tau-U has the unique advantage of allowing for the correction of an undesirable baseline trend. Although further study is needed, Tau-U shows promise as a quantitative approach to augment visual analysis of SCED data in aphasia.
An examination of fuel particle heating during fire spread
Jack D. Cohen; Mark A. Finney
2010-01-01
Recent high intensity wildfires and our demonstrated inability to control extreme fire behavior suggest a need for alternative approaches for preventing wildfire disasters. Current fire spread models are not sufficiently based on a basic understanding of fire spread processes to provide more effective management alternatives. An experimental and theoretical approach...
ERIC Educational Resources Information Center
San Antonio, Diosdado M.; Gamage, David T.
2007-01-01
Purpose: The paper aims to examine the effect of implementing participatory school administration, leadership and management (PSALM) on the levels of empowerment among the educational stakeholders. Design/methodology/approach: A mixed method approach, combining the experimental design with empirical surveys, interviews and documentary analysis,…
Assessing Financial Education Methods: Principles vs. Rules-of-Thumb Approaches
ERIC Educational Resources Information Center
Skimmyhorn, William L.; Davies, Evan R.; Mun, David; Mitchell, Brian
2016-01-01
Despite thousands of programs and tremendous public and private interest in improving financial decision-making, little is known about how best to teach financial education. Using an experimental approach, the authors estimated the effects of two different education methodologies (principles-based and rules-of-thumb) on the knowledge,…
A Parametric Geometry Computational Fluid Dynamics (CFD) Study Utilizing Design of Experiments (DOE)
NASA Technical Reports Server (NTRS)
Rhew, Ray D.; Parker, Peter A.
2007-01-01
Design of Experiments (DOE) was applied to the LAS geometric parameter study to efficiently identify and rank primary contributors to integrated drag over the vehicles ascent trajectory in an order of magnitude fewer CFD configurations thereby reducing computational resources and solution time. SME s were able to gain a better understanding on the underlying flowphysics of different geometric parameter configurations through the identification of interaction effects. An interaction effect, which describes how the effect of one factor changes with respect to the levels of other factors, is often the key to product optimization. A DOE approach emphasizes a sequential approach to learning through successive experimentation to continuously build on previous knowledge. These studies represent a starting point for expanded experimental activities that will eventually cover the entire design space of the vehicle and flight trajectory.
NASA Astrophysics Data System (ADS)
Matoušek, Václav; Kesely, Mikoláš; Vlasák, Pavel
2018-06-01
The deposition velocity is an important operation parameter in hydraulic transport of solid particles in pipelines. It represents flow velocity at which transported particles start to settle out at the bottom of the pipe and are no longer transported. A number of predictive models has been developed to determine this threshold velocity for slurry flows of different solids fractions (fractions of different grain size and density). Most of the models consider flow in a horizontal pipe only, modelling approaches for inclined flows are extremely scarce due partially to a lack of experimental information about the effect of pipe inclination on the slurry flow pattern and behaviour. We survey different approaches to modelling of particle deposition in flowing slurry and discuss mechanisms on which deposition-limit models are based. Furthermore, we analyse possibilities to incorporate the effect of flow inclination into the predictive models and select the most appropriate ones based on their ability to modify the modelled deposition mechanisms to conditions associated with the flow inclination. A usefulness of the selected modelling approaches and their modifications are demonstrated by comparing model predictions with experimental results for inclined slurry flows from our own laboratory and from the literature.
CFD Modeling of a CFB Riser Using Improved Inlet Boundary Conditions
NASA Astrophysics Data System (ADS)
Peng, B. T.; Zhang, C.; Zhu, J. X.; Qi, X. B.
2010-03-01
A computational fluid dynamics (CFD) model based on Eulerian-Eulerian approach coupled with granular kinetics theory was adopted to investigate the hydrodynamics and flow structures in a circulating fluidized bed (CFB) riser column. A new approach to specify the inlet boundary conditions was proposed in this study to simulate gas-solids flow in CFB risers more accurately. Simulation results were compared with the experimental data, and good agreement between the numerical results and experimental data was observed under different operating conditions, which indicates the effectiveness and accuracy of the CFD model with the proposed inlet boundary conditions. The results also illustrate a clear core annulus structure in the CFB riser under all operating conditions both experimentally and numerically.
ERIC Educational Resources Information Center
Memis, Esra Kabatas
2016-01-01
The aim of this study was to investigate the effect of the university-level application of an Argument-Based Inquiry Approach, as compared to the traditional laboratory teaching method, on the ability of students to learn about optics and to demonstrate critical thinking. In this quasi-experimental study, pretest-posttest scores and CCDTI were…
ERIC Educational Resources Information Center
Demircioglu, Hulya; Demircioglu, Gokhan; Calik, Muammar
2009-01-01
We investigated the effect of the context-based approach on 9th grade students' conceptions of the Periodic Table. Within a nonequivalent pretest-posttest control group design the study was conducted with 80 grade 9 students (aged 15-16) drawn from two classes (39 and 41 students) in a high school in Turkey. The experimental group was exposed to…
ERIC Educational Resources Information Center
Heller, Joan I.
2012-01-01
This study evaluated an approach to professional development for middle school science teachers by closely examining one grade 8 course that embodies that approach. Using a cluster-randomized experimental design, the study tested the effectiveness of the Making Sense of SCIENCE[TM] professional development course on force and motion (Daehler,…
Koromilas, Christos; Liapi, Charis; Zarros, Apostolos; Stolakis, Vasileios; Tsagianni, Anastasia; Skandali, Nikolina; Al-Humadi, Hussam; Tsakiris, Stylianos
2014-06-01
Hypothyroidism is known to exert significant structural and functional changes to the developing central nervous system, and can lead to the establishment of serious mental retardation and neurological problems. The aim of the present study was to shed more light on the effects of gestational and/or lactational maternal exposure to propylthiouracil-induced experimental hypothyroidism on crucial brain enzyme activities of Wistar rat offspring, at two time-points of their lives: at birth (day-1) and at 21 days of age (end of lactation). Under all studied experimental conditions, offspring brain acetylcholinesterase (AChE) activity was found to be significantly decreased due to maternal hypothyroidism, in contrast to the two studied adenosinetriphosphatase (Na(+),K(+)-ATPase and Mg(2+)-ATPase) activities that were only found to be significantly altered right after birth (increased and decreased, respectively, following an exposure to gestational maternal hypothyroidism) and were restored to control levels by the end of lactation. As our findings regarding the pattern of effects that maternal hypothyroidism has on the above-mentioned crucial offspring brain enzyme activities are compared to those reported in the literature, several differences are revealed that could be attributed to both the mode of the experimental simulation approach followed as well as to the time-frames examined. These findings could provide the basis for a debate on the need of a more consistent experimental approach to hypothyroidism during neurodevelopment as well as for a further evaluation of the herein presented and discussed neurochemical (and, ultimately, neurodevelopmental) effects of experimentally-induced maternal hypothyroidism, in a brain region-specific manner. Copyright © 2014 ISDN. Published by Elsevier Ltd. All rights reserved.
Electromagnetic structure of few-nucleon ground states
Marcucci, Laura E.; Gross, Franz L.; Peña, M. T.; ...
2016-01-08
Experimental form factors of the hydrogen and helium isotopes, extracted from an up-to-date global analysis of cross sections and polarization observables measured in elastic electron scattering from these systems, are compared to predictions obtained in three different theoretical approaches: the first is based on realistic interactions and currents, including relativistic corrections (labeled as the conventional approach); the second relies on a chiral effective field theory description of the strong and electromagnetic interactions in nuclei (labeled ChiEFT); the third utilizes a fully relativistic treatment of nuclear dynamics as implemented in the covariant spectator theory (labeled CST). Furthermore, for momentum transfers belowmore » Q < 5 fm -1 there is satisfactory agreement between experimental data and theoretical results in all three approaches. Conversely, at Q > 5 fm -1, particularly in the case of the deuteron, a relativistic treatment of the dynamics, as is done in the CST, is necessary. The experimental data on the deuteron A structure function extend to Q ~ 12 fm -1, and the close agreement between these data and the CST results suggests that, even in this extreme kinematical regime, there is no evidence for new effects coming from quark and gluon degrees of freedom at short distances.« less
Flexible manipulator control experiments and analysis
NASA Technical Reports Server (NTRS)
Yurkovich, S.; Ozguner, U.; Tzes, A.; Kotnik, P. T.
1987-01-01
Modeling and control design for flexible manipulators, both from an experimental and analytical viewpoint, are described. From the application perspective, an ongoing effort within the laboratory environment at the Ohio State University, where experimentation on a single link flexible arm is underway is described. Several unique features of this study are described here. First, the manipulator arm is slewed by a direct drive dc motor and has a rigid counterbalance appendage. Current experimentation is from two viewpoints: (1) rigid body slewing and vibration control via actuation with the hub motor, and (2) vibration suppression through the use of structure-mounted proof-mass actuation at the tip. Such an application to manipulator control is of interest particularly in design of space-based telerobotic control systems, but has received little attention to date. From an analytical viewpoint, parameter estimation techniques within the closed-loop for self-tuning adaptive control approaches are discussed. Also introduced is a control approach based on output feedback and frequency weighting to counteract effects of spillover in reduced-order model design. A model of the flexible manipulator based on experimental measurements is evaluated for such estimation and control approaches.
[Community reinforcement approach plus vouchers for cocaine dependence treatment].
Secades-Villa, Roberto; García-Rodríguez, Olaya; Alvarez Rodríguez, Helí; Río Rodríguez, Arcadio; Fernández-Hermida, José R; Luis Carballo, José
2007-01-01
Cocaine use is an increasingly serious problem in Spain. The absence of effective drugs for the treatment of cocaine addiction and of empirically validated therapy programmes makes it necessary to resort to programmes that have shown their effectiveness in other countries. The aim of the present study was to explore the effectiveness of one of the programmes that has obtained the best results in the United States: the Community Reinforcement Approach (CRA) Plus Vouchers for the treatment of cocaine addiction. We assessed treatment retention and dropout rates and cocaine use during the first three months of intervention. The sample was made up of 37 patients addicted to cocaine who were assigned at random to one of two conditions: experimental (CRA Plus Vouchers) or control (Standard Treatment), both in the outpatient context. The results showed that 85.7% of the experimental group patients completed 12 weeks of treatment, compared to 69.6% of the control group. In the experimental group, 57.1% of the patients maintained continuous abstinence, compared to 39.1% of the control group. These results coincide with those of previous studies, all from outside Spain. Nevertheless, longer-term studies with larger samples are necessary in order to confirm the effectiveness of this program.
Predicting protein interactions by Brownian dynamics simulations.
Meng, Xuan-Yu; Xu, Yu; Zhang, Hong-Xing; Mezei, Mihaly; Cui, Meng
2012-01-01
We present a newly adapted Brownian-Dynamics (BD)-based protein docking method for predicting native protein complexes. The approach includes global BD conformational sampling, compact complex selection, and local energy minimization. In order to reduce the computational costs for energy evaluations, a shell-based grid force field was developed to represent the receptor protein and solvation effects. The performance of this BD protein docking approach has been evaluated on a test set of 24 crystal protein complexes. Reproduction of experimental structures in the test set indicates the adequate conformational sampling and accurate scoring of this BD protein docking approach. Furthermore, we have developed an approach to account for the flexibility of proteins, which has been successfully applied to reproduce the experimental complex structure from the structure of two unbounded proteins. These results indicate that this adapted BD protein docking approach can be useful for the prediction of protein-protein interactions.
NASA Astrophysics Data System (ADS)
Yu, Zhang-Yu; Liu, Tao; Guo, Dao-Jun; Liu, Yong-Jun; Liu, Cheng-Bu
2010-12-01
The microenvironmental effect of dimethyl sulfoxide (DMSO) on adrenaline was studied by several approaches including the cyclic voltammetry (CV) of adrenaline at a platinum electrode in acid aqueous solution, the chemical shift of 1H nuclear magnetic resonance ( 1H NMR) of adrenaline, and the change of diffusion coefficient of adrenaline. The experimental results demonstrated that DMSO has significant microenvironmental effect on adrenaline, which was confirmed by the density functional theory (DFT) study on the hydrogen bond (H-bond) complexes of adrenaline with water and DMSO.
ERIC Educational Resources Information Center
Bünning, Frank
2013-01-01
Pedagogic approaches to TVET offer a limited range of teaching strategies which make use of experimental learning. Thus experiments were developed for teachers of structural engineering and timber processing technologies and were subject to empirical evaluation by a researcher at the Otto-von-Guericke-University Magdeburg and Kassel University.…
ERIC Educational Resources Information Center
Federico, Pat-Anthony
The learning efficiency and effectiveness of teaching an anatomical and physiological system to Air Force enlisted trainees utilizing an experimental audiovisual programed module was compared to that of a commercial linear programed text. It was demonstrated that the audiovisual programed approach to training was more efficient than and equally as…
Experimental Study of Short-Term Training in Social Cognition in Pre-Schoolers
ERIC Educational Resources Information Center
Houssa, Marine; Nader-Grosbois, Nathalie; Jacobs, Emilie
2014-01-01
Using an experimental approach, our study examined the differentiated effects on pre-schoolers' social cognition of two short-term social information processing (SIP) and Theory of Mind (ToM) training sessions dealing with emotions and beliefs. The links between ToM, SIP, and social adjustment or externalizing behavior were examined. 47…
EFFECTS OF AMBIENT PM ON CYTOKINE PRODUCTION IN MOUSE MACHROPHAGES AND EPITHELIAL CELLS
The objective of the Multi-Site Ambient Particle Study (MAPS) was to collect ambient particles from different geographical regions, examine their health effects using various in vitro and in vivo experimental approaches, and ultimately relate the health effects to particle compon...
EFFECTS OF AMBIENT PM ON CYTOKINE PRODUCTION IN MOUSE MACROPHAGES AND EPITHELIAL CELLS
The objective of the Multi-Site Ambient Particle Study (MAPS) was to collect ambient particles from different geographical regions, examine their health effects using various in vitro and in vivo experimental approaches, and ultimately relate the health effects to particle compon...
ERIC Educational Resources Information Center
Chen, Ching-Huei; Chen, Chia-Ying
2012-01-01
This study examined the effects of an inquiry-based learning (IBL) approach compared to that of a problem-based learning (PBL) approach on learner performance, attitude toward science and inquiry ability. Ninety-six students from three 7th-grade classes at a public school were randomly assigned to two experimental groups and one control group. All…
ERIC Educational Resources Information Center
Ge, Zi-Gang
2015-01-01
This study aims to investigate the effectiveness of a storytelling approach in Chinese adult e-learners' vocabulary learning. Two classes of 60 students participated in the experiment, with 30 in the experimental group and 30 in the control group. The storytelling approach and the rote memorization approach were employed by the two groups…
Effects of a blended learning approach on student outcomes in a graduate-level public health course.
Kiviniemi, Marc T
2014-03-11
Blended learning approaches, in which in-person and online course components are combined in a single course, are rapidly increasing in health sciences education. Evidence for the relative effectiveness of blended learning versus more traditional course approaches is mixed. The impact of a blended learning approach on student learning in a graduate-level public health course was examined using a quasi-experimental, non-equivalent control group design. Exam scores and course point total data from a baseline, "traditional" approach semester (n = 28) was compared to that from a semester utilizing a blended learning approach (n = 38). In addition, student evaluations of the blended learning approach were evaluated. There was a statistically significant increase in student performance under the blended learning approach (final course point total d = 0.57; a medium effect size), even after accounting for previous academic performance. Moreover, student evaluations of the blended approach were very positive and the majority of students (83%) preferred the blended learning approach. Blended learning approaches may be an effective means of optimizing student learning and improving student performance in health sciences courses.
Optimizing laboratory animal stress paradigms: The H-H* experimental design.
McCarty, Richard
2017-01-01
Major advances in behavioral neuroscience have been facilitated by the development of consistent and highly reproducible experimental paradigms that have been widely adopted. In contrast, many different experimental approaches have been employed to expose laboratory mice and rats to acute versus chronic intermittent stress. An argument is advanced in this review that more consistent approaches to the design of chronic intermittent stress experiments would provide greater reproducibility of results across laboratories and greater reliability relating to various neural, endocrine, immune, genetic, and behavioral adaptations. As an example, the H-H* experimental design incorporates control, homotypic (H), and heterotypic (H*) groups and allows for comparisons across groups, where each animal is exposed to the same stressor, but that stressor has vastly different biological and behavioral effects depending upon each animal's prior stress history. Implementation of the H-H* experimental paradigm makes possible a delineation of transcriptional changes and neural, endocrine, and immune pathways that are activated in precisely defined stressor contexts. Copyright © 2016 Elsevier Ltd. All rights reserved.
A one-dimensional stochastic approach to the study of cyclic voltammetry with adsorption effects
DOE Office of Scientific and Technical Information (OSTI.GOV)
Samin, Adib J.
In this study, a one-dimensional stochastic model based on the random walk approach is used to simulate cyclic voltammetry. The model takes into account mass transport, kinetics of the redox reactions, adsorption effects and changes in the morphology of the electrode. The model is shown to display the expected behavior. Furthermore, the model shows consistent qualitative agreement with a finite difference solution. This approach allows for an understanding of phenomena on a microscopic level and may be useful for analyzing qualitative features observed in experimentally recorded signals.
A one-dimensional stochastic approach to the study of cyclic voltammetry with adsorption effects
NASA Astrophysics Data System (ADS)
Samin, Adib J.
2016-05-01
In this study, a one-dimensional stochastic model based on the random walk approach is used to simulate cyclic voltammetry. The model takes into account mass transport, kinetics of the redox reactions, adsorption effects and changes in the morphology of the electrode. The model is shown to display the expected behavior. Furthermore, the model shows consistent qualitative agreement with a finite difference solution. This approach allows for an understanding of phenomena on a microscopic level and may be useful for analyzing qualitative features observed in experimentally recorded signals.
Cooke, Steven J; Birnie-Gauvin, Kim; Lennox, Robert J; Taylor, Jessica J; Rytwinski, Trina; Rummer, Jodie L; Franklin, Craig E; Bennett, Joseph R; Haddaway, Neal R
2017-01-01
Policy development and management decisions should be based upon the best available evidence. In recent years, approaches to evidence synthesis, originating in the medical realm (such as systematic reviews), have been applied to conservation to promote evidence-based conservation and environmental management. Systematic reviews involve a critical appraisal of evidence, but studies that lack the necessary rigour (e.g. experimental, technical and analytical aspects) to justify their conclusions are typically excluded from systematic reviews or down-weighted in terms of their influence. One of the strengths of conservation physiology is the reliance on experimental approaches that help to more clearly establish cause-and-effect relationships. Indeed, experimental biology and ecology have much to offer in terms of building the evidence base that is needed to inform policy and management options related to pressing issues such as enacting endangered species recovery plans or evaluating the effectiveness of conservation interventions. Here, we identify a number of pitfalls that can prevent experimental findings from being relevant to conservation or would lead to their exclusion or down-weighting during critical appraisal in a systematic review. We conclude that conservation physiology is well positioned to support evidence-based conservation, provided that experimental designs are robust and that conservation physiologists understand the nuances associated with informing decision-making processes so that they can be more relevant.
Birnie-Gauvin, Kim; Lennox, Robert J.; Taylor, Jessica J.; Rytwinski, Trina; Rummer, Jodie L.; Franklin, Craig E.; Bennett, Joseph R.; Haddaway, Neal R.
2017-01-01
Abstract Policy development and management decisions should be based upon the best available evidence. In recent years, approaches to evidence synthesis, originating in the medical realm (such as systematic reviews), have been applied to conservation to promote evidence-based conservation and environmental management. Systematic reviews involve a critical appraisal of evidence, but studies that lack the necessary rigour (e.g. experimental, technical and analytical aspects) to justify their conclusions are typically excluded from systematic reviews or down-weighted in terms of their influence. One of the strengths of conservation physiology is the reliance on experimental approaches that help to more clearly establish cause-and-effect relationships. Indeed, experimental biology and ecology have much to offer in terms of building the evidence base that is needed to inform policy and management options related to pressing issues such as enacting endangered species recovery plans or evaluating the effectiveness of conservation interventions. Here, we identify a number of pitfalls that can prevent experimental findings from being relevant to conservation or would lead to their exclusion or down-weighting during critical appraisal in a systematic review. We conclude that conservation physiology is well positioned to support evidence-based conservation, provided that experimental designs are robust and that conservation physiologists understand the nuances associated with informing decision-making processes so that they can be more relevant. PMID:28835842
Reducing emotional reasoning: an experimental manipulation in individuals with fear of spiders.
Lommen, Miriam J J; Engelhard, Iris M; van den Hout, Marcel A; Arntz, Arnoud
2013-01-01
Emotional reasoning involves the tendency to use subjective responses to make erroneous inferences about situations (e.g., "If I feel anxious, there must be danger") and has been implicated in various anxiety disorders. The aim of this study of individuals with fear of spiders was to test whether computerised experimental training, compared to control training, would decrease emotional reasoning, reduce fear-related danger beliefs, and increase approach behaviour towards a fear-relevant stimulus. Effects were assessed shortly after the experimental manipulation and one day later. Results showed that the manipulation significantly decreased emotional reasoning in the experimental condition, not in the control condition, and resulted in lower danger estimates of a spider, which was maintained up to one day later. No differences in approach behaviour towards the spider were found. Reducing emotional reasoning may ultimately help patients with anxiety disorders attend more to objective situational information to correct erroneous danger beliefs.
Development of advanced methods for analysis of experimental data in diffusion
NASA Astrophysics Data System (ADS)
Jaques, Alonso V.
There are numerous experimental configurations and data analysis techniques for the characterization of diffusion phenomena. However, the mathematical methods for estimating diffusivities traditionally do not take into account the effects of experimental errors in the data, and often require smooth, noiseless data sets to perform the necessary analysis steps. The current methods used for data smoothing require strong assumptions which can introduce numerical "artifacts" into the data, affecting confidence in the estimated parameters. The Boltzmann-Matano method is used extensively in the determination of concentration - dependent diffusivities, D(C), in alloys. In the course of analyzing experimental data, numerical integrations and differentiations of the concentration profile are performed. These methods require smoothing of the data prior to analysis. We present here an approach to the Boltzmann-Matano method that is based on a regularization method to estimate a differentiation operation on the data, i.e., estimate the concentration gradient term, which is important in the analysis process for determining the diffusivity. This approach, therefore, has the potential to be less subjective, and in numerical simulations shows an increased accuracy in the estimated diffusion coefficients. We present a regression approach to estimate linear multicomponent diffusion coefficients that eliminates the need pre-treat or pre-condition the concentration profile. This approach fits the data to a functional form of the mathematical expression for the concentration profile, and allows us to determine the diffusivity matrix directly from the fitted parameters. Reformulation of the equation for the analytical solution is done in order to reduce the size of the problem and accelerate the convergence. The objective function for the regression can incorporate point estimations for error in the concentration, improving the statistical confidence in the estimated diffusivity matrix. Case studies are presented to demonstrate the reliability and the stability of the method. To the best of our knowledge there is no published analysis of the effects of experimental errors on the reliability of the estimates for the diffusivities. For the case of linear multicomponent diffusion, we analyze the effects of the instrument analytical spot size, positioning uncertainty, and concentration uncertainty on the resulting values of the diffusivities. These effects are studied using Monte Carlo method on simulated experimental data. Several useful scaling relationships were identified which allow more rigorous and quantitative estimates of the errors in the measured data, and are valuable for experimental design. To further analyze anomalous diffusion processes, where traditional diffusional transport equations do not hold, we explore the use of fractional calculus in analytically representing these processes is proposed. We use the fractional calculus approach for anomalous diffusion processes occurring through a finite plane sheet with one face held at a fixed concentration, the other held at zero, and the initial concentration within the sheet equal to zero. This problem is related to cases in nature where diffusion is enhanced relative to the classical process, and the order of differentiation is not necessarily a second--order differential equation. That is, differentiation is of fractional order alpha, where 1 ≤ alpha < 2. For alpha = 2, the presented solutions reduce to the classical second-order diffusion solution for the conditions studied. The solution obtained allows the analysis of permeation experiments. Frequently, hydrogen diffusion is analyzed using electrochemical permeation methods using the traditional, Fickian-based theory. Experimental evidence shows the latter analytical approach is not always appropiate, because reported data shows qualitative (and quantitative) deviation from its theoretical scaling predictions. Preliminary analysis of data shows better agreement with fractional diffusion analysis when compared to traditional square-root scaling. Although there is a large amount of work in the estimation of the diffusivity from experimental data, reported studies typically present only the analytical description for the diffusivity, without scattering. However, because these studies do not consider effects produced by instrument analysis, their direct applicability is limited. We propose alternatives to address these, and to evaluate their influence on the final resulting diffusivity values.
Zimmer, Christoph
2016-01-01
Computational modeling is a key technique for analyzing models in systems biology. There are well established methods for the estimation of the kinetic parameters in models of ordinary differential equations (ODE). Experimental design techniques aim at devising experiments that maximize the information encoded in the data. For ODE models there are well established approaches for experimental design and even software tools. However, data from single cell experiments on signaling pathways in systems biology often shows intrinsic stochastic effects prompting the development of specialized methods. While simulation methods have been developed for decades and parameter estimation has been targeted for the last years, only very few articles focus on experimental design for stochastic models. The Fisher information matrix is the central measure for experimental design as it evaluates the information an experiment provides for parameter estimation. This article suggest an approach to calculate a Fisher information matrix for models containing intrinsic stochasticity and high nonlinearity. The approach makes use of a recently suggested multiple shooting for stochastic systems (MSS) objective function. The Fisher information matrix is calculated by evaluating pseudo data with the MSS technique. The performance of the approach is evaluated with simulation studies on an Immigration-Death, a Lotka-Volterra, and a Calcium oscillation model. The Calcium oscillation model is a particularly appropriate case study as it contains the challenges inherent to signaling pathways: high nonlinearity, intrinsic stochasticity, a qualitatively different behavior from an ODE solution, and partial observability. The computational speed of the MSS approach for the Fisher information matrix allows for an application in realistic size models.
The impact of genetically modified crops on soil microbial communities.
Giovannetti, Manuela; Sbrana, Cristiana; Turrini, Alessandra
2005-01-01
Genetically modified (GM) plants represent a potential benefit for environmentally friendly agriculture and human health. Though, poor knowledge is available on potential hazards posed by unintended modifications occurring during genetic manipulation. The increasing amount of reports on ecological risks and benefits of GM plants stresses the need for experimental works aimed at evaluating the impact of GM crops on natural and agro-ecosystems. Major environmental risks associated with GM crops include their potential impact on non-target soil microorganisms playing a fundamental role in crop residues degradation and in biogeochemical cycles. Recent works assessed the effects of GM crops on soil microbial communities on the basis of case-by-case studies, using multimodal experimental approaches involving different target and non-target organisms. Experimental evidences discussed in this review confirm that a precautionary approach should be adopted, by taking into account the risks associated with the unpredictability of transformation events, of their pleiotropic effects and of the fate of transgenes in natural and agro-ecosystems, weighing benefits against costs.
Lopes, Daniela; Jakobtorweihen, Sven; Nunes, Cláudia; Sarmento, Bruno; Reis, Salette
2017-01-01
Lipid membranes work as barriers, which leads to inevitable drug-membrane interactions in vivo. These interactions affect the pharmacokinetic properties of drugs, such as their diffusion, transport, distribution, and accumulation inside the membrane. Furthermore, these interactions also affect their pharmacodynamic properties with respect to both therapeutic and toxic effects. Experimental membrane models have been used to perform in vitro assessment of the effects of drugs on the biophysical properties of membranes by employing different experimental techniques. In in silico studies, molecular dynamics simulations have been used to provide new insights at an atomistic level, which enables the study of properties that are difficult or even impossible to measure experimentally. Each model and technique has its advantages and disadvantages. Hence, combining different models and techniques is necessary for a more reliable study. In this review, the theoretical backgrounds of these (in vitro and in silico) approaches are presented, followed by a discussion of the pharmacokinetic and pharmacodynamic properties of drugs that are related to their interactions with membranes. All approaches are discussed in parallel to present for a better connection between experimental and simulation studies. Finally, an overview of the molecular dynamics simulation studies used for drug-membrane interactions is provided. Copyright © 2016 Elsevier Ltd. All rights reserved.
Parametric study of the swimming performance of a fish robot propelled by a flexible caudal fin.
Low, K H; Chong, C W
2010-12-01
In this paper, we aim to study the swimming performance of fish robots by using a statistical approach. A fish robot employing a carangiform swimming mode had been used as an experimental platform for the performance study. The experiments conducted aim to investigate the effect of various design parameters on the thrust capability of the fish robot with a flexible caudal fin. The controllable parameters associated with the fin include frequency, amplitude of oscillation, aspect ratio and the rigidity of the caudal fin. The significance of these parameters was determined in the first set of experiments by using a statistical approach. A more detailed parametric experimental study was then conducted with only those significant parameters. As a result, the parametric study could be completed with a reduced number of experiments and time spent. With the obtained experimental result, we were able to understand the relationship between various parameters and a possible adjustment of parameters to obtain a higher thrust. The proposed statistical method for experimentation provides an objective and thorough analysis of the effects of individual or combinations of parameters on the swimming performance. Such an efficient experimental design helps to optimize the process and determine factors that influence variability.
Patterns recognition of electric brain activity using artificial neural networks
NASA Astrophysics Data System (ADS)
Musatov, V. Yu.; Pchelintseva, S. V.; Runnova, A. E.; Hramov, A. E.
2017-04-01
An approach for the recognition of various cognitive processes in the brain activity in the perception of ambiguous images. On the basis of developed theoretical background and the experimental data, we propose a new classification of oscillating patterns in the human EEG by using an artificial neural network approach. After learning of the artificial neural network reliably identified cube recognition processes, for example, left-handed or right-oriented Necker cube with different intensity of their edges, construct an artificial neural network based on Perceptron architecture and demonstrate its effectiveness in the pattern recognition of the EEG in the experimental.
ERIC Educational Resources Information Center
Murty, Vishnu P.; LaBar, Kevin S.; Hamilton, Derek A.; Adcock, R. Alison
2011-01-01
The present study investigated the effects of approach versus avoidance motivation on declarative learning. Human participants navigated a virtual reality version of the Morris water task, a classic spatial memory paradigm, adapted to permit the experimental manipulation of motivation during learning. During this task, participants were instructed…
ERIC Educational Resources Information Center
Quinn, David M.; Kim, James S.
2018-01-01
Theory and empirical work suggest that teachers' social capital influences school improvement efforts. Social ties are prerequisite for social capital, yet little causal evidence exists on how malleable factors, such as instructional management approaches, affect teachers' ties. In this cluster-randomized trial, we apply a decision-making…
Film Study: "Nothing But a Man."
ERIC Educational Resources Information Center
Manchel, Frank
1967-01-01
To examine new approaches to film study, "Nothing But a Man," which portrays the difficulties encountered by a young Negro in the South, was taught experimentally in three 11th-grade English classes at Cheshire High School, Connecticut. A different method of approaching the movie was used in each class to determine effective teaching methods for…
ERIC Educational Resources Information Center
Soltero-González, Lucinda; Sparrow, Wendy; Butvilofsky, Sandra; Escamilla, Kathy; Hopewell, Susan
2016-01-01
This longitudinal study examined whether the implementation of a Spanish-English paired literacy approach provides an academic advantage to emerging bilingual students over a sequential literacy approach. The study employed a quasi-experimental design. It compared the biliteracy outcomes of third-grade emerging bilingual learners participating in…
ERIC Educational Resources Information Center
Cattaneo, Matias D.; Titiunik, Rocío; Vazquez-Bare, Gonzalo
2017-01-01
The regression discontinuity (RD) design is a popular quasi-experimental design for causal inference and policy evaluation. The most common inference approaches in RD designs employ "flexible" parametric and nonparametric local polynomial methods, which rely on extrapolation and large-sample approximations of conditional expectations…
Toxicity and bioaccumulation of cadmium in experimental cultures of Duckweed, Lemna polyrrhiza
DOE Office of Scientific and Technical Information (OSTI.GOV)
Charpentier, S.; Garnier, J.; Flaugnatti, R.
1987-06-01
Knowledge of the mechanism of Itai-Itai disease aided the research concerning the bioaccumulation of heavy metals in plants and aquatic organisms. Because of their characteristics, lemnaceae can be considered as an interesting experimental material. Their small size, rapid growth and vegetative reproduction permitted us to obtain experimental cultures and to study the effect of cadmium: toxicity and bioaccumulation. The species Lemna polyrrhiza having a very voluminous root system, was used in this work. The effects of cadmium chloride (Cd Cl/sub 2/-2.5 H/sub 2/O) and Cadmium sulfate (3 Cd SO/sub 4/-8H/sub 2/O) were compared. The toxicity effect was approached by themore » numeration of plants.« less
ERIC Educational Resources Information Center
Castro, Ruben
2010-01-01
This study evaluated the effectiveness of Total Physical Response Storytelling (TPRS[TM]) compared to the Grammar-Translation approach for acquiring and retaining new vocabulary in an English as a Second Language (ESL) class. The subjects were adult Hispanic learners with limited literacy. An experimental design approach was used to gather…
Li, Leyuan; Zhang, Xu; Ning, Zhibin; Mayne, Janice; Moore, Jasmine I; Butcher, James; Chiang, Cheng-Kang; Mack, David; Stintzi, Alain; Figeys, Daniel
2018-01-05
In vitro culture based approaches are time- and cost-effective solutions for rapidly evaluating the effects of drugs or natural compounds against microbiomes. The nutritional composition of the culture medium is an important determinant for effectively maintaining the gut microbiome in vitro. This study combines orthogonal experimental design and a metaproteomics approach to obtaining functional insights into the effects of different medium components on the microbiome. Our results show that the metaproteomic profile respond differently to medium components, including inorganic salts, bile salts, mucin, and short-chain fatty acids. Multifactor analysis of variance further revealed significant main and interaction effects of inorganic salts, bile salts, and mucin on the different functional groups of gut microbial proteins. While a broad regulating effect was observed on basic metabolic pathways, different medium components also showed significant modulations on cell wall, membrane, and envelope biogenesis and cell motility related functions. In particular, flagellar assembly related proteins were significantly responsive to the presence of mucin. This study provides information on the functional influences of medium components on the in vitro growth of microbiome communities and gives insight on the key components that must be considered when selecting and optimizing media for culturing ex vivo microbiotas.
NASA Astrophysics Data System (ADS)
Garcia, Salvador G.; Silvia, Ferran; Escot, David; Pascual, Enrique; Pantoja, Mario F.; Riu, Pere; Anon, Manuel; Alvarez, Jesus; Cabello, M.; Pous, Marc; Fernandez, Sergio; Trallero, Rafael; Poyatos, David; Nuno, Luis
2016-05-01
The UAVEMI project, funded by the Spanish Ministry of Economy and Competitiveness, gathers a consortium formed by several research and development institutions and one industrial partner. The main goal is to develop innovative experimental and numerical approaches for the assessment of the electromagnetic compatibility of unmanned air vehicles, under high intensity radiated fields, lightning indirect effects and non-nuclear electromagnetic pulses. This contribution describes the capabilities currently being developed under the project.
Heavy atom labeled nucleotides for measurement of kinetic isotope effects.
Weissman, Benjamin P; Li, Nan-Sheng; York, Darrin; Harris, Michael; Piccirilli, Joseph A
2015-11-01
Experimental analysis of kinetic isotope effects represents an extremely powerful approach for gaining information about the transition state structure of complex reactions not available through other methodologies. The implementation of this approach to the study of nucleic acid chemistry requires the synthesis of nucleobases and nucleotides enriched for heavy isotopes at specific positions. In this review, we highlight current approaches to the synthesis of nucleic acids enriched site specifically for heavy oxygen and nitrogen and their application in heavy atom isotope effect studies. This article is part of a special issue titled: Enzyme Transition States from Theory and Experiment. Copyright © 2015 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Avitabile, P.; O'Callahan, J.
2003-07-01
Inclusion of rotational effects is critical for the accuracy of the predicted system characteristics, in almost all system modelling studies. However, experimentally derived information for the description of one or more of the components for the system will generally not have any rotational effects included in the description of the component. The lack of rotational effects has long affected the results from any system model development whether using a modal-based approach or an impedance-based approach. Several new expansion processes are described herein for the development of FRFs needed for impedance-based system models. These techniques expand experimentally derived mode shapes, residual modes from the modal parameter estimation process and FRFs directly to allow for the inclusion of the necessary rotational dof. The FRFs involving translational to rotational dofs are developed as well as the rotational to rotational dof. Examples are provided to show the use of these techniques.
Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action.
Canal, Clinton E
2018-03-13
Recent, well-controlled - albeit small-scale - clinical trials show that serotonergic psychedelics, including psilocybin and lysergic acid diethylamide, possess great promise for treating psychiatric disorders, including treatment-resistant depression. Additionally, fresh results from a deluge of clinical neuroimaging studies are unveiling the dynamic effects of serotonergic psychedelics on functional activity within, and connectivity across, discrete neural systems. These observations have led to testable hypotheses regarding neural processing mechanisms that contribute to psychedelic effects and therapeutic benefits. Despite these advances and a plethora of preclinical and clinical observations supporting a central role for brain serotonin 5-HT 2A receptors in producing serotonergic psychedelic effects, lingering and new questions about mechanisms abound. These chiefly pertain to molecular neuropharmacology. This chapter is devoted to illuminating and discussing such questions in the context of preclinical experimental approaches for studying mechanisms of action of serotonergic psychedelics, classic and new.
A Simple Numerical Procedure for the Simulation of "Lifelike" Linear-Sweep Voltammograms
NASA Astrophysics Data System (ADS)
Bozzini, Benedetto P.
2000-01-01
Practical linear-sweep voltammograms seldom resemble the theoretical ones shown in textbooks. This is because several phenomena (activation, mass transport, ohmic resistance) control the kinetics over different potential ranges scanned during the potential sweep. These effects are generally treated separately in the didactic literature, yet they have never been "assembled" in a way that allows the educational use of real experiments. This makes linear-sweep voltammetric experiments almost unusable in the teaching of physical chemistry. A simple approach to the classroom description of "lifelike" experimental results is proposed in this paper. Analytical expressions of linear sweep voltammograms are provided. The actual numerical evaluations can be carried out with a pocket calculator. Two typical examples are executed and comparison with experimental data is described. This approach to teaching electrode kinetics has proved an effective tool to provide students with an insight into the effects of electrochemical parameters and operating conditions.
Prediction of Size Effects in Notched Laminates Using Continuum Damage Mechanics
NASA Technical Reports Server (NTRS)
Camanho, D. P.; Maimi, P.; Davila, C. G.
2007-01-01
This paper examines the use of a continuum damage model to predict strength and size effects in notched carbon-epoxy laminates. The effects of size and the development of a fracture process zone before final failure are identified in an experimental program. The continuum damage model is described and the resulting predictions of size effects are compared with alternative approaches: the point stress and the inherent flaw models, the Linear-Elastic Fracture Mechanics approach, and the strength of materials approach. The results indicate that the continuum damage model is the most accurate technique to predict size effects in composites. Furthermore, the continuum damage model does not require any calibration and it is applicable to general geometries and boundary conditions.
Conceptualizing Effectiveness in Disability Research
ERIC Educational Resources Information Center
de Bruin, Catriona L.
2017-01-01
Policies promoting evidence-based practice in education typically endorse evaluations of the effectiveness of teaching strategies through specific experimental research designs and methods. A number of researchers have critiqued this approach to evaluation as narrow and called for greater methodological sophistication. This paper discusses the…
NASA Technical Reports Server (NTRS)
Beutner, Thomas John
1993-01-01
Porous wall wind tunnels have been used for several decades and have proven effective in reducing wall interference effects in both low speed and transonic testing. They allow for testing through Mach 1, reduce blockage effects and reduce shock wave reflections in the test section. Their usefulness in developing computational fluid dynamics (CFD) codes has been limited, however, by the difficulties associated with modelling the effect of a porous wall in CFD codes. Previous approaches to modelling porous wall effects have depended either upon a simplified linear boundary condition, which has proven inadequate, or upon detailed measurements of the normal velocity near the wall, which require extensive wind tunnel time. The current work was initiated in an effort to find a simple, accurate method of modelling a porous wall boundary condition in CFD codes. The development of such a method would allow data from porous wall wind tunnels to be used more readily in validating CFD codes. This would be beneficial when transonic validations are desired, or when large models are used to achieve high Reynolds numbers in testing. A computational and experimental study was undertaken to investigate a new method of modelling solid and porous wall boundary conditions in CFD codes. The method utilized experimental measurements at the walls to develop a flow field solution based on the method of singularities. This flow field solution was then imposed as a pressure boundary condition in a CFD simulation of the internal flow field. The effectiveness of this method in describing the effect of porosity changes on the wall was investigated. Also, the effectiveness of this method when only sparse experimental measurements were available has been investigated. The current work demonstrated this approach for low speed flows and compared the results with experimental data obtained from a heavily instrumented variable porosity test section. The approach developed was simple, computationally inexpensive, and did not require extensive or intrusive measurements of the boundary conditions during the wind tunnel test. It may be applied to both solid and porous wall wind tunnel tests.
ERIC Educational Resources Information Center
Hsia, Lu-Ho; Huang, Iwen; Hwang, Gwo-Jen
2016-01-01
In this paper, a web-based peer-assessment approach is proposed for conducting performing arts activities. A peer-assessment system was implemented and applied to a junior high school performing arts course to evaluate the effectiveness of the proposed approach. A total of 163 junior high students were assigned to an experimental group and a…
ERIC Educational Resources Information Center
Lin, Yu-Tzu; Wu, Cheng-Chih; Chiu, Chiung-Fang
2018-01-01
This article explores the feasibility of employing cooperative program editing tools in teaching programming. A quasi-experimental study was conducted, in which the experimental group co-edited the programs with peers using the wiki. The control group co-edited the programs with peers using only the face-to-face approach. The findings show that…
ERIC Educational Resources Information Center
Shih, Ru-Chu; Cho, Chia-Liang; Tsai, Chih-Cheng; Lou, Shi-Jer
2013-01-01
This study aimed to investigate junior high school students' learning attitudes and learning effectiveness through administering Microsoft Live@edu to assist in teaching Chinese reading. Quasi-experimental approach was used and a total of 63 eighth grade students were divided into the experimental group (N = 32) and control group (N = 31).…
Computer Assisted English Language Learning in Costa Rican Elementary Schools: An Experimental Study
ERIC Educational Resources Information Center
Alvarez-Marinelli, Horacio; Blanco, Marta; Lara-Alecio, Rafael; Irby, Beverly J.; Tong, Fuhui; Stanley, Katherine; Fan, Yinan
2016-01-01
This study presents first-year findings of a 25-week longitudinal project derived from a two-year longitudinal randomized trial study at the elementary school level in Costa Rica on effective computer-assisted language learning (CALL) approaches in an English as a foreign language (EFL) setting. A pre-test-post-test experimental group design was…
Quality factor analysis for aberrated laser beam
NASA Astrophysics Data System (ADS)
Ghafary, B.; Alavynejad, M.; Kashani, F. D.
2006-12-01
The quality factor of laser beams has attracted considerable attention and some different approaches have been reported to treat the problem. In this paper we analyze quality factor of laser beam and compare the effect of different aberrations on beam quality by expanding pure phase term of wavefront in terms of Zernike polynomials. Also we analyze experimentally the change of beam quality for different Astigmatism aberrations, and compare theoretical results with experimentally results. The experimental and theoretical results are in good agreement.
Experimental Design and Primary Data Analysis Methods for Comparing Adaptive Interventions
Nahum-Shani, Inbal; Qian, Min; Almirall, Daniel; Pelham, William E.; Gnagy, Beth; Fabiano, Greg; Waxmonsky, Jim; Yu, Jihnhee; Murphy, Susan
2013-01-01
In recent years, research in the area of intervention development is shifting from the traditional fixed-intervention approach to adaptive interventions, which allow greater individualization and adaptation of intervention options (i.e., intervention type and/or dosage) over time. Adaptive interventions are operationalized via a sequence of decision rules that specify how intervention options should be adapted to an individual’s characteristics and changing needs, with the general aim to optimize the long-term effectiveness of the intervention. Here, we review adaptive interventions, discussing the potential contribution of this concept to research in the behavioral and social sciences. We then propose the sequential multiple assignment randomized trial (SMART), an experimental design useful for addressing research questions that inform the construction of high-quality adaptive interventions. To clarify the SMART approach and its advantages, we compare SMART with other experimental approaches. We also provide methods for analyzing data from SMART to address primary research questions that inform the construction of a high-quality adaptive intervention. PMID:23025433
NASA Astrophysics Data System (ADS)
Allen, Matthew S.; Mayes, Randall L.; Bergman, Elizabeth J.
2010-11-01
Modal substructuring or component mode synthesis (CMS) has been standard practice for many decades in the analytical realm, yet a number of significant difficulties have been encountered when attempting to combine experimentally derived modal models with analytical ones or when predicting the effect of structural modifications using experimental measurements. This work presents a new method that removes the effects of a flexible fixture from an experimentally obtained modal model. It can be viewed as an extension to the approach where rigid masses are removed from a structure. The approach presented here improves the modal basis of the substructure, so that it can be used to more accurately estimate the modal parameters of the built-up system. New types of constraints are also presented, which constrain the modal degrees of freedom of the substructures, avoiding the need to estimate the connection point displacements and rotations. These constraints together with the use of a flexible fixture enable a new approach for joining structures, especially those with statically indeterminate multi-point connections, such as two circular flanges that are joined by many more bolts than required to enforce compatibility if the substructures were rigid. Fixture design is discussed, one objective of which is to achieve a mass-loaded boundary condition that exercises the substructure at the connection point as it is in the built up system. The proposed approach is demonstrated with two examples using experimental measurements from laboratory systems. The first is a simple problem of joining two beams of differing lengths, while the second consists of a three-dimensional structure comprising a circular plate that is bolted at eight locations to a flange on a cylindrical structure. In both cases frequency response functions predicted by the substructuring methods agree well with those of the actual coupled structures over a significant range of frequencies.
Bostrom, Mathias; O'Keefe, Regis
2009-01-01
Understanding the complex cellular and tissue mechanisms and interactions resulting in periprosthetic osteolysis requires a number of experimental approaches, each of which has its own set of advantages and limitations. In vitro models allow for the isolation of individual cell populations and have furthered our understanding of particle-cell interactions; however, they are limited because they do not mimic the complex tissue environment in which multiple cell interactions occur. In vivo animal models investigate the tissue interactions associated with periprosthetic osteolysis, but the choice of species and whether the implant system is subjected to mechanical load or to unloaded conditions are critical in assessing whether these models can be extrapolated to the clinical condition. Rigid analysis of retrieved tissue from clinical cases of osteolysis offers a different approach to studying the biologic process of osteolysis, but it is limited in that the tissue analyzed represents the end-stage of this process and, thus, may not reflect this process adequately. PMID:18612016
Bostrom, Mathias; O'Keefe, Regis
2008-01-01
Understanding the complex cellular and tissue mechanisms and interactions resulting in periprosthetic osteolysis requires a number of experimental approaches, each of which has its own set of advantages and limitations. In vitro models allow for the isolation of individual cell populations and have furthered our understanding of particle-cell interactions; however, they are limited because they do not mimic the complex tissue environment in which multiple cell interactions occur. In vivo animal models investigate the tissue interactions associated with periprosthetic osteolysis, but the choice of species and whether the implant system is subjected to mechanical load or to unloaded conditions are critical in assessing whether these models can be extrapolated to the clinical condition. Rigid analysis of retrieved tissue from clinical cases of osteolysis offers a different approach to studying the biologic process of osteolysis, but it is limited in that the tissue analyzed represents the end-stage of this process and, thus, may not reflect this process adequately.
Unified Approach to the Biomechanics of Dental Implantology
NASA Technical Reports Server (NTRS)
Grenoble, D. E.; Knoell, A. C.
1973-01-01
The human need for safe and effective dental implants is well-recognized. Although many implant designs have been tested and are in use today, a large number have resulted in clinical failure. These failures appear to be due to biomechanical effects, as well as biocompatibility and surgical factors. A unified approach is proposed using multidisciplinary systems technology, for the study of the biomechanical interactions between dental implants and host tissues. The approach progresses from biomechanical modeling and analysis, supported by experimental investigations, through implant design development, clinical verification, and education of the dental practitioner. The result of the biomechanical modeling, analysis, and experimental phases would be the development of scientific design criteria for implants. Implant designs meeting these criteria would be generated, fabricated, and tested in animals. After design acceptance, these implants would be tested in humans, using efficient and safe surgical and restorative procedures. Finally, educational media and instructional courses would be developed for training dental practitioners in the use of the resulting implants.
Okamoto, Takuma; Sakaguchi, Atsushi
2017-03-01
Generating acoustically bright and dark zones using loudspeakers is gaining attention as one of the most important acoustic communication techniques for such uses as personal sound systems and multilingual guide services. Although most conventional methods are based on numerical solutions, an analytical approach based on the spatial Fourier transform with a linear loudspeaker array has been proposed, and its effectiveness has been compared with conventional acoustic energy difference maximization and presented by computer simulations. To describe the effectiveness of the proposal in actual environments, this paper investigates the experimental validation of the proposed approach with rectangular and Hann windows and compared it with three conventional methods: simple delay-and-sum beamforming, contrast maximization, and least squares-based pressure matching using an actually implemented linear array of 64 loudspeakers in an anechoic chamber. The results of both the computer simulations and the actual experiments show that the proposed approach with a Hann window more accurately controlled the bright and dark zones than the conventional methods.
Modifying Automatic Approach Action Tendencies in Individuals with Elevated Social Anxiety Symptoms
Taylor, Charles T.; Amir, Nader
2012-01-01
Research suggests that social anxiety is associated with a reduced approach orientation for positive social cues. In the current study we examined the effect of experimentally manipulating automatic approach action tendencies on the social behavior of individuals with elevated social anxiety symptoms. The experimental paradigm comprised a computerized Approach Avoidance Task (AAT) in which participants responded to pictures of faces conveying positive or neutral emotional expressions by pulling a joystick toward themselves (approach) or by moving it to the right (sideways control). Participants were randomly assigned to complete an AAT designed to increase approach tendencies for positive social cues by pulling these cues toward themselves on the majority of trials, or to a control condition in which there was no contingency between the arm movement direction and picture type. Following the manipulation, participants took part in a relationship-building task with a trained confederate. Results revealed that participants trained to approach positive stimuli displayed greater social approach behaviors during the social interaction and elicited more positive reactions from their partner compared to participants in the control group. These findings suggest that modifying automatic approach tendencies may facilitate engagement in the types of social approach behaviors that are important for relationship development. PMID:22728645
Diffusion of Technical Agricultural Information in Chile.
ERIC Educational Resources Information Center
Brown, Marion Ray
This study examined current thought concerning the role of mass communication in economic development in developing nations; analyzed existing efforts to diffuse agricultural technology in Chile; assessed the effectiveness of various approaches; and tested the effects (primarily on knowledge levels) of an experimental technical information service…
Using Non-experimental Data to Estimate Treatment Effects
Stuart, Elizabeth A.; Marcus, Sue M.; Horvitz-Lennon, Marcela V.; Gibbons, Robert D.; Normand, Sharon-Lise T.
2009-01-01
While much psychiatric research is based on randomized controlled trials (RCTs), where patients are randomly assigned to treatments, sometimes RCTs are not feasible. This paper describes propensity score approaches, which are increasingly used for estimating treatment effects in non-experimental settings. The primary goal of propensity score methods is to create sets of treated and comparison subjects who look as similar as possible, in essence replicating a randomized experiment, at least with respect to observed patient characteristics. A study to estimate the metabolic effects of antipsychotic medication in a sample of Florida Medicaid beneficiaries with schizophrenia illustrates methods. PMID:20563313
Law, Andrew J.; Sharma, Gaurav; Schieber, Marc H.
2014-01-01
We present a methodology for detecting effective connections between simultaneously recorded neurons using an information transmission measure to identify the presence and direction of information flow from one neuron to another. Using simulated and experimentally-measured data, we evaluate the performance of our proposed method and compare it to the traditional transfer entropy approach. In simulations, our measure of information transmission outperforms transfer entropy in identifying the effective connectivity structure of a neuron ensemble. For experimentally recorded data, where ground truth is unavailable, the proposed method also yields a more plausible connectivity structure than transfer entropy. PMID:21096617
Experimental Evidence of Weak Excluded Volume Effects for Nanochannel Confined DNA
NASA Astrophysics Data System (ADS)
Gupta, Damini; Miller, Jeremy J.; Muralidhar, Abhiram; Mahshid, Sara; Reisner, Walter; Dorfman, Kevin D.
In the classical de Gennes picture of weak polymer nanochannel confinement, the polymer contour is envisioned as divided into a series of isometric blobs. Strong excluded volume interactions are present both within a blob and between blobs. In contrast, for semiflexible polymers like DNA, excluded volume interactions are of borderline strength within a blob but appreciable between blobs, giving rise to a chain description consisting of a string of anisometric blobs. We present experimental validation of this subtle effect of excluded volume for DNA nanochannel confinement by performing measurements of variance in chain extension of T4 DNA molecules as a function of effective nanochannel size (305-453 nm). Additionally, we show an approach to systematically reduce the effect of molecular weight dispersity of DNA samples, a typical experimental artifact, by combining confinement spectroscopy with simulations.
Health-Related Effects of Creative and Expressive Writing
ERIC Educational Resources Information Center
Lowe, Geoff
2006-01-01
Purpose: The purpose of this paper is to provide an overview of some health-related effects of creative and expressive writing. Design/methodology/approach: Reviews some of the main research studies exploring links between expressive writing and aspects of health, including two new experimental studies showing effects of poetry on mood and immune…
High-Throughput Experimental Approach Capabilities | Materials Science |
NREL High-Throughput Experimental Approach Capabilities High-Throughput Experimental Approach by yellow and is for materials in the upper right sector. NREL's high-throughput experimental ,Te) and oxysulfide sputtering Combi-5: Nitrides and oxynitride sputtering We also have several non
DOE Office of Scientific and Technical Information (OSTI.GOV)
Karpeshin, F. F., E-mail: fkarpeshin@gmail.com; Trzhaskovskaya, M. B.
2015-12-15
Special features of the effect of the electron shell on alpha decay that have important experimental implications are studied within the adiabatic approach. The magnitude of the effect is about several tenths of a percent or smaller, depending on the transition energy and on the atomic number. A dominant role of inner shells is shown: more than 80% of the effect is saturated by 1s electrons. This circumstance plays a crucial role for experiments, making it possible to measure this small effect by a difference method in the same storage rings via a comparison of, for example, decay probabilities inmore » bare nuclei and heliumlike ions. The reasons behind the relative success and the applicability limits of the frozen-shell model, which has been used to calculate the effect in question for more than half a century, are analyzed. An interesting experiment aimed at studying charged alpha-particle states is proposed. This experiment will furnish unique information for testing our ideas of the interplay of nonadiabatic and adiabatic processes.« less
Teaching Grade 5 Life Science with a Case Study Approach
ERIC Educational Resources Information Center
Olgun, Ozlem Sila; Adali, Belgin
2008-01-01
The main purpose of this study was to investigate the effects of a case study approach on students' achievement and attitudes towards viruses, bacteria, fungi, and protista. Fifth-grade students (N = 88) from two different classes were involved in the study. One intact class was assigned as the experimental group, whereas the other intact class…
An Experimental Study of a BSCS-Style Laboratory Approach for University General Biology.
ERIC Educational Resources Information Center
Leonard, William H.
1983-01-01
A Biological Sciences Curriculum Study (BSCS) inquiry approach for university general biology laboratory was tested against a well-established commercial program judged to be highly directive. The BSCS was found to be more effective in learning biology laboratory concepts than the commercial program as measured by a laboratory concepts test.…
ERIC Educational Resources Information Center
Changeiywo, Johnson M.; Wambugu, P. W.; Wachanga, S. W.
2011-01-01
Teaching method is a major factor that affects students' motivation to learn physics. This study investigated the effects of using mastery learning approach (MLA) on secondary school students' motivation to learn physics. Solomon four non-equivalent control group design under the quasi-experimental research method was used in which a random sample…
ERIC Educational Resources Information Center
Çelik, Harun; Pektas, Hüseyin Miraç
2017-01-01
A one-group quasi-experimental design and survey methodology were used to investigate the effect of virtual laboratory practices on preservice teachers' (N = 29) graphic comprehension and interpretation skills with different learning approaches. Pretest and posttest data were collected with the Test of Understanding Kinematic Graphs. The Learning…
ERIC Educational Resources Information Center
Lee, Chien-I; Yang, Ya-Fei; Mai, Shin-Yi
2016-01-01
Web-based peer assessment has been considered an important process for learning. However, students may not offer constructive feedback due to lack of expertise knowledge. Therefore, this study proposed a scaffolded assessment approach accordingly. To evaluate the effectiveness of the proposed approach, the quasi-experimental design was employed to…
ERIC Educational Resources Information Center
Fialkov, M. Jerome; And Others
1983-01-01
The diagnosis and treatment of a 13-year-old female who manifested postencephalitic behavioral syndrome 9 years after an acute measles infection are described, along with the history of the case. The case illustrates that an interdisciplinary approach using a single-case experimental design can be clinically effective. (SEW)
Brainfeed Intervention Programme: An Alternative Approach for Supporting People Living with Dyslexia
ERIC Educational Resources Information Center
Adubasim, Ijeoma
2018-01-01
This study investigated the effectiveness of Brainfeed intervention programme as an alternative approach for supporting people living with dyslexia. The study adopted a quasi-experimental research design. The population of this study is made up of twenty four thousand seven hundred and twenty seven (24,727) senior secondary school students (S.S.2)…
Constructivist Approach Enhances the Learning: A Search of Reality
ERIC Educational Resources Information Center
Dev, Meenu
2016-01-01
The primary aim of the study was to study the effect of constructivist approach of teaching on the learning of English Language on Primary School Students. The study consisted of 60 students of class VI from Janta Brahmi Sr. Secondary School, Nathupur, Sonipat. A single quasi experimental pre-test and post-test design was applied in the present…
Can a Multimedia Tool Help Students' Learning Performance in Complex Biology Subjects?
ERIC Educational Resources Information Center
Koseoglu, Pinar; Efendioglu, Akin
2015-01-01
The aim of the present study was to determine the effects of multimedia-based biology teaching (Mbio) and teacher-centered biology (TCbio) instruction approaches on learners' biology achievements, as well as their views towards learning approaches. During the research process, an experimental design with two groups, TCbio (n = 22) and Mbio (n =…
Learning Biology through Innovative Curricula: A Comparison of Game- and Nongame-Based Approaches
ERIC Educational Resources Information Center
Sadler, Troy D.; Romine, William L.; Menon, Deepika; Ferdig, Richard E.; Annetta, Leonard
2015-01-01
This study explored student learning in the context of innovative biotechnology curricula and the effects of gaming as a central element of the learning experience. The quasi-experimentally designed study compared learning outcomes between two curricular approaches: One built around a computer-based game, and the other built around a narrative…
ERIC Educational Resources Information Center
Semerci, Çetin; Batdi, Veli
2015-01-01
This study attempts to answer the question "Does a Constructivist Learning Approach have any effect on learners' academic achievement, retention and attitude scores?" As a result of a systematic investigation of experimental studies carried out between 2002 and 2015 in national and international area, 324 (218 articles, 106 theses)…
ERIC Educational Resources Information Center
Merchie, Emmelien; Van Keer, Hilde
2016-01-01
This study examined the effectiveness of two instructional mind-mapping approaches to stimulate fifth and sixth graders' graphical summarization skills. Thirty-five fifth- and sixth-grade teachers and 644 students from 17 different elementary schools participated. A randomized quasi-experimental repeated-measures design was set up with two…
ERIC Educational Resources Information Center
Ortlieb, Evan; McDowell, F. D.
2015-01-01
Reading comprehension levels of elementary students have not significantly improved in the 21st century and as a result, the need for systematic and intensive reading interventions is as high as ever. Literacy clinics are an ideal setting for struggling readers to experience success through the implementation of a cyclical approach to individual…
ERIC Educational Resources Information Center
Kyriakides, L.; Christoforidou, M.; Panayiotou, A.; Creemers, B. P. M.
2017-01-01
The dynamic approach (DA) suggests that professional development should be differentiated to meet teachers' individual needs while engaging participants into systematic and guided critical reflection. Previous experimental studies demonstrated that one-year interventions based on the DA have a positive impact on teacher effectiveness. The study…
Zimmer, Christoph
2016-01-01
Background Computational modeling is a key technique for analyzing models in systems biology. There are well established methods for the estimation of the kinetic parameters in models of ordinary differential equations (ODE). Experimental design techniques aim at devising experiments that maximize the information encoded in the data. For ODE models there are well established approaches for experimental design and even software tools. However, data from single cell experiments on signaling pathways in systems biology often shows intrinsic stochastic effects prompting the development of specialized methods. While simulation methods have been developed for decades and parameter estimation has been targeted for the last years, only very few articles focus on experimental design for stochastic models. Methods The Fisher information matrix is the central measure for experimental design as it evaluates the information an experiment provides for parameter estimation. This article suggest an approach to calculate a Fisher information matrix for models containing intrinsic stochasticity and high nonlinearity. The approach makes use of a recently suggested multiple shooting for stochastic systems (MSS) objective function. The Fisher information matrix is calculated by evaluating pseudo data with the MSS technique. Results The performance of the approach is evaluated with simulation studies on an Immigration-Death, a Lotka-Volterra, and a Calcium oscillation model. The Calcium oscillation model is a particularly appropriate case study as it contains the challenges inherent to signaling pathways: high nonlinearity, intrinsic stochasticity, a qualitatively different behavior from an ODE solution, and partial observability. The computational speed of the MSS approach for the Fisher information matrix allows for an application in realistic size models. PMID:27583802
Görgen, Kai; Hebart, Martin N; Allefeld, Carsten; Haynes, John-Dylan
2017-12-27
Standard neuroimaging data analysis based on traditional principles of experimental design, modelling, and statistical inference is increasingly complemented by novel analysis methods, driven e.g. by machine learning methods. While these novel approaches provide new insights into neuroimaging data, they often have unexpected properties, generating a growing literature on possible pitfalls. We propose to meet this challenge by adopting a habit of systematic testing of experimental design, analysis procedures, and statistical inference. Specifically, we suggest to apply the analysis method used for experimental data also to aspects of the experimental design, simulated confounds, simulated null data, and control data. We stress the importance of keeping the analysis method the same in main and test analyses, because only this way possible confounds and unexpected properties can be reliably detected and avoided. We describe and discuss this Same Analysis Approach in detail, and demonstrate it in two worked examples using multivariate decoding. With these examples, we reveal two sources of error: A mismatch between counterbalancing (crossover designs) and cross-validation which leads to systematic below-chance accuracies, and linear decoding of a nonlinear effect, a difference in variance. Copyright © 2017 Elsevier Inc. All rights reserved.
Franzoni, Linda P; Elliott, Christopher M
2003-10-01
Experiments were performed on an elongated rectangular acoustic enclosure with different levels of absorptive material placed on side walls and an end wall. The acoustic source was a broadband high-frequency sound from a loudspeaker flush-mounted to an end wall of the enclosure. Measurements of sound-pressure levels were averaged in cross sections of the enclosure and then compared to theoretical results. Discrepancies between the experimental results and theoretical predictions that treated all incidence angles as equally probable led to the development of an angle-by-angle approach. The new approach agrees well with the experimentally obtained values. In addition, treating the absorptive material as bulk reacting rather than point reacting was found to significantly change the theoretical value for the absorption coefficient and to improve agreement with experiment. The new theory refines an earlier theory based on power conservation and locally diffuse assumptions. Furthermore, the new theory includes both the angle of incidence effects on the resistive and reactive properties of the absorptive material, and the effects of angle filtering, i.e., that reflecting waves associated with shallow angles become relatively stronger than those associated with steep angles as a function of distance from the source.
A computational approach to negative priming
NASA Astrophysics Data System (ADS)
Schrobsdorff, H.; Ihrke, M.; Kabisch, B.; Behrendt, J.; Hasselhorn, M.; Herrmann, J. Michael
2007-09-01
Priming is characterized by a sensitivity of reaction times to the sequence of stimuli in psychophysical experiments. The reduction of the reaction time observed in positive priming is well-known and experimentally understood (Scarborough et al., J. Exp. Psycholol: Hum. Percept. Perform., 3, pp. 1-17, 1977). Negative priming—the opposite effect—is experimentally less tangible (Fox, Psychonom. Bull. Rev., 2, pp. 145-173, 1995). The dependence on subtle parameter changes (such as response-stimulus interval) usually varies. The sensitivity of the negative priming effect bears great potential for applications in research in fields such as memory, selective attention, and ageing effects. We develop and analyse a computational realization, CISAM, of a recent psychological model for action decision making, the ISAM (Kabisch, PhD thesis, Friedrich-Schiller-Universitat, 2003), which is sensitive to priming conditions. With the dynamical systems approach of the CISAM, we show that a single adaptive threshold mechanism is sufficient to explain both positive and negative priming effects. This is achieved by comparing results obtained by the computational modelling with experimental data from our laboratory. The implementation provides a rich base from which testable predictions can be derived, e.g. with respect to hitherto untested stimulus combinations (e.g. single-object trials).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Medasani, Bharat; Ovanesyan, Zaven; Thomas, Dennis G.
In this article we present a classical density functional theory for electrical double layers of spherical macroions that extends the capabilities of conventional approaches by accounting for electrostatic ion correlations, size asymmetry and excluded volume effects. The approach is based on a recent approximation introduced by Hansen-Goos and Roth for the hard sphere excess free energy of inhomogeneous fluids (J. Chem. Phys. 124, 154506). It accounts for the proper and efficient description of the effects of ionic asymmetry and solvent excluded volume, especially at high ion concentrations and size asymmetry ratios including those observed in experimental studies. Additionally, we utilizemore » a leading functional Taylor expansion approximation of the ion density profiles. In addition, we use the Mean Spherical Approximation for multi-component charged hard sphere fluids to account for the electrostatic ion correlation effects. These approximations are implemented in our theoretical formulation into a suitable decomposition of the excess free energy which plays a key role in capturing the complex interplay between charge correlations and excluded volume effects. We perform Monte Carlo simulations in various scenarios to validate the proposed approach, obtaining a good compromise between accuracy and computational cost. We use the proposed computational approach to study the effects of ion size, ion size asymmetry and solvent excluded volume on the ion profiles, integrated charge, mean electrostatic potential, and ionic coordination number around spherical macroions in various electrolyte mixtures. Our results show that both solvent hard sphere diameter and density play a dominant role in the distribution of ions around spherical macroions, mainly for experimental water molarity and size values where the counterion distribution is characterized by a tight binding to the macroion, similar to that predicted by the Stern model.« less
NASA Astrophysics Data System (ADS)
Song, Huixu; Shi, Zhaoyao; Chen, Hongfang; Sun, Yanqiang
2018-01-01
This paper presents a novel experimental approach and a simple model for verifying that spherical mirror of laser tracking system could lessen the effect of rotation errors of gimbal mount axes based on relative motion thinking. Enough material and evidence are provided to support that this simple model could replace complex optical system in laser tracking system. This experimental approach and model interchange the kinematic relationship between spherical mirror and gimbal mount axes in laser tracking system. Being fixed stably, gimbal mount axes' rotation error motions are replaced by spatial micro-displacements of spherical mirror. These motions are simulated by driving spherical mirror along the optical axis and vertical direction with the use of precision positioning platform. The effect on the laser ranging measurement accuracy of displacement caused by the rotation errors of gimbal mount axes could be recorded according to the outcome of laser interferometer. The experimental results show that laser ranging measurement error caused by the rotation errors is less than 0.1 μm if radial error motion and axial error motion are under 10 μm. The method based on relative motion thinking not only simplifies the experimental procedure but also achieves that spherical mirror owns the ability to reduce the effect of rotation errors of gimbal mount axes in laser tracking system.
Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction
Boiteau, Rene M.; Hoyt, David W.; Nicora, Carrie D.; ...
2018-01-17
Here, we introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS 2), and NMR in a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana. The NMR/MS 2 approach is well suited for discovery ofmore » new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases.« less
Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boiteau, Rene M.; Hoyt, David W.; Nicora, Carrie D.
Here, we introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS 2), and NMR in a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana. The NMR/MS 2 approach is well suited for discovery ofmore » new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases.« less
Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction
Hoyt, David W.; Nicora, Carrie D.; Kinmonth-Schultz, Hannah A.; Ward, Joy K.
2018-01-01
We introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS2), and NMR into a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter out the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture, and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana. The NMR/MS2 approach is well suited to the discovery of new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases. PMID:29342073
Park, Esther O; Park, Ji Hyun
2018-04-01
The effectiveness of flipped learning as one of the teaching methods of active learning has been left unexamined in nursing majors, compared to the frequent attempts to uncover the effectiveness of it in other disciplines. The purpose of this study was to reveal the effectiveness of flipped learning pedagogy in an adult health nursing course, controlling for other variables. The study applied a quasi-experimental approach, comparing pre- and post-test results in learning outcomes. Included in this analysis were the records of 81 junior nursing major students. The convenience sampling method was used to select the participants. Those in the experimental group were exposed to a flipped classroom experience that was given after the completion of their traditional class. The students' learning outcomes and the level of critical thinking skills were evaluated before and after the intervention of the flipped classroom. After the flipped classroom experience, the scores of the students' achievement in subject topics and critical thinking skills, specifically intellectual integrity and creativity, showed a greater level of increase than those of their controlled counterparts. This remained true even after controlling for previous academic performance and the level of creativity. This study confirmed the effectiveness of the flipped classroom as a measure of active learning by applying a quantitative approach. But, regarding the significance of the initial contribution of flipped learning in the discipline of nursing science, carrying out a more authentic experimental study could justify the impact of flipped learning pedagogy. © 2017 Japan Academy of Nursing Science.
Effects of a blended learning approach on student outcomes in a graduate-level public health course
2014-01-01
Background Blended learning approaches, in which in-person and online course components are combined in a single course, are rapidly increasing in health sciences education. Evidence for the relative effectiveness of blended learning versus more traditional course approaches is mixed. Method The impact of a blended learning approach on student learning in a graduate-level public health course was examined using a quasi-experimental, non-equivalent control group design. Exam scores and course point total data from a baseline, “traditional” approach semester (n = 28) was compared to that from a semester utilizing a blended learning approach (n = 38). In addition, student evaluations of the blended learning approach were evaluated. Results There was a statistically significant increase in student performance under the blended learning approach (final course point total d = 0.57; a medium effect size), even after accounting for previous academic performance. Moreover, student evaluations of the blended approach were very positive and the majority of students (83%) preferred the blended learning approach. Conclusions Blended learning approaches may be an effective means of optimizing student learning and improving student performance in health sciences courses. PMID:24612923
Florea, Cristina; Tanska, Petri; Mononen, Mika E; Qu, Chengjuan; Lammi, Mikko J; Laasanen, Mikko S; Korhonen, Rami K
2017-02-01
Cellular responses to mechanical stimuli are influenced by the mechanical properties of cells and the surrounding tissue matrix. Cells exhibit viscoelastic behavior in response to an applied stress. This has been attributed to fluid flow-dependent and flow-independent mechanisms. However, the particular mechanism that controls the local time-dependent behavior of cells is unknown. Here, a combined approach of experimental AFM nanoindentation with computational modeling is proposed, taking into account complex material behavior. Three constitutive models (porohyperelastic, viscohyperelastic, poroviscohyperelastic) in tandem with optimization algorithms were employed to capture the experimental stress relaxation data of chondrocytes at 5 % strain. The poroviscohyperelastic models with and without fluid flow allowed through the cell membrane provided excellent description of the experimental time-dependent cell responses (normalized mean squared error (NMSE) of 0.003 between the model and experiments). The viscohyperelastic model without fluid could not follow the entire experimental data that well (NMSE = 0.005), while the porohyperelastic model could not capture it at all (NMSE = 0.383). We also show by parametric analysis that the fluid flow has a small, but essential effect on the loading phase and short-term cell relaxation response, while the solid viscoelasticity controls the longer-term responses. We suggest that the local time-dependent cell mechanical response is determined by the combined effects of intrinsic viscoelasticity of the cytoskeleton and fluid flow redistribution in the cells, although the contribution of fluid flow is smaller when using a nanosized probe and moderate indentation rate. The present approach provides new insights into viscoelastic responses of chondrocytes, important for further understanding cell mechanobiological mechanisms in health and disease.
Theoretical aspects of self-assembly of proteins: A Kirkwood-Buff-theory approach
NASA Astrophysics Data System (ADS)
Ben-Naim, Arieh
2013-06-01
A new approach to the problem of self-assembly of proteins induced by temperature, pressure, or changes in solute concentration is presented. The problem is formulated in terms of Le Chatelier principle, and a solution is sought in terms of the Kirkwood-Buff theory of solutions. In this article we focus on the pressure and solute effects on the association-dissociation equilibrium. We examine the role of both hydrophobic and hydrophilic effects. We argue that the latter are more important than the former. The solute effect, on the other hand, depends on the preferential solvation of the monomer and the aggregate with respect to solvent and co-solvent molecules. An experimental approach based on model compounds to study these effects is suggested.
Theoretical aspects of self-assembly of proteins: a Kirkwood-Buff-theory approach.
Ben-Naim, Arieh
2013-06-14
A new approach to the problem of self-assembly of proteins induced by temperature, pressure, or changes in solute concentration is presented. The problem is formulated in terms of Le Chatelier principle, and a solution is sought in terms of the Kirkwood-Buff theory of solutions. In this article we focus on the pressure and solute effects on the association-dissociation equilibrium. We examine the role of both hydrophobic and hydrophilic effects. We argue that the latter are more important than the former. The solute effect, on the other hand, depends on the preferential solvation of the monomer and the aggregate with respect to solvent and co-solvent molecules. An experimental approach based on model compounds to study these effects is suggested.
Micromechanical model for protein materials: From macromolecules to macroscopic fibers
NASA Astrophysics Data System (ADS)
Puglisi, G.; De Tommasi, D.; Pantano, M. F.; Pugno, N. M.; Saccomandi, G.
2017-10-01
We propose a model for the mechanical behavior of protein materials. Based on a limited number of experimental macromolecular parameters (persistence and contour length) we obtain the macroscopic behavior of keratin fibers (human, cow, and rabbit hair), taking into account the damage and residual stretches effects that are fundamental in many functions of life. We also show the capability of our approach to describe the main dissipation and permanent strain effects observed in the more complex spider silk fibers. The comparison between our results and the data obtained experimentally from cyclic tests demonstrates that our model is robust and is able to reproduce with a remarkable accuracy the experimental behavior of all protein materials we tested.
Experimental studies of systematic multiple-energy operation at HIMAC synchrotron
NASA Astrophysics Data System (ADS)
Mizushima, K.; Katagiri, K.; Iwata, Y.; Furukawa, T.; Fujimoto, T.; Sato, S.; Hara, Y.; Shirai, T.; Noda, K.
2014-07-01
Multiple-energy synchrotron operation providing carbon-ion beams with various energies has been used for scanned particle therapy at NIRS. An energy range from 430 to 56 MeV/u and about 200 steps within this range are required to vary the Bragg peak position for effective treatment. The treatment also demands the slow extraction of beam with highly reliable properties, such as spill, position and size, for all energies. We propose an approach to generating multiple-energy operation meeting these requirements within a short time. In this approach, the device settings at most energy steps are determined without manual adjustments by using systematic parameter tuning depending on the beam energy. Experimental verification was carried out at the HIMAC synchrotron, and its results proved that this approach can greatly reduce the adjustment period.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gonnelli, Eduardo; Diniz, Ricardo
2013-05-06
The neutron lifetimes of the core, reflector, and global were experimentally obtained through macroscopic neutron noise in the IPEN/MB-01 reactor for five levels of subcriticality. The theoretical Auto Power Spectral Densities were derived by point kinetic equations taking the reflector effect into account, and one of the approaches consider an additional group of delayed neutrons.
ERIC Educational Resources Information Center
Ilter, Ilhan
2014-01-01
In this research, an experimental study was carried out in social studies 4th grade students to develop students' conceptual achievement and motivation to succeed academically. The study aims to investigate the effectiveness of project-based learning (PBL) in social studies. A quasi-experimental research design (pre- and posttest) was used in the…
[A new teaching mode improves the effect of comprehensive experimental teaching of genetics].
Fenghua, He; Jieqiang, Li; Biyan, Zhu; Feng, Gao
2015-04-01
To improve the research atmosphere in genetics experimental teaching and develop students' creativity in research, we carried out a reform in comprehensive experimental teaching which is one of important modules for genetics practice. In our new student-centered teaching mode, they chose research topics, performed experiments and took innovative approaches independently. With the open laboratory and technical platform in our experimental teaching center, students finished their experiments and were required to write a mini-research article. Comprehensive experimental teaching is a scientific research practice before they complete their thesis. Through this teaching practice, students' research skills in experimental design and operation, data analysis and results presentation, as well as their collaboration spirit and innovation consciousness are strengthened.
Youth Employability Training: Two Experiments
ERIC Educational Resources Information Center
Brown, Travor; Hillier, Tara-Lynn; Warren, Amy M.
2010-01-01
Purpose: This paper aims to assess the effectiveness of verbal self-guidance (VSG) and self-management on youth employability. It seeks to access the joint effectiveness of these interventions, grounded in social cognitive and goal setting theories, for youth job seekers. Design/methodology/approach: The studies used experimental designs involving…
Laing, Nigel G
2008-01-01
Currently a multiplicity of experimental approaches to therapy for genetic muscle diseases is being investigated. These include replacement of the missing gene, manipulation of the gene message, repair of the mutation, upregulation of an alternative gene and pharmacological interventions targeting a number of systems. A number of these approaches are in current clinical trials. There is considerable anticipation that perhaps more than one of the approaches will finally prove of clinical benefit, but there are many voices of caution. No matter which approaches might ultimately prove effective, there is a consensus that for most benefit to the patients it will be necessary to start treatment as early as possible. A consensus is also developing that the only way to do this is to implement population-based newborn screening to identify affected children shortly after birth. Population-based newborn screening is currently practised in very few places in the world and it brings with it implications for prevention rather than cure of genetic muscle diseases.
A computational fluid dynamics approach to nucleation in the water-sulfuric acid system.
Herrmann, E; Brus, D; Hyvärinen, A-P; Stratmann, F; Wilck, M; Lihavainen, H; Kulmala, M
2010-08-12
This study presents a computational fluid dynamics modeling approach to investigate the nucleation in the water-sulfuric acid system in a flow tube. On the basis of an existing experimental setup (Brus, D.; Hyvärinen, A.-P.; Viisanen, Y.; Kulmala, M.; Lihavainen, H. Atmos. Chem. Phys. 2010, 10, 2631-2641), we first establish the effect of convection on the flow profile. We then proceed to simulate nucleation for relative humidities of 10, 30, and 50% and for sulfuric acid concentration between 10(9) to 3 x 10(10) cm(-3). We describe the nucleation zone in detail and determine how flow rate and relative humidity affect its characteristics. Experimental nucleation rates are compared to rates gained from classical binary and kinetic nucleation theory as well as cluster activation theory. For low RH values, kinetic theory yields the best agreement with experimental results while binary nucleation best reproduces the experimental nucleation behavior at 50% relative humidity. Particle growth is modeled for an example case at 50% relative humidity. The final simulated diameter is very close to the experimental result.
An Ensemble Approach for Drug Side Effect Prediction
Jahid, Md Jamiul; Ruan, Jianhua
2014-01-01
In silico prediction of drug side-effects in early stage of drug development is becoming more popular now days, which not only reduces the time for drug design but also reduces the drug development costs. In this article we propose an ensemble approach to predict drug side-effects of drug molecules based on their chemical structure. Our idea originates from the observation that similar drugs have similar side-effects. Based on this observation we design an ensemble approach that combine the results from different classification models where each model is generated by a different set of similar drugs. We applied our approach to 1385 side-effects in the SIDER database for 888 drugs. Results show that our approach outperformed previously published approaches and standard classifiers. Furthermore, we applied our method to a number of uncharacterized drug molecules in DrugBank database and predict their side-effect profiles for future usage. Results from various sources confirm that our method is able to predict the side-effects for uncharacterized drugs and more importantly able to predict rare side-effects which are often ignored by other approaches. The method described in this article can be useful to predict side-effects in drug design in an early stage to reduce experimental cost and time. PMID:25327524
Testability of evolutionary game dynamics based on experimental economics data
NASA Astrophysics Data System (ADS)
Wang, Yijia; Chen, Xiaojie; Wang, Zhijian
2017-11-01
Understanding the dynamic processes of a real game system requires an appropriate dynamics model, and rigorously testing a dynamics model is nontrivial. In our methodological research, we develop an approach to testing the validity of game dynamics models that considers the dynamic patterns of angular momentum and speed as measurement variables. Using Rock-Paper-Scissors (RPS) games as an example, we illustrate the geometric patterns in the experiment data. We then derive the related theoretical patterns from a series of typical dynamics models. By testing the goodness-of-fit between the experimental and theoretical patterns, we show that the validity of these models can be evaluated quantitatively. Our approach establishes a link between dynamics models and experimental systems, which is, to the best of our knowledge, the most effective and rigorous strategy for ascertaining the testability of evolutionary game dynamics models.
Oscillational instabilities in single-mode acoustic levitators
NASA Technical Reports Server (NTRS)
Rudnick, Joseph; Barmatz, M.
1990-01-01
An extension of standard results for the acoustic force on an object in a single-mode resonant chamber yields predictions for the onset of oscillational instabilities when objects are levitated or positioned in these chambers. The results are consistent with experimental investigations. The present approach accounts for the effect of time delays on the response of a cavity to the motion of an object inside it. Quantitative features of the instabilities are investigated. The experimental conditions required for sample stability, saturation of sample oscillations, hysteretic effects, and the loss of the ability to levitate are discussed.
NASA Astrophysics Data System (ADS)
Hattori, Y.; Ushiki, H.; Engl, W.; Courbin, L.; Panizza, P.
2005-08-01
Within the framework of an effective medium approach and a mean-field approximation, we present a simple lattice model to treat electrical percolation in the presence of attractive interactions. We show that the percolation line depends on the magnitude of interactions. In 2 dimensions, the percolation line meets the binodal line at the critical point. A good qualitative agreement is observed with experimental results on a ternary AOT-based water-in-oil microemulsion system.
Impact resistance of fiber composites - Energy-absorbing mechanisms and environmental effects
NASA Technical Reports Server (NTRS)
Chamis, C. C.; Sinclair, J. H.
1985-01-01
Energy absorbing mechanisms were identified by several approaches. The energy absorbing mechanisms considered are those in unidirectional composite beams subjected to impact. The approaches used include: mechanic models, statistical models, transient finite element analysis, and simple beam theory. Predicted results are correlated with experimental data from Charpy impact tests. The environmental effects on impact resistance are evaluated. Working definitions for energy absorbing and energy releasing mechanisms are proposed and a dynamic fracture progression is outlined. Possible generalizations to angle-plied laminates are described.
Impact resistance of fiber composites: Energy absorbing mechanisms and environmental effects
NASA Technical Reports Server (NTRS)
Chamis, C. C.; Sinclair, J. H.
1983-01-01
Energy absorbing mechanisms were identified by several approaches. The energy absorbing mechanisms considered are those in unidirectional composite beams subjected to impact. The approaches used include: mechanic models, statistical models, transient finite element analysis, and simple beam theory. Predicted results are correlated with experimental data from Charpy impact tests. The environmental effects on impact resistance are evaluated. Working definitions for energy absorbing and energy releasing mechanisms are proposed and a dynamic fracture progression is outlined. Possible generalizations to angle-plied laminates are described.
Zhan, Xingxin; Zhang, Zhixia; Sun, Fang; Liu, Qian; Peng, Weijun; Zhang, Heng
2017-01-01
Background Primary health care workers (PHCWs) are a major force in delivering basic public health services (BPHS) in rural China. It is necessary to take effective training approaches to improve PHCWs’ competency on BPHS. Both electronic learning (e-learning) and blended learning have been widely used in the health workers’ education. However, there is limited evidence on the effects of blended learning in comparison with pure e-learning. Objective The aim of this study was to evaluate the effects of a blended-learning approach for rural PHCWs in improving their knowledge about BPHS as well as training satisfaction in comparison with a pure e-learning approach. Methods The study was conducted among PHCWs in 6 rural counties of Hubei Province, China, between August 2013 and April 2014. Three counties were randomly allocated blended-learning courses (29 township centers or 612 PHCWs—the experimental group), and three counties were allocated pure e-learning courses (31 township centers or 625 PHCWs—the control group). Three course modules were administered for 5 weeks, with assessments at baseline and postcourse. Primary outcomes were score changes in courses’ knowledge. Secondary outcome was participant satisfaction (5-point Likert scale anchored between 1 [strongly agree] and 5 [strongly disagree]). Results The experimental group had higher mean scores than the control group in knowledge achievement in three course modules: (1) module 1: 93.21 (95% CI 92.49-93.93) in experimental group versus 88.29 (95% CI 87.19-89.40) in the control group; adjusted difference, 4.92 (95% CI 2.61-7.24; P<.001); (2) module 2: 94.05 (95% CI 93.37-94.73) in the experimental group vs 90.22 (95% CI 89.12-91.31) in the control group; adjusted difference, 3.67 (95% CI 1.17-6.18; P=.004); (3) module 3: 93.88 (95% CI 93.08-94.68) in the experimental group versus 89.09 (95% CI 87.89-90.30) in control group; adjusted difference, 4.63 (95% CI 2.12-7.14; P<.001). The participants in the experimental learning group gave more positive responses with the four issues than control group participants: (1) the increase of interest in learning, 1.85 (95% CI 1.22-2.80; P=.003); (2) the increase of interaction with others, 1.77 (95% CI 1.20-2.60; P=.004); (3) the satisfaction with learning experience, 1.78 (95% CI 1.11-2.88; P=.02); and (4) achievement of learning objectives, 1.63 (95% CI 1.08-2.48; P=.02). Conclusions Among PHCWs in rural China, a blended-learning approach to BPHS training could result in a higher knowledge achievement and satisfaction level compared with a pure e-learning approach. The findings of the study will contribute knowledge to improve the competency of PHCWs in similar settings. PMID:28461286
Diepens, Noël J; Koelmans, Albert A; Baveco, Hans; van den Brink, Paul J; van den Heuvel-Greve, Martine J; Brock, Theo C M
A broadly accepted framework for prospective environmental risk assessment (ERA) of sediment-bound organic chemicals is currently lacking. Such a framework requires clear protection goals, evidence-based concepts that link exposure to effects and a transparent tiered-effect assessment. In this paper, we provide a tiered prospective sediment ERA procedure for organic chemicals in sediment, with a focus on the applicable European regulations and the underlying data requirements. Using the ecosystem services concept, we derived specific protection goals for ecosystem service providing units: microorganisms, benthic algae, sediment-rooted macrophytes, benthic invertebrates and benthic vertebrates. Triggers for sediment toxicity testing are discussed.We recommend a tiered approach (Tier 0 through Tier 3). Tier-0 is a cost-effective screening based on chronic water-exposure toxicity data for pelagic species and equilibrium partitioning. Tier-1 is based on spiked sediment laboratory toxicity tests with standard benthic test species and standardised test methods. If comparable chronic toxicity data for both standard and additional benthic test species are available, the Species Sensitivity Distribution (SSD) approach is a more viable Tier-2 option than the geometric mean approach. This paper includes criteria for accepting results of sediment-spiked single species toxicity tests in prospective ERA, and for the application of the SSD approach. We propose micro/mesocosm experiments with spiked sediment, to study colonisation success by benthic organisms, as a Tier-3 option. Ecological effect models can be used to supplement the experimental tiers. A strategy for unifying information from various tiers by experimental work and exposure-and effect modelling is provided.
Improving the seismic small-scale modelling by comparison with numerical methods
NASA Astrophysics Data System (ADS)
Pageot, Damien; Leparoux, Donatienne; Le Feuvre, Mathieu; Durand, Olivier; Côte, Philippe; Capdeville, Yann
2017-10-01
The potential of experimental seismic modelling at reduced scale provides an intermediate step between numerical tests and geophysical campaigns on field sites. Recent technologies such as laser interferometers offer the opportunity to get data without any coupling effects. This kind of device is used in the Mesures Ultrasonores Sans Contact (MUSC) measurement bench for which an automated support system makes possible to generate multisource and multireceivers seismic data at laboratory scale. Experimental seismic modelling would become a great tool providing a value-added stage in the imaging process validation if (1) the experimental measurement chain is perfectly mastered, and thus if the experimental data are perfectly reproducible with a numerical tool, as well as if (2) the effective source is reproducible along the measurement setup. These aspects for a quantitative validation concerning devices with piezoelectrical sources and a laser interferometer have not been yet quantitatively studied in published studies. Thus, as a new stage for the experimental modelling approach, these two key issues are tackled in the proposed paper in order to precisely define the quality of the experimental small-scale data provided by the bench MUSC, which are available in the scientific community. These two steps of quantitative validation are dealt apart any imaging techniques in order to offer the opportunity to geophysicists who want to use such data (delivered as free data) of precisely knowing their quality before testing any imaging technique. First, in order to overcome the 2-D-3-D correction usually done in seismic processing when comparing 2-D numerical data with 3-D experimental measurement, we quantitatively refined the comparison between numerical and experimental data by generating accurate experimental line sources, avoiding the necessity of geometrical spreading correction for 3-D point-source data. The comparison with 2-D and 3-D numerical modelling is based on the Spectral Element Method. The approach shows the relevance of building a line source by sampling several source points, except the boundaries effects on later arrival times. Indeed, the experimental results highlight the amplitude feature and the delay equal to π/4 provided by a line source in the same manner than numerical data. In opposite, the 2-D corrections applied on 3-D data showed discrepancies which are higher on experimental data than on numerical ones due to the source wavelet shape and interferences between different arrivals. The experimental results from the approach proposed here show that discrepancies are avoided, especially for the reflected echoes. Concerning the second point aiming to assess the experimental reproducibility of the source, correlation coefficients of recording from a repeated source impact on a homogeneous model are calculated. The quality of the results, that is, higher than 0.98, allow to calculate a mean source wavelet by inversion of a mean data set. Results obtained on a more realistic model simulating clays on limestones, confirmed the reproducibility of the source impact.
The Role of Idealization in Science and Its Implications for Science Education
NASA Astrophysics Data System (ADS)
Niaz, Mansoor
1999-06-01
The main objective of this article is to study the role of empirical evidence in the interpretation of psychological and epistemological aspects of Piagetian theory. According to Galilean methodology, after having asked the right question, a scientist could experimentally vary one impediment, and observe what happens to the dependent variable, as it approaches the ideal limiting case. Following Galileo's idealization, scientific laws being epistemological constructions do not describe the behavior of actual bodies. It is plausible to suggest that just as Galileo's ideal law can be observed only when all the impediment variables approach zero, similarly individuals in the real world have various `impediments' and it is only when these impediments are gradually removed by experimental manipulation that the real performance of individuals can approximate the competence of Piaget's epistemic subject (ideal knower). Finally, evidence is presented to the effect that by experimentally manipulating the impediment variables (e.g., Pascual-Leone's M-demand and Witkin's perceptual field effect of a task), performance of the real subjects approximates the competence of the ideal epistemic subject, which leads to the construction of a neo-Piagetian epistemological theory.
Raglio, Alfredo; Oasi, Osmano; Gianotti, Marta; Rossi, Agnese; Goulene, Karine; Stramba-Badiale, Marco
2016-01-01
The aim of this research is to evaluate the effects of active music therapy (MT) based on free-improvisation (relational approach) in addition to speech language therapy (SLT) compared with SLT alone (communicative-pragmatic approach: Promoting Aphasic's Communicative Effectiveness) in stroke patients with chronic aphasia. The experimental group (n = 10) was randomized to 30 MT individual sessions over 15 weeks in addition to 30 SLT individual sessions while the control group (n = 10) was randomized to only 30 SLT sessions during the same period. Psychological and speech language assessment were made before (T0) and after (T1) the treatments. The study shows a significant improvement in spontaneous speech in the experimental group (Aachener Aphasie subtest: p = 0.020; Cohen's d = 0.35); the 50% of the experimental group showed also an improvement in vitality scores of Short Form Health Survey (chi-square test = 4.114; p = 0.043). The current trial highlights the possibility that the combined use of MT and SLT can lead to a better result in the rehabilitation of patients with aphasia than SLT alone.
NASA Astrophysics Data System (ADS)
Ramazani, Ali; Mukherjee, Krishnendu; Prahl, Ulrich; Bleck, Wolfgang
2012-10-01
The flow behavior of dual-phase (DP) steels is modeled on the finite-element method (FEM) framework on the microscale, considering the effect of the microstructure through the representative volume element (RVE) approach. Two-dimensional RVEs were created from microstructures of experimentally obtained DP steels with various ferrite grain sizes. The flow behavior of single phases was modeled through the dislocation-based work-hardening approach. The volume change during austenite-to-martensite transformation was modeled, and the resultant prestrained areas in the ferrite were considered to be the storage place of transformation-induced, geometrically necessary dislocations (GNDs). The flow curves of DP steels with varying ferrite grain sizes, but constant martensite fractions, were obtained from the literature. The flow curves of simulations that take into account the GND are in better agreement with those of experimental flow curves compared with those of predictions without consideration of the GND. The experimental results obeyed the Hall-Petch relationship between yield stress and flow stress and the simulations predicted this as well.
Evidence to Support Peer Tutoring Programs at the Undergraduate Level
ERIC Educational Resources Information Center
Colver, Mitchell; Fry, Trevor
2016-01-01
The present study examined undergraduate peer tutoring in three phases. Phase I qualitatively surveyed students' perceptions about the effectiveness of tutoring. Phase II examined the usefulness of promoting regular use of services through a tutoring contract. Phase III utilized an archival, quasi-experimental approach to estimate the effect of…
Early-life effects on adult physical activity: Concepts, relevance, and experimental approaches
USDA-ARS?s Scientific Manuscript database
Locomotion is a defining characteristic of animal life and plays a crucial role in most behaviors. Locomotion involves physical activity, which can have far-reaching effects on physiology and neurobiology, both acutely and chronically. In human populations and in laboratory rodents, higher levels of...
Epidemiologic and experimental studies have demonstrated a variety of health effects in response to ozone (O3) exposure. Studies have demonstrated that some populations may be at increased risk of O3-related health effects. Objectives: To identify populations and lifestages pote...
High School Biology: A Group Approach to Concept Mapping.
ERIC Educational Resources Information Center
Brown, David S.
2003-01-01
Explains concept mapping as an instructional method in cooperative learning environments, and describes a study investigating the effectiveness of concept mapping on student learning during a photosynthesis and cellular respiration unit. Reports on the positive effects of concept mapping in the experimental group. (Contains 16 references.) (YDS)
Diesel exhaust particulate matter (DEP) is a ubiquitous ambient air contaminant derived from mobile and stationary diesel fuel combustion. Exposure to DEP is associated with carcinogenic and immunotoxic effects in humans and experimental animals. At the cellular level, these heal...
ERIC Educational Resources Information Center
Nielsen, Karina; Randall, Raymond; Christensen, Karl B.
2017-01-01
A mixed methods approach was applied to examine the effects of a naturally occurring teamwork intervention supported with training. The first objective was to integrate qualitative process evaluation and quantitative effect evaluation to examine "how" and "why" the training influence intervention outcomes. The intervention (N =…
The Effects of Diversity Training on Specific and General Attitudes toward Diversity
ERIC Educational Resources Information Center
Schmidtke, James M.; Badhesha, Raj Singh; Moore, Scott D.
2008-01-01
Purpose: This paper aims to examine the effects of watching a video providing knowledge about either a Sikh student or an older student on participants' knowledge about each particular group, their attitudes towards that group. Design/methodology/approach: The study used a pre-post experimental design and examined the effects of diversity…
Effects of ICT Assisted Real and Virtual Learning on the Performance of Secondary School Students
ERIC Educational Resources Information Center
Deka, Monisha; Jena, Ananta Kumar
2017-01-01
The study aimed to assess the effect of ICT assisted real and virtual learning performance over the traditional approach of secondary school students. Non-Equivalent Pretest-Posttest Quasi Experimental Design used to assess and relate the effects of independent variables virtual learning on dependent variables (i.e. learning performance).…
ERIC Educational Resources Information Center
LaMotte, Megan
2018-01-01
The purpose of the study was to examine the effects of a dance and transportation integrated curriculum on student learning and engagement. The curriculum, entitled Consequences of Our Actions: Dance and Transportation, synthesized transportation content with the art form of dance. The experimental and control groups were comprised of fifth-grade…
The Effect of DBAE Approach on Teaching Painting of Undergraduate Art Students
ERIC Educational Resources Information Center
Hedayat, Mina; Kahn, Sabzali Musa; Honarvar, Habibeh; Bakar, Syed Alwi Syed Abu; Samsuddin, Mohd Effindi
2013-01-01
The aim of this study is to implement a new method of teaching painting which uses the Discipline-Based Art Education (DBAE) approach for the undergraduate art students at Tehran University. In the current study, the quasi-experimental method was used to test the hypothesis three times (pre, mid and post-tests). Thirty students from two classes…
A Story-Telling Approach to Teaching English to Young EFL Iranian Learners
ERIC Educational Resources Information Center
Kalantari, Farzaneh; Hashemian, Mahmood
2016-01-01
This study investigated the effects of the storytelling approach on improving of EFL learners' vocabulary knowledge. To this end, 30 upper-beginner EFL learners (out of a population of 134) were selected by means of an OPT test and were assigned to 2 groups: 1 experimental and 1 group. The participants were selected from among young EFL learners…
ERIC Educational Resources Information Center
Elmaadaway, Mohamed Ali Nagy
2018-01-01
This paper reports on a study that investigated whether a flipped classroom approach enhanced perceptions of levels of engagement and skill performance among students enrolled in a Blackboard course at a Saudi university. Fifty-eight participants were divided into control and experimental groups, which were taught using a traditional and a flipped…
ERIC Educational Resources Information Center
Harper, Roosevelt
2014-01-01
This research study examined the specific categories of IT control deficiencies and their related effects on financial reporting. The approach to this study was considered non-experimental, an approach sometimes called descriptive. Descriptive statistics are used to describe the basic features of the data in a study, providing simple summaries…
ERIC Educational Resources Information Center
Abdullah, Mashita; Mohamed, Norita; Ismail, Zurida Hj
2009-01-01
The main goal of this study was to investigate whether the use of an individualized approach through microscale chemistry experiments in secondary schools can increase students' understanding of chemistry concepts, improve attitude towards chemistry practical work and motivation. Two comparable groups of Form Four students (16 years old)…
ERIC Educational Resources Information Center
Hinds, Lillian R.
Seventy Cleveland, Ohio, inner city adult illiterates, 33 from an experimental group and 37 from a contrast group, were studied to determine the efficiency and effectiveness of Words in Color or the Morphologico-Algebraic approach to teaching reading. Results indicated that the reading achievement gain of functionally illiterate adults taught by…
ERIC Educational Resources Information Center
Schoeman, Sonja
2015-01-01
This study explores the potential of adopting a whole-school approach to the pastoral care module in a Postgraduate Certificate of Education Programme to ensure that all newly qualified teachers practice effective pastoral care in their classrooms and promote the learners' academic engagement and performance. A non-experimental survey research…
Associated Υ+γ production at the LHC in the kt-factorization approach
NASA Astrophysics Data System (ADS)
Baranov, S. P.
2010-09-01
In the framework of the kt-factorization approach, the photon-associated production of Υ mesons at the present-day LHC conditions is studied. The differential cross sections and polarization parameters are calculated in the “helicity” and Collins-Soper systems. Special attention is paid to the effect of experimental cuts that can dramatically change the visible lepton angular distributions.
Associated ϒ + γ production at the LHC in the k-factorization approach
NASA Astrophysics Data System (ADS)
Baranov, S. P.
2011-05-01
In the framework of k-factorization approach, the photon-associated production of ϒ mesons at the present-day LHC conditions is studied. The differential cross sections and polarization parameters are calculated in the 'helicity' and Collins-Soper systems. Special attention is paid to the effect of experimental cuts that can dramatically change the visible lepton angular distributions.
Motivation modulates the effect of approach on implicit preferences.
Zogmaister, Cristina; Perugini, Marco; Richetin, Juliette
2016-08-01
With three studies, we investigated whether motivational states can modulate the formation of implicit preferences. In Study 1, participants played a video game in which they repeatedly approached one of two similar beverages, while disregarding the other. A subsequent implicit preference for the target beverage emerged, which increased with participants' thirst. In Study 2, participants approached one brand of potato chips while avoiding the other: Conceptually replicating the moderation observed in Study 1, the implicit preference for the approached brand increased with the number of hours from last food intake. In Study 3, we experimentally manipulated hunger, and the moderation effect emerged again, with hungry participants displaying a higher implicit preference for the approached brand, as compared to satiated participants. In the three studies, the moderation effect was not paralleled in explicit preferences although the latter were affected by the preference inducing manipulation. Theoretical implications and open questions are discussed.
The Problem of Size in Robust Design
NASA Technical Reports Server (NTRS)
Koch, Patrick N.; Allen, Janet K.; Mistree, Farrokh; Mavris, Dimitri
1997-01-01
To facilitate the effective solution of multidisciplinary, multiobjective complex design problems, a departure from the traditional parametric design analysis and single objective optimization approaches is necessary in the preliminary stages of design. A necessary tradeoff becomes one of efficiency vs. accuracy as approximate models are sought to allow fast analysis and effective exploration of a preliminary design space. In this paper we apply a general robust design approach for efficient and comprehensive preliminary design to a large complex system: a high speed civil transport (HSCT) aircraft. Specifically, we investigate the HSCT wing configuration design, incorporating life cycle economic uncertainties to identify economically robust solutions. The approach is built on the foundation of statistical experimentation and modeling techniques and robust design principles, and is specialized through incorporation of the compromise Decision Support Problem for multiobjective design. For large problems however, as in the HSCT example, this robust design approach developed for efficient and comprehensive design breaks down with the problem of size - combinatorial explosion in experimentation and model building with number of variables -and both efficiency and accuracy are sacrificed. Our focus in this paper is on identifying and discussing the implications and open issues associated with the problem of size for the preliminary design of large complex systems.
An investigation of light transport through scattering bodies with non-scattering regions.
Firbank, M; Arridge, S R; Schweiger, M; Delpy, D T
1996-04-01
Near-infra-red (NIR) spectroscopy is increasingly being used for monitoring cerebral oxygenation and haemodynamics. One current concern is the effect of the clear cerebrospinal fluid upon the distribution of light in the head. There are difficulties in modelling clear layers in scattering systems. The Monte Carlo model should handle clear regions accurately, but is too slow to be used for realistic geometries. The diffusion equation can be solved quickly for realistic geometries, but is only valid in scattering regions. In this paper we describe experiments carried out on a solid slab phantom to investigate the effect of clear regions. The experimental results were compared with the different models of light propagation. We found that the presence of a clear layer had a significant effect upon the light distribution, which was modelled correctly by Monte Carlo techniques, but not by diffusion theory. A novel approach to calculating the light transport was developed, using diffusion theory to analyze the scattering regions combined with a radiosity approach to analyze the propagation through the clear region. Results from this approach were found to agree with both the Monte Carlo and experimental data.
Tan, Katherine; Chong, Mei Chan; Subramaniam, Pathmawathy; Wong, Li Ping
2018-05-01
Outcome Based Education (OBE) is a student-centered approach of curriculum design and teaching that emphasize on what learners should know, understand, demonstrate and how to adapt to life beyond formal education. However, no systematic review has been seen to explore the effectiveness of OBE in improving the competencies of nursing students. To appraise and synthesize the best available evidence that examines the effectiveness of OBE approaches towards the competencies of nursing students. A systematic review of interventional experimental studies. Eight online databases namely CINAHL, EBSCO, Science Direct, ProQuest, Web of Science, PubMed, EMBASE and SCOPUS were searched. Relevant studies were identified using combined approaches of electronic database search without geographical or language filters but were limited to articles published from 2006 to 2016, handsearching journals and visually scanning references from retrieved studies. Two reviewers independently conducted the quality appraisal of selected studies and data were extracted. Six interventional studies met the inclusion criteria. Two of the studies were rated as high methodological quality and four were rated as moderate. Studies were published between 2009 and 2016 and were mostly from Asian and Middle Eastern countries. Results showed that OBE approaches improves competency in knowledge acquisition in terms of higher final course grades and cognitive skills, improve clinical skills and nursing core competencies and higher behavioural skills score while performing clinical skills. Learners' satisfaction was also encouraging as reported in one of the studies. Only one study reported on the negative effect. Although OBE approaches does show encouraging effects towards improving competencies of nursing students, more robust experimental study design with larger sample sizes, evaluating other outcome measures such as other areas of competencies, students' satisfaction, and patient outcomes are needed. Copyright © 2018 Elsevier Ltd. All rights reserved.
An Information Retrieval Approach for Robust Prediction of Road Surface States.
Park, Jae-Hyung; Kim, Kwanho
2017-01-28
Recently, due to the increasing importance of reducing severe vehicle accidents on roads (especially on highways), the automatic identification of road surface conditions, and the provisioning of such information to drivers in advance, have recently been gaining significant momentum as a proactive solution to decrease the number of vehicle accidents. In this paper, we firstly propose an information retrieval approach that aims to identify road surface states by combining conventional machine-learning techniques and moving average methods. Specifically, when signal information is received from a radar system, our approach attempts to estimate the current state of the road surface based on the similar instances observed previously based on utilizing a given similarity function. Next, the estimated state is then calibrated by using the recently estimated states to yield both effective and robust prediction results. To validate the performances of the proposed approach, we established a real-world experimental setting on a section of actual highway in South Korea and conducted a comparison with the conventional approaches in terms of accuracy. The experimental results show that the proposed approach successfully outperforms the previously developed methods.
An Information Retrieval Approach for Robust Prediction of Road Surface States
Park, Jae-Hyung; Kim, Kwanho
2017-01-01
Recently, due to the increasing importance of reducing severe vehicle accidents on roads (especially on highways), the automatic identification of road surface conditions, and the provisioning of such information to drivers in advance, have recently been gaining significant momentum as a proactive solution to decrease the number of vehicle accidents. In this paper, we firstly propose an information retrieval approach that aims to identify road surface states by combining conventional machine-learning techniques and moving average methods. Specifically, when signal information is received from a radar system, our approach attempts to estimate the current state of the road surface based on the similar instances observed previously based on utilizing a given similarity function. Next, the estimated state is then calibrated by using the recently estimated states to yield both effective and robust prediction results. To validate the performances of the proposed approach, we established a real-world experimental setting on a section of actual highway in South Korea and conducted a comparison with the conventional approaches in terms of accuracy. The experimental results show that the proposed approach successfully outperforms the previously developed methods. PMID:28134859
Computational Prediction of Metabolism: Sites, Products, SAR, P450 Enzyme Dynamics, and Mechanisms
2012-01-01
Metabolism of xenobiotics remains a central challenge for the discovery and development of drugs, cosmetics, nutritional supplements, and agrochemicals. Metabolic transformations are frequently related to the incidence of toxic effects that may result from the emergence of reactive species, the systemic accumulation of metabolites, or by induction of metabolic pathways. Experimental investigation of the metabolism of small organic molecules is particularly resource demanding; hence, computational methods are of considerable interest to complement experimental approaches. This review provides a broad overview of structure- and ligand-based computational methods for the prediction of xenobiotic metabolism. Current computational approaches to address xenobiotic metabolism are discussed from three major perspectives: (i) prediction of sites of metabolism (SOMs), (ii) elucidation of potential metabolites and their chemical structures, and (iii) prediction of direct and indirect effects of xenobiotics on metabolizing enzymes, where the focus is on the cytochrome P450 (CYP) superfamily of enzymes, the cardinal xenobiotics metabolizing enzymes. For each of these domains, a variety of approaches and their applications are systematically reviewed, including expert systems, data mining approaches, quantitative structure–activity relationships (QSARs), and machine learning-based methods, pharmacophore-based algorithms, shape-focused techniques, molecular interaction fields (MIFs), reactivity-focused techniques, protein–ligand docking, molecular dynamics (MD) simulations, and combinations of methods. Predictive metabolism is a developing area, and there is still enormous potential for improvement. However, it is clear that the combination of rapidly increasing amounts of available ligand- and structure-related experimental data (in particular, quantitative data) with novel and diverse simulation and modeling approaches is accelerating the development of effective tools for prediction of in vivo metabolism, which is reflected by the diverse and comprehensive data sources and methods for metabolism prediction reviewed here. This review attempts to survey the range and scope of computational methods applied to metabolism prediction and also to compare and contrast their applicability and performance. PMID:22339582
NASA Astrophysics Data System (ADS)
Baumgart, M.; Druml, N.; Consani, M.
2018-05-01
This paper presents a simulation approach for Time-of-Flight cameras to estimate sensor performance and accuracy, as well as to help understanding experimentally discovered effects. The main scope is the detailed simulation of the optical signals. We use a raytracing-based approach and use the optical path length as the master parameter for depth calculations. The procedure is described in detail with references to our implementation in Zemax OpticStudio and Python. Our simulation approach supports multiple and extended light sources and allows accounting for all effects within the geometrical optics model. Especially multi-object reflection/scattering ray-paths, translucent objects, and aberration effects (e.g. distortion caused by the ToF lens) are supported. The optical path length approach also enables the implementation of different ToF senor types and transient imaging evaluations. The main features are demonstrated on a simple 3D test scene.
A semantic medical multimedia retrieval approach using ontology information hiding.
Guo, Kehua; Zhang, Shigeng
2013-01-01
Searching useful information from unstructured medical multimedia data has been a difficult problem in information retrieval. This paper reports an effective semantic medical multimedia retrieval approach which can reflect the users' query intent. Firstly, semantic annotations will be given to the multimedia documents in the medical multimedia database. Secondly, the ontology that represented semantic information will be hidden in the head of the multimedia documents. The main innovations of this approach are cross-type retrieval support and semantic information preservation. Experimental results indicate a good precision and efficiency of our approach for medical multimedia retrieval in comparison with some traditional approaches.
The effective molarity (EM)--a computational approach.
Karaman, Rafik
2010-08-01
The effective molarity (EM) for 12 intramolecular S(N)2 processes involving the formation of substituted aziridines and substituted epoxides were computed using ab initio and DFT calculation methods. Strong correlation was found between the calculated effective molarity and the experimentally determined values. This result could open a door for obtaining EM values for intramolecular processes that are difficult to be experimentally provided. Furthermore, the calculation results reveal that the driving forces for ring-closing reactions in the two different systems are proximity orientation of the nucleophile to the electrophile and the ground strain energies of the products and the reactants. Copyright 2010 Elsevier Inc. All rights reserved.
Speck-Planche, Alejandro; Cordeiro, M N D S
2014-02-10
Escherichia coli remains one of the principal pathogens that cause nosocomial infections, medical conditions that are increasingly common in healthcare facilities. E. coli is intrinsically resistant to many antibiotics, and multidrug-resistant strains have emerged recently. Chemoinformatics has been a great ally of experimental methodologies such as high-throughput screening, playing an important role in the discovery of effective antibacterial agents. However, there is no approach that can design safer anti-E. coli agents, because of the multifactorial nature and complexity of bacterial diseases and the lack of desirable ADMET (absorption, distribution, metabolism, elimination, and toxicity) profiles as a major cause of disapproval of drugs. In this work, we introduce the first multitasking model based on quantitative-structure biological effect relationships (mtk-QSBER) for simultaneous virtual prediction of anti-E. coli activities and ADMET properties of drugs and/or chemicals under many experimental conditions. The mtk-QSBER model was developed from a large and heterogeneous data set of more than 37800 cases, exhibiting overall accuracies of >95% in both training and prediction (validation) sets. The utility of our mtk-QSBER model was demonstrated by performing virtual prediction of properties for the investigational drug avarofloxacin (AVX) under 260 different experimental conditions. Results converged with the experimental evidence, confirming the remarkable anti-E. coli activities and safety of AVX. Predictions also showed that our mtk-QSBER model can be a promising computational tool for virtual screening of desirable anti-E. coli agents, and this chemoinformatic approach could be extended to the search for safer drugs with defined pharmacological activities.
Lammers, Joris; Stoker, Janka I; Stapel, Diederik A
2009-12-01
How does power affect behavior? We posit that this depends on the type of power. We distinguish between social power (power over other people) and personal power (freedom from other people) and argue that these two types of power have opposite associations with independence and interdependence. We propose that when the distinction between independence and interdependence is relevant, social power and personal power will have opposite effects; however, they will have parallel effects when the distinction is irrelevant. In two studies (an experimental study and a large field study), we demonstrate this by showing that social power and personal power have opposite effects on stereotyping, but parallel effects on behavioral approach.
Arithmetic Circuit Verification Based on Symbolic Computer Algebra
NASA Astrophysics Data System (ADS)
Watanabe, Yuki; Homma, Naofumi; Aoki, Takafumi; Higuchi, Tatsuo
This paper presents a formal approach to verify arithmetic circuits using symbolic computer algebra. Our method describes arithmetic circuits directly with high-level mathematical objects based on weighted number systems and arithmetic formulae. Such circuit description can be effectively verified by polynomial reduction techniques using Gröbner Bases. In this paper, we describe how the symbolic computer algebra can be used to describe and verify arithmetic circuits. The advantageous effects of the proposed approach are demonstrated through experimental verification of some arithmetic circuits such as multiply-accumulator and FIR filter. The result shows that the proposed approach has a definite possibility of verifying practical arithmetic circuits.
Bandwidth correction for LED chromaticity based on Levenberg-Marquardt algorithm
NASA Astrophysics Data System (ADS)
Huang, Chan; Jin, Shiqun; Xia, Guo
2017-10-01
Light emitting diode (LED) is widely employed in industrial applications and scientific researches. With a spectrometer, the chromaticity of LED can be measured. However, chromaticity shift will occur due to the broadening effects of the spectrometer. In this paper, an approach is put forward to bandwidth correction for LED chromaticity based on Levenberg-Marquardt algorithm. We compare chromaticity of simulated LED spectra by using the proposed method and differential operator method to bandwidth correction. The experimental results show that the proposed approach achieves an excellent performance in bandwidth correction which proves the effectiveness of the approach. The method has also been tested on true blue LED spectra.
Kieburtz, Karl; Olanow, C Warren
2007-04-01
In the past decade, there has been an increasing emphasis on laboratory-based translational research. This has led to significant scientific advances in our understanding of disease mechanisms and in the development of novel approaches to therapy such as gene therapy, RNA interference, and stem cells. However, the translation of these remarkable scientific achievements into new and effective disease-modifying therapies has lagged behind these scientific accomplishments. We use the term "translational experimental therapeutics" to describe the pathway between the discovery of a basic disease mechanism or novel therapeutic approach and its translation into an effective treatment for patients with a specific disease. In this article, we review the components of this pathway, and discuss issues that might impede this process. Only by optimizing this pathway can we realize the full therapeutic potential of current scientific discoveries and translate the astounding advances that have been accomplished in the laboratory into effective treatments for our patients. Copyright (c) 2007 Mount Sinai School of Medicine.
Wang, Chun-Hua; Zhong, Yi; Zhang, Yan; Liu, Jin-Ping; Wang, Yue-Fei; Jia, Wei-Na; Wang, Guo-Cai; Li, Zheng; Zhu, Yan; Gao, Xiu-Mei
2016-02-01
Chinese medicine is known to treat complex diseases with multiple components and multiple targets. However, the main effective components and their related key targets and functions remain to be identified. Herein, a network analysis method was developed to identify the main effective components and key targets of a Chinese medicine, Lianhua-Qingwen Formula (LQF). The LQF is commonly used for the prevention and treatment of viral influenza in China. It is composed of 11 herbs, gypsum and menthol with 61 compounds being identified in our previous work. In this paper, these 61 candidate compounds were used to find their related targets and construct the predicted-target (PT) network. An influenza-related protein-protein interaction (PPI) network was constructed and integrated with the PT network. Then the compound-effective target (CET) network and compound-ineffective target network (CIT) were extracted, respectively. A novel approach was developed to identify effective components by comparing CET and CIT networks. As a result, 15 main effective components were identified along with 61 corresponding targets. 7 of these main effective components were further experimentally validated to have antivirus efficacy in vitro. The main effective component-target (MECT) network was further constructed with main effective components and their key targets. Gene Ontology (GO) analysis of the MECT network predicted key functions such as NO production being modulated by the LQF. Interestingly, five effective components were experimentally tested and exhibited inhibitory effects on NO production in the LPS induced RAW 264.7 cell. In summary, we have developed a novel approach to identify the main effective components in a Chinese medicine LQF and experimentally validated some of the predictions.
NASA Astrophysics Data System (ADS)
Correa, M. A.; Bohn, F.
2018-05-01
We perform a theoretical and experimental investigation of the magnetic properties and magnetization dynamics of a ferromagnetic magnetostrictive multilayer grown onto a flexible substrate and submitted to external stress. We calculate the magnetic behavior and magnetoimpedance effect for a trilayered system from an approach that considers a magnetic permeability model for planar geometry and a magnetic free energy density which takes into account induced uniaxial and magnetoelastic anisotropy contributions. We verify remarkable modifications of the magnetic anisotropy with external stress, as well as we show that the dynamic magnetic response is strongly affected by these changes. We discuss the magnetic features that lead to modifications of the frequency limits where distinct mechanisms are responsible by the magnetoimpedance variations, enabling us to manipulate the resonance fields. To test the robustness of the approach, we directly compare theoretical results with experimental data. Thus, we provide experimental evidence to confirm the validity of the theoretical approach, as well as to manipulate the resonance fields to tune the MI response according to real applications in devices.
Choi, Bryan; Asselin, Nicholas; Pettit, Catherine C; Dannecker, Max; Machan, Jason T; Merck, Derek L; Merck, Lisa H; Suner, Selim; Williams, Kenneth A; Jay, Gregory D; Kobayashi, Leo
2016-12-01
Effective resuscitation of out-of-hospital cardiac arrest (OHCA) patients is challenging. Alternative resuscitative approaches using electromechanical adjuncts may improve provider performance. Investigators applied simulation to study the effect of an experimental automation-assisted, goal-directed OHCA management protocol on EMS providers' resuscitation performance relative to standard protocols and equipment. Two-provider (emergency medical technicians (EMT)-B and EMT-I/C/P) teams were randomized to control or experimental group. Each team engaged in 3 simulations: baseline simulation (standard roles); repeat simulation (standard roles); and abbreviated repeat simulation (reversed roles, i.e., basic life support provider performing ALS tasks). Control teams used standard OHCA protocols and equipment (with high-performance cardiopulmonary resuscitation training intervention); for second and third simulations, experimental teams performed chest compression, defibrillation, airway, pulmonary ventilation, vascular access, medication, and transport tasks with goal-directed protocol and resuscitation-automating devices. Videorecorders and simulator logs collected resuscitation data. Ten control and 10 experimental teams comprised 20 EMT-B's; 1 EMT-I, 8 EMT-C's, and 11 EMT-P's; study groups were not fully matched. Both groups suboptimally performed chest compressions and ventilations at baseline. For their second simulations, control teams performed similarly except for reduced on-scene time, and experimental teams improved their chest compressions (P=0.03), pulmonary ventilations (P<0.01), and medication administration (P=0.02); changes in their performance of chest compression, defibrillation, airway, and transport tasks did not attain significance against control teams' changes. Experimental teams maintained performance improvements during reversed-role simulations. Simulation-based investigation into OHCA resuscitation revealed considerable variability and improvable deficiencies in small EMS teams. Goal-directed, automation-assisted OHCA management augmented select resuscitation bundle element performance without comprehensive improvement.
Design of "Eye Closure" system for the stealth of photo-electric equipments
NASA Astrophysics Data System (ADS)
Zhang, Y.; Hua, W. S.; Li, G.
2012-10-01
Based on the optical activity of liquid crystal, a new approach for the stealth of "cat's eye" targets is proposed in this paper. It imitates the physiological close reaction of human eyes when strong light irradiates eyes. With this approach, the "cat's eye" effect will vanish, which is applied in restricting photo-electric equipments being detected and located by active laser detection system. The structure and working principle of the design are presented. The drive circuit is given to control the optical switch automatically. Feasibility of this design is demonstrated by experimental method. The measured data illustrate that the proposed approach is effective to eliminate the "cat's eye" effect, so as to enhancing the viability of photo-electric equipments on the battlefield.
Understanding ocean acidification impacts on organismal to ecological scales
Andersson, Andreas J; Kline, David I; Edmunds, Peter J; Archer, Stephen D; Bednaršek, Nina; Carpenter, Robert C; Chadsey, Meg; Goldstein, Philip; Grottoli, Andrea G.; Hurst, Thomas P; King, Andrew L; Kübler, Janet E.; Kuffner, Ilsa B.; Mackey, Katherine R M; Menge, Bruce A.; Paytan, Adina; Riebesell, Ulf; Schnetzer, Astrid; Warner, Mark E; Zimmerman, Richard C
2015-01-01
Ocean acidification (OA) research seeks to understand how marine ecosystems and global elemental cycles will respond to changes in seawater carbonate chemistry in combination with other environmental perturbations such as warming, eutrophication, and deoxygenation. Here, we discuss the effectiveness and limitations of current research approaches used to address this goal. A diverse combination of approaches is essential to decipher the consequences of OA to marine organisms, communities, and ecosystems. Consequently, the benefits and limitations of each approach must be considered carefully. Major research challenges involve experimentally addressing the effects of OA in the context of large natural variability in seawater carbonate system parameters and other interactive variables, integrating the results from different research approaches, and scaling results across different temporal and spatial scales.
Pivetta, Tiziana; Isaia, Francesco; Trudu, Federica; Pani, Alessandra; Manca, Matteo; Perra, Daniela; Amato, Filippo; Havel, Josef
2013-10-15
The combination of two or more drugs using multidrug mixtures is a trend in the treatment of cancer. The goal is to search for a synergistic effect and thereby reduce the required dose and inhibit the development of resistance. An advanced model-free approach for data exploration and analysis, based on artificial neural networks (ANN) and experimental design is proposed to predict and quantify the synergism of drugs. The proposed method non-linearly correlates the concentrations of drugs with the cytotoxicity of the mixture, providing the possibility of choosing the optimal drug combination that gives the maximum synergism. The use of ANN allows for the prediction of the cytotoxicity of each combination of drugs in the chosen concentration interval. The method was validated by preparing and experimentally testing the combinations with the predicted highest synergistic effect. In all cases, the data predicted by the network were experimentally confirmed. The method was applied to several binary mixtures of cisplatin and [Cu(1,10-orthophenanthroline)2(H2O)](ClO4)2, Cu(1,10-orthophenanthroline)(H2O)2(ClO4)2 or [Cu(1,10-orthophenanthroline)2(imidazolidine-2-thione)](ClO4)2. The cytotoxicity of the two drugs, alone and in combination, was determined against human acute T-lymphoblastic leukemia cells (CCRF-CEM). For all systems, a synergistic effect was found for selected combinations. © 2013 Elsevier B.V. All rights reserved.
Numerical and experimental validation of a particle Galerkin method for metal grinding simulation
NASA Astrophysics Data System (ADS)
Wu, C. T.; Bui, Tinh Quoc; Wu, Youcai; Luo, Tzui-Liang; Wang, Morris; Liao, Chien-Chih; Chen, Pei-Yin; Lai, Yu-Sheng
2018-03-01
In this paper, a numerical approach with an experimental validation is introduced for modelling high-speed metal grinding processes in 6061-T6 aluminum alloys. The derivation of the present numerical method starts with an establishment of a stabilized particle Galerkin approximation. A non-residual penalty term from strain smoothing is introduced as a means of stabilizing the particle Galerkin method. Additionally, second-order strain gradients are introduced to the penalized functional for the regularization of damage-induced strain localization problem. To handle the severe deformation in metal grinding simulation, an adaptive anisotropic Lagrangian kernel is employed. Finally, the formulation incorporates a bond-based failure criterion to bypass the prospective spurious damage growth issues in material failure and cutting debris simulation. A three-dimensional metal grinding problem is analyzed and compared with the experimental results to demonstrate the effectiveness and accuracy of the proposed numerical approach.
Multi-criteria decision making approaches for quality control of genome-wide association studies.
Malovini, Alberto; Rognoni, Carla; Puca, Annibale; Bellazzi, Riccardo
2009-03-01
Experimental errors in the genotyping phases of a Genome-Wide Association Study (GWAS) can lead to false positive findings and to spurious associations. An appropriate quality control phase could minimize the effects of this kind of errors. Several filtering criteria can be used to perform quality control. Currently, no formal methods have been proposed for taking into account at the same time these criteria and the experimenter's preferences. In this paper we propose two strategies for setting appropriate genotyping rate thresholds for GWAS quality control. These two approaches are based on the Multi-Criteria Decision Making theory. We have applied our method on a real dataset composed by 734 individuals affected by Arterial Hypertension (AH) and 486 nonagenarians without history of AH. The proposed strategies appear to deal with GWAS quality control in a sound way, as they lead to rationalize and make explicit the experimenter's choices thus providing more reproducible results.
Ferber, Julia; Schneider, Gudrun; Havlik, Linda; Heuft, Gereon; Friederichs, Hendrik; Schrewe, Franz-Bernhard; Schulz-Steinel, Andrea; Burgmer, Markus
2014-01-01
To improve the synergy of established methods of teaching, the Department of Psychosomatics and Psychotherapy, University Hospital Münster, developed a web-based elearning tool using video clips of standardized patients. The effect of this blended-learning approach was evaluated. A multiple-choice test was performed by a naive (without the e-learning tool) and an experimental (with the tool) cohort of medical students to test the groups' expertise in psychosomatics. In addition, participants' satisfaction with the new tool was evaluated (numeric rating scale of 0-10). The experimental cohort was more satisfied with the curriculum and more interested in psychosomatics. Furthermore, the experimental cohort scored significantly better in the multiple-choice test. The new tool proved to be an important addition to the classical curriculum as a blended-learning approach which improves students' satisfaction and knowledge in psychosomatics.
Effects of Hydrolysis on Determining the Solubility Product of Potassium Bitartrate
ERIC Educational Resources Information Center
McNaught, Ian J.; Peckham, Gavin D.
2009-01-01
The method given in many publications for calculating the solubility product of potassium bitartrate is wrong in principle. A way of modifying the experimental approach and calculations to overcome the problem are presented.
K.C. Weathers; J.A. Lynch
2011-01-01
To determine the effects of air pollution on ecological systems using the critical load approach, accurate estimates of total nitrogen (N) deposition are essential. Empirical critical loads are set by relating observed ecosystem responses to N deposition (measured, experimentally manipulated, or modeled).
Levitated optomechanics with a fiber Fabry-Perot interferometer
NASA Astrophysics Data System (ADS)
Pontin, A.; Mourounas, L. S.; Geraci, A. A.; Barker, P. F.
2018-02-01
In recent years, quantum phenomena have been experimentally demonstrated on variety of optomechanical systems ranging from micro-oscillators to photonic crystals. Since single photon couplings are quite small, most experimental approaches rely on the realization of high finesse Fabry-Perot cavities in order to enhance the effective coupling. Here we show that by exploiting a, long path, low finesse fiber Fabry-Perot interferometer ground state cooling can be achieved. We model a 100 m long cavity with a finesse of 10 and analyze the impact of additional noise sources arising from the fiber. As a mechanical oscillator we consider a levitated microdisk but the same approach could be applied to other optomechanical systems.
Solution x-ray scattering and structure formation in protein dynamics
NASA Astrophysics Data System (ADS)
Nasedkin, Alexandr; Davidsson, Jan; Niemi, Antti J.; Peng, Xubiao
2017-12-01
We propose a computationally effective approach that builds on Landau mean-field theory in combination with modern nonequilibrium statistical mechanics to model and interpret protein dynamics and structure formation in small- to wide-angle x-ray scattering (S/WAXS) experiments. We develop the methodology by analyzing experimental data in the case of Engrailed homeodomain protein as an example. We demonstrate how to interpret S/WAXS data qualitatively with a good precision and over an extended temperature range. We explain experimental observations in terms of protein phase structure, and we make predictions for future experiments and for how to analyze data at different ambient temperature values. We conclude that the approach we propose has the potential to become a highly accurate, computationally effective, and predictive tool for analyzing S/WAXS data. For this, we compare our results with those obtained previously in an all-atom molecular dynamics simulation.
The scale of landscape fragmentation affects herbivore response to vegetation heterogeneity.
Banks, John E
1998-11-01
Using alternating bands of weeds and broccoli I experimentally manipulated vegetation composition and the spatial scale at which the landscape was fragmented in a factorial design. This experimental approach allowed me to distinguish the effect of spatial scale from that of simple crop heterogeneity on crop herbivores. The importance of scale depended on which insect species were examined. Cabbage aphids (Brevicoryne brassicae) were influenced by vegetation composition at all tested scales of fragmentation; cabbage butterflies (Pieris rapae) were not affected by scale or by composition and flea beetles (Phyllotreta cruciferae) revealed a striking dependence on scale of fragmentation as well as an interaction between scale and composition. This approach shows the importance of dissecting out the effects of scale from other aspects of landscape manipulation, and emphasizes the challenge of developing a theory that will enable prediction of species-specific responses to scale.
A new optimal sliding mode controller design using scalar sign function.
Singla, Mithun; Shieh, Leang-San; Song, Gangbing; Xie, Linbo; Zhang, Yongpeng
2014-03-01
This paper presents a new optimal sliding mode controller using the scalar sign function method. A smooth, continuous-time scalar sign function is used to replace the discontinuous switching function in the design of a sliding mode controller. The proposed sliding mode controller is designed using an optimal Linear Quadratic Regulator (LQR) approach. The sliding surface of the system is designed using stable eigenvectors and the scalar sign function. Controller simulations are compared with another existing optimal sliding mode controller. To test the effectiveness of the proposed controller, the controller is implemented on an aluminum beam with piezoceramic sensor and actuator for vibration control. This paper includes the control design and stability analysis of the new optimal sliding mode controller, followed by simulation and experimental results. The simulation and experimental results show that the proposed approach is very effective. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.
Visser, Lennart; Schoonenboom, Judith; Korthagen, Fred A J
2017-01-01
This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students ( N = 54). The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23), the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks), the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term.
Accurate position estimation methods based on electrical impedance tomography measurements
NASA Astrophysics Data System (ADS)
Vergara, Samuel; Sbarbaro, Daniel; Johansen, T. A.
2017-08-01
Electrical impedance tomography (EIT) is a technology that estimates the electrical properties of a body or a cross section. Its main advantages are its non-invasiveness, low cost and operation free of radiation. The estimation of the conductivity field leads to low resolution images compared with other technologies, and high computational cost. However, in many applications the target information lies in a low intrinsic dimensionality of the conductivity field. The estimation of this low-dimensional information is addressed in this work. It proposes optimization-based and data-driven approaches for estimating this low-dimensional information. The accuracy of the results obtained with these approaches depends on modelling and experimental conditions. Optimization approaches are sensitive to model discretization, type of cost function and searching algorithms. Data-driven methods are sensitive to the assumed model structure and the data set used for parameter estimation. The system configuration and experimental conditions, such as number of electrodes and signal-to-noise ratio (SNR), also have an impact on the results. In order to illustrate the effects of all these factors, the position estimation of a circular anomaly is addressed. Optimization methods based on weighted error cost functions and derivate-free optimization algorithms provided the best results. Data-driven approaches based on linear models provided, in this case, good estimates, but the use of nonlinear models enhanced the estimation accuracy. The results obtained by optimization-based algorithms were less sensitive to experimental conditions, such as number of electrodes and SNR, than data-driven approaches. Position estimation mean squared errors for simulation and experimental conditions were more than twice for the optimization-based approaches compared with the data-driven ones. The experimental position estimation mean squared error of the data-driven models using a 16-electrode setup was less than 0.05% of the tomograph radius value. These results demonstrate that the proposed approaches can estimate an object’s position accurately based on EIT measurements if enough process information is available for training or modelling. Since they do not require complex calculations it is possible to use them in real-time applications without requiring high-performance computers.
NASA Astrophysics Data System (ADS)
Xue, ShiChuan; Wu, JunJie; Xu, Ping; Yang, XueJun
2018-02-01
Quantum computing is a significant computing capability which is superior to classical computing because of its superposition feature. Distinguishing several quantum states from quantum algorithm outputs is often a vital computational task. In most cases, the quantum states tend to be non-orthogonal due to superposition; quantum mechanics has proved that perfect outcomes could not be achieved by measurements, forcing repetitive measurement. Hence, it is important to determine the optimum measuring method which requires fewer repetitions and a lower error rate. However, extending current measurement approaches mainly aiming at quantum cryptography to multi-qubit situations for quantum computing confronts challenges, such as conducting global operations which has considerable costs in the experimental realm. Therefore, in this study, we have proposed an optimum subsystem method to avoid these difficulties. We have provided an analysis of the comparison between the reduced subsystem method and the global minimum error method for two-qubit problems; the conclusions have been verified experimentally. The results showed that the subsystem method could effectively discriminate non-orthogonal two-qubit states, such as separable states, entangled pure states, and mixed states; the cost of the experimental process had been significantly reduced, in most circumstances, with acceptable error rate. We believe the optimal subsystem method is the most valuable and promising approach for multi-qubit quantum computing applications.
Dissipation-induced dipole blockade and antiblockade in driven Rydberg systems
NASA Astrophysics Data System (ADS)
Young, Jeremy T.; Boulier, Thomas; Magnan, Eric; Goldschmidt, Elizabeth A.; Wilson, Ryan M.; Rolston, Steven L.; Porto, James V.; Gorshkov, Alexey V.
2018-02-01
We study theoretically and experimentally the competing blockade and antiblockade effects induced by spontaneously generated contaminant Rydberg atoms in driven Rydberg systems. These contaminant atoms provide a source of strong dipole-dipole interactions and play a crucial role in the system's behavior. We study this problem theoretically using two different approaches. The first is a cumulant expansion approximation, in which we ignore third-order and higher connected correlations. Using this approach for the case of resonant drive, a many-body blockade radius picture arises, and we find qualitative agreement with previous experimental results. We further predict that as the atomic density is increased, the Rydberg population's dependence on Rabi frequency will transition from quadratic to linear dependence at lower Rabi frequencies. We study this behavior experimentally by observing this crossover at two different atomic densities. We confirm that the larger density system has a smaller crossover Rabi frequency than the smaller density system. The second theoretical approach is a set of phenomenological inhomogeneous rate equations. We compare the results of our rate-equation model to the experimental observations [E. A. Goldschmidt et al., Phys. Rev. Lett. 116, 113001 (2016), 10.1103/PhysRevLett.116.113001] and find that these rate equations provide quantitatively good scaling behavior of the steady-state Rydberg population for both resonant and off-resonant drives.
Isoscalar compression modes within fluid dynamic approach
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kolomietz, V. M.; Cyclotron Institute, Texas A and M University, College Station, Texas 77843-3366; Shlomo, S.
2000-06-01
We study the nuclear isoscalar monopole and dipole compression modes in nuclei within the fluid dynamic approach (FDA) with and without the effect of relaxation. For a wide region of the medium and heavy nuclei, the FDA predicts that the isoscalar giant monopole resonance (ISGMR) and the isoscalar giant dipole resonance (ISGDR) exhaust about 90% of the corresponding model-independent sum rules. In the case of neglecting the effect of relaxation, the FDA, when adjusted to reproduce the centroid energy E0 of the ISGMR, results with centroid energy E1 of the ISGDR which is in agreement with the predictions of themore » self-consistent Hartree-Fock random-phase approximation calculations and the scaling model but significantly larger than the experimental value. We also show that the FDA leads to the correct hydrodynamic limit for the ratio (E1/E0){sub FDA}. We find that the ratio (E1/E0){sub FDA} depends on the relaxation time and approaches the preliminary experimental value (E1/E0){sub exp}=1.5{+-}0.1 in a short relaxation time limit. (c) 2000 The American Physical Society.« less
An experimental investigation on thermal exposure during bone drilling.
Lee, Jueun; Ozdoganlar, O Burak; Rabin, Yoed
2012-12-01
This study presents an experimental investigation of the effects of spindle speed, feed rate, and depth of drilling on the temperature distribution during drilling of the cortical section of the bovine femur. In an effort to reduce measurement uncertainties, a new approach for temperature measurements during bone drilling is presented in this study. The new approach is based on a setup for precise positioning of multiple thermocouples, automated data logging system, and a computer numerically controlled (CNC) machining system. A battery of experiments that has been performed to assess the uncertainty and repeatability of the new approach displayed adequate results. Subsequently, a parametric study was conducted to determine the effects of spindle speed, feed rate, hole depth, and thermocouple location on the measured bone temperature. This study suggests that the exposure time during bone drilling far exceeds the commonly accepted threshold for thermal injury, which may prevail at significant distances from the drilled hole. Results of this study suggest that the correlation of the thermal exposure threshold for bone injury and viability should be further explored. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.
An External Archive-Guided Multiobjective Particle Swarm Optimization Algorithm.
Zhu, Qingling; Lin, Qiuzhen; Chen, Weineng; Wong, Ka-Chun; Coello Coello, Carlos A; Li, Jianqiang; Chen, Jianyong; Zhang, Jun
2017-09-01
The selection of swarm leaders (i.e., the personal best and global best), is important in the design of a multiobjective particle swarm optimization (MOPSO) algorithm. Such leaders are expected to effectively guide the swarm to approach the true Pareto optimal front. In this paper, we present a novel external archive-guided MOPSO algorithm (AgMOPSO), where the leaders for velocity update are all selected from the external archive. In our algorithm, multiobjective optimization problems (MOPs) are transformed into a set of subproblems using a decomposition approach, and then each particle is assigned accordingly to optimize each subproblem. A novel archive-guided velocity update method is designed to guide the swarm for exploration, and the external archive is also evolved using an immune-based evolutionary strategy. These proposed approaches speed up the convergence of AgMOPSO. The experimental results fully demonstrate the superiority of our proposed AgMOPSO in solving most of the test problems adopted, in terms of two commonly used performance measures. Moreover, the effectiveness of our proposed archive-guided velocity update method and immune-based evolutionary strategy is also experimentally validated on more than 30 test MOPs.
ERIC Educational Resources Information Center
Zaid, Mohammed A.
2009-01-01
In a quasi-experimental study, the researcher used two approaches to vocabulary instruction with 34 Level III College of Languages and Translation students, enrolled in King Khalid University, KSA. The purpose of the study was to explore the effects of each approach. One strategy emphasized direct teaching of the individual meanings for a set of…
ERIC Educational Resources Information Center
Kinchen, John Dawson, III
2012-01-01
As a result of a perceived need to improve the music theory curricula for the preparation of church music leaders, this study compared two diverse approaches to the teaching of music theory for church music university students on achievement, attitudes, and self-preparedness. This current study was a quantitative, quasi-experimental research…
ERIC Educational Resources Information Center
McInerney, Valentina; McInerney, Dennis M.
This paper presents a model of how multimethod approaches to research can be used to understand and measure individual diversity in learning, cognitions, and affect. The paper demonstrates the value of gathering qualitative data to supplement quantitative findings from quasi-experimental research in relation to achievement outcomes, acquiring a…
An Agent-based Approach to Evaluating the Impact of Technologies on C2
2006-06-01
from field experimentation and current military doctrine were identified for the evaluation of SPEYES technologies , which we aligned with field test...and procedures (TTPs). However, the introduction of new technologies to support C2 significantly impacts performance and effectiveness of military ...addressed various challenges of Military Operations in Urban Terrain (MOUT). Our novel approach combined the strengths of field assessment with
Associated {Upsilon}+{gamma} production at the LHC in the k{sub t}-factorization approach
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baranov, S. P.
In the framework of the k{sub t}-factorization approach, the photon-associated production of {Upsilon} mesons at the present-day LHC conditions is studied. The differential cross sections and polarization parameters are calculated in the ''helicity'' and Collins-Soper systems. Special attention is paid to the effect of experimental cuts that can dramatically change the visible lepton angular distributions.
The Effects of Scenario Planning on Participant Reports of Resilience
ERIC Educational Resources Information Center
Chermack, Thomas J.; Coons, Laura M.; O'barr, Gregory; Khatami, Shiva
2017-01-01
Purpose: The purpose of this research is to examine the effects of scenario planning on participant ratings of resilience. Design/methodology/approach: The research design is a quasi experimental pretest/posttest with treatment and control groups. Random selection or assignment was not achieved. Findings: Results show a significant difference in…
The Effect of Project Based Learning on Seventh Grade Students' Academic Achievement
ERIC Educational Resources Information Center
Kizkapan, Oktay; Bektas, Oktay
2017-01-01
The purpose of this study is to investigate whether there is a significant effect of project based learning approach on seventh grade students' academic achievement in the structure and properties of matter. In the study, according to the characteristics of quantitative research methods, pretest-posttest control group quasi-experimental design was…
Effects of Cueing by a Pedagogical Agent in an Instructional Animation: A Cognitive Load Approach
ERIC Educational Resources Information Center
Yung, Hsin I.; Paas, Fred
2015-01-01
This study investigated the effects of a pedagogical agent that cued relevant information in a story-based instructional animation on the cardiovascular system. Based on cognitive load theory, it was expected that the experimental condition with the pedagogical agent would facilitate students to distinguish between relevant and irrelevant…
AN EXPERIMENTAL APPROACH TO THE EFFECTS OF EXPERIENCE ON EARLY HUMAN BEHAVIOR.
ERIC Educational Resources Information Center
WHITE, BURTON L.
SEVERAL STUDIES ON SENSORIMOTOR FUNCTIONS IN INFANTS WERE REPORTED. DAY-TO-DAY OBSERVATIONS WERE MADE OF INSTITUTIONALIZED INFANTS IN AN ATTEMPT TO COLLECT BASELINE DATA ON ADAPTIVE ABILITIES IN CHILDREN. THE EVOLUTION OF FUNDAMENTAL SENSORIMOTOR SKILLS WAS TRACED TO PROVIDE CLUES FOR THE STUDY OF ENVIRONMENTAL EFFECTS ON THE DEVELOPMENTAL…
Toothbrushing at School: Effects on Toothbrushing Behaviour, Cognitions and Habit Strength
ERIC Educational Resources Information Center
Wind, Marianne; Kremers, Stef; Thijs, Carel; Brug, Johannes
2005-01-01
Purpose: To assess the impact of a school-based toothbrushing intervention aimed at encouraging primary school children to brush their teeth daily at school, on cognitions, toothbrushing behaviour and habit strength. Design/methodology/approach: The effects of an intervention were examined in a quasi-experimental trial among 296 fifth-graders in…
NASA Astrophysics Data System (ADS)
Souley, Mountaka; Lopez, Philippe; Boulon, Marc; Thoraval, Alain
2015-05-01
The experimental device previously used to study the hydromechanical behaviour of individual fractures on a laboratory scale, was adapted to make it possible to measure flow through porous rock mass samples in addition to fracture flows. A first series of tests was performed to characterize the hydromechanical behaviour of the fracture individually as well as the porous matrix (sandstone) comprising the fracture walls. A third test in this series was used to validate the experimental approach. These tests showed non-linear evolution of the contact area on the fracture walls with respect to effective normal stress. Consequently, a non-linear relationship was noted between the hydraulic aperture on the one hand, and the effective normal stress and mechanical opening on the other hand. The results of the three tests were then analysed by numerical modelling. The VIPLEF/HYDREF numerical codes used take into account the dual-porosity of the sample (fracture + rock matrix) and can be used to reproduce hydromechanical loading accurately. The analyses show that the relationship between the hydraulic aperture of the fracture and the mechanical closure has a significant effect on fracture flow rate predictions. By taking simultaneous measurements of flow in both fracture and rock matrix, we were able to carry out a global evaluation of the conceptual approach used.
3-D plasma boundary and plasma wall interaction research at UW-Madison
NASA Astrophysics Data System (ADS)
Schmitz, Oliver; Akerson, Adrian; Bader, Aaron; Barbui, Tullio; Effenberg, Florian; Flesch, Kurt; Frerichs, Heinke; Green, Jonathan; Hinson, Edward; Kremeyer, Thierry; Norval, Ryan; Stephey, Laurie; Waters, Ian; Winters, Victoria
2016-10-01
The necessity of considering 3-D effects on the plasma boundary and plasma wall interaction (PWI) in tokamaks, stellarators and reversed field pinches has been highlighted by abundant experimental and numerical results in the recent past. Prominent examples with 3-D boundary situations are numerous: ELM controlled H-modes by RMP fields in tokamaks, research on boundary plasmas and PWI in stellarators in general, quasi-helical states in RFPs, asymmetric fueling situations, and structural and wall elements which are not aligned with the magnetic guiding fields. A systematic approach is being taken at UW-Madison to establish a targeted experimental basis for identifying the most significant effects for plasma edge transport and resulting PWI in such 3-D plasma boundary situations. We deploy advanced 3-D modeling using the EMC3-EIRENE, ERO and MCI codes in combination with laboratory experiments at UW-Madison to investigate the relevance of 3-D effects in large scale devices with a concerted approach on DIII-D, NSTX-U, and Wendelstein 7-X. Highlights of experimental results from the on-site laboratory activities at UW-Madison and the large scale facilities are presented and interlinks will be discussed. This work was supported by US DOE DE-SC0013911, DE-SC00012315 and DE-SC00014210.
Richardson, Miles
2017-04-01
In ergonomics there is often a need to identify and predict the separate effects of multiple factors on performance. A cost-effective fractional factorial approach to understanding the relationship between task characteristics and task performance is presented. The method has been shown to provide sufficient independent variability to reveal and predict the effects of task characteristics on performance in two domains. The five steps outlined are: selection of performance measure, task characteristic identification, task design for user trials, data collection, regression model development and task characteristic analysis. The approach can be used for furthering knowledge of task performance, theoretical understanding, experimental control and prediction of task performance. Practitioner Summary: A cost-effective method to identify and predict the separate effects of multiple factors on performance is presented. The five steps allow a better understanding of task factors during the design process.
New approach to calculate the true-coincidence effect of HpGe detector
NASA Astrophysics Data System (ADS)
Alnour, I. A.; Wagiran, H.; Ibrahim, N.; Hamzah, S.; Siong, W. B.; Elias, M. S.
2016-01-01
The corrections for true-coincidence effects in HpGe detector are important, especially at low source-to-detector distances. This work established an approach to calculate the true-coincidence effects experimentally for HpGe detectors of type Canberra GC3018 and Ortec GEM25-76-XLB-C, which are in operation at neutron activation analysis lab in Malaysian Nuclear Agency (NM). The correction for true-coincidence effects was performed close to detector at distances 2 and 5 cm using 57Co, 60Co, 133Ba and 137Cs as standard point sources. The correction factors were ranged between 0.93-1.10 at 2 cm and 0.97-1.00 at 5 cm for Canberra HpGe detector; whereas for Ortec HpGe detector ranged between 0.92-1.13 and 0.95-100 at 2 and 5 cm respectively. The change in efficiency calibration curve of the detector at 2 and 5 cm after correction was found to be less than 1%. Moreover, the polynomial parameters functions were simulated through a computer program, MATLAB in order to find an accurate fit to the experimental data points.
Exploring novel objective functions for simulating muscle coactivation in the neck.
Mortensen, J; Trkov, M; Merryweather, A
2018-04-11
Musculoskeletal modeling allows for analysis of individual muscles in various situations. However, current techniques to realistically simulate muscle response when significant amounts of intentional coactivation is required are inadequate. This would include stiffening the neck or spine through muscle coactivation in preparation for perturbations or impacts. Muscle coactivation has been modeled previously in the neck and spine using optimization techniques that seek to maximize the joint stiffness by maximizing total muscle activation or muscle force. These approaches have not sought to replicate human response, but rather to explore the possible effects of active muscle. Coactivation remains a challenging feature to include in musculoskeletal models, and may be improved by extracting optimization objective functions from experimental data. However, the components of such an objective function must be known before fitting to experimental data. This study explores the effect of components in several objective functions, in order to recommend components to be used for fitting to experimental data. Four novel approaches to modeling coactivation through optimization techniques are presented, two of which produce greater levels of stiffness than previous techniques. Simulations were performed using OpenSim and MATLAB cooperatively. Results show that maximizing the moment generated by a particular muscle appears analogous to maximizing joint stiffness. The approach of optimizing for maximum moment generated by individual muscles may be a good candidate for developing objective functions that accurately simulate muscle coactivation in complex joints. This new approach will be the focus of future studies with human subjects. Copyright © 2018 Elsevier Ltd. All rights reserved.
Approaches to answering critical CER questions.
Kinnier, Christine V; Chung, Jeanette W; Bilimoria, Karl Y
2015-01-01
While randomized controlled trials (RCTs) are the gold standard for research, many research questions cannot be ethically and practically answered using an RCT. Comparative effectiveness research (CER) techniques are often better suited than RCTs to address the effects of an intervention under routine care conditions, an outcome otherwise known as effectiveness. CER research techniques covered in this section include: effectiveness-oriented experimental studies such as pragmatic trials and cluster randomized trials, treatment response heterogeneity, observational and database studies including adjustment techniques such as sensitivity analysis and propensity score analysis, systematic reviews and meta-analysis, decision analysis, and cost effectiveness analysis. Each section describes the technique and covers the strengths and weaknesses of the approach.
Trial opens to evaluate experimental cancer drug against solid tumors | Center for Cancer Research
Chemotherapy drugs have long been the mainstay of treatment for advanced solid tumors, but the toxic side effects of these drugs often limit the amount that can safely be given to patients. Doctors hope that PEN-866, an experimental cancer drug, can help to overcome this difficulty. Anish Thomas, M.D., who is leading this new trial, says, “This is a first-of-its-kind approach
D-Optimal Experimental Design for Contaminant Source Identification
NASA Astrophysics Data System (ADS)
Sai Baba, A. K.; Alexanderian, A.
2016-12-01
Contaminant source identification seeks to estimate the release history of a conservative solute given point concentration measurements at some time after the release. This can be mathematically expressed as an inverse problem, with a linear observation operator or a parameter-to-observation map, which we tackle using a Bayesian approach. Acquisition of experimental data can be laborious and expensive. The goal is to control the experimental parameters - in our case, the sparsity of the sensors, to maximize the information gain subject to some physical or budget constraints. This is known as optimal experimental design (OED). D-optimal experimental design seeks to maximize the expected information gain, and has long been considered the gold standard in the statistics community. Our goal is to develop scalable methods for D-optimal experimental designs involving large-scale PDE constrained problems with high-dimensional parameter fields. A major challenge for the OED, is that a nonlinear optimization algorithm for the D-optimality criterion requires repeated evaluation of objective function and gradient involving the determinant of large and dense matrices - this cost can be prohibitively expensive for applications of interest. We propose novel randomized matrix techniques that bring down the computational costs of the objective function and gradient evaluations by several orders of magnitude compared to the naive approach. The effect of randomized estimators on the accuracy and the convergence of the optimization solver will be discussed. The features and benefits of our new approach will be demonstrated on a challenging model problem from contaminant source identification involving the inference of the initial condition from spatio-temporal observations in a time-dependent advection-diffusion problem.
Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es; Pino, Francisco; Silva-Rodríguez, Jesús
2014-03-15
Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approachesmore » on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the projection noise than MC-SRM. Conclusions: The authors' findings show that both approaches provide good solutions to the problem of calculating the SRM in pinhole SPECT reconstruction. The AE-SRM was faster to create and handle the projection noise better than MC-SRM. Nevertheless, the AE-SRM required a tedious experimental characterization of the intrinsic detector response. Creation of the MC-SRM required longer computation time and handled the projection noise worse than the AE-SRM. Nevertheless, the MC-SRM inherently incorporates extensive modeling of the system and therefore experimental characterization was not required.« less
Strangeness S =-1 hyperon-nucleon scattering in covariant chiral effective field theory
NASA Astrophysics Data System (ADS)
Li, Kai-Wen; Ren, Xiu-Lei; Geng, Li-Sheng; Long, Bingwei
2016-07-01
Motivated by the successes of covariant baryon chiral perturbation theory in one-baryon systems and in heavy-light systems, we study relevance of relativistic effects in hyperon-nucleon interactions with strangeness S =-1 . In this exploratory work, we follow the covariant framework developed by Epelbaum and Gegelia to calculate the Y N scattering amplitude at leading order. By fitting the five low-energy constants to the experimental data, we find that the cutoff dependence is mitigated, compared with the heavy-baryon approach. Nevertheless, the description of the experimental data remains quantitatively similar at leading order.
Oscillational instabilities in single mode acoustics levitators
NASA Technical Reports Server (NTRS)
Rudnick, J.; Barmatz, Martin
1990-01-01
An extention of standard results for the acoustic force on an object in a single-mode resonant chamber yields predictions for the onset of oscillational instabilities when objects are levitated or positioned in these chambers. The authors' results are consistent with those of experimental investigators. The present approach accounts for the effects of time delays in the response of a cavity to the motion of an object inside of it. Quantitative features of the instabilities are investigated. The experimental conditions required for sample stability, saturation of sample oscillations, hysteretic effects, and the loss of ability to levitate are discussed.
Reducing multi-sensor data to a single time course that reveals experimental effects
2013-01-01
Background Multi-sensor technologies such as EEG, MEG, and ECoG result in high-dimensional data sets. Given the high temporal resolution of such techniques, scientific questions very often focus on the time-course of an experimental effect. In many studies, researchers focus on a single sensor or the average over a subset of sensors covering a “region of interest” (ROI). However, single-sensor or ROI analyses ignore the fact that the spatial focus of activity is constantly changing, and fail to make full use of the information distributed over the sensor array. Methods We describe a technique that exploits the optimality and simplicity of matched spatial filters in order to reduce experimental effects in multivariate time series data to a single time course. Each (multi-sensor) time sample of each trial is replaced with its projection onto a spatial filter that is matched to an observed experimental effect, estimated from the remaining trials (Effect-Matched Spatial filtering, or EMS filtering). The resulting set of time courses (one per trial) can be used to reveal the temporal evolution of an experimental effect, which distinguishes this approach from techniques that reveal the temporal evolution of an anatomical source or region of interest. Results We illustrate the technique with data from a dual-task experiment and use it to track the temporal evolution of brain activity during the psychological refractory period. We demonstrate its effectiveness in separating the means of two experimental conditions, and in significantly improving the signal-to-noise ratio at the single-trial level. It is fast to compute and results in readily-interpretable time courses and topographies. The technique can be applied to any data-analysis question that can be posed independently at each sensor, and we provide one example, using linear regression, that highlights the versatility of the technique. Conclusion The approach described here combines established techniques in a way that strikes a balance between power, simplicity, speed of processing, and interpretability. We have used it to provide a direct view of parallel and serial processes in the human brain that previously could only be measured indirectly. An implementation of the technique in MatLab is freely available via the internet. PMID:24125590
Single subject controlled experiments in aphasia: The science and the state of the science
Thompson, Cynthia K.
2007-01-01
This paper discusses the use of single subject controlled experimental designs for investigating the effect of treatment for aphasia. A brief historical perspective is presented, followed by discussions of the advantages and disadvantages of single subject and group approaches, the basic requirements of single subject experimental research, and crucial considerations in design selection. In the final sections, results of reviews of published single subject controlled experiments are discussed, with emphasis on internal validity issues, the number of participants enrolled in published studies, operational specification of the dependent and independent variables, and reliability of measurement. Learning outcomes As a result of reading this paper, the participant will: (1) understand the mechanisms required for demonstration of internal and external validity using single subject controlled experimental designs, (2) become familiar with the basic requirements of single subject controlled experimental research, (3) understand the types of single subject controlled experimental designs that are the most appropriate for studying the effects of treatment for aphasia, and (4) become familiar with trends in the published aphasia treatment literature in which single subject controlled experimental designs have been used. PMID:16635494
Statistical modelling of networked human-automation performance using working memory capacity.
Ahmed, Nisar; de Visser, Ewart; Shaw, Tyler; Mohamed-Ameen, Amira; Campbell, Mark; Parasuraman, Raja
2014-01-01
This study examines the challenging problem of modelling the interaction between individual attentional limitations and decision-making performance in networked human-automation system tasks. Analysis of real experimental data from a task involving networked supervision of multiple unmanned aerial vehicles by human participants shows that both task load and network message quality affect performance, but that these effects are modulated by individual differences in working memory (WM) capacity. These insights were used to assess three statistical approaches for modelling and making predictions with real experimental networked supervisory performance data: classical linear regression, non-parametric Gaussian processes and probabilistic Bayesian networks. It is shown that each of these approaches can help designers of networked human-automated systems cope with various uncertainties in order to accommodate future users by linking expected operating conditions and performance from real experimental data to observable cognitive traits like WM capacity. Practitioner Summary: Working memory (WM) capacity helps account for inter-individual variability in operator performance in networked unmanned aerial vehicle supervisory tasks. This is useful for reliable performance prediction near experimental conditions via linear models; robust statistical prediction beyond experimental conditions via Gaussian process models and probabilistic inference about unknown task conditions/WM capacities via Bayesian network models.
Statistical Analysis for Collision-free Boson Sampling.
Huang, He-Liang; Zhong, Han-Sen; Li, Tan; Li, Feng-Guang; Fu, Xiang-Qun; Zhang, Shuo; Wang, Xiang; Bao, Wan-Su
2017-11-10
Boson sampling is strongly believed to be intractable for classical computers but solvable with photons in linear optics, which raises widespread concern as a rapid way to demonstrate the quantum supremacy. However, due to its solution is mathematically unverifiable, how to certify the experimental results becomes a major difficulty in the boson sampling experiment. Here, we develop a statistical analysis scheme to experimentally certify the collision-free boson sampling. Numerical simulations are performed to show the feasibility and practicability of our scheme, and the effects of realistic experimental conditions are also considered, demonstrating that our proposed scheme is experimentally friendly. Moreover, our broad approach is expected to be generally applied to investigate multi-particle coherent dynamics beyond the boson sampling.
Clinical and experimental study of TMJ distraction: preliminary results.
Festa, F; Galluccio, G
1998-01-01
A physiotherapeutic approach, with manual maneuvers and/or distraction appliances, is indicated in the treatment of temporomandibular joint disorders (TMDs) to prevent the progressive fibrosis of the muscle fibers. In this article, the authors report preliminary results of experimental and clinical studies conducted to assess the real effect of distraction in temporomandibular joint disorders. The experimental invivo studies confirmed the structural alteration due to compression and distraction on the capsular and condylar tissues. Clinical cases are reported to show the increase of the intraarticular vertical dimension, with a forward and downward movement of the condyles in a more physiologic condition.
Experimental modal analysis of the fuselage panels of an Aero Commander aircraft
NASA Technical Reports Server (NTRS)
Geisler, D.
1981-01-01
The reduction of interior noise in light aircraft was investigated with emphasis the thin fuselage sidewall. The approach used is theoretical and involves modeling of the sidewall panels and stiffeners. Experimental data obtained from tests investigating the effects of mass and stiffness treatments to the sidewalls are presented. The dynamic characteristics of treated panels are contrasted with the untreated sidewall panels using experimental modal analysis techniques. The results include the natural frequencies, modal dampling, and mode shapes of selected panels. Frequency response functions, data relating to the global fuselage response, and acoustic response are also presented.
Jin, Biao; Haderlein, Stefan B; Rolle, Massimo
2013-02-05
We propose a self-consistent method to predict the evolution of carbon and chlorine isotope ratios during degradation of chlorinated hydrocarbons. The method treats explicitly the cleavage of isotopically different C-Cl bonds and thus considers, simultaneously, combined carbon-chlorine isotopologues. To illustrate the proposed modeling approach we focus on the reductive dehalogenation of chlorinated ethenes. We compare our method with the currently available approach, in which carbon and chlorine isotopologues are treated separately. The new approach provides an accurate description of dual-isotope effects regardless of the extent of the isotope fractionation and physical characteristics of the experimental system. We successfully applied the new approach to published experimental results on dehalogenation of chlorinated ethenes both in well-mixed systems and in situations where mass-transfer limitations control the overall rate of biodegradation. The advantages of our self-consistent dual isotope modeling approach proved to be most evident when isotope fractionation factors of carbon and chlorine differed significantly and for systems with mass-transfer limitations, where both physical and (bio)chemical transformation processes affect the observed isotopic values.
Tse, Mimi M Y; Chan, M F; Benzie, Iris F F
2005-01-01
The prevalence of unrelieved postoperative pain is high and may lead to adverse effects including prolonged hospitalization and delayed recovery. Distraction may be an effective pain-relieving strategy, and can be implemented by several means including affective imaging, games, and possibly music. The aim of this study was to explore the effect of music therapy on postoperative pain. Fifty-seven patients (24 females, 33 males; mean +/- SD age 39.9 +/- 14.35 years [range 15 to 69 years] were matched for age and sex and then nonselectively assigned to either an experimental (n = 27) or a control (n = 30) group. Music was played intermittently to members of the experimental group during the first 24 hour postoperative period. Pain intensity was measured using the Pain Verbal Rating Scales (VRS). Significant decreases in pain intensity over time were found in the experimental group compared to the control group (p < 0.0001). In addition, the experimental group had a lower systolic blood pressure and heart rate, and took fewer oral analgesics for pain. These findings suggest that music therapy is an effective nonpharmacologic approach for postoperative pain management.
Longhi, Daniel Angelo; Martins, Wiaslan Figueiredo; da Silva, Nathália Buss; Carciofi, Bruno Augusto Mattar; de Aragão, Gláucia Maria Falcão; Laurindo, João Borges
2017-01-02
In predictive microbiology, the model parameters have been estimated using the sequential two-step modeling (TSM) approach, in which primary models are fitted to the microbial growth data, and then secondary models are fitted to the primary model parameters to represent their dependence with the environmental variables (e.g., temperature). The Optimal Experimental Design (OED) approach allows reducing the experimental workload and costs, and the improvement of model identifiability because primary and secondary models are fitted simultaneously from non-isothermal data. Lactobacillus viridescens was selected to this study because it is a lactic acid bacterium of great interest to meat products preservation. The objectives of this study were to estimate the growth parameters of L. viridescens in culture medium from TSM and OED approaches and to evaluate both the number of experimental data and the time needed in each approach and the confidence intervals of the model parameters. Experimental data for estimating the model parameters with TSM approach were obtained at six temperatures (total experimental time of 3540h and 196 experimental data of microbial growth). Data for OED approach were obtained from four optimal non-isothermal profiles (total experimental time of 588h and 60 experimental data of microbial growth), two profiles with increasing temperatures (IT) and two with decreasing temperatures (DT). The Baranyi and Roberts primary model and the square root secondary model were used to describe the microbial growth, in which the parameters b and T min (±95% confidence interval) were estimated from the experimental data. The parameters obtained from TSM approach were b=0.0290 (±0.0020) [1/(h 0.5 °C)] and T min =-1.33 (±1.26) [°C], with R 2 =0.986 and RMSE=0.581, and the parameters obtained with the OED approach were b=0.0316 (±0.0013) [1/(h 0.5 °C)] and T min =-0.24 (±0.55) [°C], with R 2 =0.990 and RMSE=0.436. The parameters obtained from OED approach presented smaller confidence intervals and best statistical indexes than those from TSM approach. Besides, less experimental data and time were needed to estimate the model parameters with OED than TSM. Furthermore, the OED model parameters were validated with non-isothermal experimental data with great accuracy. In this way, OED approach is feasible and is a very useful tool to improve the prediction of microbial growth under non-isothermal condition. Copyright © 2016 Elsevier B.V. All rights reserved.
ERIC Educational Resources Information Center
Rosén, Monica; Gustafsson, Jan-Eric
2016-01-01
Research on effects of home computer use on children's development of cognitive abilities and skills has yielded conflicting results, with some studies showing positive effects, others no effects, and yet others negative effects. These studies have typically used non-experimental designs and one of the main reasons for the conflicting results is…
Zhan, Xingxin; Zhang, Zhixia; Sun, Fang; Liu, Qian; Peng, Weijun; Zhang, Heng; Yan, Weirong
2017-05-01
Primary health care workers (PHCWs) are a major force in delivering basic public health services (BPHS) in rural China. It is necessary to take effective training approaches to improve PHCWs' competency on BPHS. Both electronic learning (e-learning) and blended learning have been widely used in the health workers' education. However, there is limited evidence on the effects of blended learning in comparison with pure e-learning. The aim of this study was to evaluate the effects of a blended-learning approach for rural PHCWs in improving their knowledge about BPHS as well as training satisfaction in comparison with a pure e-learning approach. The study was conducted among PHCWs in 6 rural counties of Hubei Province, China, between August 2013 and April 2014. Three counties were randomly allocated blended-learning courses (29 township centers or 612 PHCWs-the experimental group), and three counties were allocated pure e-learning courses (31 township centers or 625 PHCWs-the control group). Three course modules were administered for 5 weeks, with assessments at baseline and postcourse. Primary outcomes were score changes in courses' knowledge. Secondary outcome was participant satisfaction (5-point Likert scale anchored between 1 [strongly agree] and 5 [strongly disagree]). The experimental group had higher mean scores than the control group in knowledge achievement in three course modules: (1) module 1: 93.21 (95% CI 92.49-93.93) in experimental group versus 88.29 (95% CI 87.19-89.40) in the control group; adjusted difference, 4.92 (95% CI 2.61-7.24; P<.001); (2) module 2: 94.05 (95% CI 93.37-94.73) in the experimental group vs 90.22 (95% CI 89.12-91.31) in the control group; adjusted difference, 3.67 (95% CI 1.17-6.18; P=.004); (3) module 3: 93.88 (95% CI 93.08-94.68) in the experimental group versus 89.09 (95% CI 87.89-90.30) in control group; adjusted difference, 4.63 (95% CI 2.12-7.14; P<.001). The participants in the experimental learning group gave more positive responses with the four issues than control group participants: (1) the increase of interest in learning, 1.85 (95% CI 1.22-2.80; P=.003); (2) the increase of interaction with others, 1.77 (95% CI 1.20-2.60; P=.004); (3) the satisfaction with learning experience, 1.78 (95% CI 1.11-2.88; P=.02); and (4) achievement of learning objectives, 1.63 (95% CI 1.08-2.48; P=.02). Among PHCWs in rural China, a blended-learning approach to BPHS training could result in a higher knowledge achievement and satisfaction level compared with a pure e-learning approach. The findings of the study will contribute knowledge to improve the competency of PHCWs in similar settings. ©Xingxin Zhan, Zhixia Zhang, Fang Sun, Qian Liu, Weijun Peng, Heng Zhang, Weirong Yan. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 01.05.2017.
NASA Astrophysics Data System (ADS)
S, Chidambara Raja; P, Karthikeyan; Kumaraswamidhas, L. A.; M, Ramu
2018-05-01
Most of the thermal design systems involve two phase materials and analysis of such systems requires detailed understanding of the thermal characteristics of the two phase material. This article aimed to develop geometry dependent unit cell approach model by considering the effects of all primary parameters (conductivity ratio and concentration) and secondary parameters (geometry, contact resistance, natural convection, Knudsen and radiation) for the estimation of effective thermal conductivity of two-phase materials. The analytical equations have been formulated based on isotherm approach for 2-D and 3-D spatially periodic medium. The developed models are validated with standard models and suited for all kind of operating conditions. The results have shown substantial improvement compared to the existing models and are in good agreement with the experimental data.
A Semantic Medical Multimedia Retrieval Approach Using Ontology Information Hiding
Guo, Kehua; Zhang, Shigeng
2013-01-01
Searching useful information from unstructured medical multimedia data has been a difficult problem in information retrieval. This paper reports an effective semantic medical multimedia retrieval approach which can reflect the users' query intent. Firstly, semantic annotations will be given to the multimedia documents in the medical multimedia database. Secondly, the ontology that represented semantic information will be hidden in the head of the multimedia documents. The main innovations of this approach are cross-type retrieval support and semantic information preservation. Experimental results indicate a good precision and efficiency of our approach for medical multimedia retrieval in comparison with some traditional approaches. PMID:24082915
Developing chemical criteria for wildlife: The benchmark dose versus NOAEL approach
DOE Office of Scientific and Technical Information (OSTI.GOV)
Linder, G.
1995-12-31
Wildlife may be exposed to a wide variety of chemicals in their environment, and various strategies for evaluating wildlife risk for these chemicals have been developed. One, a ``no-observable-adverse-effects-level`` or NOAEL-approach has increasingly been applied to develop chemical criteria for wildlife. In this approach, the NOAEL represents the highest experimental concentration at which there is no statistically significant change in some toxicity endpoint relative to a control. Another, the ``benchmark dose`` or BMD-approach relies on the lower confidence limit for a concentration that corresponds to a small, but statistically significant, change in effect over some reference condition. Rather than correspondingmore » to a single experimental concentration as does the NOAEL, the BMD-approach considers the full concentration response curve for derivation of the BMD. Here, using a variety of vertebrates and an assortment of chemicals (including carbofuran, paraquat, methylmercury, cadmium, zinc, and copper), the NOAEL-approach will be critically evaluated relative to the BMD approach. Statistical models used in the BMD approach suggest these methods are potentially available for eliminating safety factors in risk calculations. A reluctance to recommend this, however, stems from the uncertainty associated with the shape of concentration-response curves at low concentrations. Also, with existing data the derivation of BMDs has shortcomings when sample size is small (10 or fewer animals per treatment). The success of BMD models clearly depends upon the continued collection of wildlife data in the field and laboratory, the design of toxicity studies sufficient for BMD calculations, and complete reporting of these results in the literature. Overall, the BMD approach for developing chemical criteria for wildlife should be given further consideration, since it more fully evaluates concentration-response data.« less
Shao, Q; Rowe, R C; York, P
2007-06-01
Understanding of the cause-effect relationships between formulation ingredients, process conditions and product properties is essential for developing a quality product. However, the formulation knowledge is often hidden in experimental data and not easily interpretable. This study compares neurofuzzy logic and decision tree approaches in discovering hidden knowledge from an immediate release tablet formulation database relating formulation ingredients (silica aerogel, magnesium stearate, microcrystalline cellulose and sodium carboxymethylcellulose) and process variables (dwell time and compression force) to tablet properties (tensile strength, disintegration time, friability, capping and drug dissolution at various time intervals). Both approaches successfully generated useful knowledge in the form of either "if then" rules or decision trees. Although different strategies are employed by the two approaches in generating rules/trees, similar knowledge was discovered in most cases. However, as decision trees are not able to deal with continuous dependent variables, data discretisation procedures are generally required.
KAVEH, MOHAMMAD HOSSEIN; HESAMPOUR, MARYAM; GHAHREMANI, LEILA; TABATABAEE, HAMID REZA
2014-01-01
Introduction: Low self-esteem in adolescence is one of the risk factors for negative outcomes in important domains of adulthood life. Due to the lack of trials based on modern methods of teaching in the field of self-esteem, this study aimed to investigate the effects of a peer-led training program on female second graders’ self-esteem in public secondary schools in Shiraz. Methods: The present study is an educational controlled trial. 223 public school female students in the second grade were selected with the Multi-stage random cluster sampling method. The selected Schools were assigned randomly to experimental and control groups. The data were collected before, one and six weeks after an intervention in the control and experimental group, using Pope's 5-scale test of self-esteem with Cronbach's alpha reliability of 0.85. The educational intervention in the experimental group was a peer-led approach, using discussion techniques in small groups (the group work, role play and group play) and a 5-volume training manual. The data were analyzed through SPSS, version 14, using Mann-Whitney test, Chi-square test, Wilcoxon and repeated measure Analysis of Variance (ANOVA). Results: The results showed that the mean of total self-esteem scores and the sub-scales (except for family self-esteem) in the experimental groups compared to that in the control groups, one and six weeks after the peer-led based approach intervention was significantly different (p<0.001). Before the intervention, the mean for self-esteem in the experimental groups was 51.80±13.91 but in the first post-test and second post-test the mean increased to 73.72±12.94, and 69.48±12.63, respectively. Before the educational intervention, the frequency distribution of females’ self-esteem in the experimental and control groups did not differ significantly from each other (p=0.337). But during one and six weeks after the intervention, a significant increase was observed between the two groups (p<0.001). Conclusion: The results of this study suggest that peer education is an effective way to promote self-esteem in adolescents. Providing opportunities such as a peer-led approach can help adolescents to acquire practical ways to increase their self-esteem. PMID:25512922
Kaveh, Mohammad Hossein; Hesampour, Maryam; Ghahremani, Leila; Tabatabaee, Hamid Reza
2014-04-01
Low self-esteem in adolescence is one of the risk factors for negative outcomes in important domains of adulthood life. Due to the lack of trials based on modern methods of teaching in the field of self-esteem, this study aimed to investigate the effects of a peer-led training program on female second graders' self-esteem in public secondary schools in Shiraz. The present study is an educational controlled trial. 223 public school female students in the second grade were selected with the Multi-stage random cluster sampling method. The selected Schools were assigned randomly to experimental and control groups. The data were collected before, one and six weeks after an intervention in the control and experimental group, using Pope's 5-scale test of self-esteem with Cronbach's alpha reliability of 0.85. The educational intervention in the experimental group was a peer-led approach, using discussion techniques in small groups (the group work, role play and group play) and a 5-volume training manual. The data were analyzed through SPSS, version 14, using Mann-Whitney test, Chi-square test, Wilcoxon and repeated measure Analysis of Variance (ANOVA). The results showed that the mean of total self-esteem scores and the sub-scales (except for family self-esteem) in the experimental groups compared to that in the control groups, one and six weeks after the peer-led based approach intervention was significantly different (p<0.001). Before the intervention, the mean for self-esteem in the experimental groups was 51.80±13.91 but in the first post-test and second post-test the mean increased to 73.72±12.94, and 69.48±12.63, respectively. Before the educational intervention, the frequency distribution of females' self-esteem in the experimental and control groups did not differ significantly from each other (p=0.337). But during one and six weeks after the intervention, a significant increase was observed between the two groups (p<0.001). The results of this study suggest that peer education is an effective way to promote self-esteem in adolescents. Providing opportunities such as a peer-led approach can help adolescents to acquire practical ways to increase their self-esteem.
Modified Skvor/Starr approach in the mechanical-thermal noise analysis of condenser microphone.
Tan, Chee Wee; Miao, Jianmin
2009-11-01
Simple analytical expressions of mechanical resistance, such as those formulated by Skvor/Starr, are widely used to describe the mechanical-thermal noise performance of a condenser microphone. However, the Skvor/Starr approach does not consider the location effect of acoustic holes in the backplate and overestimates the total equivalent mechanical resistance and mechanical-thermal noise. In this paper, a modified form of the Skvor/Starr approach is proposed to address this hole location dependent effect. A mode shape factor, which consists of the zero order Bessel and modified Bessel functions, is included in Skvor's mechanical resistance formulation to consider the effect of the hole location in the backplate. With reference to two B&K microphones, the theoretical results of the A-weighted mechanical-thermal noise obtained by the modified Skvor/Starr approach are in good agreements with those reported experimental ones.
Mechanical properties of PA6/PP compatibilized nanocomposites using a twin screw extruder
NASA Astrophysics Data System (ADS)
De Almeida, M. F.; Correia, Aldina; e Silva, Eliana Costa; Lopes, I. Cristina
2017-11-01
In this article, a new approach to study the compatibilization effect of organophilic clays in PA6/PP polymer blends through experimental results of mechanical tests is presented. This study focus on the description of the interphase in compatibilization by addition of the organoclays C15A and C30B into the polymer PA6/PP blend by melt compounding using a Twin Screw Extruder. The experimental results variations are studied, by addition of the organoclays in uncompatibilized polymer blend, using non-parametric analysis of variance (Kruskal-Wallis Test). For all the experimental results, significant differences are identified between the types of polymer blends. It was observed the compatibilization effect of both organophilic clays, being the differences most evident in the presence of PP modified.
TGT for chemistry learning to enhance students' achievement and critical thinking skills
NASA Astrophysics Data System (ADS)
Bolhassan, Norlailatulakma; Taha, Hafsah
2017-05-01
The form of cooperative learning known as Teams-Games-Tournament (TGT) in this study favors the use of teams work and learning tools combined with student play and practice to foster students' achievement and critical thinking skills. Using this paradigm, this study incorporates Teams-Games-Tournament and Flash Cards Games Kit during an 8-weeks experimental instruction period that includes 67 Form Four students; 34 students in the experimental group and 33 in the control group. The learning design in experimental group emphasizes scaffolding, guided practices, cooperative learning, and active participation in learning. While the experimental group experienced the TGT approach, the control group encountered the conventional teaching approach of chemistry drills. An achievement chemistry test and Watson Glaser Critical Thinking Appraisal (WGCTA) were used for the pretest and posttest. The finding indicates that TGT learning was more effective than drills in promoting chemistry performance, and the playful competiveness among students promotes students' critical thinking. In addition, TGT cooperative learning also creates an active learning environment in solving problems and discussions among students and teachers.
Second-order sliding mode control with experimental application.
Eker, Ilyas
2010-07-01
In this article, a second-order sliding mode control (2-SMC) is proposed for second-order uncertain plants using equivalent control approach to improve the performance of control systems. A Proportional + Integral + Derivative (PID) sliding surface is used for the sliding mode. The sliding mode control law is derived using direct Lyapunov stability approach and asymptotic stability is proved theoretically. The performance of the closed-loop system is analysed through an experimental application to an electromechanical plant to show the feasibility and effectiveness of the proposed second-order sliding mode control and factors involved in the design. The second-order plant parameters are experimentally determined using input-output measured data. The results of the experimental application are presented to make a quantitative comparison with the traditional (first-order) sliding mode control (SMC) and PID control. It is demonstrated that the proposed 2-SMC system improves the performance of the closed-loop system with better tracking specifications in the case of external disturbances, better behavior of the output and faster convergence of the sliding surface while maintaining the stability. 2010 ISA. Published by Elsevier Ltd. All rights reserved.
Effects of blade-to-blade dissimilarities on rotor-body lead-lag dynamics
NASA Technical Reports Server (NTRS)
Mcnulty, M. J.
1986-01-01
Small blade-to-blade property differences are investigated to determine their effects on the behavior of a simple rotor-body system. An analytical approach is used which emphasizes the significance of these effects from the experimental point of view. It is found that the primary effect of blade-to-blade dissimilarities is the appearance of additional peaks in the frequency spectrum which are separated from the convention response modes by multiples of the rotor speed. These additional responses are potential experimental problems because when they occur near a mode of interest they act as contaminant frequencies which can make damping measurements difficult. The effects of increased rotor-body coupling and a rotor shaft degree of freedom act to improve the situation by altering the frequency separation of the modes.
Paraskeva, Nicole; Lewis-Smith, Helena; Diedrichs, Phillippa C
2017-02-01
Disclaimer labels on airbrushed media images have generated political attention and advocacy as a social policy approach to promoting positive body image. Experimental research suggests that labelling is ineffective and consumers' viewpoints have been overlooked. A mixed-method study explored British consumers' ( N = 1555, aged 11-78 years) opinions on body image and social policy approaches. Thematic analysis indicated scepticism about the effectiveness of labelling images. Quantitatively, adults, although not adolescents, reported that labelling was unlikely to improve body image. Appearance diversity in media and reorienting social norms from appearance to function and health were perceived as effective strategies. Social policy and research implications are discussed.
Hybrid Robust Multi-Objective Evolutionary Optimization Algorithm
2009-03-10
pp. 594-606. 8. Inverse Approaches to Drying of Thin Bodies With Significant Shrinkage Effects (with G. H. Kanevce, L. P. Kanevce, V. B. Mitrevski ...Kanevce, L. Kanevce, V. Mitrevski ), ICCES: International Conference on Computational & Experimental Engineering and Sciences, Honolulu, Hawaii, March 17...Miami Beach, FL, April 16-18, 2007. 16. Inverse Approaches to Drying of Sliced Foods (with Kanevce, G. H., Kanevce, Lj. P., and Mitrevski , V. B
ERIC Educational Resources Information Center
Ho, Vinh-Thang; Nakamori, Yoshiteru; Ho, Tu-Bao; Lim, Cher Ping
2016-01-01
The purpose of this study was to examine the effectiveness of a blended learning model on hands-on approach for in-service secondary school teachers using a quasi-experimental design. A 24-h teacher-training course using the blended learning model was administered to 117 teachers, while face-to-face instruction was given to 60 teachers. The…
Modeling the surface tension of complex, reactive organic-inorganic mixtures
NASA Astrophysics Data System (ADS)
Schwier, A. N.; Viglione, G. A.; Li, Z.; McNeill, V. F.
2013-01-01
Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as cloud condensation nuclei (CCN) ability. We present new experimental data for the surface tension of complex, reactive organic-inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2-6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well-described by a weighted Szyszkowski-Langmuir (S-L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling because the Henning model (using data obtained from organic-inorganic systems) and Tuckermann approach provide similar modeling fits and goodness of fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.
Homeopathic Prevention and Management of Epidemic Diseases.
Jacobs, Jennifer
2018-05-12
Homeopathy has been used to treat epidemic diseases since the time of Hahnemann, who used Belladonna to treat scarlet fever. Since then, several approaches using homeopathy for epidemic diseases have been proposed, including individualization, combination remedies, genus epidemicus, and isopathy. The homeopathic research literature was searched to find examples of each of these approaches and to evaluate which were effective. There is good experimental evidence for each of these approaches. While individualization is the gold standard, it is impractical to use on a widespread basis. Combination remedies can be effective but must be based on the symptoms of a given epidemic in a specific location. Treatment with genus epidemicus can also be successful if based on data from many practitioners. Finally, isopathy shows promise and might be more readily accepted by mainstream medicine due to its similarity to vaccination. Several different homeopathic methods can be used to treat epidemic diseases. The challenge for the future is to refine these approaches and to build on the knowledge base with additional rigorous trials. If and when conventional medicine runs out of options for treating epidemic diseases, homeopathy could be seen as an attractive alternative, but only if there is viable experimental evidence of its success. The Faculty of Homeopathy.
Shin, Jaemin; Ahn, Sinyeob; Hu, Xiaoping
2015-01-01
Purpose To develop an improved and generalized technique for correcting T1-related signal fluctuations (T1 effect) in cardiac-gated functional magnetie resonance imaging (fMRI) data with flip angle estimation. Theory and Methods Spatial maps of flip angle and T1 are jointly estimated from cardiac-gated time series using a Kalman filter. These maps are subsequently used for removing the T1 effect in the presence of B1 inhomogeneity. The new technique was compared with a prior technique that uses T1 only while assuming a homogeneous flip angle of 90°. The robustness of the new technique is demonstrated with simulated and experimental data. Results Simulation results revealed that the new method led to increased temporal signal-to-noise ratio across a large range of flip angles, T1s, and stimulus onset asynchrony means compared to the T1 only approach. With the experimental data, the new approach resulted in higher average gray matter temporal signal-to-noise ratio of seven subjects (84 vs. 48). The new approach also led to a higher statistical score of activation in the lateral geniculate nucleus (P < 0.002). Conclusion The new technique is able to remove the T1 effect robustly and is a promising tool for improving the ability to map activation in fMRI, especially in subcortical regions. PMID:23390029
NASA Astrophysics Data System (ADS)
Dimas, George; Iakovidis, Dimitris K.; Karargyris, Alexandros; Ciuti, Gastone; Koulaouzidis, Anastasios
2017-09-01
Wireless capsule endoscopy is a non-invasive screening procedure of the gastrointestinal (GI) tract performed with an ingestible capsule endoscope (CE) of the size of a large vitamin pill. Such endoscopes are equipped with a usually low-frame-rate color camera which enables the visualization of the GI lumen and the detection of pathologies. The localization of the commercially available CEs is performed in the 3D abdominal space using radio-frequency (RF) triangulation from external sensor arrays, in combination with transit time estimation. State-of-the-art approaches, such as magnetic localization, which have been experimentally proved more accurate than the RF approach, are still at an early stage. Recently, we have demonstrated that CE localization is feasible using solely visual cues and geometric models. However, such approaches depend on camera parameters, many of which are unknown. In this paper the authors propose a novel non-parametric visual odometry (VO) approach to CE localization based on a feed-forward neural network architecture. The effectiveness of this approach in comparison to state-of-the-art geometric VO approaches is validated using a robotic-assisted in vitro experimental setup.
Jun, Won Hee; Lee, Eun Ju; Park, Jeong Soon
2014-07-01
To investigate the effects of a suicide prevention programme on the levels of depression, self-esteem, suicidal ideation and spirituality in patients with mental illness. Instances of suicide have significant correlations with depression, low self-esteem, suicidal ideation and a low level of spirituality in the victims. Therefore, addressing depression, low self-esteem and suicidal ideation as suicide risk factors and increasing levels of spirituality can constitute an effective programme to prevent suicide among patients with mental illness. The study was a quasi-experimental study with a nonequivalent control group, nonsynchronised design. The study sample consisted of 45 patients with mental illness who had been admitted to the psychiatric unit in a university hospital in South Korea. The patients were assigned to control and experimental groups of 23 and 22 members, respectively. The suicide prevention programme was conducted with the experimental group over four weeks and included eight sessions (two per week). The control group received only routine treatments in the hospital. The experimental group that participated in the programme had significantly decreased mean scores for depression and suicidal ideation compared with the control group. However, there were no significant differences in the mean scores for self-esteem and spirituality between the groups. The suicide prevention programme might be usefully applied as a nursing intervention for patients hospitalised in psychiatric wards or clinics where the goals are to decrease depression and suicidal ideation. Typical treatments for hospitalised patients with mental illness are not enough to prevent suicide. Intervention for suicide prevention needs to apply an integrated approach. The suicide prevention programme using an integrated approach is more effective in reducing depression and suicidal ideation in patients with mental illness than applying routine treatments in the hospital. © 2013 John Wiley & Sons Ltd.
[Effects of Learning Activities on Application of Learning Portfolio in Nursing Management Course].
Choi, So Eun; Kim, Eun A
2016-02-01
This study was conducted to examine effects of a learning portfolio by identifying the learning of nursing students taking a learning portfolio-utilized nursing management class. A non-equivalent control group pretest-posttest design was used. Participants were 83 senior students taking the nursing management course in one of the Departments of Nursing at 2 Universities. Experimental group (n=42) received a learning portfolio-utilized nursing management class 15 times over 15 weeks (3 hours weekly). Self-directed learning abilities, approaches to learning and learning flow of the participants were examined with self-report structured questionnaires. Data were collected between September 2 and December 16, 2014, and were analyzed using chi-square test, Fisher's exact test, independent t-test and ANCOVA with SPSS/PC version 21.0. After the intervention the experimental group showed significant increases in self-directed learning abilities, deep approaches to learning and learning flow compared to the control group. However, no significant difference was found between groups for surface approaches to learning. Learning activities using the learning portfolios could be effective in cultivating the learning competency for growth of knowledge, technology and professionalism by increasing personal concentration and organization ability of the nursing students so that they can react to the rapidly changing environment.
Jayanegara, A; Leiber, F; Kreuzer, M
2012-06-01
A meta-analysis was conducted to evaluate the extent to which dietary tannin level is related to methane emissions from ruminants. Data from a total of 30 experiments comprising 171 treatments were entered in a database. In vitro batch culture and in vivo measurements were distinguished as experimental approaches. With any approach, methane declined when dietary tannins increased. The in vitro approach predicted the in vivo response quite accurately. However, in vitro, the response followed a quadratic response pattern (R(2) = 0.66; lower response with increasing tannin level), whereas in vivo, this decline was linear (R(2) = 0.29). This indicates that the in vitro batch culture is of limited accuracy for estimating effects at levels >100 g tannin/kg dry matter. The large variation in methane/digestible organic matter (OM) found at low tannin levels may explain contrasting literature reports. Methane reduction with tannins was associated with a reduced apparent digestion of OM, and especially fibre, but methane/apparently digestible OM declined also. The present findings are helpful as they identified an underlying general antimethanogenic effect of tannins across tannin sources and experimental conditions, thus allowing concentrating the search on sources with satisfactory palatability and low adverse effects on animal performance. © 2011 Blackwell Verlag GmbH.
Fitts Cochrane, Jean; Lonsdorf, Eric; Allison, Taber D; Sanders-Reed, Carol A
2015-09-01
Challenges arise when renewable energy development triggers "no net loss" policies for protected species, such as where wind energy facilities affect Golden Eagles in the western United States. When established mitigation approaches are insufficient to fully avoid or offset losses, conservation goals may still be achievable through experimental implementation of unproven mitigation methods provided they are analyzed within a framework that deals transparently and rigorously with uncertainty. We developed an approach to quantify and analyze compensatory mitigation that (1) relies on expert opinion elicited in a thoughtful and structured process to design the analysis (models) and supplement available data, (2) builds computational models as hypotheses about cause-effect relationships, (3) represents scientific uncertainty in stochastic model simulations, (4) provides probabilistic predictions of "relative" mortality with and without mitigation, (5) presents results in clear formats useful to applying risk management preferences (regulatory standards) and selecting strategies and levels of mitigation for immediate action, and (6) defines predictive parameters in units that could be monitored effectively, to support experimental adaptive management and reduction in uncertainty. We illustrate the approach with a case study characterized by high uncertainty about underlying biological processes and high conservation interest: estimating the quantitative effects of voluntary strategies to abate lead poisoning in Golden Eagles in Wyoming due to ingestion of spent game hunting ammunition.
ERIC Educational Resources Information Center
Blackmer, Rachel; Hayes-Harb, Rachel
2016-01-01
We present a community-based research project aimed at identifying effective methods and materials for teaching English literacy skills to adult English as a second language emergent readers. We conducted a quasi-experimental study whereby we evaluated the efficacy of two approaches, one based on current practices at the English Skills Learning…
Effects of Concept Mapping Instruction Approach on Students' Achievement in Basic Science
ERIC Educational Resources Information Center
Ogonnaya, Ukpai Patricia; Okafor, Gabriel; Abonyi, Okechukwu S.; Ugama, J. O.
2016-01-01
The study investigated the effects of concept mapping on students' achievement in basic science. The study was carried out in Ebonyi State of Nigeria. The study employed a quasi-experimental design. Specifically the pretest posttest non-equivalent control group research design was used. The sample was 122 students selected from two secondary…
ERIC Educational Resources Information Center
Byers, Terry; Hartnell-Young, Elizabeth; Imms, Wesley
2018-01-01
This study explored the effect of different classroom spatial layouts on student perceptions of digital technology in a secondary schooling environment. A quasi-experimental approach facilitated by a Single Subject research design (SSRD) isolated the impact of two learning spaces--"traditional classrooms," and "new generation…
The Effect of an Embedded Pedagogical Agent on the Students' Science Achievement
ERIC Educational Resources Information Center
Kizilkaya, Gonca; Askar, Petek
2008-01-01
Purpose: The purpose of this paper is to investigate the effect of an embedded pedagogical agent into a tutorial on achievement. Design/methodology/approach: Research methodology is designed according to the post test control group model in which the experimental group (69 students) was exposed to a tutorial with an embedded pedagogical agent;…
The Effect of Mobile Learning on Students' Achievement and Conversational Skills
ERIC Educational Resources Information Center
Elfeky, Abdellah Ibrahim Mohammed; Masadeh, Thouqan Saleem Yakoub
2016-01-01
The present study aimed to examine the effect of Mobile Learning, which is a kind of E-learning that uses mobile devices, on the development of the academic achievement and conversational skills of English language specialty students at Najran University. The study used the quasi-experimental approach. Participants consisted of (50) students who…
Three-Level Analysis of Single-Case Experimental Data: Empirical Validation
ERIC Educational Resources Information Center
Moeyaert, Mariola; Ugille, Maaike; Ferron, John M.; Beretvas, S. Natasha; Van den Noortgate, Wim
2014-01-01
One approach for combining single-case data involves use of multilevel modeling. In this article, the authors use a Monte Carlo simulation study to inform applied researchers under which realistic conditions the three-level model is appropriate. The authors vary the value of the immediate treatment effect and the treatment's effect on the time…
Effects of a Format-based Second Language Teaching Method in Kindergarten.
ERIC Educational Resources Information Center
Uilenburg, Noelle; Plooij, Frans X.; de Glopper, Kees; Damhuis, Resi
2001-01-01
Focuses on second language teaching with a format-based method. The differences between a format-based teaching method and a standard approach used as treatments in a quasi-experimental, non-equivalent control group are described in detail. Examines whether the effects of a format-based teaching method and a standard foreign language method differ…
Free vibration of thermally loaded panels including initial imperfections and post-buckling effects
NASA Technical Reports Server (NTRS)
Murphy, K. D.; Virgin, L. N.; Rizzi, S. A.
1994-01-01
A combined theoretical and experimental approach is developed to consider the small amplitude free vibration characteristics of fully clamped panels under the influence of uniform heating. Included in this study are the effects of higher modes, in-plane boundary elasticity, initial imperfections, and post-buckling. Comparisons between theory and experiment reveal excellent agreement.
Evaluating long-term cumulative hydrologic effects of forest management: a conceptual approach
Robert R. Ziemer
1992-01-01
It is impractical to address experimentally many aspects of cumulative hydrologic effects, since to do so would require studying large watersheds for a century or more. Monte Carlo simulations were conducted using three hypothetical 10,000-ha fifth-order forested watersheds. Most of the physical processes expressed by the model are transferable from temperate to...
NASA Technical Reports Server (NTRS)
Ramachandran, Narayanan
2000-01-01
Normal vibrational modes on large spacecraft are excited by crew activity, operating machinery, and other mechanical disturbances. Periodic engine burns for maintaining vehicle attitude and random impulse type disturbances also contribute to the acceleration environment of a Spacecraft. Accelerations from these vibrations (often referred to as g-jitter) are several orders of magnitude larger than the residual accelerations from atmospheric drag and gravity gradient effects. Naturally, the effects of such accelerations have been a concern to prospective experimenters wishing to take advantage of the microgravity environment offered by spacecraft operating in low Earth orbit and the topic has been studied extensively, both numerically and analytically. However, these studies have not produced a general theory that predicts the effects of multi-spectral periodic accelerations on a general class of experiments nor have they produced scaling laws that a prospective experimenter could use to assess how his/her experiment might be affected by this acceleration environment. Furthermore, there are no actual flight experimental data that correlates heat or mass transport with measurements of the periodic acceleration environment. The present investigation approaches this problem with carefully conducted terrestrial experiments and rigorous numerical modeling thereby providing comparative theoretical and experimental data. The modeling, it is hoped will provide a predictive tool that can be used for assessing experiment response to Spacecraft vibrations.
2017-09-01
collaborator, Dr. Luke Dow. We bred these pairs of mice to create a colony of transgenic mice, and continue to breed them as needed. When experimental...colony of transgenic mice. When experimental mice are 8 weeks of age, they are treated with 4-hydroxytamofixen (4OHT) and put on continuous doxycycline...and human cells and transgenic mouse models. These experiments will determine the effectiveness of this approach and, if successful, will lead to
Boucher, Danielle; Gagné, Camille; Côté, Françoise
2015-01-01
This study evaluates the effectiveness of an intervention mapping developed to promote fruit and vegetable consumption. Students (n = 394) from two similar public colleges in the Quebec City area (Canada) were asked to participate. A quasi-experimental design was used with a 14-week pause between the pretest and posttest. The control and experimental groups both received information on Canada's Food Guide recommendations. The experimental group was submitted to an intervention consisting of six interactive workshops carried out inside the college, and three personal exercises to be completed at home. proportion of respondents consuming at least five servings of fruits and vegetables daily. psychosocial variables assessed (theory of planned behaviour). The data collected from 344 participants by means of a self-administered questionnaire were analysed (167 experimental and 177 control). The posttest revealed a significant increase (15%) in the number of participants in the experimental group achieving the primary outcome (d = .38). The intervention also had a significant effect on the targeted psychosocial variables (η(2) = .03 to .06). Regularity of consumption acts as a mediator between intention and behaviour. These results may be used to guide health promoters working with college students.
Pilot performance and workload using simulated GPS track angle error displays
DOT National Transportation Integrated Search
1995-01-01
The effect on simulated GPS instrument approach performance and workload resulting from the addition of Track Angle Error (TAE) information to cockpit RNAV receiver displays in explicit analog form was studied experimentally (S display formats, 6 pil...
Propiconazole inhibits steroidogenesis and reproduction in the fathead minnow (Pimephales promelas)
This study assessed effects of the conazole-fungicide propiconazole on endocrine function and reproductive success of the fathead minnow, using an experimental approach based on previously defined adverse outcome pathways (AOPs) for chemicals that inhibit steroidogenesis in fish...
Mitigation methods for temporary concrete traffic barrier effects on flood water flows.
DOT National Transportation Integrated Search
2011-07-01
A combined experimental and analytical approach was put together to evaluate the hydraulic performance and : stability of TxDOT standard and modified temporary concrete traffic barriers (TCTBs) in extreme flood. : Rating curves are developed for diff...
Beam Shaping for CARS Measurements in Turbulent Environments
NASA Technical Reports Server (NTRS)
Magnotti, Gaetano; Cutler, Andrew D.; Danehy, Paul M.
2010-01-01
This paper describes a new technique to mitigate the effect of beam steering on CARS measurements in turbulent, variable density environments. The new approach combines Planar BOXCARS phase-matching with elliptical shaping of one of the beams to generate a signal insensitive to beam steering, while keeping the same spatial resolution. Numerical and experimental results are provided to demonstrate the effectiveness of this approach. One set of experiments investigated the effect of beam shaping in the presence of a controlled and well quantified displacement of the beams at the focal plane. Another set of experiments, more qualitative, proved the effectiveness of the technique in the presence of severe beam steering due to turbulence.
Embracing uncertainty in applied ecology.
Milner-Gulland, E J; Shea, K
2017-12-01
Applied ecologists often face uncertainty that hinders effective decision-making.Common traps that may catch the unwary are: ignoring uncertainty, acknowledging uncertainty but ploughing on, focussing on trivial uncertainties, believing your models, and unclear objectives.We integrate research insights and examples from a wide range of applied ecological fields to illustrate advances that are generally underused, but could facilitate ecologists' ability to plan and execute research to support management.Recommended approaches to avoid uncertainty traps are: embracing models, using decision theory, using models more effectively, thinking experimentally, and being realistic about uncertainty. Synthesis and applications . Applied ecologists can become more effective at informing management by using approaches that explicitly take account of uncertainty.
Tracer tomography: design concepts and field experiments using heat as a tracer.
Doro, Kennedy O; Cirpka, Olaf A; Leven, Carsten
2015-04-01
Numerical and laboratory studies have provided evidence that combining hydraulic tomography with tomographic tracer tests could improve the estimation of hydraulic conductivity compared with using hydraulic data alone. Field demonstrations, however, have been lacking so far, which we attribute to experimental difficulties. In this study, we present a conceptual design and experimental applications of tracer tomography at the field scale using heat as a tracer. In our experimental design, we improve active heat tracer testing by minimizing possible effects of heat losses, buoyancy, viscosity, and changing boundary conditions. We also utilize a cost-effective approach of measuring temperature changes in situ at high resolution. We apply the presented method to the 8 m thick heterogeneous, sandy gravel, alluvial aquifer at the Lauswiesen Hydrogeological Research Site in Tübingen, Germany. Results of our tomographic heat-tracer experiments are in line with earlier work on characterizing the aquifer at the test site. We demonstrate from the experimental perspective that tracer tomography is applicable and suitable at the field scale using heat as a tracer. The experimental results also demonstrate the potential of heat-tracer tomography as a cost-effective means for characterizing aquifer heterogeneity. © 2014, National Ground Water Association.
Changing children's eating behaviour - A review of experimental research.
DeCosta, Patricia; Møller, Per; Frøst, Michael Bom; Olsen, Annemarie
2017-06-01
The interest in children's eating behaviours and how to change them has been growing in recent years. This review examines the following questions: What strategies have been used to change children's eating behaviours? Have their effects been experimentally demonstrated? And, are the effects transient or enduring? Medline and Cab abstract (Ovid) and Web of Science (Thomson Reuters) were used to identify the experimental studies. A total of 120 experimental studies were identified and they are presented grouped within these 11 topics; parental control, reward, social facilitation, cooking programs, school gardens, sensory education, availability and accessibility, choice architecture and nudging, branding and food packaging, preparation and serving style, and offering a choice. In conclusion, controlling strategies for changing children's eating behaviour in a positive direction appear to be counterproductive. Hands-on approaches such as gardening and cooking programs may encourage greater vegetable consumption and may have a larger effect compared to nutrition education. Providing children with free, accessible fruits and vegetables have been experimentally shown to positively affect long-term eating behaviour. The authors recommend future research to examine how taste and palatability can positively affect children's attitudes and eating behaviour. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Ravikumar, Balaguru; Parri, Elina; Timonen, Sanna; Airola, Antti; Wennerberg, Krister
2017-01-01
Due to relatively high costs and labor required for experimental profiling of the full target space of chemical compounds, various machine learning models have been proposed as cost-effective means to advance this process in terms of predicting the most potent compound-target interactions for subsequent verification. However, most of the model predictions lack direct experimental validation in the laboratory, making their practical benefits for drug discovery or repurposing applications largely unknown. Here, we therefore introduce and carefully test a systematic computational-experimental framework for the prediction and pre-clinical verification of drug-target interactions using a well-established kernel-based regression algorithm as the prediction model. To evaluate its performance, we first predicted unmeasured binding affinities in a large-scale kinase inhibitor profiling study, and then experimentally tested 100 compound-kinase pairs. The relatively high correlation of 0.77 (p < 0.0001) between the predicted and measured bioactivities supports the potential of the model for filling the experimental gaps in existing compound-target interaction maps. Further, we subjected the model to a more challenging task of predicting target interactions for such a new candidate drug compound that lacks prior binding profile information. As a specific case study, we used tivozanib, an investigational VEGF receptor inhibitor with currently unknown off-target profile. Among 7 kinases with high predicted affinity, we experimentally validated 4 new off-targets of tivozanib, namely the Src-family kinases FRK and FYN A, the non-receptor tyrosine kinase ABL1, and the serine/threonine kinase SLK. Our sub-sequent experimental validation protocol effectively avoids any possible information leakage between the training and validation data, and therefore enables rigorous model validation for practical applications. These results demonstrate that the kernel-based modeling approach offers practical benefits for probing novel insights into the mode of action of investigational compounds, and for the identification of new target selectivities for drug repurposing applications. PMID:28787438
Lecloux, André J; Atluri, Rambabu; Kolen'ko, Yury V; Deepak, Francis Leonard
2017-10-12
The first part of this study was dedicated to the modelling of the influence of particle shape, porosity and particle size distribution on the volume specific surface area (VSSA) values in order to check the applicability of this concept to the identification of nanomaterials according to the European Commission Recommendation. In this second part, experimental VSSA values are obtained for various samples from nitrogen adsorption isotherms and these values were used as a screening tool to identify and classify nanomaterials. These identification results are compared to the identification based on the 50% of particles with a size below 100 nm criterion applied to the experimental particle size distributions obtained by analysis of electron microscopy images on the same materials. It is concluded that the experimental VSSA values are able to identify nanomaterials, without false negative identification, if they have a mono-modal particle size, if the adsorption data cover the relative pressure range from 0.001 to 0.65 and if a simple, qualitative image of the particles by transmission or scanning electron microscopy is available to define their shape. The experimental conditions to obtain reliable adsorption data as well as the way to analyze the adsorption isotherms are described and discussed in some detail in order to help the reader in using the experimental VSSA criterion. To obtain the experimental VSSA values, the BET surface area can be used for non-porous particles, but for porous, nanostructured or coated nanoparticles, only the external surface of the particles, obtained by a modified t-plot approach, should be considered to determine the experimental VSSA and to avoid false positive identification of nanomaterials, only the external surface area being related to the particle size. Finally, the availability of experimental VSSA values together with particle size distributions obtained by electron microscopy gave the opportunity to check the representativeness of the two models described in the first part of this study. They were also used to calculate the VSSA values and these calculated values were compared to the experimental results. For narrow particle size distributions, both models give similar VSSA values quite comparable to the experimental ones. But when the particle size distribution broadens or is of multi-bimodal shape, as theoretically predicted, one model leads to VSSA values higher than the experimental ones while the other most often leads to VSSA values lower than the experimental ones. The experimental VSSA approach then appears as a reliable, simple screening tool to identify nano and non-nano-materials. The modelling approach cannot be used as a formal identification tool but could be useful to screen for potential effects of shape, polydispersity and size, for example to compare various possible nanoforms.
Dinh, Duy; Tamine, Lynda; Boubekeur, Fatiha
2013-02-01
The aim of this work is to evaluate a set of indexing and retrieval strategies based on the integration of several biomedical terminologies on the available TREC Genomics collections for an ad hoc information retrieval (IR) task. We propose a multi-terminology based concept extraction approach to selecting best concepts from free text by means of voting techniques. We instantiate this general approach on four terminologies (MeSH, SNOMED, ICD-10 and GO). We particularly focus on the effect of integrating terminologies into a biomedical IR process, and the utility of using voting techniques for combining the extracted concepts from each document in order to provide a list of unique concepts. Experimental studies conducted on the TREC Genomics collections show that our multi-terminology IR approach based on voting techniques are statistically significant compared to the baseline. For example, tested on the 2005 TREC Genomics collection, our multi-terminology based IR approach provides an improvement rate of +6.98% in terms of MAP (mean average precision) (p<0.05) compared to the baseline. In addition, our experimental results show that document expansion using preferred terms in combination with query expansion using terms from top ranked expanded documents improve the biomedical IR effectiveness. We have evaluated several voting models for combining concepts issued from multiple terminologies. Through this study, we presented many factors affecting the effectiveness of biomedical IR system including term weighting, query expansion, and document expansion models. The appropriate combination of those factors could be useful to improve the IR performance. Copyright © 2012 Elsevier B.V. All rights reserved.
Efficient Modeling and Active Learning Discovery of Biological Responses
Naik, Armaghan W.; Kangas, Joshua D.; Langmead, Christopher J.; Murphy, Robert F.
2013-01-01
High throughput and high content screening involve determination of the effect of many compounds on a given target. As currently practiced, screening for each new target typically makes little use of information from screens of prior targets. Further, choices of compounds to advance to drug development are made without significant screening against off-target effects. The overall drug development process could be made more effective, as well as less expensive and time consuming, if potential effects of all compounds on all possible targets could be considered, yet the cost of such full experimentation would be prohibitive. In this paper, we describe a potential solution: probabilistic models that can be used to predict results for unmeasured combinations, and active learning algorithms for efficiently selecting which experiments to perform in order to build those models and determining when to stop. Using simulated and experimental data, we show that our approaches can produce powerful predictive models without exhaustive experimentation and can learn them much faster than by selecting experiments at random. PMID:24358322
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shi, Ming W.; Stewart, Scott G.; Sobolev, Alexandre N.
The trans-epoxysuccinyl amide group as a biologically active moiety in cysteine protease inhibitors such as loxistatin acid E64c has been used as a benchmark system for theoretical studies of environmental effects on the electron density of small active ingredients in relation to their biological activity. Here, the synthesis and the electronic properties of the smallest possible active site model compound are reported to close the gap between the unknown experimental electron density of trans-epoxysuccinyl amides and the well-known function of related drugs. Intramolecular substituent effects are separated from intermolecular crystal packing effects on the electron density, which allows us tomore » predict the conditions under which an experimental electron density investigation on trans-epoxysuccinyl amides will be possible. In this context, the special importance of the carboxylic acid function in the model compound for both crystal packing and biological activity is revealed through the novel tool of model energy analysis.« less
NASA Technical Reports Server (NTRS)
Boulet, C.; Ma, Q.
2016-01-01
Line mixing effects have been calculated in the ?1 parallel band of self-broadened NH3. The theoretical approach is an extension of a semi-classical model to symmetric-top molecules with inversion symmetry developed in the companion paper [Q. Ma and C. Boulet, J. Chem. Phys. 144, 224303 (2016)]. This model takes into account line coupling effects and hence enables the calculation of the entire relaxation matrix. A detailed analysis of the various coupling mechanisms is carried out for Q and R inversion doublets. The model has been applied to the calculation of the shape of the Q branch and of some R manifolds for which an obvious signature of line mixing effects has been experimentally demonstrated. Comparisons with measurements show that the present formalism leads to an accurate prediction of the available experimental line shapes. Discrepancies between the experimental and theoretical sets of first order mixing parameters are discussed as well as some extensions of both theory and experiment.
Larval aquatic insect responses to cadmium and zinc in experimental streams
Mebane, Christopher A.; Schmidt, Travis S.; Balistrieri, Laurie S.
2017-01-01
To evaluate the risks of metal mixture effects to natural stream communities under ecologically relevant conditions, the authors conducted 30-d tests with benthic macroinvertebrates exposed to cadmium (Cd) and zinc (Zn) in experimental streams. The simultaneous exposures were with Cd and Zn singly and with Cd+Zn mixtures at environmentally relevant ratios. The tests produced concentration–response patterns that for individual taxa were interpreted in the same manner as classic single-species toxicity tests and for community metrics such as taxa richness and mayfly (Ephemeroptera) abundance were interpreted in the same manner as with stream survey data. Effect concentrations from the experimental stream exposures were usually 2 to 3 orders of magnitude lower than those from classic single-species tests. Relative to a response addition model, which assumes that the joint toxicity of the mixtures can be predicted from the product of their responses to individual toxicants, the Cd+Zn mixtures generally showed slightly less than additive toxicity. The authors applied a modeling approach called Tox to explore the mixture toxicity results and to relate the experimental stream results to field data. The approach predicts the accumulation of toxicants (hydrogen, Cd, and Zn) on organisms using a 2-pKa bidentate model that defines interactions between dissolved cations and biological receptors (biotic ligands) and relates that accumulation through a logistic equation to biological response. The Tox modeling was able to predict Cd+Zn mixture responses from the single-metal exposures as well as responses from field data. The similarity of response patterns between the 30-d experimental stream tests and field data supports the environmental relevance of testing aquatic insects in experimental streams.
NASA Astrophysics Data System (ADS)
Tarar, K. S.; Pluta, M.; Amjad, U.; Grill, W.
2011-04-01
Based on the lattice dynamics approach the dependence of the time-of-flight (TOF) on stress has been modeled for transversal polarized acoustic waves. The relevant dispersion relation is derived from the appropriate mass-spring model together with the dependencies on the restoring forces including the effect of externally applied stress. The lattice dynamics approach can also be interpreted as a discrete and strictly periodic lumped circuit. In that case the modeling represents a finite element approach. In both cases the properties relevant for wavelengths large with respect to the periodic structure can be derived from the respective limit relating also to low frequencies. The model representing a linear chain with stiffness to shear and additional stiffness introduced by extensional stress is presented and compared to existing models, which so far represent each only one of the effects treated here in combination. For a string this effect is well known from musical instruments. The counteracting effects are discussed and compared to experimental results.
Steinka-Fry, Katarzyna T.; Tanner-Smith, Emily E.; Hennessy, Emily A.
2015-01-01
Objective Alcohol-impaired driving persists as a major cause of traffic fatalities and injuries among young drivers. This meta-analysis examined whether brief alcohol interventions were effective in reducing driving after drinking among adolescents and young adults. Method Our systematic search identified 12 experimental/quasi-experimental evaluations (16 intervention groups) that measured driving while intoxicated and related consequences and provided data for effect size calculation (N = 5,664; M age =17 years; 57% male). The studies were published between 1991 and 2011. Three-level random-effects meta-analyses using a structural equation modeling approach were used to summarize the effects of the interventions. Results Compared with controls, participants in brief alcohol interventions reported reduced drinking and driving and related consequences (ḡ = 0.15, 95% CI [0.08, 0.21]). Supplemental analyses indicated that reductions in driving while intoxicated were positively associated with the reduced post-intervention heavy use of alcohol. These findings were not attenuated by study design or implementation factors. Conclusions Brief alcohol interventions under 5 hours of contact may constitute a promising preventive approach targeting drinking and driving among adolescents and young adults. Reducing heavy episodic alcohol consumption appeared to be a major factor in reducing drunk-driving instances. Interpretation of the findings must be made with caution, however, given the possibility of publication bias and the small observed effect size. Future research should focus on the exact mechanisms of behavior change leading to beneficial outcomes of brief alcohol interventions and the potential effectiveness of combined brief interventions and other preventive approaches. PMID:26221619
Visser, Lennart; Schoonenboom, Judith; Korthagen, Fred A. J.
2017-01-01
This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students (N = 54). The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23), the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks), the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term. PMID:29163317
NASA Astrophysics Data System (ADS)
Rifa’i, A.; Lestari, H. P.
2018-03-01
This study was designed to know the effects of Think Pair Share using Scientific Approach on students' self-confidence and mathematical problem-solving. Quasi-experimental with pre-test post-test non-equivalent group method was used as a basis for design this study. Self-confidence questionnaire and problem-solving test have been used for measurement of the two variables. Two classes of the first grade in religious senior high school (MAN) in Indonesia were randomly selected for this study. Teaching sequence and series from mathematics book at control group in the traditional way and at experiment group has been in TPS using scientific approach learning method. For data analysis regarding students’ problem-solving skill and self-confidence, One-Sample t-Test, Independent Sample t-Test, and Multivariate of Variance (MANOVA) were used. The results showed that (1) TPS using a scientific approach and traditional learning had positive effects (2) TPS using scientific approach learning in comparative with traditional learning had a more significant effect on students’ self-confidence and problem-solving skill.
Effects of a weight-loss program for obese children: a "mix of attributes" approach.
Yin, Teresa J C; Wu, Fei-Ling; Liu, Ying-Lung; Yu, Shu
2005-03-01
Childhood obesity is an important global public health issue. There is a need for more effective, low cost and child-centered intervention programs for reducing body weight. In response to this need, we developed a mix of attributes approach (including content, interactivity, control, channel, and objectivity) to help obese children (weight-for-length index, WLI >/= 1.20) reduce their body weight and improve their knowledge, attitude, and behavior. The prevalence of obesity in our sample was 15.9 % (140 obese children out of 882 children studying in the fourth grade) . An experimental, randomized research design was conducted in this study. Anthropometric measurements (including Body Mass Index [BMI] , WLI, body fat percentage, triceps, and subscapular skinfold thickness) and questionnaires (including the Scale of Obesity and Body Weight Loss Knowledge, Attitude, and Practice) were evaluated at baseline (pretest) and after one month of the intervention (posttest) for all obese children. Of 140 obese children, 118 completed this study (66 in the experimental group, 52 in the control group). The mix of attributes approach significantly reduced the degree of obesity revealed in anthropometric measurements. (p < .05). This approach also significantly improved obese children ' s knowledge (p < .001) and slightly improved their behaviors (p = .057); however, this program did not change the children ' s attitudes so easily (p = .597). To more effectively lose weight, we suggest an additional attribute, " individuality, " as a means of increasing efforts to change attitudes in obese children.
Large perturbation flow field analysis and simulation for supersonic inlets
NASA Technical Reports Server (NTRS)
Varner, M. O.; Martindale, W. R.; Phares, W. J.; Kneile, K. R.; Adams, J. C., Jr.
1984-01-01
An analysis technique for simulation of supersonic mixed compression inlets with large flow field perturbations is presented. The approach is based upon a quasi-one-dimensional inviscid unsteady formulation which includes engineering models of unstart/restart, bleed, bypass, and geometry effects. Numerical solution of the governing time dependent equations of motion is accomplished through a shock capturing finite difference algorithm, of which five separate approaches are evaluated. Comparison with experimental supersonic wind tunnel data is presented to verify the present approach for a wide range of transient inlet flow conditions.
Xiao, Ruiyang; Gao, Lingwei; Wei, Zongsu; Spinney, Richard; Luo, Shuang; Wang, Donghong; Dionysiou, Dionysios D; Tang, Chong-Jian; Yang, Weichun
2017-12-01
Advanced oxidation processes (AOPs) based on formation of free radicals at ambient temperature and pressure are effective for treating endocrine disrupting chemicals (EDCs) in waters. In this study, we systematically investigated the degradation kinetics of bisphenol A (BPA), a representative EDC by hydroxyl radical (OH) with a combination of experimental and theoretical approaches. The second-order rate constant (k) of BPA with OH was experimentally determined to be 7.2 ± 0.34 × 10 9 M -1 s -1 at pH 7.55. We also calculated the thermodynamic and kinetic behaviors for the bimolecular reactions by density functional theory (DFT) using the M05-2X method with 6-311++G** basis set and solvation model based on density (SMD). The results revealed that H-abstraction on the phenol group is the most favorable pathway for OH. The theoretical k value corrected by the Collins-Kimball approach was determined to be 1.03 × 10 10 M -1 s -1 , which is in reasonable agreement with the experimental observation. These results are of fundamental and practical importance in understanding the chemical interactions between OH and BPA, and aid further AOPs design in treating EDCs during wastewater treatment processes. Copyright © 2017 Elsevier Ltd. All rights reserved.
A reproducible approach to high-throughput biological data acquisition and integration
Rahnavard, Gholamali; Waldron, Levi; McIver, Lauren; Shafquat, Afrah; Franzosa, Eric A.; Miropolsky, Larissa; Sweeney, Christopher
2015-01-01
Modern biological research requires rapid, complex, and reproducible integration of multiple experimental results generated both internally and externally (e.g., from public repositories). Although large systematic meta-analyses are among the most effective approaches both for clinical biomarker discovery and for computational inference of biomolecular mechanisms, identifying, acquiring, and integrating relevant experimental results from multiple sources for a given study can be time-consuming and error-prone. To enable efficient and reproducible integration of diverse experimental results, we developed a novel approach for standardized acquisition and analysis of high-throughput and heterogeneous biological data. This allowed, first, novel biomolecular network reconstruction in human prostate cancer, which correctly recovered and extended the NFκB signaling pathway. Next, we investigated host-microbiome interactions. In less than an hour of analysis time, the system retrieved data and integrated six germ-free murine intestinal gene expression datasets to identify the genes most influenced by the gut microbiota, which comprised a set of immune-response and carbohydrate metabolism processes. Finally, we constructed integrated functional interaction networks to compare connectivity of peptide secretion pathways in the model organisms Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa. PMID:26157642
Predicting evolutionary responses to climate change in the sea.
Munday, Philip L; Warner, Robert R; Monro, Keyne; Pandolfi, John M; Marshall, Dustin J
2013-12-01
An increasing number of short-term experimental studies show significant effects of projected ocean warming and ocean acidification on the performance on marine organisms. Yet, it remains unclear if we can reliably predict the impact of climate change on marine populations and ecosystems, because we lack sufficient understanding of the capacity for marine organisms to adapt to rapid climate change. In this review, we emphasise why an evolutionary perspective is crucial to understanding climate change impacts in the sea and examine the approaches that may be useful for addressing this challenge. We first consider what the geological record and present-day analogues of future climate conditions can tell us about the potential for adaptation to climate change. We also examine evidence that phenotypic plasticity may assist marine species to persist in a rapidly changing climate. We then outline the various experimental approaches that can be used to estimate evolutionary potential, focusing on molecular tools, quantitative genetics, and experimental evolution, and we describe the benefits of combining different approaches to gain a deeper understanding of evolutionary potential. Our goal is to provide a platform for future research addressing the evolutionary potential for marine organisms to cope with climate change. © 2013 John Wiley & Sons Ltd/CNRS.
Effects Of Winter Manure Application In Ohio On The Quality Of Surface Runoff
Winter application of manure can pose environmental risks depending upon the application approach. Seven continuous corn, instrumented watersheds (approximately 1 ha each) at the USDA-ARS North Applachian Experimental Watershed research station near Coshocton, Ohio were used to ...
Experimentation in Institutions: Ethics, Creativity, and Existential Competence
ERIC Educational Resources Information Center
O'Donnell, Aislinn
2018-01-01
The existential, experiential, ethical, pathic and pre-pathic dimensions of education are essential for the creative composition of subjectivities in institutional spaces, yet educational research and policy tend increasingly to privilege technical discourses and prescriptive approaches both when evaluating "what is effective in…
ERIC Educational Resources Information Center
Colicchia, Giuseppe
2007-01-01
The investigation of the focusing in fish eyes, both theoretical and experimental, by using a simple fish eye model, provides an interesting biological context for teaching the introductory principles of optics. Moreover, the students will learn concepts of biology by an approach of cause and effect.
Single particle fluorescence: a simple experimental approach to evaluate coincidence effects.
Wu, Xihong; Omenetto, Nicoló; Smith, Benjamin W; Winefordner, James D
2007-07-01
Real-time characterization of the chemical and physical properties of individual aerosol particles is an important issue in environmental studies. A well-established way of accomplishing this task relies on the use of laser-induced fluorescence or laser ionization mass spectrometry. We describe here a simple approach aimed at experimentally verifying that single particles are indeed addressed. The approach has been tested with a system consisting of a series of aerodynamic lenses to form a beam of dye-doped particles aerosolized from a solution of known concentration with a medical nebulizer. Two independent spectral detection channels simultaneously measure the fluorescence signals generated in two different spectral regions by the passage of a mixture of two dye-doped particles through a focused laser beam in a vacuum chamber. Coincidence effects, arising from the simultaneous observation of both fluorescence emissions, can then be directly observed. Both dual-color fluorescence and pulse height distribution have been analyzed. As expected, the probability of single- or multiple-particle interaction strongly depends on the particle flux in the chamber, which is related to the concentration of particles in the nebulized solution. In our case, to achieve a two-particle coincidence smaller than 10%, a particle concentration lower than 1.2x10(5) particles/mL is required. Moreover, it was found that the experimental observations are in agreement with a simple mathematical model based on Poisson statistics. Although the results obtained refer to particle concentrations in solution, our approach can equally be applicable to experiments involving direct air sampling, provided that the number density of particles in air can be measured a priori, e.g., with a particle counter.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ghosh, Soumya; Soudackov, Alexander V.; Hammes-Schiffer, Sharon
Electron transfer and proton coupled electron transfer (PCET) reactions at electrochemical interfaces play an essential role in a broad range of energy conversion processes. The reorganization energy, which is a measure of the free energy change associated with solute and solvent rearrangements, is a key quantity for calculating rate constants for these reactions. We present a computational method for including the effects of the double layer and ionic environment of the diffuse layer in calculations of electrochemical solvent reorganization energies. This approach incorporates an accurate electronic charge distribution of the solute within a molecular-shaped cavity in conjunction with a dielectricmore » continuum treatment of the solvent, ions, and electrode using the integral equations formalism polarizable continuum model. The molecule-solvent boundary is treated explicitly, but the effects of the electrode-double layer and double layer-diffuse layer boundaries, as well as the effects of the ionic strength of the solvent, are included through an external Green’s function. The calculated total reorganization energies agree well with experimentally measured values for a series of electrochemical systems, and the effects of including both the double layer and ionic environment are found to be very small. This general approach was also extended to electrochemical PCET and produced total reorganization energies in close agreement with experimental values for two experimentally studied PCET systems. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center, funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.« less
Bray, Jeremy W.; Kelly, Erin L.; Hammer, Leslie B.; Almeida, David M.; Dearing, James W.; King, Rosalind B.; Buxton, Orfeu M.
2013-01-01
Recognizing a need for rigorous, experimental research to support the efforts of workplaces and policymakers in improving the health and wellbeing of employees and their families, the National Institutes of Health and the Centers for Disease Control and Prevention formed the Work, Family & Health Network (WFHN). The WFHN is implementing an innovative multisite study with a rigorous experimental design (adaptive randomization, control groups), comprehensive multilevel measures, a novel and theoretically based intervention targeting the psychosocial work environment, and translational activities. This paper describes challenges and benefits of designing a multilevel and transdisciplinary research network that includes an effectiveness study to assess intervention effects on employees, families, and managers; a daily diary study to examine effects on family functioning and daily stress; a process study to understand intervention implementation; and translational research to understand and inform diffusion of innovation. Challenges were both conceptual and logistical, spanning all aspects of study design and implementation. In dealing with these challenges, however, the WFHN developed innovative, transdisciplinary, multi-method approaches to conducting workplace research that will benefit both the research and business communities. PMID:24618878
Smith, R Scott; Kay, Bruce D
2012-03-15
Experimental measurements of the properties of supercooled liquids at temperatures near their glass transition temperatures, Tg, are requisite for understanding the behavior of glasses and amorphous solids. Unfortunately, many supercooled molecular liquids rapidly crystallize at temperatures far above their Tg, making such measurements difficult to nearly impossible. In this Perspective, we discuss some recent alternative approaches to obtain experimental data in the temperature regime near Tg. These new approaches may yield the additional experimental data necessary to test current theoretical models of the dynamical slowdown that occurs in supercooled liquids approaching the glass transition.
Nonlinear Reduced-Order Simulation Using An Experimentally Guided Modal Basis
NASA Technical Reports Server (NTRS)
Rizzi, Stephen A.; Przekop, Adam
2012-01-01
A procedure is developed for using nonlinear experimental response data to guide the modal basis selection in a nonlinear reduced-order simulation. The procedure entails using nonlinear acceleration response data to first identify proper orthogonal modes. Special consideration is given to cases in which some of the desired response data is unavailable. Bases consisting of linear normal modes are then selected to best represent the experimentally determined transverse proper orthogonal modes and either experimentally determined inplane proper orthogonal modes or the special case of numerically computed in-plane companions. The bases are subsequently used in nonlinear modal reduction and dynamic response simulations. The experimental data used in this work is simulated to allow some practical considerations, such as the availability of in-plane response data and non-idealized test conditions, to be explored. Comparisons of the nonlinear reduced-order simulations are made with the surrogate experimental data to demonstrate the effectiveness of the approach.
The CTD2 Center at University of California San Francisco (UCSF-2) used an integrative genomics approach to reveal unidentified mRNA splicing patterns in neuroblastoma. Read the abstract Experimental Approaches Read the detailed Experimental Approaches
Effect of leading-edge load constraints on the design and performance of supersonic wings
NASA Technical Reports Server (NTRS)
Darden, C. M.
1985-01-01
A theoretical and experimental investigation was conducted to assess the effect of leading-edge load constraints on supersonic wing design and performance. In the effort to delay flow separation and the formation of leading-edge vortices, two constrained, linear-theory optimization approaches were used to limit the loadings on the leading edge of a variable-sweep planform design. Experimental force and moment tests were made on two constrained camber wings, a flat uncambered wing, and an optimum design with no constraints. Results indicate that vortex strength and separation regions were mildest on the severely and moderately constrained wings.
NASA Astrophysics Data System (ADS)
Edrisi, Siroos; Bidhendi, Norollah Kasiri; Haghighi, Maryam
2017-01-01
Effective thermal conductivity of the porous media was modeled based on a self-consistent method. This model estimates the heat transfer between insulator surface and air cavities accurately. In this method, the pore size and shape, the temperature gradient and other thermodynamic properties of the fluid was taken into consideration. The results are validated by experimental data for fire bricks used in cracking furnaces at the olefin plant of Maroon petrochemical complexes well as data published for polyurethane foam (synthetic polymers) IPTM and IPM. The model predictions present a good agreement against experimental data with thermal conductivity deviating <1 %.
Damping in aerospace composite materials
NASA Astrophysics Data System (ADS)
Agneni, A.; Balis Crema, L.; Castellani, A.
Experimental results are presented on specimens of carbon and Kevlar fibers in epoxy resin, materials used in many aerospace structures (control surfaces and wings in aircraft, large antennas in spacecraft, etc.). Some experimental methods of estimating damping ratios are first reviewed, either in the time domain or in the frequency domain. Some damping factor estimates from experimental tests are then shown; in order to evaluate the effects of the aerospace environment, damping factors have been obtained in a typical range of temperature, namely between +120 C and -120 C, and in the pressure range from room pressure to 10 exp -6 torr. Finally, a theoretical approach for predicting the bounds of the damping coefficients is shown, and prediction data are compared with experimental results.
Experimental and numerical modeling of rarefied gas flows through orifices and short tubes
NASA Astrophysics Data System (ADS)
Gimelshein, S. F.; Markelov, G. N.; Lilly, T. C.; Selden, N. P.; Ketsdever, A. D.
2005-05-01
Flow through circular orifices with thickness-to-diameter ratios varying from 0.015 to 1.2 is studied experimentally and numerically with kinetic and continuum approaches. Helium and nitrogen gases are used in the range of Reynolds numbers from 0.02 to over 700. Good agreement between experimental and numerical results is observed for mass flow and thrust corrected for the experimental facility background pressure. For thick-to-thin orifice ratios of mass flow and thrust vs pressure, a minimum is established. The thick orifice propulsion efficiency is much higher than that of a thin orifice. The effects of edge roundness and surface specularity on a thick orifice specific impulse were found to be relatively small.
Web Based Learning Support for Experimental Design in Molecular Biology.
ERIC Educational Resources Information Center
Wilmsen, Tinri; Bisseling, Ton; Hartog, Rob
An important learning goal of a molecular biology curriculum is a certain proficiency level in experimental design. Currently students are confronted with experimental approaches in textbooks, in lectures and in the laboratory. However, most students do not reach a satisfactory level of competence in the design of experimental approaches. This…
Rajaraman, Prathish K; Manteuffel, T A; Belohlavek, M; Heys, Jeffrey J
2017-01-01
A new approach has been developed for combining and enhancing the results from an existing computational fluid dynamics model with experimental data using the weighted least-squares finite element method (WLSFEM). Development of the approach was motivated by the existence of both limited experimental blood velocity in the left ventricle and inexact numerical models of the same flow. Limitations of the experimental data include measurement noise and having data only along a two-dimensional plane. Most numerical modeling approaches do not provide the flexibility to assimilate noisy experimental data. We previously developed an approach that could assimilate experimental data into the process of numerically solving the Navier-Stokes equations, but the approach was limited because it required the use of specific finite element methods for solving all model equations and did not support alternative numerical approximation methods. The new approach presented here allows virtually any numerical method to be used for approximately solving the Navier-Stokes equations, and then the WLSFEM is used to combine the experimental data with the numerical solution of the model equations in a final step. The approach dynamically adjusts the influence of the experimental data on the numerical solution so that more accurate data are more closely matched by the final solution and less accurate data are not closely matched. The new approach is demonstrated on different test problems and provides significantly reduced computational costs compared with many previous methods for data assimilation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
2012-09-01
Technologies. Helius was developed as a user material subroutine for ABAQUS and ANSYS (9). Through an ABAQUS plug-in and graphical interface, a...incorporated into an ABAQUS subroutine and compared to experimental data. Xie and Biggers (18) look at the effect width-to-hole-diameter ratio on open- hole...smearing-unsmearing” approach, nonlinear anisotropy, and progressive failure analysis into ABAQUS . The subroutine UMAT is used to define the
Park, Chorong; Song, Misoon; Cho, Belong; Lim, Jaeyoung; Song, Wook; Chang, Heekyung; Park, Yeon-Hwan
2015-04-01
The purpose of this study was to develop a multi-disciplinary self-management intervention based on empowerment theory and to evaluate the effectiveness of the intervention for older adults with chronic illness. A randomized controlled trial design was used with 43 Korean older adults with chronic illness (Experimental group=22, Control group=21). The intervention consisted of two phases: (1) 8-week multi-disciplinary, team guided, group-based health education, exercise session, and individual empowerment counseling, (2) 16-week self-help group activities including weekly exercise and group discussion to maintain acquired self-management skills and problem-solving skills. Baseline, 8-week, and 24-week assessments measured health empowerment, exercise self-efficacy, physical activity, and physical function. Health empowerment, physical activity, and physical function in the experimental group increased significantly compared to the control group over time. Exercise self-efficacy significantly increased in experimental group over time but there was no significant difference between the two groups. The self-management program based on empowerment theory improved health empowerment, physical activity, and physical function in older adults. The study finding suggests that a health empowerment strategy may be an effective approach for older adults with multiple chronic illnesses in terms of achieving a sense of control over their chronic illness and actively engaging self-management.
Accurate Simulation and Detection of Coevolution Signals in Multiple Sequence Alignments
Ackerman, Sharon H.; Tillier, Elisabeth R.; Gatti, Domenico L.
2012-01-01
Background While the conserved positions of a multiple sequence alignment (MSA) are clearly of interest, non-conserved positions can also be important because, for example, destabilizing effects at one position can be compensated by stabilizing effects at another position. Different methods have been developed to recognize the evolutionary relationship between amino acid sites, and to disentangle functional/structural dependencies from historical/phylogenetic ones. Methodology/Principal Findings We have used two complementary approaches to test the efficacy of these methods. In the first approach, we have used a new program, MSAvolve, for the in silico evolution of MSAs, which records a detailed history of all covarying positions, and builds a global coevolution matrix as the accumulated sum of individual matrices for the positions forced to co-vary, the recombinant coevolution, and the stochastic coevolution. We have simulated over 1600 MSAs for 8 protein families, which reflect sequences of different sizes and proteins with widely different functions. The calculated coevolution matrices were compared with the coevolution matrices obtained for the same evolved MSAs with different coevolution detection methods. In a second approach we have evaluated the capacity of the different methods to predict close contacts in the representative X-ray structures of an additional 150 protein families using only experimental MSAs. Conclusions/Significance Methods based on the identification of global correlations between pairs were found to be generally superior to methods based only on local correlations in their capacity to identify coevolving residues using either simulated or experimental MSAs. However, the significant variability in the performance of different methods with different proteins suggests that the simulation of MSAs that replicate the statistical properties of the experimental MSA can be a valuable tool to identify the coevolution detection method that is most effective in each case. PMID:23091608
Nozari, Ali Yazdanpanah; Siamian, Hasan
2014-12-01
Nowadays, regarding the learners' needs and social conditions, it is obviously needed to revise and reconsider the traditional methods and approaches in teaching. The problem solving approach is one of the new ways in Teaching and learning process. This study aimed at studying and examining the effect of "problem-solving" approach on creative thinking of high school female students. An experimental method is used for this research. In this research, 342 out of 3047 female-students from Sari high schools were randomly selected. These 342 students were divided into two groups (experimental and control) in which there were seven classrooms. The total number of students in every group was about 171. After testing them with Jamal Abedi creativity test, it was revealed that two groups were equal in creativity score. The tests were done through Requirements. The experimental group was taught by problem solving method for three months while the control group was taught by traditional method. The research results showed that using descriptive indices and t-test for the two independent sample groups in which problem solving teaching method was used in teaching processes had an effect on creativity level in comparison with traditional method used in the control group. Considering the results of this study, the application of problem-solving teaching methods increased the creativity and its components (fluidity, expansion, originality and flexibility) in learners, therefore, it is recommended that students be encouraged to take classes on frequent responses on various topics (variability) and draw attention on different issues, and expand their analysis on elements in particular courses like art (expansion). To enhance the learner's mental flexibility and attention to various aspects, they are encouraged to provide a variety of responses.
Development and Experimental Verification of Surface Effects in a Fluidic Model
2006-01-01
FROM A HE PLASMA INSIDE A POLYSTYRENE MICROCHANNEL. 43 FIGURE 30: THE EMISSION SPECTRA FROM A MIXED HEXAFLUOROETHYLENE/HE PLASMA INSIDE THE...MICROCHANNEL 47 FIGURE 35: THE ADSORPTION OF GLUCOSE OXIDASE TO DIFFERENT POLYMER SURFACES WAS SHOWN TO HAVE A SIGNIFICANT EFFECT ON ELECTROOSMOTIC FLOW...approach involves neglecting non-ideal (convective-diffusive) effects 5 by assuming well- mixed protein in contact with an idealized surface. Coupled
Making sound vortices by metasurfaces
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ye, Liping; Qiu, Chunyin, E-mail: cyqiu@whu.edu.cn; Lu, Jiuyang
Based on the Huygens-Fresnel principle, a metasurface structure is designed to generate a sound vortex beam in airborne environment. The metasurface is constructed by a thin planar plate perforated with a circular array of deep subwavelength resonators with desired phase and amplitude responses. The metasurface approach in making sound vortices is validated well by full-wave simulations and experimental measurements. Potential applications of such artificial spiral beams can be anticipated, as exemplified experimentally by the torque effect exerting on an absorbing disk.
Making sound vortices by metasurfaces
NASA Astrophysics Data System (ADS)
Ye, Liping; Qiu, Chunyin; Lu, Jiuyang; Tang, Kun; Jia, Han; Ke, Manzhu; Peng, Shasha; Liu, Zhengyou
2016-08-01
Based on the Huygens-Fresnel principle, a metasurface structure is designed to generate a sound vortex beam in airborne environment. The metasurface is constructed by a thin planar plate perforated with a circular array of deep subwavelength resonators with desired phase and amplitude responses. The metasurface approach in making sound vortices is validated well by full-wave simulations and experimental measurements. Potential applications of such artificial spiral beams can be anticipated, as exemplified experimentally by the torque effect exerting on an absorbing disk.
Adaptive Control of Four-Leg VSC Based DSTATCOM in Distribution System
NASA Astrophysics Data System (ADS)
Singh, Bhim; Arya, Sabha Raj
2014-01-01
This work discusses an experimental performance of a four-leg Distribution Static Compensator (DSTATCOM) using an adaptive filter based approach. It is used for estimation of reference supply currents through extracting the fundamental active power components of three-phase distorted load currents. This control algorithm is implemented on an assembled DSTATCOM for harmonics elimination, neutral current compensation and load balancing, under nonlinear loads. Experimental results are discussed, and it is noticed that DSTATCOM is effective solution to perform satisfactory performance under load dynamics.
Network meta-analysis in health psychology and behavioural medicine: a primer.
Molloy, G J; Noone, C; Caldwell, D; Welton, N J; Newell, J
2018-04-05
Progress in the science and practice of health psychology depends on the systematic synthesis of quantitative psychological evidence. Meta-analyses of experimental studies have led to important advances in understanding health-related behaviour change interventions. Fundamental questions regarding such interventions have been systematically investigated through synthesising relevant experimental evidence using standard pairwise meta-analytic procedures that provide reliable estimates of the magnitude, homogeneity and potential biases in effects observed. However, these syntheses only provide information about whether particular types of interventions work better than a control condition or specific alternative approaches. To increase the impact of health psychology on health-related policy-making, evidence regarding the comparative efficacy of all relevant intervention approaches - which may include biomedical approaches - is necessary. With the development of network meta-analysis (NMA), such evidence can be synthesised, even when direct head-to-head trials do not exist. However, care must be taken in its application to ensure reliable estimates of the effect sizes between interventions are revealed. This review paper describes the potential importance of NMA to health psychology, how the technique works and important considerations for its appropriate application within health psychology.
NASA Astrophysics Data System (ADS)
Kerschbaum, M.; Hopmann, C.
2016-06-01
The computationally efficient simulation of the progressive damage behaviour of continuous fibre reinforced plastics is still a challenging task with currently available computer aided engineering methods. This paper presents an original approach for an energy based continuum damage model which accounts for stress-/strain nonlinearities, transverse and shear stress interaction phenomena, quasi-plastic shear strain components, strain rate effects, regularised damage evolution and consideration of load reversal effects. The physically based modelling approach enables experimental determination of all parameters on ply level to avoid expensive inverse analysis procedures. The modelling strategy, implementation and verification of this model using commercially available explicit finite element software are detailed. The model is then applied to simulate the impact and penetration of carbon fibre reinforced cross-ply specimens with variation of the impact speed. The simulation results show that the presented approach enables a good representation of the force-/displacement curves and especially well agreement with the experimentally observed fracture patterns. In addition, the mesh dependency of the results were assessed for one impact case showing only very little change of the simulation results which emphasises the general applicability of the presented method.
Remmerswaal, Danielle; Muris, Peter; Huijding, Jorg
2013-06-01
Using an experimental approach, we examined the effects of verbal information as provided by the mothers on children's fear of real novel animals. Mothers of children aged 8 to 12 years (N=47) were shown a cage containing a pair of exotic rodents (i.e., Mongolian gerbils) and then received either positive or negative information about these animals. Mothers were told that their child would have to approach the animals and had the opportunity to prepare their children for this confrontation. Results showed that mothers spontaneously passed over the information they had received to their children. Most importantly, this information to some extent determined children's fear reactions towards the animals. That is, whereas no clear effects of information were found on subjective fear ratings, the data did indicate that children of mothers in the negative information condition were more reluctant to approach the animals as compared to children of mothers who had received positive information. The findings provide further support for the idea that verbal information as provided by parents may induce fear in their offspring. Copyright © 2013. Published by Elsevier Ltd.
NASA Astrophysics Data System (ADS)
Williams, Caitlin R. S.; Sorrentino, Francesco; Murphy, Thomas E.; Roy, Rajarshi
2013-12-01
We experimentally study the complex dynamics of a unidirectionally coupled ring of four identical optoelectronic oscillators. The coupling between these systems is time-delayed in the experiment and can be varied over a wide range of delays. We observe that as the coupling delay is varied, the system may show different synchronization states, including complete isochronal synchrony, cluster synchrony, and two splay-phase states. We analyze the stability of these solutions through a master stability function approach, which we show can be effectively applied to all the different states observed in the experiment. Our analysis supports the experimentally observed multistability in the system.
Model wall and recovery temperature effects on experimental heat transfer data analysis
NASA Technical Reports Server (NTRS)
Throckmorton, D. A.; Stone, D. R.
1974-01-01
Basic analytical procedures are used to illustrate, both qualitatively and quantitatively, the relative impact upon heat transfer data analysis of certain factors which may affect the accuracy of experimental heat transfer data. Inaccurate knowledge of adiabatic wall conditions results in a corresponding inaccuracy in the measured heat transfer coefficient. The magnitude of the resulting error is extreme for data obtained at wall temperatures approaching the adiabatic condition. High model wall temperatures and wall temperature gradients affect the level and distribution of heat transfer to an experimental model. The significance of each of these factors is examined and its impact upon heat transfer data analysis is assessed.
Simulation of Fatigue Behavior of High Temperature Metal Matrix Composites
NASA Technical Reports Server (NTRS)
Tong, Mike T.; Singhal, Suren N.; Chamis, Christos C.; Murthy, Pappu L. N.
1996-01-01
A generalized relatively new approach is described for the computational simulation of fatigue behavior of high temperature metal matrix composites (HT-MMCs). This theory is embedded in a specialty-purpose computer code. The effectiveness of the computer code to predict the fatigue behavior of HT-MMCs is demonstrated by applying it to a silicon-fiber/titanium-matrix HT-MMC. Comparative results are shown for mechanical fatigue, thermal fatigue, thermomechanical (in-phase and out-of-phase) fatigue, as well as the effects of oxidizing environments on fatigue life. These results show that the new approach reproduces available experimental data remarkably well.
ERIC Educational Resources Information Center
Koksal, Ela Ayse; Berberoglu, Giray
2014-01-01
The purpose of this study is to investigate the effectiveness of guided-inquiry approach in science classes over existing science and technology curriculum in developing content-based science achievement, science process skills, and attitude toward science of grade level 6 students in Turkey. Non-equivalent control group quasi-experimental design…
Effect of Constructivist Based Training on Learning and Teaching: An Experiment in Classroom
ERIC Educational Resources Information Center
Pandey, Laxmi; Ameta, Devendra
2017-01-01
The aim of the study was to study the effect of constructive based training approach on teachers' attitude and students' achievement. The study comprised 80 students of class VI from Nagar Palika Girls Middle School Balmiki Basti New Delhi and Nagar Palika Girls Sr. Sec. School, Havelock Square, New Delhi. A quasi experimental pre-test and…
ERIC Educational Resources Information Center
Sancar-Tokmak, Hatice
2015-01-01
This study aimed to investigate the effect of curriculum-generated play instruction on the mathematics teaching efficacy of early childhood education pre-service teachers. The study used a one group pre-test/post-test experimental research design, supported by a qualitative approach. The participants of the study consisted of 35 pre-service…
ERIC Educational Resources Information Center
Sancar-Tokmak, Hatice; Yanpar-Yelken, Tugba
2015-01-01
This study aimed to examine the effects of creating digital stories (DSs) on the self-confidence of foreign language education (FLE) pre-service teachers with regard to technological, pedagogical and content knowledge (TPACK). A one-group pretest/posttest experimental research design was applied, supported by a qualitative approach. A total of 71…
ERIC Educational Resources Information Center
Yu, Fu-Yun; Sung, Shannon
2016-01-01
This study examined the effects of identity revelation and concealment on the number of times students' work was assessed in an online peer assessment context. It also examined the underlying reasons guiding the assessor's targeting behavior. Two fifth-grade classes participated. The one-group pretest-posttest experimental research design coupled…
The Effects of Reading Short Stories in Improving Foreign Language Writing Skills
ERIC Educational Resources Information Center
Bartan, Özgür Sen
2017-01-01
This study is an inquiry into the effects of reading short stories in improving foreign language writing skills through Read for Writing model, which is the adaptation of the approach called Talk for Writing (Corbett, 2013). It is a quasi-experimental 13-week field study which was implemented in a primary school. The purpose of this study is to…
ERIC Educational Resources Information Center
Young, Edna Carter; Thompson, Cynthia K.
1987-01-01
The effects of treatment on errors in consonant clusters and in ambisyllabic consonants were investigated in two adults with histories of developmental phonological problems. Results indicated that treatment, consisting of a sound-referenced rebus approach, affected change in production of trained words as well as generalization to untrained words…
ERIC Educational Resources Information Center
Rabgay, Tshewang
2018-01-01
The study investigated the effect of using cooperative learning method on tenth grade students' learning achievement in biology and their attitude towards the subject in a Higher Secondary School in Bhutan. The study used a mixed method approach. The quantitative component included an experimental design where cooperative learning was the…
ERIC Educational Resources Information Center
Wu, Ying-Tien; Tsai, Chin-Chung
2011-01-01
Learners' ability in dealing with socio-scientific issues has been highlighted in contemporary science education. This study explored the effects of different on-line searching activities on high school students' cognitive structure outcomes and informal reasoning outcomes. By using a quasi-experimental research approach, thirty-three students…
ERIC Educational Resources Information Center
Bramwell-Lalor, Sharon; Rainford, Marcia
2014-01-01
This paper reports on teachers' use of concept mapping as an alternative assessment strategy in advanced level biology classes and its effects on students' cognitive skills on selected biology concepts. Using a mixed methods approach, the study employed a pre-test/post-test quasi-experimental design involving 156 students and 8 teachers from…
The Effect on the 8th Grade Students' Attitude towards Statistics of Project Based Learning
ERIC Educational Resources Information Center
Koparan, Timur; Güven, Bülent
2014-01-01
This study investigates the effect of the project based learning approach on 8th grade students' attitude towards statistics. With this aim, an attitude scale towards statistics was developed. Quasi-experimental research model was used in this study. Following this model in the control group the traditional method was applied to teach statistics…
New approach to calculate the true-coincidence effect of HpGe detector
DOE Office of Scientific and Technical Information (OSTI.GOV)
Alnour, I. A., E-mail: aaibrahim3@live.utm.my, E-mail: ibrahim.elnour@yahoo.com; Wagiran, H.; Ibrahim, N.
The corrections for true-coincidence effects in HpGe detector are important, especially at low source-to-detector distances. This work established an approach to calculate the true-coincidence effects experimentally for HpGe detectors of type Canberra GC3018 and Ortec GEM25-76-XLB-C, which are in operation at neutron activation analysis lab in Malaysian Nuclear Agency (NM). The correction for true-coincidence effects was performed close to detector at distances 2 and 5 cm using {sup 57}Co, {sup 60}Co, {sup 133}Ba and {sup 137}Cs as standard point sources. The correction factors were ranged between 0.93-1.10 at 2 cm and 0.97-1.00 at 5 cm for Canberra HpGe detector; whereas for Ortec HpGemore » detector ranged between 0.92-1.13 and 0.95-100 at 2 and 5 cm respectively. The change in efficiency calibration curve of the detector at 2 and 5 cm after correction was found to be less than 1%. Moreover, the polynomial parameters functions were simulated through a computer program, MATLAB in order to find an accurate fit to the experimental data points.« less
Microstructure and rheology of thermoreversible nanoparticle gels.
Ramakrishnan, S; Zukoski, C F
2006-08-29
Naïve mode coupling theory is applied to particles interacting with short-range Yukawa attractions. Model results for the location of the gel line and the modulus of the resulting gels are reduced to algebraic equations capturing the effects of the range and strength of attraction. This model is then applied to thermo reversible gels composed of octadecyl silica particles suspended in decalin. The application of the model to the experimental system requires linking the experimental variable controlling strength of attraction, temperature, to the model strength of attraction. With this link, the model predicts temperature and volume fraction dependencies of gelation and modulus with five parameters: particle size, particle volume fraction, overlap volume of surface hairs, and theta temperature. In comparing model predictions with experimental results, we first observe that in these thermal gels there is no evidence of clustering as has been reported in depletion gels. One consequence of this observation is that there are no additional adjustable parameters required to make quantitative comparisons between experimental results and model predictions. Our results indicate that the naïve mode coupling approach taken here in conjunction with a model linking temperature to strength of attraction provides a robust approach for making quantitative predictions of gel mechanical properties. Extension of model predictions to additional experimental systems requires linking experimental variables to the Yukawa strength and range of attraction.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, Fangyong; Lartey, Michael; Damodaran, Krishnan
2013-01-01
Ionic liquids are an emerging class of materials with applications in a variety of fields. Steady progress has been made in the creation of ionic liquids tailored to specific applications. However, the understanding of the underlying structure–property relationships has been slower to develop. As a step in the effort to alleviate this deficiency, the influence of side groups on ionic liquid properties has been studied through an integrated approach utilizing synthesis, experimental determination of properties, and simulation techniques. To achieve this goal, a classical force field in the framework of OPLS/Amber force fields has been developed to predict ionic liquidmore » properties accurately. Cu(I)-catalyzed click chemistry was employed to synthesize triazolium-based ionic liquids with diverse side groups. Values of densities were predicted within 3% of experimental values, whereas self-diffusion coefficients were underestimated by about an order of magnitude though the trends were in excellent agreement, the activation energy calculated in simulation correlates well with experimental values. The predicted Henry coefficient for CO{sub 2} solubility reproduced the experimentally observed trends. This study highlights the importance of integrating experimental and computational approaches in property prediction and materials development, which is not only useful in the development of ionic liquids for CO{sub 2} capture but has application in many technological fields.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, Fangyong; Lartey, Michael; Damodaran, Krishnan
Ionic liquids are an emerging class of materials with applications in a variety of fields. Steady progress has been made in the creation of ionic liquids tailored to specific applications. However, the understanding of the underlying structure–property relationships has been slower to develop. As a step in the effort to alleviate this deficiency, the influence of side groups on ionic liquid properties has been studied through an integrated approach utilizing synthesis, experimental determination of properties, and simulation techniques. To achieve this goal, a classical force field in the framework of OPLS/Amber force fields has been developed to predict ionic liquidmore » properties accurately. Cu(I)-catalyzed click chemistry was employed to synthesize triazolium-based ionic liquids with diverse side groups. Values of densities were predicted within 3% of experimental values, whereas self-diffusion coefficients were underestimated by about an order of magnitude though the trends were in excellent agreement, the activation energy calculated in simulation correlates well with experimental values. The predicted Henry coefficient for CO{sub 2} solubility reproduced the experimentally observed trends. This study highlights the importance of integrating experimental and computational approaches in property prediction and materials development, which is not only useful in the development of ionic liquids for CO{sub 2} capture but has application in many technological fields.« less
2017-01-01
In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effects in vivo. Here, I demonstrate profound changes in life histories of the rotifer Brachionus plicatilis fed 15N-enriched algae (0.4–5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies. PMID:28405367
Issues and approach to develop validated analysis tools for hypersonic flows: One perspective
NASA Technical Reports Server (NTRS)
Deiwert, George S.
1993-01-01
Critical issues concerning the modeling of low density hypervelocity flows where thermochemical nonequilibrium effects are pronounced are discussed. Emphasis is on the development of validated analysis tools, and the activity in the NASA Ames Research Center's Aerothermodynamics Branch is described. Inherent in the process is a strong synergism between ground test and real gas computational fluid dynamics (CFD). Approaches to develop and/or enhance phenomenological models and incorporate them into computational flowfield simulation codes are discussed. These models were partially validated with experimental data for flows where the gas temperature is raised (compressive flows). Expanding flows, where temperatures drop, however, exhibit somewhat different behavior. Experimental data for these expanding flow conditions is sparse and reliance must be made on intuition and guidance from computational chemistry to model transport processes under these conditions. Ground based experimental studies used to provide necessary data for model development and validation are described. Included are the performance characteristics of high enthalpy flow facilities, such as shock tubes and ballistic ranges.
De la Cruz, Susan E W; Takekawa, John Y; Spragens, Kyle A; Yee, Julie; Golightly, Richard T; Massey, Greg; Henkel, Laird A; Scott Larsen, R; Ziccardi, Michael
2013-02-15
Birds are often the most numerous vertebrates damaged and rehabilitated in marine oil spills; however, the efficacy of avian rehabilitation is frequently debated and rarely examined experimentally. We compared survival of three radio-marked treatment groups, oiled, rehabilitated (ORHB), un-oiled, rehabilitated (RHB), and un-oiled, non-rehabilitated (CON), in an experimental approach to examine post-release survival of surf scoters (Melanitta perspicillata) following the 2007 M/V Cosco Busan spill in San Francisco Bay. Live encounter-dead recovery modeling indicated that survival differed among treatment groups and over time since release. The survival estimate (±SE) for ORHB was 0.143±0.107 compared to CON (0.498±0.168) and RHB groups (0.772±0.229), suggesting scoters tolerated the rehabilitation process itself well, but oiling resulted in markedly lower survival. Future efforts to understand the physiological effects of oil type and severity on scoters are needed to improve post-release survival of this species. Published by Elsevier Ltd.
De La Cruz, Susan E. W.; Takekawa, John Y.; Spragens, Kyle A.; Yee, Julie; Golightly, Richard T.; Massey, Greg; Henkel, Laird A.; Larsen, Scott; Ziccardi, Michael
2013-01-01
Birds are often the most numerous vertebrates damaged and rehabilitated in marine oil spills; however, the efficacy of avian rehabilitation is frequently debated and rarely examined experimentally. We compared survival of three radio-marked treatment groups, oiled, rehabilitated (ORHB), un-oiled, rehabilitated (RHB), and un-oiled, non-rehabilitated (CON), in an experimental approach to examine post-release survival of surf scoters (Melanitta perspicillata) following the 2007 M/V Cosco Busan spill in San Francisco Bay. Live encounter-dead recovery modeling indicated that survival differed among treatment groups and over time since release. The survival estimate (±SE) for ORHB was 0.143 ± 0.107 compared to CON (0.498 ± 0.168) and RHB groups (0.772 ± 0.229), suggesting scoters tolerated the rehabilitation process itself well, but oiling resulted in markedly lower survival. Future efforts to understand the physiological effects of oil type and severity on scoters are needed to improve post-release survival of this species.
Computational Approaches to Nucleic Acid Origami.
Jabbari, Hosna; Aminpour, Maral; Montemagno, Carlo
2015-10-12
Recent advances in experimental DNA origami have dramatically expanded the horizon of DNA nanotechnology. Complex 3D suprastructures have been designed and developed using DNA origami with applications in biomaterial science, nanomedicine, nanorobotics, and molecular computation. Ribonucleic acid (RNA) origami has recently been realized as a new approach. Similar to DNA, RNA molecules can be designed to form complex 3D structures through complementary base pairings. RNA origami structures are, however, more compact and more thermodynamically stable due to RNA's non-canonical base pairing and tertiary interactions. With all these advantages, the development of RNA origami lags behind DNA origami by a large gap. Furthermore, although computational methods have proven to be effective in designing DNA and RNA origami structures and in their evaluation, advances in computational nucleic acid origami is even more limited. In this paper, we review major milestones in experimental and computational DNA and RNA origami and present current challenges in these fields. We believe collaboration between experimental nanotechnologists and computer scientists are critical for advancing these new research paradigms.
Issues and approach to develop validated analysis tools for hypersonic flows: One perspective
NASA Technical Reports Server (NTRS)
Deiwert, George S.
1992-01-01
Critical issues concerning the modeling of low-density hypervelocity flows where thermochemical nonequilibrium effects are pronounced are discussed. Emphasis is on the development of validated analysis tools. A description of the activity in the Ames Research Center's Aerothermodynamics Branch is also given. Inherent in the process is a strong synergism between ground test and real-gas computational fluid dynamics (CFD). Approaches to develop and/or enhance phenomenological models and incorporate them into computational flow-field simulation codes are discussed. These models have been partially validated with experimental data for flows where the gas temperature is raised (compressive flows). Expanding flows, where temperatures drop, however, exhibit somewhat different behavior. Experimental data for these expanding flow conditions are sparse; reliance must be made on intuition and guidance from computational chemistry to model transport processes under these conditions. Ground-based experimental studies used to provide necessary data for model development and validation are described. Included are the performance characteristics of high-enthalpy flow facilities, such as shock tubes and ballistic ranges.
Studying light-harvesting models with superconducting circuits.
Potočnik, Anton; Bargerbos, Arno; Schröder, Florian A Y N; Khan, Saeed A; Collodo, Michele C; Gasparinetti, Simone; Salathé, Yves; Creatore, Celestino; Eichler, Christopher; Türeci, Hakan E; Chin, Alex W; Wallraff, Andreas
2018-03-02
The process of photosynthesis, the main source of energy in the living world, converts sunlight into chemical energy. The high efficiency of this process is believed to be enabled by an interplay between the quantum nature of molecular structures in photosynthetic complexes and their interaction with the environment. Investigating these effects in biological samples is challenging due to their complex and disordered structure. Here we experimentally demonstrate a technique for studying photosynthetic models based on superconducting quantum circuits, which complements existing experimental, theoretical, and computational approaches. We demonstrate a high degree of freedom in design and experimental control of our approach based on a simplified three-site model of a pigment protein complex with realistic parameters scaled down in energy by a factor of 10 5 . We show that the excitation transport between quantum-coherent sites disordered in energy can be enabled through the interaction with environmental noise. We also show that the efficiency of the process is maximized for structured noise resembling intramolecular phononic environments found in photosynthetic complexes.
Quantitative Comparisons of a Coarse-Grid LES with Experimental Data for Backward-Facing Step Flow
NASA Astrophysics Data System (ADS)
McDonough, J. M.
1999-11-01
A novel approach to LES employing an additive decomposition of both solutions and governing equations (similar to ``multi-level'' approaches of Dubois et al.,Dynamic Multilevel Methods and the Simulation of Turbulence, Cambridge University Press, 1999) is presented; its main structural features are lack of filtering of governing equations (instead, solutions are filtered to remove aliasing due to under resolution) and direct modeling of subgrid-scale primitive variables (rather than modeling their correlations) in the manner proposed by Hylin and McDonough (Int. J. Fluid Mech. Res. 26, 228-256, 1999). A 2-D implementation of this formalism is applied to the backward-facing step flow studied experimentally by Driver and Seegmiller (AIAA J. 23, 163-171, 1985) and Driver et al. (AIAA J. 25, 914-919, 1987), and run on grids sufficiently coarse to permit easy extension to 3-D, industrially-realistic problems. Comparisons of computed and experimental mean quantities (velocity profiles, turbulence kinetic energy, reattachment lengths, etc.) and effects of grid refinement will be presented.
NASA Astrophysics Data System (ADS)
Zhang, Yunshen
2017-11-01
With the spiritual guidance of the Circular on the Construction of National Virtual Simulation Experimental Teaching Center by the National Department of Education, according to the requirements of construction task and work content, and based on the reality of the simulation experimental teaching center of virtual chemical laboratory at Tianjin University, this paper mainly strengthens the understanding of virtual simulation experimental teaching center from three aspects, and on this basis, this article puts forward specific construction ideas, which refer to the “four combinations, five in one, the optimization of the resources and school-enterprise cooperation”, and on this basis, this article has made effective explorations. It also shows the powerful functions of the virtual simulation experimental teaching platform in all aspects by taking the synthesis and analysis of organic compounds as an example.
Applying Emax model and bivariate thin plate splines to assess drug interactions
Kong, Maiying; Lee, J. Jack
2014-01-01
We review the semiparametric approach previously proposed by Kong and Lee and extend it to a case in which the dose-effect curves follow the Emax model instead of the median effect equation. When the maximum effects for the investigated drugs are different, we provide a procedure to obtain the additive effect based on the Loewe additivity model. Then, we apply a bivariate thin plate spline approach to estimate the effect beyond additivity along with its 95% point-wise confidence interval as well as its 95% simultaneous confidence interval for any combination dose. Thus, synergy, additivity, and antagonism can be identified. The advantages of the method are that it provides an overall assessment of the combination effect on the entire two-dimensional dose space spanned by the experimental doses, and it enables us to identify complex patterns of drug interaction in combination studies. In addition, this approach is robust to outliers. To illustrate this procedure, we analyzed data from two case studies. PMID:20036878
Applying Emax model and bivariate thin plate splines to assess drug interactions.
Kong, Maiying; Lee, J Jack
2010-01-01
We review the semiparametric approach previously proposed by Kong and Lee and extend it to a case in which the dose-effect curves follow the Emax model instead of the median effect equation. When the maximum effects for the investigated drugs are different, we provide a procedure to obtain the additive effect based on the Loewe additivity model. Then, we apply a bivariate thin plate spline approach to estimate the effect beyond additivity along with its 95 per cent point-wise confidence interval as well as its 95 per cent simultaneous confidence interval for any combination dose. Thus, synergy, additivity, and antagonism can be identified. The advantages of the method are that it provides an overall assessment of the combination effect on the entire two-dimensional dose space spanned by the experimental doses, and it enables us to identify complex patterns of drug interaction in combination studies. In addition, this approach is robust to outliers. To illustrate this procedure, we analyzed data from two case studies.
An inquiry approach to science and language teaching
NASA Astrophysics Data System (ADS)
Rodriguez, Imelda; Bethel, Lowell J.
The purpose of this study was to determine the effectiveness of an inquiry approach to science and language teaching to further develop classification and oral communication skills of bilingual Mexican American third graders. A random sample consisting of 64 subjects was selected for experimental and control groups from a population of 120 bilingual Mexican American third graders. The Solomon Four-Group experimental design was employed. Pre- and posttesting was performed by use of the Goldstein-Sheerer Object Sorting Test, (GSOST) and the Test of Oral Communication Skills, (TOCS). The experimental group participated in a sequential series of science lessons which required manipulation of objects, exploration, peer interaction, and teacher-pupil interaction. The children made observations and comparisons of familiar objects and then grouped them on the basis of perceived and inferred attributes. Children worked individually and in small groups. Analysis of variance procedures was used on the posttest scores to determine if there was a significant improvement in classification and oral communication skills in the experimental group. The results on the posttest scores indicated a significant improvement at the 0.01 level for the experimental group in both classification and oral communication skills. It was concluded that participation in the science inquiry lessons facilitated the development of classification and oral communication skills of bilingual children.
FAST TRACK COMMUNICATION A DFT + DMFT approach for nanosystems
NASA Astrophysics Data System (ADS)
Turkowski, Volodymyr; Kabir, Alamgir; Nayyar, Neha; Rahman, Talat S.
2010-11-01
We propose a combined density-functional-theory-dynamical-mean-field-theory (DFT + DMFT) approach for reliable inclusion of electron-electron correlation effects in nanosystems. Compared with the widely used DFT + U approach, this method has several advantages, the most important of which is that it takes into account dynamical correlation effects. The formalism is illustrated through different calculations of the magnetic properties of a set of small iron clusters (number of atoms 2 <= N <= 5). It is shown that the inclusion of dynamical effects leads to a reduction in the cluster magnetization (as compared to results from DFT + U) and that, even for such small clusters, the magnetization values agree well with experimental estimations. These results justify confidence in the ability of the method to accurately describe the magnetic properties of clusters of interest to nanoscience.
Topics in space gerontology: Effects of altered gravity and the problem of biological age
NASA Technical Reports Server (NTRS)
Economos, A. C.
1982-01-01
The use of altered gravity experimentation as a gerontological research tool is examined and a rationale for a systems approach to the adaptation to spaceflight is presented. The dependence of adaptation capacity on biological age is also discussed.
Frustration, Failure, and a "Meaningful" Lab Experience for Adult Nonscience Majors
ERIC Educational Resources Information Center
Fryshman, Bernard
1974-01-01
Describes an open-ended research approach used in an attempt to develop an appreciation of experimental science. The research project involved such topics as "properties of lead,""reasons for lead additives in gasoline," and "the effect of lead on health." (GS)
ERIC Educational Resources Information Center
Cohen, Lorraine
1995-01-01
Maintains that, during the 1980s, it was difficult to find classroom approaches that effectively challenged racial and class stereotypes. Describes a college community service project designed to teach students about racial, social, and gender discrimination. (CFR)
Decentralising Curriculum Reform: The Link Teacher Model of In-Service Training.
ERIC Educational Resources Information Center
Wildy, Helen; And Others
1996-01-01
Presents a (Western Australian) case study of the link teacher model, a decentralized, "train the trainer" approach to inservice education. Discusses the model's perceived effectiveness, the link teachers' role, central authority support, and new experimentation opportunities. Combining centralized syllabus change with decentralized…
NASA Astrophysics Data System (ADS)
Huang, Yanhui; Zhao, He; Wang, Yixing; Ratcliff, Tyree; Breneman, Curt; Brinson, L. Catherine; Chen, Wei; Schadler, Linda S.
2017-08-01
It has been found that doping dielectric polymers with a small amount of nanofiller or molecular additive can stabilize the material under a high field and lead to increased breakdown strength and lifetime. Choosing appropriate fillers is critical to optimizing the material performance, but current research largely relies on experimental trial and error. The employment of computer simulations for nanodielectric design is rarely reported. In this work, we propose a multi-scale modeling approach that employs ab initio, Monte Carlo, and continuum scales to predict the breakdown strength and lifetime of polymer nanocomposites based on the charge trapping effect of the nanofillers. The charge transfer, charge energy relaxation, and space charge effects are modeled in respective hierarchical scales by distinctive simulation techniques, and these models are connected together for high fidelity and robustness. The preliminary results show good agreement with the experimental data, suggesting its promise for use in the computer aided material design of high performance dielectrics.
NASA Astrophysics Data System (ADS)
Sun, Ning; Wu, Yiming; Chen, He; Fang, Yongchun
2018-03-01
Underactuated cranes play an important role in modern industry. Specifically, in most situations of practical applications, crane systems exhibit significant double pendulum characteristics, which makes the control problem quite challenging. Moreover, most existing planners/controllers obtained with standard methods/techniques for double pendulum cranes cannot minimize the energy consumption when fulfilling the transportation tasks. Therefore, from a practical perspective, this paper proposes an energy-optimal solution for transportation control of double pendulum cranes. By applying the presented approach, the transportation objective, including fast trolley positioning and swing elimination, is achieved with minimized energy consumption, and the residual oscillations are suppressed effectively with all the state constrains being satisfied during the entire transportation process. As far as we know, this is the first energy-optimal solution for transportation control of underactuated double pendulum cranes with various state and control constraints. Hardware experimental results are included to verify the effectiveness of the proposed approach, whose superior performance is reflected by being experimentally compared with some comparative controllers.
An Experimental Study of Implicit Racial Bias in Recognition of Child Abuse.
Rojas, Mary; Walker-Descartes, Ingrid; Laraque-Arena, Danielle
2017-05-01
We evaluated whether implicit racial bias influences pediatricians' suspicion of child abuse. Child abuse experts developed 9 injury vignettes. Pediatricians (N = 342) were randomly assigned one of 2 versions to rate for suspicion of abuse, with the child's race in each vignette varying between white and black. Data were collected online and anonymously. There were no statistically significant differences in suspicion for an abuse-related injury based on the race of the child. We adjusted for pediatrician race/ethnicity, years since graduation, location, and gender and did not find race effects. We demonstrated an experimental approach to study the influence of implicit racial bias on recognition of child abuse. Though we failed to find an effect, it is too early to conclude that none exists. The relationship among human cognition, behavior, and healthcare disparities is complex. Studies are needed that incorporate diverse approaches, clinical contexts and scenarios, patient and physician characteristics, and validated measures if we are to understand how it might be used to reduce healthcare disparities.
Therapeutic interventions in sepsis: current and anticipated pharmacological agents
Shukla, Prashant; Rao, G Madhava; Pandey, Gitu; Sharma, Shweta; Mittapelly, Naresh; Shegokar, Ranjita; Mishra, Prabhat Ranjan
2014-01-01
Sepsis is a clinical syndrome characterized by a multisystem response to a pathogenic assault due to underlying infection that involves a combination of interconnected biochemical, cellular and organ–organ interactive networks. After the withdrawal of recombinant human-activated protein C (rAPC), researchers and physicians have continued to search for new therapeutic approaches and targets against sepsis, effective in both hypo- and hyperinflammatory states. Currently, statins are being evaluated as a viable option in clinical trials. Many agents that have shown favourable results in experimental sepsis are not clinically effective or have not been clinically evaluated. Apart from developing new therapeutic molecules, there is great scope for for developing a variety of drug delivery strategies, such as nanoparticulate carriers and phospholipid-based systems. These nanoparticulate carriers neutralize intracorporeal LPS as well as deliver therapeutic agents to targeted tissues and subcellular locations. Here, we review and critically discuss the present status and new experimental and clinical approaches for therapeutic intervention in sepsis. PMID:24977655
Probing noncommutative theories with quantum optical experiments
NASA Astrophysics Data System (ADS)
Dey, Sanjib; Bhat, Anha; Momeni, Davood; Faizal, Mir; Ali, Ahmed Farag; Dey, Tarun Kumar; Rehman, Atikur
2017-11-01
One of the major difficulties of modern science underlies at the unification of general relativity and quantum mechanics. Different approaches towards such theory have been proposed. Noncommutative theories serve as the root of almost all such approaches. However, the identification of the appropriate passage to quantum gravity is suffering from the inadequacy of experimental techniques. It is beyond our ability to test the effects of quantum gravity thorough the available scattering experiments, as it is unattainable to probe such high energy scale at which the effects of quantum gravity appear. Here we propose an elegant alternative scheme to test such theories by detecting the deformations emerging from the noncommutative structures. Our protocol relies on the novelty of an opto-mechanical experimental setup where the information of the noncommutative oscillator is exchanged via the interaction with an optical pulse inside an optical cavity. We also demonstrate that our proposal is within the reach of current technology and, thus, it could uncover a feasible route towards the realization of quantum gravitational phenomena thorough a simple table-top experiment.
Wave Manipulation in Metamaterials: A LEGO® Bricks Enabled Platform
NASA Astrophysics Data System (ADS)
Celli, Paolo; Gonella, Stefano
In this work, we show how simple, reconfigurable arrangements of LEGO® bricks can be turned into the building blocks of an experimental platform for the investigation of wave phenomena in metamaterial architectures. The approach involves the assembly of reconfigurable specimens consisting of patterns of bricks on a baseplate and the use of a 3D laser vibrometer to reconstruct global and local wave features. The ability to seamlessly transition between different topologies makes this an effective approach for rapid experimental verification and proof of concept in the arena of mechanical metamaterials engineering. The intuitive nature of the brick-and-baseplate assembly paradigm can also be leveraged to implement families of intuitive lab demonstrations with significant didactic and scientific outreach potential. The versatility of the platform is tested through a series of experiments that illustrate a variety of wave manipulation effects, such as waveguiding and seismic isolation, both in periodic and disordered topologies. We acknowledge the support of the National Science Foundation (Grant CMMI-1266089).
Solanki, Prem K; Rabin, Yoed
2018-01-01
This study presents experimental results and an analysis approach for polarized light effects associated with thermomechanical stress during cooling of glass promoting solutions, with applications to cryopreservation and tissue banking in a process known as vitrification. Polarized light means have been previously integrated into the cryomacroscope-a visualization device to detect physical effects associated with cryopreservation success, such as crystallization, fracture formation, and contamination. The experimental study concerns vitrification in a cuvette, which is a rectangular container. Polarized light modeling in the cuvette is based on subdividing the tridimensional (3D) domain into a series of planar (2D) problems, for which a mathematical solution is available in the literature. The current analysis is based on tracking the accumulated changes in light polarization and magnitude, as it passes through the sequence of planar problems. Results of this study show qualitative agreement in light intensity history and distribution between experimental data and simulated results. The simulated results help explaining differences between 2D and 3D effects in photoelasticity, most notably, the counterintuitive observation that high stress areas may correlate with low light intensity regions based on the particular experimental conditions. Finally, it is suggested that polarized-light analysis must always be accompanied by thermomechanical stress modeling in order to explain 3D effects.
2018-01-01
This study presents experimental results and an analysis approach for polarized light effects associated with thermomechanical stress during cooling of glass promoting solutions, with applications to cryopreservation and tissue banking in a process known as vitrification. Polarized light means have been previously integrated into the cryomacroscope—a visualization device to detect physical effects associated with cryopreservation success, such as crystallization, fracture formation, and contamination. The experimental study concerns vitrification in a cuvette, which is a rectangular container. Polarized light modeling in the cuvette is based on subdividing the tridimensional (3D) domain into a series of planar (2D) problems, for which a mathematical solution is available in the literature. The current analysis is based on tracking the accumulated changes in light polarization and magnitude, as it passes through the sequence of planar problems. Results of this study show qualitative agreement in light intensity history and distribution between experimental data and simulated results. The simulated results help explaining differences between 2D and 3D effects in photoelasticity, most notably, the counterintuitive observation that high stress areas may correlate with low light intensity regions based on the particular experimental conditions. Finally, it is suggested that polarized-light analysis must always be accompanied by thermomechanical stress modeling in order to explain 3D effects. PMID:29912973
Large-scale flow experiments for managing river systems
Konrad, Christopher P.; Olden, Julian D.; Lytle, David A.; Melis, Theodore S.; Schmidt, John C.; Bray, Erin N.; Freeman, Mary C.; Gido, Keith B.; Hemphill, Nina P.; Kennard, Mark J.; McMullen, Laura E.; Mims, Meryl C.; Pyron, Mark; Robinson, Christopher T.; Williams, John G.
2011-01-01
Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments have both scientific and social value when they help to resolve specific questions about the ecological action of flow with a clear nexus to water policies and decisions. Water managers must integrate new information into operating policies for large-scale experiments to be effective. Modeling and monitoring can be integrated with experiments to analyze long-term ecological responses. Experimental design should include spatially extensive observations and well-defined, repeated treatments. Large-scale flow manipulations are only a part of dam operations that affect river systems. Scientists can ensure that experimental manipulations continue to be a valuable approach for the scientifically based management of river systems.
Some conditions of compliance and resistance among hypnotic subjects.
Levitt, E E; Baker, E L; Fish, R C
1990-04-01
Five experimental approaches to the resolution of the century-old Bernheim/Janet dispute and the issue of involuntariness or coercion (the classical suggestion effect) are presented. Four experiments are reported that follow one of the approaches: attempts to induce hypnotic subjects to resist suggestions made in trance. The design is one in which a "resistance instructor" proposes a reward for the resisting subject. Tentative inferences from the results are that the classical suggestion effect is found with a small number of subjects; for a larger number of subjects there is no classical suggestion effect, and for many subjects the outcome is equivocal. Relational factors in the hypnotic dyad influence responsiveness in the subject, the effect being least for those whose susceptibility is high.
Mridula, Meenu R; Nair, Ashalatha S; Kumar, K Satheesh
2018-02-01
In this paper, we compared the efficacy of observation based modeling approach using a genetic algorithm with the regular statistical analysis as an alternative methodology in plant research. Preliminary experimental data on in vitro rooting was taken for this study with an aim to understand the effect of charcoal and naphthalene acetic acid (NAA) on successful rooting and also to optimize the two variables for maximum result. Observation-based modelling, as well as traditional approach, could identify NAA as a critical factor in rooting of the plantlets under the experimental conditions employed. Symbolic regression analysis using the software deployed here optimised the treatments studied and was successful in identifying the complex non-linear interaction among the variables, with minimalistic preliminary data. The presence of charcoal in the culture medium has a significant impact on root generation by reducing basal callus mass formation. Such an approach is advantageous for establishing in vitro culture protocols as these models will have significant potential for saving time and expenditure in plant tissue culture laboratories, and it further reduces the need for specialised background.
NASA Astrophysics Data System (ADS)
Ivchenko, Dmitrii; Zhang, Tao; Mariaux, Gilles; Vardelle, Armelle; Goutier, Simon; Itina, Tatiana E.
2018-01-01
Plasma spray physical vapor deposition aims to substantially evaporate powders in order to produce coatings with various microstructures. This is achieved by powder vapor condensation onto the substrate and/or by deposition of fine melted powder particles and nanoclusters. The deposition process typically operates at pressures ranging between 10 and 200 Pa. In addition to the experimental works, numerical simulations are performed to better understand the process and optimize the experimental conditions. However, the combination of high temperatures and low pressure with shock waves initiated by supersonic expansion of the hot gas in the low-pressure medium makes doubtful the applicability of the continuum approach for the simulation of such a process. This work investigates (1) effects of the pressure dependence of thermodynamic and transport properties on computational fluid dynamics (CFD) predictions and (2) the validity of the continuum approach for thermal plasma flow simulation under very low-pressure conditions. The study compares the flow fields predicted with a continuum approach using CFD software with those obtained by a kinetic-based approach using a direct simulation Monte Carlo method (DSMC). It also shows how the presence of high gradients can contribute to prediction errors for typical PS-PVD conditions.
Inverse Doppler Effects in Broadband Acoustic Metamaterials
Zhai, S. L.; Zhao, X. P.; Liu, S.; Shen, F. L.; Li, L. L.; Luo, C. R.
2016-01-01
The Doppler effect refers to the change in frequency of a wave source as a consequence of the relative motion between the source and an observer. Veselago theoretically predicted that materials with negative refractions can induce inverse Doppler effects. With the development of metamaterials, inverse Doppler effects have been extensively investigated. However, the ideal material parameters prescribed by these metamaterial design approaches are complex and also challenging to obtain experimentally. Here, we demonstrated a method of designing and experimentally characterising arbitrary broadband acoustic metamaterials. These omni-directional, double-negative, acoustic metamaterials are constructed with ‘flute-like’ acoustic meta-cluster sets with seven double meta-molecules; these metamaterials also overcome the limitations of broadband negative bulk modulus and mass density to provide a region of negative refraction and inverse Doppler effects. It was also shown that inverse Doppler effects can be detected in a flute, which has been popular for thousands of years in Asia and Europe. PMID:27578317
Inverse Doppler Effects in Broadband Acoustic Metamaterials
NASA Astrophysics Data System (ADS)
Zhai, S. L.; Zhao, X. P.; Liu, S.; Shen, F. L.; Li, L. L.; Luo, C. R.
2016-08-01
The Doppler effect refers to the change in frequency of a wave source as a consequence of the relative motion between the source and an observer. Veselago theoretically predicted that materials with negative refractions can induce inverse Doppler effects. With the development of metamaterials, inverse Doppler effects have been extensively investigated. However, the ideal material parameters prescribed by these metamaterial design approaches are complex and also challenging to obtain experimentally. Here, we demonstrated a method of designing and experimentally characterising arbitrary broadband acoustic metamaterials. These omni-directional, double-negative, acoustic metamaterials are constructed with ‘flute-like’ acoustic meta-cluster sets with seven double meta-molecules; these metamaterials also overcome the limitations of broadband negative bulk modulus and mass density to provide a region of negative refraction and inverse Doppler effects. It was also shown that inverse Doppler effects can be detected in a flute, which has been popular for thousands of years in Asia and Europe.
NASA Astrophysics Data System (ADS)
Hirave, Vivek; Kalyanshetti, Mahesh
2018-02-01
Conventional fixed-base analysis ignoring the effect of soil-flexibility may result in unsafe design. Therefore, to evaluate the realistic behavior of structure the soil structure interaction (SSI) effect shall be incorporated in the analysis. In seismic analysis, provision of bracing system is one of the important option for the structure to have sufficient strength with adequate stiffness to resist lateral forces. The different configuration of these bracing systems alters the response of buildings, and therefore, it is important to evaluate the most effective bracing systems in view point of stability against SSI effect. In present study, three RC building frames, G+3, G+5 and G+7 and their respective scaled down steel model with two types of steel bracing system incorporating the effect of soil flexibility is considered for experimental and analytical study. The analytical study is carried out using Elastic continuum approach and the experimental study is carried out using Shake Table. The influence of SSI on various seismic parameters is presented. The study reveals that, steel bracing system is beneficial to control SSI effect and it is observed that V bracing is more effective, in resisting seismic load considering SSI.
The decay of Λ _b→ p~K^- in QCD factorization approach
NASA Astrophysics Data System (ADS)
Zhu, Jie; Ke, Hong-Wei; Wei, Zheng-Tao
2016-05-01
With only the tree-level operator, the decay of Λ _b→ pK is predicted to be one order smaller than the experimental data. The QCD penguin effects should be taken into account. In this paper, we explore the one-loop QCD corrections to the decay of Λ _b→ pK within the framework of QCD factorization approach. For the baryon system, the diquark approximation is adopted. The transition hadronic matrix elements between Λ _b and p are calculated in the light-front quark model. The branching ratio of Λ _b→ pK is predicted to be about 4.85× 10^{-6}, which is consistent with experimental data (4.9± 0.9)× 10^{-6}. The CP violation is about 5 % in theory.
The Local Integrity Approach for Urban Contexts: Definition and Vehicular Experimental Assessment
Margaria, Davide; Falletti, Emanuela
2016-01-01
A novel cooperative integrity monitoring concept, called “local integrity”, suitable to automotive applications in urban scenarios, is discussed in this paper. The idea is to take advantage of a collaborative Vehicular Ad hoc NETwork (VANET) architecture in order to perform a spatial/temporal characterization of possible degradations of Global Navigation Satellite System (GNSS) signals. Such characterization enables the computation of the so-called “Local Protection Levels”, taking into account local impairments to the received signals. Starting from theoretical concepts, this paper describes the experimental validation by means of a measurement campaign and the real-time implementation of the algorithm on a vehicular prototype. A live demonstration in a real scenario has been successfully carried out, highlighting effectiveness and performance of the proposed approach. PMID:26821028
Aarons, Jolyon; Jones, Lewys; Varambhia, Aakash; MacArthur, Katherine E; Ozkaya, Dogan; Sarwar, Misbah; Skylaris, Chris-Kriton; Nellist, Peter D
2017-07-12
Many studies of heterogeneous catalysis, both experimental and computational, make use of idealized structures such as extended surfaces or regular polyhedral nanoparticles. This simplification neglects the morphological diversity in real commercial oxygen reduction reaction (ORR) catalysts used in fuel-cell cathodes. Here we introduce an approach that combines 3D nanoparticle structures obtained from high-throughput high-precision electron microscopy with density functional theory. Discrepancies between experimental observations and cuboctahedral/truncated-octahedral particles are revealed and discussed using a range of widely used descriptors, such as electron-density, d-band centers, and generalized coordination numbers. We use this new approach to determine the optimum particle size for which both detrimental surface roughness and particle shape effects are minimized.
Ma, Hsen-Hsing
2009-05-01
The aim of the present study is to demonstrate the percentage of data points exceeding the median of baseline phase (PEM) approach using data on autism treatment for illustrative purposes to compare the effectiveness of different interventions on the problem behaviors of individuals with autism. Electronic databases such as The ProQuest and Google were searched. A total of 163 articles were located, producing 1,502 effect sizes. The results demonstrate that five highly effective intervention strategies were priming, self-control, training, positive reinforcement and punishment, and presenting preferential activities. The least effective strategy was to teach perspective-taking skills. The PEM approach is recommended for use in meta-analysis for single-case experimental designs.
Wide color gamut display with white and emerald backlighting.
Duan, Lvyin; Lei, Zhichun
2018-02-20
This paper proposes a wide color gamut approach that uses white and emerald lighting units as the backlight of the liquid crystal display. The white and emerald backlights are controlled by the image to be displayed. The mixing ratio of the white and the emerald lighting is analyzed so that the maximal color gamut coverage ratio can be achieved. Experimental results prove the effectiveness of the wide color gamut approach using white and emerald backlights.
Barone, Vincenzo; Improta, Roberto; Rega, Nadia
2008-05-01
Interpretation of structural properties and dynamic behavior of molecules in solution is of fundamental importance to understand their stability, chemical reactivity, and catalytic action. While information can be gained, in principle, by a variety of spectroscopic techniques, the interpretation of the rich indirect information that can be inferred from the analysis of experimental spectra is seldom straightforward because of the subtle interplay of several different effects, whose specific role is not easy to separate and evaluate. In such a complex scenario, theoretical studies can be very helpful at two different levels: (i) supporting and complementing experimental results to determine the structure of the target molecule starting from its spectral properties; (ii) dissecting and evaluating the role of different effects in determining the observed spectroscopic properties. This is the reason why computational spectroscopy is rapidly evolving from a highly specialized research field into a versatile and widespread tool for the assignment of experimental spectra and their interpretation in terms of chemical physical effects. In such a situation, it becomes important that both computationally and experimentally oriented chemists are aware that new methodological advances and integrated computational strategies are available, providing reliable estimates of fundamental spectral parameters not only for relatively small molecules in the gas phase but also for large and flexible molecules in condensed phases. In this Account, we review the most significant methodological contributions from our research group in this field, and by exploiting some recent results of their application to the computation of IR, UV-vis, NMR, and EPR spectral parameters, we discuss the microscopic mechanisms underlying solvent and vibrational effects on the spectral parameters. After reporting some recent achievements for the study of excited states by first principle quantum mechanical approaches, we focus on the treatment of environmental effects by means of mixed discrete-continuum solvent models and on effective methods for computing vibronic contributions to the spectra. We then discuss some new developments, mainly based on time-dependent approaches, allowing us to go beyond the determination of spectroscopic parameters toward the simulation of line widths and shapes. Although further developments are surely needed to improve the accuracy and effectiveness of several items in the proposed approach, we try to show that the first important steps toward a direct comparison between the results obtained in vitro and those obtained in silico have been made, making easier fruitful crossovers among experiments, computations and theoretical models, which would be decisive for a deeper understanding of the spectral behavior associated with complex systems and processes.
Modeling the surface tension of complex, reactive organic-inorganic mixtures
NASA Astrophysics Data System (ADS)
Schwier, A. N.; Viglione, G. A.; Li, Z.; McNeill, V. Faye
2013-11-01
Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as heterogeneous reactivity, ice nucleation, and cloud droplet formation. We present new experimental data for the surface tension of complex, reactive organic-inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2-6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two semi-empirical surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well described by a weighted Szyszkowski-Langmuir (S-L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling of aerosol systems because the Henning model (using data obtained from organic-inorganic systems) and Tuckermann approach provide similar modeling results and goodness-of-fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.
NASA Astrophysics Data System (ADS)
Wang, Li; Yang, Xiaonan; Wang, Quandai; Yang, Zhiqiang; Duan, Hui; Lu, Bingheng
2017-07-01
The construction of stable hydrophobic surfaces has increasingly gained attention owing to its wide range of potential applications. However, these surfaces may become wet and lose their slip effect owing to insufficient hydrophobic stability. Pillars with a mushroom-shaped tip are believed to enhance hydrophobicity stability. This work presents a facile method of manufacturing mushroom-shaped structures, where, compared with the previously used method, the modulation of the cap thickness, cap diameter, and stem height of the structures is more convenient. The effects of the development time on the cap diameter and overhanging angle are investigated and well-defined mushroom-shaped structures are demonstrated. The effect of the microstructure geometry on the contact state of a droplet is predicted by taking an energy minimization approach and is experimentally validated with nonvolatile ultraviolet-curable polymer with a low surface tension by inspecting the profiles of liquid-vapor interface deformation and tracking the trace of the receding contact line after exposure to ultraviolet light. Theoretical and experimental results show that, compared with regular pillar arrays having a vertical sidewall, the mushroom-like structures can effectively enhance hydrophobic stability. The proposed manufacturing method will be useful for fabricating robust hydrophobic surfaces in a cost-effective and convenient manner.
O'Hagan, Steve; Knowles, Joshua; Kell, Douglas B.
2012-01-01
Comparatively few studies have addressed directly the question of quantifying the benefits to be had from using molecular genetic markers in experimental breeding programmes (e.g. for improved crops and livestock), nor the question of which organisms should be mated with each other to best effect. We argue that this requires in silico modelling, an approach for which there is a large literature in the field of evolutionary computation (EC), but which has not really been applied in this way to experimental breeding programmes. EC seeks to optimise measurable outcomes (phenotypic fitnesses) by optimising in silico the mutation, recombination and selection regimes that are used. We review some of the approaches from EC, and compare experimentally, using a biologically relevant in silico landscape, some algorithms that have knowledge of where they are in the (genotypic) search space (G-algorithms) with some (albeit well-tuned ones) that do not (F-algorithms). For the present kinds of landscapes, F- and G-algorithms were broadly comparable in quality and effectiveness, although we recognise that the G-algorithms were not equipped with any ‘prior knowledge’ of epistatic pathway interactions. This use of algorithms based on machine learning has important implications for the optimisation of experimental breeding programmes in the post-genomic era when we shall potentially have access to the full genome sequence of every organism in a breeding population. The non-proprietary code that we have used is made freely available (via Supplementary information). PMID:23185279
A self-cognizant dynamic system approach for prognostics and health management
NASA Astrophysics Data System (ADS)
Bai, Guangxing; Wang, Pingfeng; Hu, Chao
2015-03-01
Prognostics and health management (PHM) is an emerging engineering discipline that diagnoses and predicts how and when a system will degrade its performance and lose its partial or whole functionality. Due to the complexity and invisibility of rules and states of most dynamic systems, developing an effective approach to track evolving system states becomes a major challenge. This paper presents a new self-cognizant dynamic system (SCDS) approach that incorporates artificial intelligence into dynamic system modeling for PHM. A feed-forward neural network (FFNN) is selected to approximate a complex system response which is challenging task in general due to inaccessible system physics. The trained FFNN model is then embedded into a dual extended Kalman filter algorithm to track down system dynamics. A recursive computation technique used to update the FFNN model using online measurements is also derived. To validate the proposed SCDS approach, a battery dynamic system is considered as an experimental application. After modeling the battery system by a FFNN model and a state-space model, the state-of-charge (SoC) and state-of-health (SoH) are estimated by updating the FFNN model using the proposed approach. Experimental results suggest that the proposed approach improves the efficiency and accuracy for battery health management.
USDA-ARS?s Scientific Manuscript database
Autoimmune disease is prevalent in humans. Since conventional therapies have limited efficacy and often come with significant side effects, nutrition may provide an alternative and complementary approach to improving the autoimmune disorders. Naringenin, a flavonoid found in citrus fruits, has been ...
A fundamental approach to the sticking of insect residues to aircraft wings
NASA Technical Reports Server (NTRS)
Eiss, N. S., Jr.; Wightman, J. P.
1983-01-01
The sticking of insect residues to aircraft wings is investigated. The major topics of this review are: Experimentally tested methods, testing techniques, the effect of surface roughness height on aerodynamic drag, materials tested and, the adhesive properties of insect body fluids are reviewed.
USDA-ARS?s Scientific Manuscript database
Changes in land use are likely to cause a non-linear response in watershed hydrology. Specifically, small increases in urban expansion may greatly increase surface runoff while decreasing infiltration, impacting aquifer recharge and changing streamflow regimes. Quantifying the effects of urbanizatio...
Vanadium supersaturated silicon system: a theoretical and experimental approach
NASA Astrophysics Data System (ADS)
Garcia-Hemme, Eric; García, Gregorio; Palacios, Pablo; Montero, Daniel; García-Hernansanz, Rodrigo; Gonzalez-Diaz, Germán; Wahnon, Perla
2017-12-01
The effect of high dose vanadium ion implantation and pulsed laser annealing on the crystal structure and sub-bandgap optical absorption features of V-supersaturated silicon samples has been studied through the combination of experimental and theoretical approaches. Interest in V-supersaturated Si focusses on its potential as a material having a new band within the Si bandgap. Rutherford backscattering spectrometry measurements and formation energies computed through quantum calculations provide evidence that V atoms are mainly located at interstitial positions. The response of sub-bandgap spectral photoconductance is extended far into the infrared region of the spectrum. Theoretical simulations (based on density functional theory and many-body perturbation in GW approximation) bring to light that, in addition to V atoms at interstitial positions, Si defects should also be taken into account in explaining the experimental profile of the spectral photoconductance. The combination of experimental and theoretical methods provides evidence that the improved spectral photoconductance up to 6.2 µm (0.2 eV) is due to new sub-bandgap transitions, for which the new band due to V atoms within the Si bandgap plays an essential role. This enables the use of V-supersaturated silicon in the third generation of photovoltaic devices.
Modelling strategies to predict the multi-scale effects of rural land management change
NASA Astrophysics Data System (ADS)
Bulygina, N.; Ballard, C. E.; Jackson, B. M.; McIntyre, N.; Marshall, M.; Reynolds, B.; Wheater, H. S.
2011-12-01
Changes to the rural landscape due to agricultural land management are ubiquitous, yet predicting the multi-scale effects of land management change on hydrological response remains an important scientific challenge. Much empirical research has been of little generic value due to inadequate design and funding of monitoring programmes, while the modelling issues challenge the capability of data-based, conceptual and physics-based modelling approaches. In this paper we report on a major UK research programme, motivated by a national need to quantify effects of agricultural intensification on flood risk. Working with a consortium of farmers in upland Wales, a multi-scale experimental programme (from experimental plots to 2nd order catchments) was developed to address issues of upland agricultural intensification. This provided data support for a multi-scale modelling programme, in which highly detailed physics-based models were conditioned on the experimental data and used to explore effects of potential field-scale interventions. A meta-modelling strategy was developed to represent detailed modelling in a computationally-efficient manner for catchment-scale simulation; this allowed catchment-scale quantification of potential management options. For more general application to data-sparse areas, alternative approaches were needed. Physics-based models were developed for a range of upland management problems, including the restoration of drained peatlands, afforestation, and changing grazing practices. Their performance was explored using literature and surrogate data; although subject to high levels of uncertainty, important insights were obtained, of practical relevance to management decisions. In parallel, regionalised conceptual modelling was used to explore the potential of indices of catchment response, conditioned on readily-available catchment characteristics, to represent ungauged catchments subject to land management change. Although based in part on speculative relationships, significant predictive power was derived from this approach. Finally, using a formal Bayesian procedure, these different sources of information were combined with local flow data in a catchment-scale conceptual model application , i.e. using small-scale physical properties, regionalised signatures of flow and available flow measurements.
Swider, P.; Guérin, G.; Baas, Joergen; Søballe, Kjeld; Bechtold, Joan E.
2013-01-01
Orthopaedic implant fixation is strongly dependant upon the effective mechanical properties of newly formed tissue. In this study, we evaluated the potential of modal analysis to derive viscoelastic properties of periprosthetic tissue. We hypothesized that Young's modulus and loss factor could be obtained by a combined theoretical, computational and experimental modal analysis approach. This procedure was applied to ex vivo specimens from a cylindrical experimental implant placed in cancellous bone in an unloaded press-fit configuration, obtained after a four week observation period. Four sections each from seven textured titanium implants were investigated. The first resonant frequency and loss factor were measured. Average experimentally determined loss factor was 2% (SD 0.4%) and average first resonant frequency was 2.1 KHz (SD: 50). A 2D axisymmetric finite element (FE) model identified effective Young's modulus of tissue using experimental resonant frequencies as input. Average value was 42 MPa (SD: 2.4) and no significant difference between specimens was observed. In this pilot study, the non-destructive method allowed accurate measure of dynamic loss factor and resonant frequency and derivation of effective Young's modulus. Prior to implementing this dynamic protocol for broader mechanical evaluation of experimental implant fixation, further work is needed to determine if this affects results from subsequent destructive shear push-out tests. PMID:19464687
Lee, Kyung Eun
2018-04-01
An important goal of nursing education is helping students achieve core competencies efficiently. One proposed way of improving nursing education is team-based learning (TBL). The aim of this study was to assess the comparative effectiveness of TBL and lecture-style classes in terms of teaching core competencies in nursing education, which include clinical competence skills, problem-solving ability, communication competencies, critical thinking ability, and self-leadership. This quasi-experimental study enrolled 183 students as participants, with 95 and 88 in the experimental and control groups, respectively. These two groups attended 6 hours (2 hours weekly for 3 weeks) of TBL and lecture-style classes, respectively. Differences in core competencies between the two groups were compared before and after the intervention. The experimental group achieved significantly higher scores for clinical competence skills, communication competence, critical thinking ability, and self-leadership at posttest than at pretest, whereas the control group achieved significantly higher scores for clinical competence skills and critical thinking ability at posttest than at pretest. After the intervention, the experimental group had significantly better clinical competence skills, communication competence, and self-leadership than the control group. TBL is an effective approach method to teaching core competencies in nursing education.
Ebrahimi, Hossein; Sadeghi, Mahdi; Amanpour, Farzaneh; Vahedi, Hamid
2016-04-01
Diabetes education is a major subject in achieving optimal glycemic control. Effective empowerment approach can be beneficial for improving patients' health. The aim of this study was to evaluate the effect of empowerment model on indicators of metabolic control in patients with type 2 diabetes. a randomized controlled trial of 103 patients with type 2 diabetes were randomly assigned to either the intervention (empowerment approach training) or the control group (conventional training) 2014. Empowerment approach training were performed for the experimental group for eight weeks. Data collection tool included demographic information form and indicators of metabolic control checklist. Analysis was performed by one-way analysis of variance, chi-square test, paired t-test, independent t-test and multiple linear regression. Before the intervention, two groups were homogeneous in terms of demographic variables, glycosylated hemoglobin (HbA1C), and other indicators of metabolic control. After the intervention, average HbA1C and other metabolic indicators except for LDL showed significant differences in the experimental group compared to the control group. study results indicated the positive effects of applying the empowerment model on the metabolic control indicators. Therefore, applying this model is recommended to nurses and the relevant authorities in order to improve clinical outcomes in diabetic patients. Copyright © 2015 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Liu, Yang; Song, Fazhi; Yang, Xiaofeng; Dong, Yue; Tan, Jiubin
2018-06-01
Due to their structural simplicity, linear motors are increasingly receiving attention for use in high velocity and high precision applications. The force ripple, as a space-periodic disturbance, however, would deteriorate the achievable dynamic performance. Conventional force ripple measurement approaches are time-consuming and have high requirements on the experimental conditions. In this paper, a novel learning identification algorithm is proposed for force ripple intelligent measurement and compensation. Existing identification schemes always use all the error signals to update the parameters in the force ripple. However, the error induced by noise is non-effective for force ripple identification, and even deteriorates the identification process. In this paper only the most pertinent information in the error signal is utilized for force ripple identification. Firstly, the effective error signals caused by the reference trajectory and the force ripple are extracted by projecting the overall error signals onto a subspace spanned by the physical model of the linear motor as well as the sinusoidal model of the force ripple. The time delay in the linear motor is compensated in the basis functions. Then, a data-driven approach is proposed to design the learning gain. It balances the trade-off between convergence speed and robustness against noise. Simulation and experimental results validate the proposed method and confirm its effectiveness and superiority.
Thermodynamics of Hydrophobic Amino Acids in Solution: A Combined Experimental–Computational Study
Song, Lingshuang; Yang, Lin; Meng, Jie; ...
2016-12-29
Here, we present a joint experimental-computational study to quantitatively describe the thermodynamics of hydrophobic leucine amino acids in aqueous solution. X-ray scattering data were acquired at a series of solute and salt concentrations to effectively measure inter-leucine interactions, indicating that a major scattering peak is observed consistently at q = 0.83 Å -1. Atomistic molecular dynamics simulations were then performed and compared with the scattering data, achieving high consistency at both small and wider scattering angles (q = 0$-$1.5 Å -1). This experimental-computational consistence enables a first glimpse of the leucineleucine interacting landscape, where two leucine molecules are aligned mostlymore » in a parallel fashion, as opposed to anti-parallel, but also allows us to derive effective leucine-leucine interactions in solution. Collectively, this combined approach of employing experimental scattering and molecular simulation enables a quantitative characterization on effective inter-molecular interactions of hydrophobic amino acids, critical for protein function and dynamics such as protein folding.« less
Space Weathering in Houston: A Role for the Experimental Impact Laboratory at JSC
NASA Technical Reports Server (NTRS)
Cintala, M. J.; Keller, L. P.; Christoffersen, R.; Hoerz, F.
2015-01-01
The effective investigation of space weathering demands an interdisciplinary approach that is at least as diversified as any other in planetary science. Because it is a macroscopic process affecting all bodies in the solar system, impact and its resulting shock effects must be given detailed attention in this regard. Direct observation of the effects of impact is most readily done for the Moon, but it still remains difficult for other bodies in the solar system. Analyses of meteorites and precious returned samples provide clues for space weathering on asteroids, but many deductions arising from those studies must still be considered circumstantial. Theoretical work is also indispensable, but it can only go as far as the sometimes meager data allow. Experimentation, however, can permit near real-time study of myriad processes that could contribute to space weathering. This contribution describes some of the capabilities of the Johnson Space Center's Experimental Impact Laboratory (EIL) and how they might help in understanding the space weathering process.
Thermodynamics of Hydrophobic Amino Acids in Solution: A Combined Experimental–Computational Study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Song, Lingshuang; Yang, Lin; Meng, Jie
Here, we present a joint experimental-computational study to quantitatively describe the thermodynamics of hydrophobic leucine amino acids in aqueous solution. X-ray scattering data were acquired at a series of solute and salt concentrations to effectively measure inter-leucine interactions, indicating that a major scattering peak is observed consistently at q = 0.83 Å -1. Atomistic molecular dynamics simulations were then performed and compared with the scattering data, achieving high consistency at both small and wider scattering angles (q = 0$-$1.5 Å -1). This experimental-computational consistence enables a first glimpse of the leucineleucine interacting landscape, where two leucine molecules are aligned mostlymore » in a parallel fashion, as opposed to anti-parallel, but also allows us to derive effective leucine-leucine interactions in solution. Collectively, this combined approach of employing experimental scattering and molecular simulation enables a quantitative characterization on effective inter-molecular interactions of hydrophobic amino acids, critical for protein function and dynamics such as protein folding.« less
New insights into the electronic and optical properties of the Bi4M3O12 (M = Si or Ge) scintillators
NASA Astrophysics Data System (ADS)
Sousa, O. M.; Lima, A. F.; Lalic, M. V.
2017-11-01
Electronic and optical properties of the Bi4Ge3O12 (BGO) and Bi4Si3O12 (BSO) compounds with eulytine structure have been revisited in terms of the first-principles calculations on density functional theory (DFT) level. Exchange and correlation (XC) effects have been described by Tran-Blaha modified Becke-Johnson (TB-mBJ) potential in its semiconductor variance form. The calculated band gaps agree very well with experimental data obtained from direct reflectivity measurements and disagree with data obtained on the base of ellipsometry technique. The calculated reflectivity spectra also agree very well with low-temperature experimental data. These facts prove that present approach is more successful than previous DFT approaches which failed to describe correctly either one or both of these properties. On the basis of this observation, it was concluded that: (1) DFT calculations with TB-mBJ XC potential correctly describe the BGO and BSO electronic structures, whose principal features are demonstrated; (2) the BGO and BSO band gaps should be around 5.0 and 5.4 eV respectively and their experimental optical absorption edges should be masked by exciton effects, in agreement with the conclusions from reflectivity measurements.
Use of experimental ecosystems in regulatory decision making
NASA Astrophysics Data System (ADS)
La Point, Thomas W.; Perry, James A.
1989-09-01
Tiered testing for the effects of chemicals on aquatic ecosystems has begun to include tests at the ecosystem level as a component in pesticide regristration. Because such tests are expensive, regulators and industry need to know what additional information they can gain from such tests relative to the costs of the simpler single-species toxicity bioassays. Requirements for ecosystem-level testing have developed because resource managers have not fully understood the implications of potential damage to resources without having evaluations of the predicted impacts under field conditions. We review approaches taken in the use of experimental ecosystems, discuss benefits and limitations of small- and large-scale ecosystem tests, and point to correlative approaches between laboratory and field toxicity testing. Laboratory experimental ecosystems (microcosms) have been successfully used to measure contaminant bioavailability, to determine routes of uptake in moderately complex aquatic systems, and to isolate factors modifying contaminant uptake into the biota. Such factors cannot be as readily studied in outdoor experimental ecosystems because direct cause-and-effect relations are often confounded and difficult to isolate. However, laboratory tests can be designed to quantify the relations among three variables: known concentrations of Stressors; specific sublethal behavioral, biochemical, and physiological effects displayed by organisms; and responses that have been observed in ecosystem-level analyses. For regulatory purposes, the specificity of test results determines how widely they can be applied. Ecotoxicological research should be directed at attempts to identify instances where single-species testing would be the appropriate level of analysis for identifying critical ecological endpoints and for clarifying relationships between ecosystem structure and function, and where it would be inadequate for a given level of analysis.
Macroscopic analysis of gas-jet wiping: Numerical simulation and experimental approach
NASA Astrophysics Data System (ADS)
Lacanette, Delphine; Gosset, Anne; Vincent, Stéphane; Buchlin, Jean-Marie; Arquis, Éric
2006-04-01
Coating techniques are frequently used in industrial processes such as paper manufacturing, wire sleeving, and in the iron and steel industry. Depending on the application considered, the thickness of the resulting substrate is controlled by mechanical (scraper), electromagnetic (if the entrained fluid is appropriated), or hydrodynamic (gas-jet wiping) operations. This paper deals with the latter process, referred to as gas-jet wiping, in which a turbulent slot jet is used to wipe the coating film dragged by a moving substrate. This mechanism relies on the gas-jet-liquid film interaction taking place on the moving surface. The aim of this study is to compare the results obtained by a lubrication one-dimensional model, numerical volume of fluid-large eddy simulation (VOF-LES) modeling and an experimental approach. The investigation emphasizes the effect of the controlling wiping parameters, i.e., the pressure gradient and shear stress distributions induced by the jet, on the shape of the liquid film. Those profiles obtained experimentally and numerically for a jet impinging on a dry fixed surface are compared. The effect of the substrate motion and the presence of the dragged liquid film on these actuators are analyzed through numerical simulations. Good agreement is found between the film thickness profile in the wiping zone obtained from the VOF-LES simulations and with the analytical model, provided that a good model for the wiping actuators is used. The effect of the gas-jet nozzle to substrate standoff distance on the final coating thickness is analyzed; the experimental and predicted values are compared for a wide set of conditions. Finally, the occurrence of the splashing phenomenon, which is characterized by the ejection of droplets from the runback film flow at jet impingement, thus limiting the wiping process, is investigated through experiments and numerical simulations.
Use of experimental ecosystems in regulatory decision making
La Point, Thomas W.; Perry, James A.
1989-01-01
Tiered testing for the effects of chemicals on aquatic ecosystems has begun to include tests at the ecosystem level as a component in pesticide regristration. Because such tests are expensive, regulators and industry need to know what additional information they can gain from such tests relative to the costs of the simpler single-species toxicity bioassays. Requirements for ecosystem-level testing have developed because resource managers have not fully understood the implications of potential damage to resources without having evaluations of the predicted impacts under field conditions. We review approaches taken in the use of experimental ecosystems, discuss benefits and limitations of small- and large-scale ecosystem tests, and point to correlative approaches between laboratory and field toxicity testing.Laboratory experimental ecosystems (microcosms) have been successfully used to measure contaminant bioavailability, to determine routes of uptake in moderately complex aquatic systems, and to isolate factors modifying contaminant uptake into the biota. Such factors cannot be as readily studied in outdoor experimental ecosystems because direct cause-and-effect relations are often confounded and difficult to isolate. However, laboratory tests can be designed to quantify the relations among three variables: known concentrations of Stressors; specific sublethal behavioral, biochemical, and physiological effects displayed by organisms; and responses that have been observed in ecosystem-level analyses. For regulatory purposes, the specificity of test results determines how widely they can be applied. Ecotoxicological research should be directed at attempts to identify instances where single-species testing would be the appropriate level of analysis for identifying critical ecological endpoints and for clarifying relationships between ecosystem structure and function, and where it would be inadequate for a given level of analysis.
ERIC Educational Resources Information Center
Elaldi, Senel
2016-01-01
This study aimed to determine the effect of mastery learning model supported with reflective thinking activities on the fifth grade medical students' academic achievement. Mixed methods approach was applied in two samples (n = 64 and n = 6). Quantitative part of the study was based on a pre-test-post-test control group design with an experiment…