Research on Hygiene Based on Fieldwork and Experimental Studies.

PubMed

Yajima, Ichiro

2017-01-01

Several experimental studies on hygiene have recently been performed and fieldwork studies are also important and essential tools. However, the implementation of experimental studies is insufficient compared with that of fieldwork studies on hygiene. Here, we show our well-balanced implementation of both fieldwork and experimental studies of toxic-element-mediated diseases including skin cancer and hearing loss. Since the pollution of drinking well water by toxic elements induces various diseases including skin cancer, we performed both fieldwork and experimental studies to determine the levels of toxic elements and the mechanisms behind the development of toxic-element-related diseases and to develop a novel remediation system. Our fieldwork studies in several countries including Bangladesh, Vietnam and Malaysia demonstrated that drinking well water was polluted with high concentrations of several toxic elements including arsenic, barium, iron and manganese. Our experimental studies using the data from our fieldwork studies demonstrated that these toxic elements caused skin cancer and hearing loss. Further experimental studies resulted in the development of a novel remediation system that adsorbs toxic elements from polluted drinking water. A well-balanced implementation of both fieldwork and experimental studies is important for the prediction, prevention and therapy of toxic-element-mediated diseases.

The Effect of Communication Skills Training on Quality of Care, Self-Efficacy, Job Satisfaction and Communication Skills Rate of Nurses in Hospitals of Tabriz, Iran

PubMed Central

Khodadadi, Esmail; Ebrahimi, Hossein; Moghaddasian, Sima; Babapour, Jalil

2013-01-01

Introduction: Having an effective relationship with the patient in the process of treatment is essential. Nurses must have communication skills in order to establish effective relationships with the patients. This study evaluated the impact of communication skills training on quality of care, self-efficacy, job satisfaction and communication skills of nurses. Methods: This is an experimental study with a control group that has been done in 2012. The study sample consisted of 73 nurses who work in hospitals of Tabriz; they were selected by proportional randomizing method. The intervention was only conducted on the experimental group. In order to measure the quality of care 160 patients, who had received care by nurses, participated in this study. The Data were analyzed by SPSS (ver.13). Results: Comparing the mean scores of communication skills showed a statistically significant difference between control and experimental groups after intervention. The paired t-test showed a statistically significant difference in the experimental group before and after the intervention. Independent t-test showed a statistically significant difference between the rate of quality of care in patients of control and experimental groups after the intervention. Conclusion: The results showed that the training of communication skills can increase the nurse's rate of communication skills and cause elevation in quality of nursing care. Therefore, in order to improve the quality of nursing care it is recommended that communication skills be established and taught as a separate course in nursing education. PMID:25276707

[Experimental study on establishment of a simple model of rats crush injury-crush syndrome].

PubMed

Chen, Xi; Liu, Yuehong; Xu, Wei; Qin, Tingwu; Zhao, Luping; Liu, Shuping; Zhang, Yi; Tan, Hong; Zhou, Yu

2013-01-01

To establish a repeatable, simple, and effective model of rat crush injury and crush syndrome. A total of 42 female Sprague Dawley rats (2-month-old, (CS) so as to lay a foundation for further study on CS. weighing 160-180 g) were divided randomly into the control group (n=6) and experimental group (n=36). The rats of the experimental group were used to establish the crush injury and CS model in both lower limbs by self-made crush injury mould. The survival rate and hematuria rate were observed after decompression. The biochemical indexes of blood were measured at 2, 4, 8, 12, 24, and 48 hours after decompression. The samples of muscle, kidney, and heart were harvested for morphological observation. There was no treatment in the control group, and the same tests were performed. Seven rats died and 15 rats had hematuria during compression in the experimental group. Swelling of the lower limb and muscle tissue was observed in the survival rats after reperfusion. The liver function test results showed that the levels of alanine transaminase and aspartate aminotransferase in the experimental group were significantly higher than those in the control group (P < 0.05). The renal function test results showed that blood urea nitrogen level increased significantly after 2 hours of decompression in the experimental group, showing significant difference when compared with that in the control group at 12, 24, and 48 hours after decompression (P < 0.05); the creatinine level of the experimental group was higher than that of the control group at 4, 8, 12, and 24 hours, showing significant difference at 8, 12, and 24 hours (P < 0.05). The serum K+ concentration of the experimental group was higher than that of the control group at all time, showing significant difference at the other time (P < 0.05) except at 2 hours. The creatine kinase level showed an increasing tendency in the experimental group, showing significant difference when compared with the level of the control group at 4, 8, 12, and 24 hours (P < 0.05). The histological examination of the experimental group showed that obvious edema and necrosis of the muscle were observed at different time points; glomeruli congestion and swelling, renal tubular epithelial cell degeneration, edema, necrosis, and myoglobin tube type were found in the kidneys; and myocardial structure had no obvious changes. The method of the crush injury and CS model by self-made crush injury mould is a simple and effective procedure and the experimental result is stable. It is a simple method to establish an effective model of rats crush injury and CS.

The effect of preferred music genre selection versus preferred song selection on experimentally induced anxiety levels.

PubMed

Walworth, Darcy DeLoach

2003-01-01

The purpose of this study was to investigate the differences of experimentally induced anxiety levels reached by subjects listening to no music (n = 30), subjects listening to music selected by the experimenter from the subject's preferred genre or artist listed as relaxing (n = 30), and subjects listening to a specific song they listed as relaxing (n = 30). Subjects consisted of 90 individuals, male and female, randomly assigned to one of the three groups mentioned above. Subjects in either music group filled out a questionnaire prior to participating in the study indicating their preference of music used for relaxation purposes. Subjects in Experimental Group 1 marked their preferred genres and/or artists, and Experimental Group 2 marked specific songs used for relaxation purposes. While the experimenter hypothesized subjects in Experimental Group 2 would show less anxiety than both the control group and Experimental Group 1, there were no significant differences found between the 2 music groups in anxiety levels reached. However, there was a statistically significant difference between the no music control group and both music groups in the anxiety level reached by subjects. Subjects listening to music, both songs chosen by the experimenter and subject selected songs, showed significantly less anxiety than subjects not listening to music.

The Effect of Self-Care Education on Emotional Intelligence of Iranian Nursing Students: A Quasi-experimental Study.

PubMed

Goudarzian, Amir Hossein; Nesami, Masoumeh Bagheri; Sedghi, Parisa; Gholami, Mahsan; Faraji, Maryam; Hatkehlouei, Mahdi Babaei

2018-01-20

This study aimed to determine the effect of self-care training on emotional intelligence of nursing students. This quasi-experimental study was conducted on nursing students of Mazandaran University of Medical Sciences in 2016. The subjects (60 students) that were collected with random sampling method were divided into experimental and control groups, and then, self-care behaviors were taught to the experimental group' students in 12 sessions by using a checklist. The subjects of control group were not taught. Emotional intelligence was measured by using Bradberry and Greaves' standard questionnaire before and after the intervention. Emotional intelligence scores of students in the experimental group showed positive and significant change between before (75.33 ± 7.23) and after (125.70 ± 7.79) of training (P < 0.001). Also t test shows a significant change in control (78.73 ± 6.54) and experimental groups (125.70 ± 7.79), after of training (P < 0.001). It is recommended that special programs be organized in order to improve the emotional intelligence of students that improve the likelihood of their success in life.

Spectroscopic investigation, vibrational assignments, HOMO-LUMO, NBO, MEP analysis and molecular docking studies of oxoaporphine alkaloid liriodenine

NASA Astrophysics Data System (ADS)

Costa, Renyer A.; Pitt, Priscilla Olliveira; Pinheiro, Maria Lucia B.; Oliveira, Kelson M. T.; Salomé, Kahlil Schwanka; Barison, Andersson; Costa, Emmanoel Vilaça

2017-03-01

A combined experimental and theoretical DFT study of the structural, vibrational and electronic properties of liriodenine is presented using B3LYP function with 6-311G (2d, p) basis set. The theoretical geometry optimization data were compared with the X-ray data for a similar structure in the associated literature, showing similar values. In addition, natural bond orbitals (NBOs), HOMO-LUMO energy gap, mapped molecular Electrostatic Potential (MEP) surface calculation, first and second order hyperpolarizabilities were also performed with the same calculation level. Theoretical UV spectrum agreed well with the measured experimental data, with transitions assigned. The molecular electrostatic potential map shows opposite potentials regions that forms hydrogen bonds that stabilize the dimeric form, which were confirmed by the close values related to the C dbnd O bond stretching between the dimeric form and the experimental IR spectra (1654 cm- 1 for the experimental, 1700 cm- 1 for the dimer form). Calculated HOMO/LUMO gaps shows the excitation energy for Liriodenine, justifying its stability and kinetics reaction. Molecular docking studies with Candida albicans dihydrofolate reductase (DHFR) and Candida albicans secreted aspartic protease (SAP) showed binding free energies values of - 8.5 and - 8.3 kcal/mol, suggesting good affinity between the liriodenine and the target macromolecules.

Group virtue: the importance of morality (vs. competence and sociability) in the positive evaluation of in-groups.

PubMed

Leach, Colin Wayne; Ellemers, Naomi; Barreto, Manuela

2007-08-01

Although previous research has focused on competence and sociability as the characteristics most important to positive group evaluation, the authors suggest that morality is more important. Studies with preexisting and experimentally created in-groups showed that a set of positive traits constituted distinct factors of morality, competence, and sociability. When asked directly, Study 1 participants reported that their in-group's morality was more important than its competence or sociability. An unobtrusive factor analytic method also showed morality to be a more important explanation of positive in-group evaluation than competence or sociability. Experimental manipulations of morality and competence (Study 4) and morality and sociability (Study 5) showed that only in-group morality affected aspects of the group-level self-concept related to positive evaluation (i.e., pride in, or distancing from, the in-group). Consistent with this finding, identification with experimentally created (Study 2b) and preexisting (Studies 4 and 5) in-groups predicted the ascription of morality, but not competence or sociability, to the in-group.

Experimental study on steam condensation with non-condensable gas in horizontal microchannels

NASA Astrophysics Data System (ADS)

Ma, Xuehu; Fan, Xiaoguang; Lan, Zhong; Jiang, Rui; Tao, Bai

2013-07-01

This paper experimentally studied steam condensation with non-condensable gas in trapezoidal microchannels. The effect of noncondensable gas on condensation two-phase flow patterns and the characteristics of heat transfer and frictional pressure drop were investigated. The visualization study results showed that the special intermittent annular flow was found in the microchannel under the condition of larger mole fraction of noncondensable gas and lower steam mass flux; the apical area of injection was much larger and the neck of injection was longer for mixture gas with lower mole fraction of noncondensable gas in comparison with pure steam condensation; meanwhile, the noncondensable gas resulted in the decrease of flow patterns transitional steam mass flux and quality. The experimental results also indicated that the frictional pressure drop increased with the increasing mole fraction of noncondensable gas when the steam mass flux was fixed. Unlike nature convective condensation heat transfer, the mole fraction of noncondensable gas had little effect on Nusselt number. Based on experimental data, the predictive correlation of Nusselt number for mixture gas condensation in microchannels was established showed good agreement with experimental data.

Attrition in trials evaluating complex interventions for schizophrenia: Systematic review and meta-analysis.

PubMed

Szymczynska, P; Walsh, S; Greenberg, L; Priebe, S

2017-07-01

Essential criteria for the methodological quality and validity of randomized controlled trials are the drop-out rates from both the experimental intervention and the study as a whole. This systematic review and meta-analysis assessed these drop-out rates in non-pharmacological schizophrenia trials. A systematic literature search was used to identify relevant trials with ≥100 sample size and to extract the drop-out data. The rates of drop-out from the experimental intervention and study were calculated with meta-analysis of proportions. Meta-regression was applied to explore the association between the study and sample characteristics and the drop-out rates. 43 RCTs were found, with drop-out from intervention ranging from 0% to 63% and study drop-out ranging from 4% to 71%. Meta-analyses of proportions showed an overall drop-out rate of 14% (95% CI: 13-15%) at the experimental intervention level and 20% (95% CI: 17-24%) at the study level. Meta-regression showed that the active intervention drop-out rates were predicted by the number of intervention sessions. In non-pharmacological schizophrenia trials, drop-out rates of less than 20% can be achieved for both the study and the experimental intervention. A high heterogeneity of drop-out rates across studies shows that even lower rates are achievable. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effects of a Physical Education Intervention to Support the Satisfaction of Basic Psychological Needs on the Motivation and Intentions to be Physically Active.

PubMed

Franco, Evelia; Coterón, Javier

2017-10-01

The aim of the study was to investigate the effects of an intervention to support the basic psychological needs on the satisfaction of these needs, intrinsic motivation, intention to be physically active and some enjoyment-related outcomes in Physical Education. The present study incorporated strategies presented by Standage and Ryan (2012) in a previous study. A quasi-experimental study was conducted with two groups (n experimental = 30; n control = 23) of 2nd year Secondary Education students aged between 13 and 15 (M = 13.35, SD = .62) by delivering 24 physical education classes. The teacher in the experimental group underwent prior and continual training. The results revealed that the students from the experimental group showed a significant increase in the perception of autonomy and competence. Furthermore, the experimental group showed a greater perception than the control group in the enjoyment related to learning and contents. These results provide information about the efficacy of an intervention programme based on the strategies presented by Standage and Ryan (2012) to foster satisfaction of basic psychological needs and facilitate support for basic psychological needs to promote the development of positive learning-related outcomes.

Synthesis, crystal structures and spectroscopic properties of triazine-based hydrazone derivatives; a comparative experimental-theoretical study.

PubMed

Arshad, Muhammad Nadeem; Bibi, Aisha; Mahmood, Tariq; Asiri, Abdullah M; Ayub, Khurshid

2015-04-03

We report here a comparative theoretical and experimental study of four triazine-based hydrazone derivatives. The hydrazones are synthesized by a three step process from commercially available benzil and thiosemicarbazide. The structures of all compounds were determined by using the UV-Vis., FT-IR, NMR (1H and 13C) spectroscopic techniques and finally confirmed unequivocally by single crystal X-ray diffraction analysis. Experimental geometric parameters and spectroscopic properties of the triazine based hydrazones are compared with those obtained from density functional theory (DFT) studies. The model developed here comprises of geometry optimization at B3LYP/6-31G (d, p) level of DFT. Optimized geometric parameters of all four compounds showed excellent correlations with the results obtained from X-ray diffraction studies. The vibrational spectra show nice correlations with the experimental IR spectra. Moreover, the simulated absorption spectra also agree well with experimental results (within 10-20 nm). The molecular electrostatic potential (MEP) mapped over the entire stabilized geometries of the compounds indicated their chemical reactivates. Furthermore, frontier molecular orbital (electronic properties) and first hyperpolarizability (nonlinear optical response) were also computed at the B3LYP/6-31G (d, p) level of theory.

The nature and barium partitioning between immiscible melts - A comparison of experimental and natural systems with reference to lunar granite petrogenesis

NASA Technical Reports Server (NTRS)

Neal, C. R.; Taylor, L. A.

1989-01-01

Elemental partitioning between immiscible melts has been studied using experimental liquid-liquid Kds and those determined by analysis of immiscible glasses in basalt mesostases in order to investigate lunar granite petrogenesis. Experimental data show that Ba is partitioned into the basic immiscible melt, while probe analysis results show that Ba is partitioned into the granitic immiscible melt. It is concluded that lunar granite of significant size can only occur in a plutonic or deep hypabyssal environment.

Mechanical Twinning and Microstructures in Experimentally Stressed Quartzite

NASA Astrophysics Data System (ADS)

Minor, A.; Sintubin, M.; Wenk, H. R.; Rybacki, E.

2015-12-01

Since Dauphiné twins in quartz have been identified as a stress-related intracrystalline microstructure, several electron backscatter diffraction (EBSD) studies revealed that Dauphiné twins are present in naturally deformed quartz-bearing rocks in a wide range of tectono-metamorphic conditions. EBSD studies on experimentally stressed quartzite showed that crystals with particular crystallographic orientations contain many Dauphiné twin boundaries, while neighboring crystals with different orientations are largely free of twin boundaries. To understand the relationship between stress direction and orientation of Dauphiné twinned quartz crystals, a detailed EBSD study was performed on experimentally stressed quartzite samples and compared with an undeformed reference sample. We stressed 4 cylindrical samples in triaxial compression in a Paterson type gas deformation apparatus at GFZ Potsdam. Experimental conditions were 300MPa confining pressure, 500°C temperature and axial stresses of 145MPa, 250MPa and 460MPa for about 30 hours, resulting in a minor strain <0.04%. EBSD scans were obtained with a Zeiss Evo scanning electron microscope and TSL software at UC Berkeley. The EBSD maps show that Dauphiné twinning is present in the starting material as well as in experimentally stressed samples. Pole figures of the bulk orientation of the reference sample compared with stressed samples show a significant difference regarding the distribution for the r and z directions. The reference sample shows an indistinct maximum for r and z, whereas the stressed samples show a maximum for r poles and a minimum for z poles in the axial stress direction. EBSD scans of the reference and stressed samples were further analyzed manually to identify the orientations of single grains, which are free of twin boundaries and those, which contain twin boundaries. This analysis aims to quantify the relationship of crystal orientation and stress magnitude to initiate mechanical twinning.

Surface modification of carbon nanotubes using 3-aminopropyltriethoxysilane to improve mechanical properties of nanocomposite based polymer matrix: Experimental and Density functional theory study

NASA Astrophysics Data System (ADS)

Hamed Mashhadzadeh, A.; Fereidoon, Ab.; Ghorbanzadeh Ahangari, M.

2017-10-01

In current study we combined theoretical and experimental studies to evaluate the effect of functionalization and silanization on mechanical behavior of polymer-based/CNT nanocomposites. Epoxy was selected as thermoset polymer, polypropylene and poly vinyl chloride were selected as thermoplastic polymers. The whole procedure is divided to two sections . At first we applied density functional theory (DFT) to analyze the effect of functionalization on equilibrium distance and adsorption energy of unmodified, functionalized by sbnd OH group and silanized epoxy/CNT, PP/CNT and PVC/CNT nanocomposites and the results showed that functionalization increased adsorption energy and reduced the equilibrium distance in all studied nanocomposites and silanization had higher effect comparing to OH functionalizing. Then we prepared experimental samples of all mentioned nanocomposites and tested their tensile and flexural strength properties. The obtained results showed that functionalization increased the studied mechanical properties in all evaluated nanocomposites. Finally we compared the results of experimental and theoretical sections with each other and estimated a suitable agreement between these parts.

Experimental Study on Permeability of Concrete

NASA Astrophysics Data System (ADS)

Yang, Honglu; Liu, Rentai; Zheng, Zhuo; Liu, Haojie; Gao, Yan; Liu, Yankai

2018-01-01

To study the influencing factors on permeability of pervious concrete, by adding inorganic organic composite materials obtained experimental results show that different aggregate size, aggregate cement ratio of different, different water cement ratio on the permeability performance. The permeability of the concrete was tested by using the self - made permeable device. The experimental results showed that the permeation coefficient of the experiment was obtained and the factors influencing the permeability of the concrete were compared and analyzed. At the same time, the porosity of pervious concrete was measured, the influence of various variables on porosity was studied, and the influence of various factors on the permeability of voids was found. Finally, through comprehensive analysis of a variety of factors, the optimal water cement ratio is 0.28. At this time, the pervious performance of concrete is optimal.

Traditional Instruction versus Virtual Reality Simulation: A Comparative Study of Phlebotomy Training among Nursing Students in Kuwait

ERIC Educational Resources Information Center

William, Abeer; Vidal, Victoria L.; John, Pamela

2016-01-01

This quasi-experimental study compared differences in phlebotomy performance on a live client, between a control group taught through the traditional method and an experimental group using virtual reality simulation. The study showed both groups had performed successfully, using the following metrics: number of reinsertions, pain factor, hematoma…

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.…

The effects of environment and ownership on children's innovation of tools and tool material selection.

PubMed

Sheridan, Kimberly M; Konopasky, Abigail W; Kirkwood, Sophie; Defeyter, Margaret A

2016-03-19

Research indicates that in experimental settings, young children of 3-7 years old are unlikely to devise a simple tool to solve a problem. This series of exploratory studies done in museums in the US and UK explores how environment and ownership of materials may improve children's ability and inclination for (i) tool material selection and (ii) innovation. The first study takes place in a children's museum, an environment where children can use tools and materials freely. We replicated a tool innovation task in this environment and found that while 3-4 year olds showed the predicted low levels of innovation rates, 4-7 year olds showed higher rates of innovation than the younger children and than reported in prior studies. The second study explores the effect of whether the experimental materials are owned by the experimenter or the child on tool selection and innovation. Results showed that 5-6 year olds and 6-7 year olds were more likely to select tool material they owned compared to tool material owned by the experimenter, although ownership had no effect on tool innovation. We argue that learning environments supporting tool exploration and invention and conveying ownership over materials may encourage successful tool innovation at earlier ages. © 2016 The Author(s).

Comparative study on direct burning of oil shale and coal

NASA Astrophysics Data System (ADS)

Hammad, Ahmad; Al Asfar, Jamil

2017-07-01

A comparative study of the direct burning processes of oil shale and coal in a circulating fluidized bed (CFB) was done in this study using ANSYS Fluent software to solve numerically the governing equations of continuity, momentum, energy and mass diffusion using finite volume method. The model was built based on an existing experimental combustion burner unit. The model was validated by comparing the theoretical results of oil shale with proved experimental results from the combustion unit. It was found that the temperature contours of the combustion process showed that the adiabatic flame temperature was 1080 K for oil shale compared with 2260 K for coal, while the obtained experimental results of temperatures at various locations of burner during the direct burning of oil shale showed that the maximum temperature reached 962 K for oil shale. These results were used in economic and environmental analysis which show that oil shale may be used as alternative fuel for coal in cement industry in Jordan.

Invitro Study on the Fluid From Banana Stem Bioprocess as Direct Fed Microbial

NASA Astrophysics Data System (ADS)

Mutaqin, B. K.; Tanuwiria, U. H.; Hernawan, E.

2018-02-01

The purpose of this research was to study the liquid produced by the bioprocess of banana stem as a Direct Fed Microbial (DFM) in order to enhance local sheep productivity invitro. Studying was the use of DFM in two invitro feeds. The object observed in this research was fermentability and digestibility value. The method was experimental with the experimental design, i.e. factorial experimental design with two factors. The first factor was DFM, the levels of which were 0, 0,2, 0,4 and 0,6%, while the second factor was two feed types (complete feed and Pennisetum purpureum only) with the treatment of threefold repetition. This research showed that fermentability and digestibility value were influenced by the DFM in the invitro complete feed. The research result analyzed using MANOVA with further testing using Duncan Test. The conclusion of the research result were shows the interaction DFM in the complete feed improve fermentability and digestibility values and DFM 0,6% shows the highest value.

Computational study of the interplay between intermolecular interactions and CO2 orientations in type I hydrates.

PubMed

Pérez-Rodríguez, M; Vidal-Vidal, A; Míguez, J M; Blas, F J; Torré, J-P; Piñeiro, M M

2017-01-25

Carbon dioxide (CO 2 ) molecules show a rich orientation landscape when they are enclathrated in type I hydrates. Previous studies have described experimentally their preferential orientations, and some theoretical works have explained, but only partially, these experimental results. In the present paper, we use classical molecular dynamics and electronic density functional theory to advance in the theoretical description of CO 2 orientations within type I hydrates. Our results are fully compatible with those previously reported, both theoretical and experimental, the geometric shape of the cavities in hydrate being, and therefore, the steric constraints, responsible for some (but not all) preferential angles. In addition, our calculations also show that guest-guest interactions in neighbouring cages are a key factor to explain the remaining experimental angles. Besides the implication concerning equation of state hydrate modeling approximations, the conclusion is that these guest-guest interactions should not be neglected, contrary to the usual practice.

Global simulation of edge pedestal micro-instabilities

NASA Astrophysics Data System (ADS)

Wan, Weigang; Parker, Scott; Chen, Yang

2011-10-01

We study micro turbulence of the tokamak edge pedestal with global gyrokinetic particle simulations. The simulation code GEM is an electromagnetic δf code. Two sets of DIII-D experimental profiles, shot #131997 and shot #136051 are used. The dominant instabilities appear to be two kinds of modes both propagating in the electron diamagnetic direction, with comparable linear growth rates. The low n mode is at the Alfven frequency range and driven by density and ion temperature gradients. The high n mode is driven by electron temperature gradient and has a low real frequency. A β scan shows that the low n mode is electromagnetic. Frequency analysis shows that the high n mode is sometimes mixed with an ion instability. Experimental radial electric field is applied and its effects studied. We will also show some preliminary nonlinear results. We thank R. Groebner, P. Snyder and Y. Zheng for providing experimental profiles and helpful discussions.

Pot binding as a variable confounding plant phenotype: theoretical derivation and experimental observations.

PubMed

Sinclair, Thomas R; Manandhar, Anju; Shekoofa, Avat; Rosas-Anderson, Pablo; Bagherzadi, Laleh; Schoppach, Remy; Sadok, Walid; Rufty, Thomas W

2017-04-01

Theoretical derivation predicted growth retardation due to pot water limitations, i.e., pot binding. Experimental observations were consistent with these limitations. Combined, these results indicate a need for caution in high-throughput screening and phenotyping. Pot experiments are a mainstay in many plant studies, including the current emphasis on developing high-throughput, phenotyping systems. Pot studies can be vulnerable to decreased physiological activity of the plants particularly when pot volume is small, i.e., "pot binding". It is necessary to understand the conditions under which pot binding may exist to avoid the confounding influence of pot binding in interpreting experimental results. In this paper, a derivation is offered that gives well-defined conditions for the occurrence of pot binding based on restricted water availability. These results showed that not only are pot volume and plant size important variables, but the potting media is critical. Artificial potting mixtures used in many studies, including many high-throughput phenotyping systems, are particularly susceptible to the confounding influences of pot binding. Experimental studies for several crop species are presented that clearly show the existence of thresholds of plant leaf area at which various pot sizes and potting media result in the induction of pot binding even though there may be no immediate, visual plant symptoms. The derivation and experimental results showed that pot binding can readily occur in plant experiments if care is not given to have sufficiently large pots, suitable potting media, and maintenance of pot water status. Clear guidelines are provided for avoiding the confounding effects of water-limited pot binding in studying plant phenotype.

A minimal-contact intervention for cardiac inpatients: long-term effects on smoking cessation.

PubMed

Bolman, Catherine; de Vries, Hein; van Breukelen, Gerard

2002-08-01

This study examined the 1-year effects of a minimal-contact smoking cessation intervention for cardiac inpatients. The multicenter study included cardiac inpatients who had smoked prior to hospitalization. A pretest-posttest quasi-experimental design was used. Patients' experimental condition depended on the hospital they were assigned to. The design was partially randomized: 4 of the 11 hospitals selected the experimental condition themselves (2 experimental, 2 control), while the remaining 7 hospitals were randomly assigned. The experimental group consisted of patients of 5 hospitals (N = 388). Patients of 6 other hospitals served as the control group (N = 401). The intervention included stop-smoking advice by the cardiologist, brief counseling by the nurse, the provision of self-help materials, and aftercare by the cardiologist. Logistic regression analyses controlling for baseline differences and covariates did not show significant intervention effects on point prevalence and continuous abstinence. The study also showed that the outcomes were not significantly related to the way hospitals were assigned to the experimental condition. While short-term effects were found, the minimal-contact intervention did not result in significant effects after 12 months, at least if patients lost to follow-up were treated as posttest smokers. Efforts should be made to improve the intervention, especially the aftercare.

The anharmonic quartic force field infrared spectra of five non-linear polycyclic aromatic hydrocarbons: Benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene

NASA Astrophysics Data System (ADS)

Mackie, Cameron J.; Candian, Alessandra; Huang, Xinchuan; Maltseva, Elena; Petrignani, Annemieke; Oomens, Jos; Mattioda, Andrew L.; Buma, Wybren Jan; Lee, Timothy J.; Tielens, Alexander G. G. M.

2016-08-01

The study of interstellar polycyclic aromatic hydrocarbons (PAHs) relies heavily on theoretically predicted infrared spectra. Most earlier studies use scaled harmonic frequencies for band positions and the double harmonic approximation for intensities. However, recent high-resolution gas-phase experimental spectroscopic studies have shown that the harmonic approximation is not sufficient to reproduce experimental results. In our previous work, we presented the anharmonic theoretical spectra of three linear PAHs, showing the importance of including anharmonicities into the theoretical calculations. In this paper, we continue this work by extending the study to include five non-linear PAHs (benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene), thereby allowing us to make a full assessment of how edge structure, symmetry, and size influence the effects of anharmonicities. The theoretical anharmonic spectra are compared to spectra obtained under matrix isolation low-temperature conditions, low-resolution, high-temperature gas-phase conditions, and high-resolution, low-temperature gas-phase conditions. Overall, excellent agreement is observed between the theoretical and experimental spectra although the experimental spectra show subtle but significant differences.

The anharmonic quartic force field infrared spectra of five non-linear polycyclic aromatic hydrocarbons: Benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene.

PubMed

Mackie, Cameron J; Candian, Alessandra; Huang, Xinchuan; Maltseva, Elena; Petrignani, Annemieke; Oomens, Jos; Mattioda, Andrew L; Buma, Wybren Jan; Lee, Timothy J; Tielens, Alexander G G M

2016-08-28

The study of interstellar polycyclic aromatic hydrocarbons (PAHs) relies heavily on theoretically predicted infrared spectra. Most earlier studies use scaled harmonic frequencies for band positions and the double harmonic approximation for intensities. However, recent high-resolution gas-phase experimental spectroscopic studies have shown that the harmonic approximation is not sufficient to reproduce experimental results. In our previous work, we presented the anharmonic theoretical spectra of three linear PAHs, showing the importance of including anharmonicities into the theoretical calculations. In this paper, we continue this work by extending the study to include five non-linear PAHs (benz[a]anthracene, chrysene, phenanthrene, pyrene, and triphenylene), thereby allowing us to make a full assessment of how edge structure, symmetry, and size influence the effects of anharmonicities. The theoretical anharmonic spectra are compared to spectra obtained under matrix isolation low-temperature conditions, low-resolution, high-temperature gas-phase conditions, and high-resolution, low-temperature gas-phase conditions. Overall, excellent agreement is observed between the theoretical and experimental spectra although the experimental spectra show subtle but significant differences.

Impact of Individual Differences on Reliance Optimization

DTIC Science & Technology

2016-05-31

Research Laboratory developed methodologies and configurations of an RPA simulation to support experimental studies that were collected at partner...that influence reliance on automation. Additionally, this research extended the study of Szalma and Taylor (2011) that showed personality traits...individuals attracted to video gaming have high initial spatial ability, for example. Experimental studies have examined directly the effect of training on

Numerical Modeling of Active Flow Control in a Boundary Layer Ingesting Offset Inlet

NASA Technical Reports Server (NTRS)

Allan, Brian G.; Owens, Lewis R.; Berrier, Bobby L.

2004-01-01

This investigation evaluates the numerical prediction of flow distortion and pressure recovery for a boundary layer ingesting offset inlet with active flow control devices. The numerical simulations are computed using a Reynolds averaged Navier-Stokes code developed at NASA. The numerical results are validated by comparison to experimental wind tunnel tests conducted at NASA Langley Research Center at both low and high Mach numbers. Baseline comparisons showed good agreement between numerical and experimental results. Numerical simulations for the inlet with passive and active flow control also showed good agreement at low Mach numbers where experimental data has already been acquired. Numerical simulations of the inlet at high Mach numbers with flow control jets showed an improvement of the flow distortion. Studies on the location of the jet actuators, for the high Mach number case, were conducted to provide guidance for the design of a future experimental wind tunnel test.

The immediate effects of taping therapy on knee pain and depression in patients with degenerative arthritis.

PubMed

Han, Ji-Won; Lee, Dong-Kyu; Park, Chi-Bok

2018-05-01

[Purpose] This study aims to identify the immediate effects of taping therapy on knee pain and depression among patients with degenerative arthritis. [Subjects and Methods] In total, 32 patients with degenerative arthritis were randomly assigned to one of two groups: the experimental group that underwent taping therapy and the control group that underwent regular treatment (16 patients per group). In the experimental group, therapeutic tape was wrapped all around the knee joint. Pain and depression were measured using the visual analogue scale (VAS) and the Beck Depression Inventory (BDI), respectively. [Results] The intra-group comparison showed significant differences in VAS and BDI for the experimental group. The intergroup comparison showed that the differences in VAS and BDI within the experimental group appeared significant relative to the control group. [Conclusion] It was observed that taping therapy showed an immediate effect in decreasing knee pain and depression among patients with degenerative arthritis.

Comparison between variable and constant rotor speed operation on WINDMEL-II

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

Sasamoto, Akira; Matsumiya, Hikaru; Kawamura, Shunji

1996-10-01

On a wind turbine control system for rotor revolution speed, it is believed that variable speed operation has the advantages over constant speed from a view point of both aerodynamics and mechanics. However, there is no experimental study which shows the differences. In this report, the authors intend to clarify the differences about shaft torque by using experimental data, from a new wind turbine system which has both variable and constant operation. The result in observation of the experimental data shows that variable speed operational shaft torque is lower than constant speed operational one.

Trajectory control of robot manipulators with closed-kinematic chain mechanism

NASA Technical Reports Server (NTRS)

Nguyen, Charles C.; Pooran, Farhad J.; Premack, Timothy

1987-01-01

The problem of Cartesian trajectory control of a closed-kinematic chain mechanism robot manipulator, recently built at CAIR to study the assembly of NASA hardware for the future Space Station, is considered. The study is performed by both computer simulation and experimentation for tracking of three different paths: a straight line, a sinusoid, and a circle. Linearization and pole placement methods are employed to design controller gains. Results show that the controllers are robust and there are good agreements between simulation and experimentation. The results also show excellent tracking quality and small overshoots.

Source term evaluation for accident transients in the experimental fusion facility ITER

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

Virot, F.; Barrachin, M.; Cousin, F.

2015-03-15

We have studied the transport and chemical speciation of radio-toxic and toxic species for an event of water ingress in the vacuum vessel of experimental fusion facility ITER with the ASTEC code. In particular our evaluation takes into account an assessed thermodynamic data for the beryllium gaseous species. This study shows that deposited beryllium dusts of atomic Be and Be(OH){sub 2} are formed. It also shows that Be(OT){sub 2} could exist in some conditions in the drain tank. (authors)

Designing artificial enzymes from scratch: Experimental study and mesoscale simulation

NASA Astrophysics Data System (ADS)

Komarov, Pavel V.; Zaborina, Olga E.; Klimova, Tamara P.; Lozinsky, Vladimir I.; Khalatur, Pavel G.; Khokhlov, Alexey R.

2016-09-01

We present a new concept for designing biomimetic analogs of enzymatic proteins; these analogs are based on the synthetic protein-like copolymers. α-Chymotrypsin is used as a prototype of the artificial catalyst. Our experimental study shows that in the course of free radical copolymerization of hydrophobic and hydrophilic monomers the target globular nanostructures of a "core-shell" morphology appear in a selective solvent. Using a mesoscale computer simulation, we show that the protein-like globules can have a large number of catalytic centers located at the hydrophobic core/hydrophilic shell interface.

Adolescents' prosocial responses to ostracism: an experimental study.

PubMed

Coyne, Sarah M; Gundersen, Nicola; Nelson, David A; Stockdale, Laura

2011-01-01

Ostracism can lead to strong behavioral responses, including diminished prosocial behavior. To date, experimental research examining this effect has only been conducted with adults. The current study consisted of 40 adolescents, half of whom were experimentally ostracized using the Cyberball paradigm. Participants' subsequent levels of pronounced prosocial behavior were measured, and personality traits were examined as possible moderators in participant behavioral responses. Results revealed that, compared to controls, ostracized adolescents showed less prosocial behavior, and this was moderated by having an "open" personality.

[Various methods of overcoming secondary resistance to treatment developing in relation to adaptation to psychotropic drugs during long-term treatment (clinico-experimental study)].

PubMed

Avrutskiĭ, G Ia; Allikmets, L Kh; Neduva, A A; Zharkovskiĭ, A M; Beliakov, A V

1984-01-01

Clinical and experimental studies into the phenomenon of adaptation to neuroleptic agents and into the methods of its overcoming were carried out. An experimental study of the long-term administrations of haloperidol revealed the formation of adaptation to the drug which can be overcome by a zigzag-like sharp elevation of the dosage followed by rapid reduction to the baseline level. The trial of this method under clinical conditions showed that it was expedient to use on a large scale the experimental findings on the specific features of the formation and prevention of the secondary therapeutic resistance.

Reproductive isolation between host races of Phytomyza glabricola on Ilex coriacea and I. glabra

USDA-ARS?s Scientific Manuscript database

Recently diverged taxa often show discordance in genetic divergence among genomic loci, where some loci show strong divergence and others show none at all. Genetic studies alone cannot distinguish among the possible mechanisms but experimental studies on other aspects of divergence may provide guida...

Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats.

PubMed

Letaif, Olavo Biraghi; Cristante, Alexandre Fogaça; Barros Filho, Tarcísio Eloy Pessoa de; Ferreira, Ricardo; Santos, Gustavo Bispo dos; Rocha, Ivan Dias da; Marcon, Raphael Martus

2015-10-01

To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion. In this experimental study, 20 male Wistar rats were divided into two groups: one group with rats undergoing spinal cord injury (SCI) at T10 and receiving estrogen therapy with 17-beta estradiol (4mg/kg) immediately following the injury and after the placement of skin sutures and a control group with rats only subjected to SCI. A moderate standard experimentally induced SCI was produced using a computerized device that dropped a weight on the rat's spine from a height of 12.5 mm. Functional recovery was verified with the Basso, Beattie and Bresnahan scale on the 2nd, 7th, 14th, 21st, 28th, 35th and 42nd days after injury and by quantifying the motor-evoked potential on the 42nd day after injury. Histopathological evaluation of the SCI area was performed after euthanasia on the 42nd day. The experimental group showed a significantly greater functional improvement from the 28th to the 42nd day of observation compared to the control group. The experimental group showed statistically significant improvements in the motor-evoked potential compared with the control group. The results of pathological histomorphometry evaluations showed a better neurological recovery in the experimental group, with respect to the proportion and diameter of the quantified nerve fibers. Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury.

Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats

PubMed Central

Letaif, Olavo Biraghi; Cristante, Alexandre Fogaça; de Barros Filho, Tarcísio Eloy Pessoa; Ferreira, Ricardo; dos Santos, Gustavo Bispo; da Rocha, Ivan Dias; Marcon, Raphael Martus

2015-01-01

OBJECTIVES: To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion. METHODS: In this experimental study, 20 male Wistar rats were divided into two groups: one group with rats undergoing spinal cord injury (SCI) at T10 and receiving estrogen therapy with 17-beta estradiol (4mg/kg) immediately following the injury and after the placement of skin sutures and a control group with rats only subjected to SCI. A moderate standard experimentally induced SCI was produced using a computerized device that dropped a weight on the rat's spine from a height of 12.5 mm. Functional recovery was verified with the Basso, Beattie and Bresnahan scale on the 2nd, 7th, 14th, 21st, 28th, 35th and 42nd days after injury and by quantifying the motor-evoked potential on the 42nd day after injury. Histopathological evaluation of the SCI area was performed after euthanasia on the 42nd day. RESULTS: The experimental group showed a significantly greater functional improvement from the 28th to the 42nd day of observation compared to the control group. The experimental group showed statistically significant improvements in the motor-evoked potential compared with the control group. The results of pathological histomorphometry evaluations showed a better neurological recovery in the experimental group, with respect to the proportion and diameter of the quantified nerve fibers. CONCLUSIONS: Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury. PMID:26598084

[Effects of Electric Stimulation and Biofeedback for Pelvic Floor Muscle Exercise in Women with Vaginal Rejuvenation Women].

PubMed

Lee, Jung Bok; Choi, So Young

2015-10-01

The purpose of this study was to investigate the effects of pelvic floor muscle exercise using electric stimulation and biofeedback on maximum pressure of vaginal contraction, vaginal contraction duration and sexual function in women who have had vaginal rejuvenation. The research design was a non-equivalent control group non-synchronized design study. Participants in this study were women who had vaginal rejuvenation at C obstetrics and gynecology hospital. The 15 participants in the experimental group were given pelvic floor muscle exercise using electric stimulation and biofeedback and the 15 participants in the control group received self pelvic floor muscle exercise. For maximum pressure of vaginal contraction, the experimental group showed a statistically significant increase compared to than the control group (t=5.96, p<.001). For vaginal contraction duration, the experimental group also showed a statistically significant increase compared to the control group (t=3.23, p=.003). For women's sexual function, the experimental group showed a significant increase when compared to the control group in total sexual function scores (t=3.41, p=.002). The results indicate that pelvic floor muscle exercise with electric stimulation and biofeedback after vaginal rejuvenation is effective in strengthening vaginal contraction pressure, vaginal contraction and that it also positively functions to increase women's sexual function.

Immunoblot analysis of immunoglobulin G response to the Lyme disease agent (Borrelia burgdorferi) in experimentally and naturally exposed dogs.

PubMed Central

Greene, R T; Walker, R L; Nicholson, W L; Heidner, H W; Levine, J F; Burgess, E C; Wyand, M; Breitschwerdt, E B; Berkhoff, H A

1988-01-01

Immunoblots were used to study the immunoglobulin G response to Borrelia burgdorferi in experimentally and naturally exposed dogs. Adsorption studies confirmed that the antibodies were specific for B. burgdorferi. Experimentally exposed dogs were asymptomatic. Naturally exposed dogs included both asymptomatic animals and animals showing signs compatible with Lyme disease. Naturally exposed dogs were from four geographic regions of the country. No differences were detected between immunoblot patterns of naturally exposed symptomatic or asymptomatic dogs from different areas of the country. The immunoblot patterns obtained with sera from experimentally exposed dogs were different from those obtained with sera from naturally exposed dogs and were characterized by reactivity to fewer and different protein bands. Immunoblot analysis using an OspA-protein-producing Escherichia coli recombinant showed that experimentally exposed dogs produced antibodies to OspA, whereas naturally exposed dogs did not. Modifications of the immune response over time, different routes of antigen presentation, and strain variation are factors postulated to account for the observed differences. Images PMID:3366860

Can Facebook Make Students Remember? An Experimental Study from Japan

ERIC Educational Resources Information Center

Acar, Adam

2014-01-01

This study experimentally manipulated the way students submit their assignments and tested the number of new words that are learned in each condition. The results showed that students who submitted their assignments through Facebook learned as much as those who submitted their assignment in a traditional way. In the light of these findings, we can…

Effects of Three Pedagogies on Learning Outcomes in a Psychology of Gender Lecture: A Quasi-Experimental Study

ERIC Educational Resources Information Center

Reber, Jeffrey S.; Downs, Samuel D.; Peterson Nelson, Julie A.

2017-01-01

This study employed a quasi-experimental design to test the effects of three pedagogies on learning outcomes in a simulated psychology of gender lecture. Results showed that meaning and relational pedagogies, as well as a combination of meaning, relational, and explanatory pedagogies, significantly improved participant learning beyond self-study…

A Decade of Literacy Research in the "Journal of Experimental Education."

ERIC Educational Resources Information Center

Knudson, Ruth E.; Theurer, Joan Leikam; Onofrey, Karen A.

This study examined various trends that exist among the 246 refereed articles published in the "Journal of Experimental Education" between 1990 and 1999. The study's results showed that 39 (16%) of the Journal articles published during this 9-year span focused on literacy. Information was categorized for each article with respect to authors'…

Fatigue creep damage at the cement-bone interface: an experimental and a micro-mechanical finite element study

PubMed Central

Waanders, Daan; Janssen, Dennis; Miller, Mark A.; Mann, Kenneth A.; Verdonschot, Nico

2009-01-01

The goal of this study was to quantify the micromechanics of the cement-bone interface under tensile fatigue loading using finite element analysis (FEA) and to understand the underlying mechanisms that play a role in the fatigue behavior of this interface. Laboratory cement-bone specimens were subjected to a tensile fatigue load, while local displacements and crack growth on the specimen's surface were monitored. FEA models were created from these specimens based upon micro-computed tomography data. To accurately model interfacial gaps at the interface between the bone and cement, a custom-written erosion algorithm was applied to the bone model. A fatigue load was simulated in the FEA models while monitoring the local displacements and crack propagation. The results showed the FEA models were able to capture the general experimental creep damage behavior and creep stages of the interface. Consistent with the experiments, the majority of the deformation took place at the contact interface. Additionally, the FEA models predicted fatigue crack patterns similar to experimental findings. Experimental surface cracks correlated moderately with FEA surface cracks (r2=0.43), but did not correlate with the simulated crack volume fraction (r2=0.06). Although there was no relationship between experimental surface cracks and experimental creep damage displacement (r2=0.07), there was a strong relationship between the FEA crack volume fraction and the FEA creep damage displacement (r2=0.76). This study shows the additional value of FEA of the cement-bone interface relative to experimental studies and can therefore be used to optimize its mechanical properties. PMID:19682690

Genetics instruction with history of science: Nature of science learning

NASA Astrophysics Data System (ADS)

Kim, Sun Young

2007-12-01

This study explored the effect of history of genetics in teaching genetics and learning the nature of science (NOS). A quasi-experimental control group research design with pretests, posttests, and delayed posttests was used, combining qualitative data and quantitative data. Two classes which consisted of tenth grade biology students participated in this study. The present study involved two instructional interventions, Best Practice Instruction with History of Genetics (BPIw/HG) and Best Practice Instruction (BPI). The experimental group received BPIw/HG utilizing various historical materials from the history of genetics, while the control group was not introduced to historical materials. Scientific Attitude Inventory II, Genetics Terms' Definitions with Concept Mapping (GTDCM), NOS Terms' Definitions with Concept Mapping (NTDCM), and View of Nature of Science (VNOS-C) were used to investigate students' scientific attitude inventory, and their understanding of genetics as well as the NOS. The results showed that students' scientific attitude inventory, and their understanding of genetics and the NOS were not statistically significantly different in the pretest (p>.05). After the intervention, the experimental group of students who received BPIw/HG demonstrated better understanding of the NOS. NTDCM results showed that the experimental group was better in defining the NOS terms and constructing a concept map ( p<.01). In addition, the experimental group retained their understanding of the NOS two-months after the completion of the intervention, showing no statistically significant difference between the posttest and the delayed posttest of NTDCM (p>.05). Further, VNOS-C data indicated that a greater percentage of the experimental group than the control group improved their understanding of the NOS. However, the two groups' understanding of genetics concepts did not show any statistically significant difference in the pretest, the posttest, and the delayed posttest (p>.05). This result implicated that allocating classroom time in introducing history of science neither helped nor hindered learning science content.

Submerged plant’s ability to present photosynthesis based on oxygen production

NASA Astrophysics Data System (ADS)

Supriatno, B.; Ulfa, K.

2018-05-01

This study aims to provide information about alternative experimental photosynthesis for experimental teaching practices in school in the coastal region. The research method was conducted experimentally by taking examples of Submerged plant in littoral area of Leuweng Sancang beach, Garut. Plant samples were given the same light intensity treatment, then the oxygen productivity was studied as an indicator of photosynthesis rate. The results showed that there were different photosynthetic rates in different types of submerged plants. Algae as submerged plants generally photosynthesize at high light intensity. However, there are also plants with photosynthesis in low light. The comparison between sea grass (Thallasia sp) with sea weed (Ulva sp) shows the difference in oxygen productivity. Submerged plants based on their ability to produce measurable oxygen can be utilized for experiments on photosynthesis learning.

Experimental animal studies of radon and cigarette smoke

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

Cross, F.T.; Dagle, G.E.; Gies, R.A.

Cigarette-smoking is a dominant cause of lung cancer and confounds risk assessment of exposure to radon decay products. Evidence in humans on the interaction between cigarette-smoking and exposure to radon decay products, although limited, indicates a possible synergy. Experimental animal data, in addition to showing synergy, also show a decrease or no change in risk with added cigarette-smoke exposures. This article reviews previous animal data developed at Compagnie Generale des Matieres Nucleaires and Pacific Northwest Laboratory (PNL) on mixed exposures to radon and cigarette smoke, and highlights new initiation-promotion-initiation (IPI) studies at PNL that were designed within the framework ofmore » a two-mutation carcinogenesis model. Also presented are the PNL exposure system, experimental protocols, dosimetry, and biological data observed to date in IPI animals.« less

A Simple Experiment to Explore Standing Waves in a Flexible Corrugated Sound Tube

NASA Astrophysics Data System (ADS)

Amorim, Maria Eva; Sousa, Teresa Delmira; Carvalho, P. Simeão; Sousa, Adriano Sampaioe

2011-09-01

Sound tubes, pipes, and singing rods are used as musical instruments and as toys to perform amusing experiments. In particular, corrugated tubes present unique characteristics with respect to the sounds they can produce; that is why they have been studied so intensively, both at theoretical and experimental levels.1-4 Experimental studies usually involve expensive and sophisticated equipment that is out of reach of school laboratory facilities.3-6 In this paper we show how to investigate quantitatively the sounds produced by a flexible sound tube corrugated on the inside by using educational equipment readily available in school laboratories, such as the oscilloscope, the microphone, the anemometer, and the air pump. We show that it is possible for students to study the discontinuous spectrum of sounds produced by a flexible corrugated tube and go even further, computing the speed of sound in air with a simple experimental procedure.

A comparison of between- and within-subjects imitation designs.

PubMed

Kressley, Regina A; Knopf, Monika

2006-12-01

Two experimental methods, which have dominated the study of declarative memory in preverbal children with imitation tasks, namely the deferred imitation and elicited imitation paradigm, differ in the amount of physical contact with test stimuli afforded infants prior to a test for long-term recall. The current study assessed effects of pre- and post-demonstration contact with test stimuli on deferred imitation of novel, single-step unrelated actions with multiple objects by 8(1/2)- and 10(1/2)-month-old infants (N=50). The rate of target action completion after a delay remained consistent at both ages across different conditions of prior contact with test stimuli. This study shows that a within-subjects baseline appraisal is valid within certain experimental parameters and offers a more economical alternative. The results show furthermore that different experimental designs utilized to assess deferred imitation are highly comparable for the first year despite differences in determining baseline.

Ga- and N-polar GaN Growths on SiC Substrate

DTIC Science & Technology

2018-03-15

a transition process of a two-section NR are formulated and numerically studied to show the consistent results with experimental data. The relative...contributions of the VLS and VS growths in such a transition process are also numerically illustrated. Besides, the experimentally observed decrease... experimental data, a few important kinetic parameters can be determined. The anti-reflection functions of a surface nanostructure, including

The effect of respiratory exercise on trunk control, pulmonary function, and trunk muscle activity in chronic stroke patients.

PubMed

Lee, Dong-Kyu; Kim, Se-Hun

2018-05-01

[Purpose] This study aims to identify the effect of respiratory exercise on trunk control, pulmonary function, and trunk muscle activity in chronic stroke patients. [Subjects and Methods] The study included 24 chronic stroke patients who were randomly assigned, 12 each, to the experimental and control groups, and received neurodevelopmental treatment. Moreover, the experimental group underwent respiratory exercise. In each patient, the trunk control was measured using the Trunk Impairment Scale (TIS); muscle activity of the trunk, through the surface electromyogram; and pulmonary function, using the pneumatometer. [Results] The intragroup comparison showed significant differences in TIS, Forced vital capacity (FVC), Forced expiratory volume at one second (FEV1), Rectus Abdominis (RA), Internal Oblique (IO) and External Oblique (EO) in the experimental group. The intergroup comparison showed that the differences in TIS, FVC, FEV1, RA, IO and EO within the experimental group appeared significant relative to the control group. [Conclusion] Based on these results, this study proved that respiratory exercise was effective in improving trunk control, pulmonary function, and trunk muscle activity in patients with chronic stroke.

The Effectiveness of the Barton's Intervention Program on Reading Comprehension and Reading Attitude of Students with Dyslexia.

PubMed

Mihandoost, Zeinab; Elias, Habibah

2011-01-01

The current research tested the differences in reading attitude and reading comprehension in the dyslexic students between the control group and the experimental group following the Barton intervention program. Dyslexia screening instrument and reading text were employed in order to identify dyslexic students. The population of the study included 138 dyslexic students studying in schools in Ilam, Iran. From this population, 64 students were randomly selected and assigned to an experimental group as well as a control group. The experimental group was taught for 36 sessions, using the Barton's method at two levels, and ten lessons were provided to improve the reading skill. The reading comprehension and reading attitude instruments were employed for the measurement of the attitude and comprehension before and after the intervention program. The analysis of covariance showed a significant difference between the control group and the experimental group following the Barton intervention program. This study showed that dyslexic students learned to read, and a more direct instruction related to decoding could influence their progress more than the general exposure to education.

College students' attitudes towards sexually themed science content: a socioscientific issues approach to resolution

NASA Astrophysics Data System (ADS)

Mikhail Yahaya, Jamil; Nurulazam, Ahmad; Karpudewan, Mageswary

2016-05-01

A socioscientific issues integrated instruction was used in the study to resolve college students attitude towards sexually-themed science content. Some 200 college students participated in the study as experimental and control groups. The former consisting of 98 students from one college was taught the content using the socioscientific issues integrated instruction. The later with 102 students from another college was taught the same content using a traditionally teacher dominated lectures. Both groups were taught over a period of eight weeks. Qualitative and quantitative data were obtained before and after the intervention. The quantitative data were analysed using analysis of covariance. The results revealed that there was a significant difference between the experimental and the control groups (F (1, 247) = 426.97, p = .00, partial eta squared = 0.64) where the experimental group showed a significant change in attitude towards the content studied. The qualitative data obtained some experimental group students showed a change in attitude the second interview. It was concluded that the use of the approach has significantly made the college students feel comfortable and confident to learn and teach the content.

Using an experimental model for the study of therapeutic touch.

PubMed

dos Santos, Daniella Soares; Marta, Ilda Estéfani Ribeiro; Cárnio, Evelin Capellari; de Quadros, Andreza Urba; Cunha, Thiago Mattar; de Carvalho, Emilia Campos

2013-02-01

to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

Effect of dietary aloe vera on growth and lipid peroxidation indices in rainbow trout (Oncorhynchus mykiss)

PubMed Central

Golestan, Ghazale; Salati, Amir Parviz; Keyvanshokooh, Saeed; Zakeri, Mohammad; Moradian, Hossein

2015-01-01

Aloe vera has been used worldwide in pharmaceutical, food and cosmetic industries due to the plethora of biological activities of its constituents. This study was done to evaluate the effects of dietary aloe vera on growth and lipid peroxidation in rainbow trout (Oncorhynchus mykiss). A total number of 480 O. mykiss (mean weight 9.50 ± 0.85 g) were randomized into four experimental groups including one control and three experimental groups that aloe vera was incorporated in their diet at 0.5, 1.0 and 2.0 g kg-1. Trial was done for eight weeks. Then biometry and blood sampling were done. Plasma malondialdehyde, ferric reducing ability of plasma and growth index were estimated at the end of study. The results showed that aloe vera extract did not affect growth indices. Malondialdehyde was increased in the experimental group compared to the control group but ferric reducing ability of plasma showed a decrease in experimental groups (p < 0.05) compared to the control group. Our findings showed that dietary aloe vera have adverse effects on antioxidant defense system in O. mykiss. PMID:25992253

Clinical and experimental study of TMJ distraction: preliminary results.

PubMed

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.

A convenient method for preparation of 2-amino-4,6-diphenylnicotinonitrile using HBF4 as an efficient catalyst via an anomeric based oxidation: A joint experimental and theoretical study

NASA Astrophysics Data System (ADS)

Zolfigol, Mohammad Ali; Kiafar, Mahya; Yarie, Meysam; Taherpour, Avat(Arman); Fellowes, Thomas; Nicole Hancok, Amber; Yari, Ako

2017-06-01

Experimental and computational studies in the synthesis of 2-amino-4,6-diphenylnicotinonitrile using HBF4 as an oxidizing promoter catalyst under mild and solvent free conditions were carried out. The suggested anomeric based oxidation (ABO) mechanism is supported by experimental and theoretical evidence. The theoretical study shows that the intermediate isomers with 5R- and 5S- chiral positions have suitable structures for the aromatization through an anomeric based oxidation in the final step of the mechanistic pathway.

Spatial Statistics of atmospheric particulate matter in China

NASA Astrophysics Data System (ADS)

Huang, Yongxiang; Wang, Yangjun; Liu, Yulu

2017-04-01

In this work, the spatial dynamics of the atmospheric particulate matters (resp. PM10 and PM2.5) are studied using turbulence methodologies. The hourly concentrations of particulate matter were released by the Chinese government (http://www.cnemc.cn). We first processed these data into daily average concentrations. Totally, there are 305 monitor stations with an observations period of 425 days. It is found experimentally that the spatial correlation function ρ(r) shows a log-law on the mesoscale range, i.e., 50 ≤ r ≤ 500 km, with an experimental scaling exponent β = 0.45. The spatial structure function shows a power-law behavior on the mesoscale range 90 ≤ r ≤ 500 km. The experimental scaling exponent ζ(q) is convex, showing that the intermittent correction is relevant in characterizing the spatial dynamics of particulate matter. The measured singularity spectrum f(α) also shows its multifractal nature. Experimentally, the particulate matter is more intermittent than the passive scalar, which could be partially due to the mesoscale movements of the atmosphere, and also due to local sources, such as local industry activities.

[Comparative study of two treatment methods for acute periodontal abscess].

PubMed

Jin, Dong-mei; Wang, Wei-qian

2012-10-01

The aim of this short-term study was to compare the clinical efficacy of 2 different methods to treat acute periodontal abscesses. After patient selection, 100 cases of acute periodontal abscess were randomly divided into two groups. The experimental group was treated by supra- and subgingival scaling, while the control group was treated by incision and drainage. A clinical examination was carried out to record the following variables: subjective clinical variables including pain, edema, redness and swelling; objective clinical variables including gingival index(GI), bleeding index(BI), probing depth(PD),suppuration, lymphadenopathy and tooth mobility. The data was analyzed with SPSS 19.0 software package. RESULES: Subjective clinical variables demonstrated statistically significant improvements with both methods from the first day after treatment and lasted for at least 30 days(P<0.05), but the results of experimental group showed much better than the control group 1 day and 7 days after treatment. 30 days after treatment, there was no significant difference between the two groups in pain and swelling improvement(P>0.05), but the experimental group showed more improvement in edema and redness than the control group(P<0.05).On improving objective variables, the experimental group showed significant improvement in GI,BI,PD and suppuration 1 day after treatment(P<0.05).After 7 days, all objective clinical variables in the experimental group improved significantly(P<0.05) in the control group, there were significant improvements in GI,suppuration,lymphadenopathy and tooth mobility(P<0.05) but the four variables of the experimental group showed more improvement than the control group(P<0.05).After 30 days, all objective clinical variables improved significantly in both groups as compared to baseline, but in the experimental group, improvements were more significant regarding to GI,BI,PD,suppuration and tooth mobility(P<0.05). The method of supra- and subgingival scaling was rapid and effective in treatment of acute periodontal abscesses.

Synchronization states and multistability in a ring of periodic oscillators: Experimentally variable coupling delays

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.

An experimental study on compressive behavior of rubble stone walls retrofitted with BFRP grids

NASA Astrophysics Data System (ADS)

Huang, Hui; Jia, Bin; Li, Wenjing; Liu, Xiao; Yang, Dan; Deng, Chuanli

2018-03-01

An experimental study was conducted to investigate the compressive behavior of rubble stone walls retrofitted with BFRP grids. The experimental program consisted of four rubble stone walls: one unretrofitted rubble stone wall (reference wall) and three BFRP grids retrofitted rubble stone walls. The main purpose of the tests was to gain a better understanding of the compressive behavior of rubble stone walls retrofitted with different amount of BFRP grids. The experimental results showed that the reference wall failed with out-of-plane collapse due to poor connection between rubble stone blocks and the three BFRP grids retrofitted walls failed with BFRP grids rupture followed by out-of-plane collapse. The measured compressive strength of the BFRP grids retrofitted walls is about 1.4 to 2.5 times of that of the reference wall. Besides, the rubble stone wall retrofitted with the maximum amount of BFRP grids showed the minimum vertical and out-of-plane displacements under the same load.

Simulation and experimental analysis of nanoindentation and mechanical properties of amorphous NiAl alloys.

PubMed

Wang, Chih-Hao; Fang, Te-Hua; Cheng, Po-Chien; Chiang, Chia-Chin; Chao, Kuan-Chi

2015-06-01

This paper used numerical and experimental methods to investigate the mechanical properties of amorphous NiAl alloys during the nanoindentation process. A simulation was performed using the many-body tight-binding potential method. Temperature, plastic deformation, elastic recovery, and hardness were evaluated. The experimental method was based on nanoindentation measurements, allowing a precise prediction of Young's modulus and hardness values for comparison with the simulation results. The indentation simulation results showed a significant increase of NiAl hardness and elastic recovery with increasing Ni content. Furthermore, the results showed that hardness and Young's modulus increase with increasing Ni content. The simulation results are in good agreement with the experimental results. Adhesion test of amorphous NiAl alloys at room temperature is also described in this study.

Prayer Lessons to Promote Happiness among Kindergarten School Children: A Cross-Country Experimental Study

ERIC Educational Resources Information Center

Pandya, Samta P.

2018-01-01

Based on a one-year longitudinal experimental study with 3,782 kindergarten school children across 15 countries, this article examines the association between prayer and happiness. Results show that the post-test scores on the faces scale were higher for the participant group who had taken the prayer lessons vis-à-vis the comparison group.…

A Comparison Between Lecture and Independent Study Methods of Instruction in Dental Radiology with Provision for Individual Differences.

ERIC Educational Resources Information Center

Diemer, Richard M.; Mazzocco, Daniel M.

Hypothesizing that experimentation with various teaching methodologies and individual student differences may show certain teaching methods to be more effective than others for a certain type of student, the authors studied the application of such experimentation to a portion of the radiology sequence in the dental curriculum. A review of the…

Assessing effects of a semi-customized experimental cervical pillow on symptomatic adults with chronic neck pain with and without headache

PubMed Central

Erfanian, Parham; Tenzif, Siamak; Guerriero, Rocco C

2004-01-01

Objective To determine the effects of a semi-customized experimental cervical pillow on symptomatic adults with chronic neck pain (with and without headache) during a four week study. Design A randomized controlled trial. Sample size Thirty-six adults were recruited for the trial, and randomly assigned to experimental or non-experimental groups of 17 and 19 participants respectively. Subjects Adults with chronic biomechanical neck pain who were recruited from the Canadian Memorial Chiropractic College (CMCC) Walk-in Clinic. Outcome measures Subjective findings were assessed using a mail-in self-report daily pain diary, and the CMCC Neck Disability Index (NDI). Statistical analysis Using repeated measure analysis of variance weekly NDI scores, average weekly AM and PM pain scores between the experimental and non-experimental groups were compared throughout the study. Results The experimental group had statistically significant lower NDI scores (p < 0.05) than the non-experimental group. The average weekly AM scores were lower and statistically significant (p < 0.05) in the experimental group. The PM scores in the experimental group were lower but not statistically significant than the other group. Conclusions The study results show that compared to conventional pillows, this experimental semi-customized cervical pillow was effective in reducing low-level neck pain intensity, especially in the morning following its use in a 4 week long study. PMID:17549216

Computational and Experimental Study of Supersonic Nozzle Flow and Shock Interactions

NASA Technical Reports Server (NTRS)

Carter, Melissa B.; Elmiligui, Alaa A.; Nayani, Sudheer N.; Castner, Ray; Bruce, Walter E., IV; Inskeep, Jacob

2015-01-01

This study focused on the capability of NASA Tetrahedral Unstructured Software System's CFD code USM3D capability to predict the interaction between a shock and supersonic plume flow. Previous studies, published in 2004, 2009 and 2013, investigated USM3D's supersonic plume flow results versus historical experimental data. This current study builds on that research by utilizing the best practices from the early papers for properly capturing the plume flow and then adding a wedge acting as a shock generator. This computational study is in conjunction with experimental tests conducted at the Glenn Research Center 1'x1' Supersonic Wind Tunnel. The comparison of the computational and experimental data shows good agreement for location and strength of the shocks although there are vertical shifts between the data sets that may be do to the measurement technique.

Developing a new experimental system for an undergraduate laboratory exercise to teach theories of visuomotor learning.

PubMed

Kasuga, Shoko; Ushiba, Junichi

2014-01-01

Humans have a flexible motor ability to adapt their movements to changes in the internal/external environment. For example, using arm-reaching tasks, a number of studies experimentally showed that participants adapt to a novel visuomotor environment. These results helped develop computational models of motor learning implemented in the central nervous system. Despite the importance of such experimental paradigms for exploring the mechanisms of motor learning, because of the cost and preparation time, most students are unable to participate in such experiments. Therefore, in the current study, to help students better understand motor learning theories, we developed a simple finger-reaching experimental system using commonly used laptop PC components with an open-source programming language (Processing Motor Learning Toolkit: PMLT). We found that compared to a commercially available robotic arm-reaching device, our PMLT accomplished similar learning goals (difference in the error reduction between the devices, P = 0.10). In addition, consistent with previous reports from visuomotor learning studies, the participants showed after-effects indicating an adaptation of the motor learning system. The results suggest that PMLT can serve as a new experimental system for an undergraduate laboratory exercise of motor learning theories with minimal time and cost for instructors.

Impact of Hypnosis Intervention in Alleviating Psychological and Physical Symptoms During Pregnancy.

PubMed

Beevi, Zuhrah; Low, Wah Yun; Hassan, Jamiyah

2016-04-01

Physical symptoms (e.g., vomiting) and psychological symptoms (stress, anxiety, and depression) during pregnancy are common. Various strategies such as hypnosis are available to reduce these symptoms. The objective of the authors in this study is to investigate the impact of a hypnosis intervention in reducing physical and psychological symptoms during pregnancy. A pre-test/post-test quasi-experimental design was employed in this study. The hypnosis intervention was given to the experimental group participants at weeks 16 (baseline), 20 (time point 1), 28 (time point 2), and 36 (time point 3) of their pregnancy. Participants in the control group received only the traditional antenatal care. Participants from both groups completed the Depression Anxiety Stress Scale-21 (DASS-21) and a Pregnancy Symptoms Checklist at weeks 16, 20, 28 and 36 of pregnancy. Results indicated that stress and anxiety symptoms were significantly reduced for the experimental group, but not for the control group. Although mean differences for the depressive symptoms were not significant, the experimental group had lower symptoms at time point 3. The physical symptoms' results showed significant group differences at time point 3, indicating a reduction in the experience of physical symptoms for the experimental group participants. Our study showed that hypnosis intervention during pregnancy aided in reducing physical and psychological symptoms during pregnancy.

The effect of mirror therapy integrating functional electrical stimulation on the gait of stroke patients.

PubMed

Ji, Sang-Goo; Cha, Hyun-Gyu; Kim, Myoung-Kwon; Lee, Chang-Ryeol

2014-04-01

[Purpose] The aim of the present study was to examine whether mirror therapy in conjunction with FES in stroke patients can improve gait ability. [Subjects] This study was conducted with 30 subjects who were diagnosed with hemiparesis due to stroke. [Methods] Experimental group I contained 10 subjects who received mirror therapy in conjunction with functional electrical stimulation, experimental group II contained 10 subjects who received mirror therapy, and the control group contained 10 subjects who received a sham therapy. A gait analysis was performed using a three-dimensional motion capture system, which was a real-time tracking device that delivers data in an infrared mode via reflective markers using six cameras. [Results] The results showed a significant difference in gait velocity between groups after the experiment, and post hoc analysis revealed significant differences between experimental group I and the control group and between experimental group II and the control group, respectively. There were also significant differences in step length and stride length between the groups after the experiment, and post hoc analysis revealed significant differences between experimental group I and control group. [Conclusion] The present study showed that mirror therapy in conjunction with FES is more effective for improving gait ability than mirror therapy alone.

Effect of aquatic dual-task training on balance and gait in stroke patients

PubMed Central

Kim, Kyoung; Lee, Dong-Kyu; Kim, Eun-Kyung

2016-01-01

[Purpose] The purpose of this study was to determine the effect of aquatic dual-task training on balance and gait in stroke patients. [Subjects and Methods] Twenty stroke patients were divided into the experimental (n=10) and control (n=10) groups. Both groups underwent neurodevelopmental treatment. The experimental group additionally underwent aquatic dual-task training for 30 minutes a day, 5 days a week, for 6 weeks. Balance was measured using the Berg balance scale, Five Times Sit-to Stand Test, and Functional Reach Test. Gait was measured using the 10-Meter Walk Test, Timed Up and Go Test, and Functional Gait Assessment. [Results] For intragroup comparison, the experimental group showed a significant change after the experiment in all balance and gait assessment tests. For intergroup comparison, the experimental group showed relatively more significant change after the experiment in all balance and gait assessment tests. [Conclusion] Our results showed that aquatic dual-task training has a positive effect on balance and gait in stroke patients. PMID:27512261

Effect of aquatic dual-task training on balance and gait in stroke patients.

PubMed

Kim, Kyoung; Lee, Dong-Kyu; Kim, Eun-Kyung

2016-07-01

[Purpose] The purpose of this study was to determine the effect of aquatic dual-task training on balance and gait in stroke patients. [Subjects and Methods] Twenty stroke patients were divided into the experimental (n=10) and control (n=10) groups. Both groups underwent neurodevelopmental treatment. The experimental group additionally underwent aquatic dual-task training for 30 minutes a day, 5 days a week, for 6 weeks. Balance was measured using the Berg balance scale, Five Times Sit-to Stand Test, and Functional Reach Test. Gait was measured using the 10-Meter Walk Test, Timed Up and Go Test, and Functional Gait Assessment. [Results] For intragroup comparison, the experimental group showed a significant change after the experiment in all balance and gait assessment tests. For intergroup comparison, the experimental group showed relatively more significant change after the experiment in all balance and gait assessment tests. [Conclusion] Our results showed that aquatic dual-task training has a positive effect on balance and gait in stroke patients.

Observational studies using propensity score analysis underestimated the effect sizes in critical care medicine.

PubMed

Zhang, Zhongheng; Ni, Hongying; Xu, Xiao

2014-08-01

Propensity score (PS) analysis has been increasingly used in critical care medicine; however, its validation has not been systematically investigated. The present study aimed to compare effect sizes in PS-based observational studies vs. randomized controlled trials (RCTs) (or meta-analysis of RCTs). Critical care observational studies using PS were systematically searched in PubMed from inception to April 2013. Identified PS-based studies were matched to one or more RCTs in terms of population, intervention, comparison, and outcome. The effect sizes of experimental treatments were compared for PS-based studies vs. RCTs (or meta-analysis of RCTs) with sign test. Furthermore, ratio of odds ratio (ROR) was calculated from the interaction term of treatment × study type in a logistic regression model. A ROR < 1 indicates greater benefit for experimental treatment in RCTs compared with PS-based studies. RORs of each comparison were pooled by using meta-analytic approach with random-effects model. A total of 20 PS-based studies were identified and matched to RCTs. Twelve of the 20 comparisons showed greater beneficial effect for experimental treatment in RCTs than that in PS-based studies (sign test P = 0.503). The difference was statistically significant in four comparisons. ROR can be calculated from 13 comparisons, of which four showed significantly greater beneficial effect for experimental treatment in RCTs. The pooled ROR was 0.71 (95% CI: 0.63, 0.79; P = 0.002), suggesting that RCTs (or meta-analysis of RCTs) were more likely to report beneficial effect for the experimental treatment than PS-based studies. The result remained unchanged in sensitivity analysis and meta-regression. In critical care literature, PS-based observational study is likely to report less beneficial effect of experimental treatment compared with RCTs (or meta-analysis of RCTs). Copyright © 2014 Elsevier Inc. All rights reserved.

Histological Study of the Toxic Effects of Solder Fumes on Spermatogenesis in Rats

PubMed Central

Arab, Mohammad Reza; Heidari, Mohammad Hossein; Mashhadi, Rezvaneh; Mirzaei, Ramazan; Jahantigh, Mehdi

2011-01-01

Objective: Toxic fumes generated during the soldering process contain various contaminants released at sufficient rates to cause both short- and long-term health problems. Studies have shown that these fumes change the quality and quantity of semen fluid in exposed workers. The aim of the present study was to determine the potentially toxic effects of solder fumes on spermatogenesis in seminiferous tubules of rats as an experimental model, with conditioned media in an exposed chamber. Materials and Methods: A total number of 48 male Sprague Dawley adult rats were randomly divided into experimental (n=30) and control (n=18) groups. Based on exposure time, each group was further subdivided into two, four and six subgroups. Rats in the experimental groups were exposed to solder fumes in an exposure chamber for one hour/ day. The concentrations of fumes [formaldehyde, stanum (Sn) and lead (Pb)] were measured by a standard method via atomic absorption and spectrophotometry. According to a timetable, under deep anesthesia, the rats of both experimental and control subgroups were killed. After fixation of testes, specimens were weighed and routinely processed. Paraffin sections were stained by hematoxylin and eosin. Spermiogenesis index was calculated and data analyzed by Mann Whitney NPAR test. Results: Analysis of air samples in the exposure chamber showed the following fume concentrations: 0.193 mg/m3 for formaldehyde, 0.35 mg/m3 for Sn and 3 mg/m3 for Pb. Although there was no significant difference in testes weight between control and experimental subgroups, there was only a significant difference in spermiogenesis index between the six week experimental and control subgroups (p<0.02). Conclusion: The results of this study showed that solder fumes can change the spermiogenesis index in experimental groups in a time dependent manner. PMID:23671821

Experimental investigations and finite element simulation of cutting heat in vibrational and conventional drilling of cortical bone.

PubMed

Wang, Yu; Cao, Meng; Zhao, Xiangrui; Zhu, Gang; McClean, Colin; Zhao, Yuanyuan; Fan, Yubo

2014-11-01

Heat generated during bone drilling could cause irreversible thermal damage, which can lead to bone necrosis or even osteomyelitis. In this study, vibrational drilling was applied to fresh bovine bones to investigate the cutting heat in comparison with conventional drilling through experimental investigation and finite element analysis (FEA). The influence of vibrational frequency and amplitude on cutting heat generation and conduction were studied. The experimental results showed that, compared with the conventional drilling, vibrational drilling could significantly reduce the cutting temperature in drilling of cortical bone (P<0.05): the cutting temperature tended to decrease with increasing vibrational frequency and amplitude. The FEA results also showed that the vibrational amplitude holds a significant effect on the cutting heat conduction. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Both experimental hypothyroidism and hyperthyroidism increase cardiac irisin levels in rats.

PubMed

Atici, E; Menevse, E; Baltaci, A K; Mogulkoc, R

2018-01-01

Irisin is a newly discovered myokine and adipokine that increases total body energy expenditure. The aim of this study was to determine the effect of experimental hypothyroidism and hyperthyroidism on the levels of irisin in heart tissue in rats. The study was performed on the 40 male Sprague-Dawley rats. Experimental groups were designed as; Control, Hypothyroidism, Hypothyroidism+L-Thyroxine, Hyperthyroidism and Hyperthyroidism + PTU. Following 3 weeks experimental period, irisin levels were determined in heart tissues. Hypothyroidism group values of irisin were higher than in the control group, but lower than in the hyperthyroidism group. The hyperthyroidism group had the highest levels of cardiac irisin. The results of the study showed that the experimental hypothyroidism and hyperthyroidism increased the heart irisin levels, but the increase in the hyperthyroidism group was much higher than in the hypothyroidism group. However, treatment of hypothyroidism and hyperthyroidism corrected cardiac irisin levels (Fig. 1, Ref. 28).

Molecular modeling and biological evaluation of 2-N,N-dimethylaminecyclohexyl 1-N‧,N‧-dimethylcarbamate isomers and their methylsulfate salts as cholinesterases inhibitors

NASA Astrophysics Data System (ADS)

Bocca, Cleverson C.; Rittner, Roberto; Höehr, Nelci F.; Pinheiro, Glaucia M. S.; Abiko, Layara A.; Basso, Ernani A.

2010-11-01

This work presents a detailed theoretical and experimental study on the inhibitory properties of 2- N,N-dimethylaminecyclohexyl 1- N',N'-dimethylcarbamate isomers and their methylsulfate salts against the cholinesterases enzymes. The in vitro inhibition test performed by the Ellman's method showed that the salt form compounds were more active than the neutral ones in cholinesterases inhibition. The trans salt showed good selectivity towards the inhibition of erythrocyte cholinesterase with a maximum limit around 90% and 55% for the plasma cholinesterase inhibition. Molecular modeling, docking and experimental results performed in this study showed to be important initial steps toward the development of a novel pharmaceuticals in the fight against Alzheimer's disease.

Studies on biomass char gasification and dynamics

NASA Astrophysics Data System (ADS)

You, Zhanping; You, Shijun; Ma, Xiaoyan

2018-01-01

The gasification performances of two kinds of biomass char by experiment methods are studied, including conversion rate and gasification gas component with temperature and time. Experimental results show that gasification temperature has important effects on the conversion rate and gas component. In the range of experimental temperature, char conversion rates are no more than 30.0%. The apparent activation energies and apparent reaction frequency factors of two biomass chars are obtained through kinetic studies.

An experimental study of hydrophilic plastics for urological use.

PubMed

Ramsay, J W; Miller, R A; Crocker, P R; Ringrose, B J; Jones, S; Levison, D A; Whitfield, H N; Wickham, J E

1986-02-01

Hydrophilic graft copolymers of polyethylene vinyl acetate (PEVA) were extruded into tubular form. These materials increase both external and internal diameters by 60% on contact with water. The tubes were used as ureteric stents in an experimental study and were superior to silicone stents of the same calibre in the limitation of urinary extravasation. Histological, cytotoxic and electron microscopic studies showed that PEVA is a biocompatible material suitable for clinical use in urology.

Comparative thermodynamic and experimental study of some heavy metal behaviors during automotive shredder residues incineration

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

Trouve, G.; Kauffmann, A.; Delfosse, L.

1998-12-31

Experimental and theoretical studies of the behavior of some heavy metals were undertaken during Automotive Shredder Residues (ASR) incineration. A thermodynamic study at equilibrium was performed using a software minimizing the free Gibbs energy. The metals studied were barium, copper, lead and zinc. The studies were performed mostly at two temperatures: 1123 and 1373 K. The thermodynamic study showed that the chlorine content is the most important parameter influencing the volatility of the studied metals. It also showed that in default of chlorine in a system containing several metals, barium chloride in its condensed form is the most easily formed.more » Other metals remained in their metallic form or in the form of oxides. The presence of hydrogen in the system has a general limiting influence on the metal volatility because, especially at high temperatures, hydrogen chloride is more likely to be formed. In the experimental field, the behaviors of metals were studied using commercial polymers as waste models: a PVC mastic, a polyurethane mastic and a rubber powder. Copper and barium presented a non volatile behavior during the incineration of waste matrixes as ASR, being present also in residual ash. On the other hand, lead was completely formed in the gas phase and zinc showed an equal partitioning between the two principal phases of the treatment.« less

Study of complex molecular systems by probe vibrational spectroscopy method

NASA Astrophysics Data System (ADS)

Boldeskul, A. E.; Zatsepin, V. M.; Atakhodjaev, A. K.; Shermatov, A. N.; Ashburiev, R.

1984-03-01

Experimental study of benzonitril as a probe in aqueous solution of sodium lauril sulphate /SDS/ by Raman spectroscopy technique showed integral moments of √ /C X N/ line to be extremely sensitive to the structural transitions in micellar systems. The central part of the experimental contour was used to determine integral moments with the help of line shape approximant received by Mori method

Resilience of predators to fishing pressure on coral patch reefs

USGS Publications Warehouse

Schroeder, R.E.; Parrish, J.D.

2005-01-01

Numbers and biomass of piscivorous fish and their predation on other fish may often be high in undisturbed coral reef communities. The effects of such predation have sometimes been studied by removal of piscivores (either experimentally or by fishermen). Such perturbations have usually involved removal of large, highly vulnerable, mobile piscivores that are often actively sought in fisheries. The effects of fishing on smaller, demersal, semi-resident piscivores have been little studied. We studied such effects on the fish communities of patch reefs at Midway atoll by experimentally removing major resident, demersal, piscivorous fishes. First, four control reefs and four experimental reefs were selected, their dimensions and habitats mapped, and their visible fish communities censused repeatedly over 1 year. Census of all control and experimental reefs was continued for the following 39 months, during which known piscivores were collected repeatedly by hand spearing. Records were kept of catch and effort to calculate CPUE as an index of predator density. Spearfishing on the experimental reefs removed 2504 piscivorous fish from 12 families and 43 taxa (mostly species). The species richness of the catch did not show an overall change over the duration of the experiment. Spearman rank correlation analysis showed some unexpected positive correlations for density in numbers and biomass of major fished piscivorous groups (especially lizardfish) over the experiment. Only two relatively minor fished piscivorous taxa declined in abundance over the experiment, while the overall abundance of piscivores increased. Visual censuses of fish on the experimental reefs also failed to show reduction of total piscivores over the full experimental period. No significant trend in the abundance of lizardfish censused over the full period was apparent on any of the control reefs. The high resilience of piscivores on these experimental reefs to relatively intense fishing pressure could result from their protracted recruitment seasons, high immigration rates, cryptic habits, or naturally high abundances. A major factor was the high immigration rates of lizardfish, replacing lizardfish and other less mobile piscivores removed from the reefs by spearing. On the fished reefs, the removed lizardfish population replaced itself >20 times during the experiment; other piscivorous taxa replaced themselves only 5 times.

Caprylate Salts Based on Amines as Volatile Corrosion Inhibitors for Metallic Zinc: Theoretical and Experimental Studies.

PubMed

Valente, Marco A G; Teixeira, Deiver A; Azevedo, David L; Feliciano, Gustavo T; Benedetti, Assis V; Fugivara, Cecílio S

2017-01-01

The interaction of volatile corrosion inhibitors (VCI), caprylate salt derivatives from amines, with zinc metallic surfaces is assessed by density functional theory (DFT) computer simulations, electrochemical impedance (EIS) measurements and humid chamber tests. The results obtained by the different methods were compared, and linear correlations were obtained between theoretical and experimental data. The correlations between experimental and theoretical results showed that the molecular size is the determining factor in the inhibition efficiency. The models used and experimental results indicated that dicyclohexylamine caprylate is the most efficient inhibitor.

Experimental and analytical studies of flow through a ventral and axial exhaust nozzle system for STOVL aircraft

NASA Technical Reports Server (NTRS)

Esker, Barbara S.; Debonis, James R.

1991-01-01

Flow through a combined ventral and axial exhaust nozzle system was studied experimentally and analytically. The work is part of an ongoing propulsion technology effort at NASA Lewis Research Center for short takeoff, vertical landing (STOVL) aircraft. The experimental investigation was done on the NASA Lewis Powered Lift Facility. The experiment consisted of performance testing over a range of tailpipe pressure ratios from 1 to 3.2 and flow visualization. The analytical investigation consisted of modeling the same configuration and solving for the flow using the PARC3D computational fluid dynamics program. The comparison of experimental and analytical results was very good. The ventral nozzle performance coefficients obtained from both the experimental and analytical studies agreed within 1.2 percent. The net horizontal thrust of the nozzle system contained a significant reverse thrust component created by the flow overturning in the ventral duct. This component resulted in a low net horizontal thrust coefficient. The experimental and analytical studies showed very good agreement in the internal flow patterns.

Experimental study of forced convection heat transport in porous media

NASA Astrophysics Data System (ADS)

Pastore, Nicola; Cherubini, Claudia; Rapti, Dimitra; Giasi, Concetta I.

2018-04-01

The present study is aimed at extending this thematic issue through heat transport experiments and their interpretation at laboratory scale. An experimental study to evaluate the dynamics of forced convection heat transfer in a thermally isolated column filled with porous medium has been carried out. The behavior of two porous media with different grain sizes and specific surfaces has been observed. The experimental data have been compared with an analytical solution for one-dimensional heat transport for local nonthermal equilibrium condition. The interpretation of the experimental data shows that the heterogeneity of the porous medium affects heat transport dynamics, causing a channeling effect which has consequences on thermal dispersion phenomena and heat transfer between fluid and solid phases, limiting the capacity to store or dissipate heat in the porous medium.

Adjustable low frequency and broadband metamaterial absorber based on magnetic rubber plate and cross resonator

NASA Astrophysics Data System (ADS)

Cheng, Yongzhi; Nie, Yan; Wang, Xian; Gong, Rongzhou

2014-02-01

In this paper, the magnetic rubber plate absorber (MRPA) and metamaterial absorber (MA) based on MRP substrate were proposed and studied numerically and experimentally. Based on the characteristic of L-C resonances, experimental results show that the MA composed of cross resonator (CR) embedded single layer MRP could be adjustable easily by changing the wire length and width of CR structure and MRP thickness. Finally, experimental results show that the MA composed of CR-embedded two layers MRP with the total thickness of 2.42 mm exhibit a -10 dB absorption bandwidth from 1.65 GHz to 3.7 GHz, which is 1.86 times wider than the same thickness MRPA.

Modeling and experimental parametric study of a tri-leg compliant orthoplanar spring based multi-mode piezoelectric energy harvester

NASA Astrophysics Data System (ADS)

Dhote, Sharvari; Yang, Zhengbao; Zu, Jean

2018-01-01

This paper presents the modeling and experimental parametric study of a nonlinear multi-frequency broad bandwidth piezoelectric vibration-based energy harvester. The proposed harvester consists of a tri-leg compliant orthoplanar spring (COPS) and multiple masses with piezoelectric plates attached at three different locations. The vibration modes, resonant frequencies, and strain distributions are studied using the finite element analysis. The prototype is manufactured and experimentally investigated to study the effect of single as well as multiple light-weight masses on the bandwidth. The dynamic behavior of the harvester with a mass at the center is modeled numerically and characterized experimentally. The simulation and experimental results are in good agreement. A wide bandwidth with three close nonlinear vibration modes is observed during the experiments when four masses are added to the proposed harvester. The current generator with four masses shows a significant performance improvement with multiple nonlinear peaks under both forward and reverse frequency sweeps.

The Effectiveness of the Barton’s Intervention Program on Reading Comprehension and Reading Attitude of Students with Dyslexia

PubMed Central

Mihandoost, Zeinab; Elias, Habibah

2011-01-01

Objective: The current research tested the differences in reading attitude and reading comprehension in the dyslexic students between the control group and the experimental group following the Barton intervention program. Methods: Dyslexia screening instrument and reading text were employed in order to identify dyslexic students. The population of the study included 138 dyslexic students studying in schools in Ilam, Iran. From this population, 64 students were randomly selected and assigned to an experimental group as well as a control group. The experimental group was taught for 36 sessions, using the Barton’s method at two levels, and ten lessons were provided to improve the reading skill. The reading comprehension and reading attitude instruments were employed for the measurement of the attitude and comprehension before and after the intervention program. Results: The analysis of covariance showed a significant difference between the control group and the experimental group following the Barton intervention program. Conclusion: This study showed that dyslexic students learned to read, and a more direct instruction related to decoding could influence their progress more than the general exposure to education. PMID:24644446

Alcohol and Sexuality Research in the AIDS Era: Trends in Publication Activity, Target Populations and Research Design

PubMed Central

George, William H.

2009-01-01

Research addressing relationships between alcohol and human sexuality has proliferated, due in part to efforts to characterize alcohol's role in HIV risk behavior. This study provides a descriptive review of the alcohol–sexuality literature, using abstracts from 264 identified studies to estimate changes in publication activity, target populations, and the prevalence of HIV-related studies over time. We also examine methodological trends by estimating the prevalence of experimental vs. non-experimental studies. Findings show considerable increases in research activity and diversity of populations studied since the mid-1980's and highlight the emergence of HIV-related studies as a focal point of alcohol–sexuality research efforts. Results also demonstrate a substantial decline in the proportion of studies utilizing experimental methods, in part because of frequent use of non-experimental approaches in studies of alcohol and HIV risk behavior. We discuss implications and review the role of experiments in evaluating causal relationships between alcohol and sexual risk behavior. PMID:16897352

Alcohol and sexuality research in the AIDS era: trends in publication activity, target populations and research design.

PubMed

Hendershot, Christian S; George, William H

2007-03-01

Research addressing relationships between alcohol and human sexuality has proliferated, due in part to efforts to characterize alcohol's role in HIV risk behavior. This study provides a descriptive review of the alcohol-sexuality literature, using abstracts from 264 identified studies to estimate changes in publication activity, target populations, and the prevalence of HIV-related studies over time. We also examine methodological trends by estimating the prevalence of experimental vs. non-experimental studies. Findings show considerable increases in research activity and diversity of populations studied since the mid-1980's and highlight the emergence of HIV-related studies as a focal point of alcohol-sexuality research efforts. Results also demonstrate a substantial decline in the proportion of studies utilizing experimental methods, in part because of frequent use of non-experimental approaches in studies of alcohol and HIV risk behavior. We discuss implications and review the role of experiments in evaluating causal relationships between alcohol and sexual risk behavior.

Histologic evaluation of human pulp tissue after orthodontic intrusion.

PubMed

Lazzaretti, Dieison Nardi; Bortoluzzi, Gianna Steffens; Torres Fernandes, Lauren Fioreze; Rodriguez, Rubens; Grehs, Renésio Armindo; Martins Hartmann, Mateus Silveira

2014-10-01

The forces applied during orthodontic treatment bring about effects on the teeth and surrounding tissues. The aim of this study was to evaluate the possible changes in the human pulpal tissue resulting from orthodontic intrusion in a 21-day period using histologic examination. The sample consisted of 17 young individuals of both sexes between the ages of 12 and 19 years. A total of 34 premolars were evaluated with orthodontic indication of extraction. Because it is a split-mouth study, in each patient, intrusion force of 60 g was applied randomly on 1 of the dental elements experimental group for 21 days. The counterpart control group received no force. After extractions, these dental elements were fixed in 10% formaldehyde, processed automatically, submitted to histotechnical preparation, and stained with hematoxylin-eosin for analysis under optical microscope. The paired Fisher exact test (P ≤ .05) showed a significant increase of fibrous tissue in the experimental group. The nonparametric paired Wilcoxon test (P ≤ .05) showed a significant increase in the number of pulpal nodules in the elements of the experimental group and showed no difference in the number of blood vessels between the groups. Large-caliber vessels and congested elements were observed in 8 of the experimental group elements. The orthodontic intrusion force, in these conditions, caused vascular changes in the pulpal tissue and also increased the presence of fibrosis and the number of pulp calcifications in the experimental elements. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Experimental and theoretical studies of vibrational density of states in Fe3O4 single-crystalline thin films

NASA Astrophysics Data System (ADS)

Handke, B.; Kozłowski, A.; Parliński, K.; Przewoźnik, J.; Ślęzak, T.; Chumakov, A. I.; Niesen, L.; Kąkol, Z.; Korecki, J.

2005-04-01

This paper presents experimental and theoretical studies of lattice vibrations in a single-crystalline Fe3O4(001) thin film. The investigations were carried out in order to see how the lattice dynamics changes at the Verwey transition. Vibrational densities of states (DOS) were obtained from nuclear inelastic scattering (NIS) of synchrotron radiation in the temperature range 25 to 296 K, while theoretical DOS were calculated ab initio within density functional theory. Experimental phonon density of states shows good agreement with calculated DOS, reproducing both the general features of main line groups as well as the groups’ structure. This is also in qualitative accord with heat capacity data, provided that experimental DOS is augmented with that calculated for oxygen atoms. We have observed a gradual change in the NIS raw data as well as the relevant DOS while lowering the temperature. In particular, the main peak in the energy region 15-25 meV shows increasing splitting on cooling. The Lamb-Mössbauer factor calculated in the course of DOS evaluation shows a pronounced drop in the vicinity of the Verwey transition that may be partly connected to the observed abrupt lowering of the count rate at approximately 7 meV for T

Experimental study of the condensation heat transfer characteristics of CO2 in a horizontal microfin tube with a diameter of 4.95 mm

NASA Astrophysics Data System (ADS)

Son, Chang-Hyo; Oh, Hoo-Kyu

2012-11-01

The condensation heat transfer characteristics for CO2 flowing in a horizontal microfin tube were investigated by experiment with respect to condensation temperature and mass flux. The test section consists of a 2,400 mm long horizontal copper tube of 4.6 mm inner diameter. The experiments were conducted at refrigerant mass flux of 400-800 kg/m2s, and saturation temperature of 20-30 °C. The main experimental results showed that annular flow was highly dominated the majority of condensation flow in the horizontal microfin tube. The condensation heat transfer coefficient increases with decreasing saturation temperature and increasing mass flux. The experimental data were compared against previous heat transfer correlations. Most correlations failed to predict the experimental data. However, the correlation by Cavallini et al. showed relatively good agreement with experimental data in the microfin tube. Therefore, a new condensation heat transfer correlation is proposed with mean and average deviations of 3.14 and -7.6 %, respectively.

Comparison of two methods for detection of strain localization in sheet forming

NASA Astrophysics Data System (ADS)

Lumelskyj, Dmytro; Lazarescu, Lucian; Banabic, Dorel; Rojek, Jerzy

2018-05-01

This paper presents a comparison of two criteria of strain localization in experimental research and numerical simulation of sheet metal forming. The first criterion is based on the analysis of the through-thickness thinning (through-thickness strain) and its first time derivative in the most strained zone. The limit strain in the second method is determined by the maximum of the strain acceleration. Experimental and numerical investigation have been carried out for the Nakajima test performed for different specimens of the DC04 grade steel sheet. The strain localization has been identified by analysis of experimental and numerical curves showing the evolution of strains and their derivatives in failure zones. The numerical and experimental limit strains calculated from both criteria have been compared with the experimental FLC evaluated according to the ISO 12004-2 norm. It has been shown that the first method predicts formability limits closer to the experimental FLC. The second criterion predicts values of strains higher than FLC determined according to ISO norm. These values are closer to the strains corresponding to the fracture limit. The results show that analysis of strain evolution allows us to determine strain localization in numerical simulation and experimental studies.

Effect of external magnetic field on locking range of spintronic feedback nano oscillator

NASA Astrophysics Data System (ADS)

Singh, Hanuman; Konishi, K.; Bose, A.; Bhuktare, S.; Miwa, S.; Fukushima, A.; Yakushiji, K.; Yuasa, S.; Kubota, H.; Suzuki, Y.; Tulapurkar, A. A.

2018-05-01

In this work we have studied the effect of external applied magnetic field on the locking range of spintronic feedback nano oscillator. Injection locking of spintronic feedback nano oscillator at integer and fractional multiple of its auto oscillation frequency was demonstrated recently. Here we show that the locking range increases with increasing external magnetic field. We also show synchronization of spintronic feedback nano oscillator at integer (n=1,2,3) multiples of auto oscillation frequency and side band peaks at higher external magnetic field values. We have verified experimental results with macro-spin simulation using similar conditions as used for the experimental study.

Coupled-channel calculation for cross section of fusion and barrier distribution of {}^{16,17,18}O + {}^{16}O reactions

NASA Astrophysics Data System (ADS)

Fereidonnejad, R.; Sadeghi, H.; Ghambari, M.

2018-03-01

In this work, the effect of multi-phonon excitation on heavy-ion fusion reactions has been studied and fusion barrier distributions of energy intervals near and below the Coulomb barrier have been studied for 16,17,18O + 16O reactions. The structure and deformation of nuclear projectiles have been studied. Given the adaptation of computations to experimental data, our calculations predict the behavior of reactions in intervals of energy in which experimental measurements are not available. In addition the S-factor for these reactions has been calculated. The results showed that the structure and deformation of a nuclear projectile are important factors. The S-factor, obtained in the coupled-channel calculations for the {}^{16}O + {}^{16}O, {}^{17}O +{}^{16}O and {}^{18}O +{}^{16}O reactions, showed good agreement with the experimental data and had a maximum value at an energy near 5, 4.5 and 4 MeV, respectively.

Analyzing and Modelling the Corrosion Behavior of Ni/Al2O3, Ni/SiC, Ni/ZrO2 and Ni/Graphene Nanocomposite Coatings

PubMed Central

Saeed, Adil; Braun, Wolfgang; Bajwa, Rizwan; Rafique, Saqib

2017-01-01

A study has been presented on the effects of intrinsic mechanical parameters, such as surface stress, surface elastic modulus, surface porosity, permeability and grain size on the corrosion failure of nanocomposite coatings. A set of mechano-electrochemical equations was developed by combining the popular Butler–Volmer and Duhem expressions to analyze the direct influence of mechanical parameters on the electrochemical reactions in nanocomposite coatings. Nanocomposite coatings of Ni with Al2O3, SiC, ZrO2 and Graphene nanoparticles were studied as examples. The predictions showed that the corrosion rate of the nanocoatings increased with increasing grain size due to increase in surface stress, surface porosity and permeability of nanocoatings. A detailed experimental study was performed in which the nanocomposite coatings were subjected to an accelerated corrosion testing. The experimental results helped to develop and validate the equations by qualitative comparison between the experimental and predicted results showing good agreement between the two. PMID:29068395

The impact of inquiry-based learning on the critical thinking dispositions of pre-service science teachers

NASA Astrophysics Data System (ADS)

Arsal, Zeki

2017-07-01

In the study, the impact of inquiry-based learning on pre-service teachers' critical thinking dispositions was investigated. The sample of the study comprised of 56 pre-service teachers in the science education teacher education programme at the public university in the north of Turkey. In the study, quasi-experimental design with an experimental and a control group were applied to find out the impact of inquiry-based learning on the critical thinking dispositions of the pre-service teachers in the teacher education programme. The results showed that the pre-service teachers in the experimental group did not show statistically significant greater progress in terms of critical thinking dispositions than those in the control group. Teacher educators who are responsible for pedagogical courses in the teacher education programme should consider that the inquiry-based learning could not be effective method to improve pre-service teachers' critical thinking dispositions. The results are discussed in relation to potential impact on science teacher education and implications for future research.

Foot massage: effectiveness on postoperative pain in breast surgery patients.

PubMed

Ucuzal, Meral; Kanan, Nevin

2014-06-01

The aim of this study was to determine the effect of foot massage on pain after breast surgery, and provide guidance for nurses in nonpharmacologic interventions for pain relief. This was a quasiexperimental study with a total of 70 patients who had undergone breast surgery (35 in the experimental group and 35 in the control group). Patients in the control group received only analgesic treatment, whereas those in the experimental group received foot massage in addition to analgesic treatment. Patients received the first dose of analgesics during surgery. As soon as patients came from the operating room, they were evaluated for pain severity. Patients whose pain severity scored ≥4 according to the Short-Form McGill Pain Questionnaire were accepted into the study. In the experimental group, pain and vital signs (arterial blood pressure, pulse, and respiration) were evaluated before foot massage at the time patients complained about pain (time 0) and then 5, 30, 60, 90, and 120 minutes after foot massage. In the control group, pain and vital signs were also evaluated when the patients complained about pain (time 0) and again at 5, 30, 60, 90, and 120 minutes, in sync with the times when foot massage was completed in the experimental group. A patient information form was used to collect descriptive characteristics data of the patients, and the Short-Form McGill Pain Questionnaire was used to determine pain severity. Data were analyzed for frequencies, mean, standard deviation, chi-square, Student t, Pillai trace, and Bonferroni test. The results of the statistical analyses showed that patients in the experimental group experienced significantly less pain (p ≤ .001). Especially notable, patients in the experimental group showed a decrease in all vital signs 5 minutes after foot massage, but patients in the control group showed increases in vital signs except for heart rate at 5 minutes. The data obtained showed that foot massage in breast surgery patients was effective in postoperative pain management. Copyright © 2014 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

A teaching-learning sequence on a socio-scientific issue: analysis and evaluation of its implementation in the classroom*

NASA Astrophysics Data System (ADS)

Vázquez-Alonso, Ángel; Aponte, Abdiel; Manassero-Mas, María-Antonia; Montesano, Marisa

2016-07-01

This study examines the effectiveness of a teaching-learning sequence (TLS) to improve the understanding of the influences and interactions between a technology (mining) and society. The aim of the study is also to show the possibility of both teaching and assessing the most innovative issues and aspects of scientific competence and their impact on the understanding of the nature of science. The methodology used a quasi-experimental, pre-post-test design with a control group, with pre-post-test differences as the empirical indicators of improved understanding. Improvements were modest, as the empirical differences (pre-post and experimental-control group) were not large, but the experimental group scored more highly than the control group. The areas that showed improvement were identified. The paper includes the TLS itself and the standardized assessment tools that are functional and transferable to other researchers and teachers.

Scale and Time Effects in Hydraulic Fracturing.

DTIC Science & Technology

1984-07-01

An experimental study was conducted to determine the effects of scale and time on hydraulic fracturing in compacted samples of Teton Dam silt and...occurrence of hydraulic fracturing . Finite element analyses were used to investigate the possible effects of nonlinear soil behavior. Both experimental and...theoretical studies show that hydraulic fracturing can be initiated by seepage-induced forces without the presence of a preexisting flaw in the soil. (Author)

Experimental and clinical evidence for modification of hepatic ischaemia–reperfusion injury by N-acetylcysteine during major liver surgery

PubMed Central

Jegatheeswaran, Santhalingam; Siriwardena, Ajith K

2011-01-01

Background Hepatic ischaemia–reperfusion (I/R) injury occurs in both liver resectional surgery and in transplantation. The biochemistry of I/R injury involves short-lived oxygen free radicals. N-acetylcysteine (NAC) is a thiol-containing synthetic compound used in the treatment of acetaminophen toxicity. The present study is a detailed overview of the experimental and clinical evidence for the use of NAC as a pharmaco-protection agent in patients undergoing major liver surgery or transplantation. Methods A computerized search of the Medline, Embase and SCI databases for the period from 1st January 1988 to 31st December 2008 produced 40 reports. For clinical studies, the quality of reports was assessed according to the criteria reported by the Cochrane communication review group. Results Nineteen studies evaluated NAC in experimental liver I/R injury. NAC was administered before induction of ischaemia in 13. The most widely used concentration was 150 mg/kg by intravenous bolus. Fifteen studies report an improvement in outcome, predominantly a reduction in transaminase. Seven studies used an isolated perfused liver model with all showing improvement (predominantly an improvement in bile production after N-acetylcysteine). Two out of four transplantation models showed an improvement in hepatic function. Clinical studies in transplantation show a modest improvement in transaminase levels with no beneficial effect on either patient or graft survival. Conclusion N-acetylcysteine, given before induction of a liver I/R injury in an experimental model can ameliorate liver injury. Clinical outcome data are limited and there is currently little evidence to justify use either in liver transplantation or in liver resectional surgery. PMID:21241423

An Experimental and numerical Study for squeezing flow

NASA Astrophysics Data System (ADS)

Nathan, Rungun; Lang, Ji; Wu, Qianhong; Vucbmss Team

2017-11-01

We report an experimental and numerical study to examine the transient squeezing flow driven by sudden external impacts. The phenomenon is widely observed in industrial applications, e.g. squeeze dampers, or in biological systems, i.e. joints lubrication. However, there is a lack of investigation that captures the transient flow feature during the process. An experimental setup was developed that contains a piston instrumented with a laser displacement sensor and a pressure transducer. The heavy piston was released from rest, creating a fast compaction on the thin fluid gap underneath. The motion of the piston and the fluid pressure build-up was recorded. For this dynamic process, a CFD simulation was performed which shows excellent agreement with the experimental data. Both the numerical and experimental results show that, the squeezing flow starts with the inviscid limit when the viscous fluid effect has no time to appear, and thereafter becomes a developing flow, in which the inviscid core flow region decreases and the viscous wall region increases until the entire fluid gap is filled with viscous fluid flow. The study presented herein, filling the gap in the literature, will have broad impacts in industrial and biomedical applications. This research was supported by the National Science Foundation under Award 1511096, and supported by the Seed Grant from The Villanova Center for the Advancement of Sustainability in Engineering (VCASE).

The Research of Sunshine Sports to Psychologically Healthy to Shanghai University Students

ERIC Educational Resources Information Center

Huang-sheng, Kong

2012-01-01

This article used self-reporting inventory, self-test questionnaire, and other methods, chose four vocational schools in Shanghai for comparing experimental study of mental health, conducted experiments on experimental group and control group, and analyzed the current mental health of young students in Shanghai. It shows that the sunshine sports…

Quantum walk computation

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

Kendon, Viv

2014-12-04

Quantum versions of random walks have diverse applications that are motivating experimental implementations as well as theoretical studies. Recent results showing quantum walks are “universal for quantum computation” relate to algorithms, to be run on quantum computers. We consider whether an experimental implementation of a quantum walk could provide useful computation before we have a universal quantum computer.

Cascaded Bragg scattering in fiber optics.

PubMed

Xu, Y Q; Erkintalo, M; Genty, G; Murdoch, S G

2013-01-15

We report on a theoretical and experimental study of cascaded Bragg scattering in fiber optics. We show that the usual energy-momentum conservation of Bragg scattering can be considerably relaxed via cascade-induced phase-matching. Experimentally we demonstrate frequency translation over six- and 11-fold cascades, in excellent agreement with derived phase-matching conditions.

Experimental Evidence of the Knowledge Gap: Message Arousal, Motivation, and Time Delay

ERIC Educational Resources Information Center

Grabe, Maria Elizabeth; Yegiyan, Narine; Kamhawi, Rasha

2008-01-01

This study experimentally tested the knowledge gap from an information processing perspective. Specifically, knowledge acquisition was investigated under conditions of medium and low news message arousal, with time delay. Results show the persistence of a knowledge gap, particularly for low arousing messages. In fact, at low levels of message…

The effect of reflective writing interventions on the critical thinking skills and dispositions of baccalaureate nursing students.

PubMed

Naber, Jessica; Wyatt, Tami H

2014-01-01

The importance of critical thinking is well-documented by the American Association of Colleges of Nursing and the National League for Nursing. Reflective writing is often used to increase understanding and analytical ability. The lack of empirical evidence about the effect of reflective writing interventions on critical thinking supports the examination of this concept. Study objectives were: This study used an experimental, pretest-posttest design. The setting was two schools of nursing at universities in the southern United States. The convenience sample included 70 fourth-semester students in baccalaureate nursing programs. Randomly assigned control and experimental groups completed the California Critical Thinking Skills Test (CCTST) and the California Critical Thinking Dispositions Inventory Test (CCTDI). The experimental group completed six reflective writing assignments. Both groups completed the two tests again. Results showed that the experimental group had a significant increase (p=0.03) on the truthseeking subscale of the CCTDI when compared to the control group. The experimental group's scores increased on four CCTST subscales and were higher than the control group's on three CCTST subscales. The results of this study make it imperative for nursing schools to consider including reflective writing-especially assignments based on Paul's (1993) model-in nursing courses. If future studies, testing over longer periods of time, show significant increases in critical thinking, those interventions could be incorporated into nursing curriculum and change the way nurse educators evaluate students. Copyright © 2013 Elsevier Ltd. All rights reserved.

An ab initio study of the structure and atomic transport in bulk liquid Ag and its liquid-vapor interface

NASA Astrophysics Data System (ADS)

del Rio, Beatriz G.; González, David J.; González, Luis E.

2016-10-01

Several static and dynamic properties of bulk liquid Ag at a thermodynamic state near its triple point have been calculated by means of ab initio molecular dynamics simulations. The calculated static structure shows a very good agreement with the available experimental data. The dynamical structure reveals propagating excitations whose dispersion at long wavelengths is compatible with the experimental sound velocity. Results are also reported for other transport coefficients. Additional simulations have also been performed so as to study the structure of the free liquid surface. The calculated longitudinal ionic density profile shows an oscillatory behaviour, whose properties are analyzed through macroscopic and microscopic methods. The intrinsic X-ray reflectivity of the surface is predicted to show a layering peak associated to the interlayer distance.

Impact of an inquiry unit on grade 4 students' science learning

NASA Astrophysics Data System (ADS)

Di Mauro, María Florencia; Furman, Melina

2016-09-01

This paper concerns the identification of teaching strategies that enhance the development of 4th grade students' experimental design skills at a public primary school in Argentina. Students' performance in the design of relevant experiments was evaluated before and after an eight-week intervention compared to a control group, as well as the persistence of this learning after eight months. The study involved a quasi-experimental longitudinal study with pre-test/post-test/delayed post-test measures, complemented with semi-structured interviews with randomly selected students. Our findings showed improvement in the experimental design skills as well as its sustainability among students working with the inquiry-based sequence. After the intervention, students were able to establish valid comparisons, propose pertinent designs and identify variables that should remain constant. Contrarily, students in the control group showed no improvement and continued to solve the posed problems based on prior beliefs. In summary, this paper shows evidence that implementing inquiry-based units involving problems set in cross-domain everyday situations that combine independent student work with teacher guidance significantly improves the development of scientific skills in real classroom contexts.

Cryotherapy and ankle motion in chronic venous disorders

PubMed Central

Kelechi, Teresa J.; Mueller, Martina; Zapka, Jane G.; King, Dana E.

2013-01-01

This study compared ankle range of motion (AROM) including dorsiflexion, plantar flexion, inversion and eversion, and venous refill time (VRT) in leg skin inflamed by venous disorders, before and after a new cryotherapy ulcer prevention treatment. Fifty-seven-individuals participated in the randomized clinical trial; 28 in the experimental group and 29 received usual care only. Results revealed no statistically significant differences between the experimental and usual care groups although AROM measures in the experimental group showed a consistent, non-clinically relevant decrease compared to the usual care group except for dorsiflexion. Within treatment group comparisons of VRT results showed a statistically significant increase in both dorsiflexion and plantar flexion for patients with severe VRT in the experimental group (6.9 ± 6.8; p = 0.002 and 5.8 ± 12.6; p = 0.02, respectively). Cryotherapy did not further restrict already compromised AROM, and in some cases, there were minor improvements. PMID:23516043

[Maca (Lepidium meyenii Walp), a review of its biological properties].

PubMed

Gonzales, Gustavo F; Villaorduña, Leonidas; Gasco, Manuel; Rubio, Julio; Gonzales, Carla

2014-01-01

Maca (Lepidium meyenii) is a plant that grows above 4000 altitude meters in Peru's Central Andes; it has different varieties according to the color of the hypocotyl. This review summarizes the results of studies about the effects of maca on sexual function, spermatogenesis, female reproductive function, memory, depression and anxiety, and energy as well as effects on benign prostatic hyperplasia, osteoporosis and metabolic syndrome. Its anti-aging effect is also discussed as well as safety in consumption. Differences have been shown between the effects of the black, yellow and red maca varieties. Black maca shows the best results on spermatogenesis, memory and fatigue, while red maca is the variety that reverses the benign prostatic hyperplasia and experimentally induced osteoporosis. In addition, maca reduces the glucose levels, and its consumption is related to the lowering of blood pressure and an improved health score. Experimental studies have proven that short and long term consumption don't show in vivo and in vitro toxicity. Although experimental studies have shown that maca has diverse beneficial effects, more clinical studies are needed to confirm these results.

Host-guest interaction of ZnBDC-MOF + doxorubicin: A theoretical and experimental study

NASA Astrophysics Data System (ADS)

Vasconcelos, Iane B.; Wanderley, Kaline A.; Rodrigues, Nailton M.; da Costa, Nivan B.; Freire, Ricardo O.; Junior, Severino A.

2017-03-01

The incorporation of drugs in biodegradable polymeric particles is one of many processes that controllably and significantly increase their release and action. In this paper, we describe the synthesis and physicochemical characterization of ZnBDC-MOF + doxorubicin (DOXO@ZnBDC) and the system's effectiveness in the sustained release of the drug doxorubicin. An experimental and theoretical study is presented of the interaction between the [Zn(BDC)(H2O)2]n MOF and the drug doxorubicin (DOXO). The synthesis was characterized by elemental analysis and X-ray powder diffraction (XRPD). The experimental incorporation was accomplished and analyzed by Fourier transform infrared spectroscopy (FTIR), XRPD and UV-Vis (ultraviolet-visible) spectrophotometry. Based on an analysis of the doxorubicin release profile, our results suggest that the drug delivery system showed slower release than other systems under development. Studies of cytotoxicity by the MTT method showed good results for the system developed with antineoplastic doxorubicin, and together with the other results of this study, suggest the successful development of a MOF-based drug delivery system.

The Effect of Phosphatidylcholine and Deoxycholate Compound Injections to the Localized Adipose Tissue: An Experimental Study with a Murine Model

PubMed Central

Noh, Yongjoon

2012-01-01

Background Phosphatidylcholine (PPC) and deoxycholate (DCA) compound has been recently used for the purpose of partial lipolysis and is valued for its efficacy and lower invasiveness compared to liposuction and dermolipectomy used previously. In this article, the authors discuss the efficacy of the PPC dissolved in DCA via an experimental rat study model, along with suggesting a useful animal experimental model for the study of adipose tissue and lipolysis. Methods Bilateral inguinal fat pads of an experimental rat were elevated with the deep inferior epigastric vessel as the sole vascular pedicle. Normal saline was injected on one side as a control group and a PPC and DCA compound was injected on the other side. After 4 days, the rats were euthanized for microscopic tissue examination. The pathology was scored by a semiquantitative system in 4 categories: normal fat amount, fat necrosis, inflammatory activity, and stage of fibrosis. A Wilcoxon signed-rank test powered by SPSS packet program was used for statistical analysis and to determine significance. Results Microscopic examination was performed on the obtained samples, and the experimental data of all four categories showed significant histologic differences compared to the control group. All of the data also showed statistical significance by the Wilcoxon signedrank test (P<0.01). Conclusions In the inguinal fat pad rat model, the control group and the experimental group had a differed significantly in the amount of normal fat tissue, inflammation, necrosis, and fibrosis. We recommend the rat inguinal fat pad model used in this study, as it is likely to be useful in related research. PMID:23094238

[Experimental-morphologic study of bone tissue reaction to carbon-containing material implantation with initiated X-ray contrast property].

PubMed

Grigorian, A S; Nabiev, F Kh; Golovin, R V

2005-01-01

In experimental study on 15 rabbits (chinchilla) influence of titanium plates implanted lapped on adjacent tissues in the region of the lower jaw body (comparison group) and carbon material with added boron in the concentrations of 8 and 15% (the study group) was studied. Results of the experimental-morphological investigation show that carbon-based materials with boron addition (with its content 8 and 15%) did not impede adaptive rebuilding of bone tissues and in particular bone structure regeneration in the process of reactive rebuilding of the "maternal" bone. Moreover, as the result of reactive processes developing in osseous tissues after implantation of the tested materials their successful integration in surrounding tissue structures was detected.

Caprylate Salts Based on Amines as Volatile Corrosion Inhibitors for Metallic Zinc: Theoretical and Experimental Studies

PubMed Central

Valente, Marco A. G.; Teixeira, Deiver A.; Azevedo, David L.; Feliciano, Gustavo T.; Benedetti, Assis V.; Fugivara, Cecílio S.

2017-01-01

The interaction of volatile corrosion inhibitors (VCI), caprylate salt derivatives from amines, with zinc metallic surfaces is assessed by density functional theory (DFT) computer simulations, electrochemical impedance (EIS) measurements and humid chamber tests. The results obtained by the different methods were compared, and linear correlations were obtained between theoretical and experimental data. The correlations between experimental and theoretical results showed that the molecular size is the determining factor in the inhibition efficiency. The models used and experimental results indicated that dicyclohexylamine caprylate is the most efficient inhibitor. PMID:28620602

Placebo analgesia is not due to compliance or habituation: EEG and behavioural evidence.

PubMed

Watson, Alison; El-Deredy, Wael; Vogt, Brent A; Jones, Anthony K P

2007-05-28

This study was designed to resolve whether experimental placebo responses are due to either increased compliance or habituation. We stimulated both forearms and recorded laser-evoked potentials from 18 healthy volunteers treated on one arm with a sham analgesic cream and an inactive cream on the other (treatment group), and 13 volunteers with an inactive cream on both arms (controls). The treatment group showed a significant reduction in the pain ratings and laser-evoked potentials with both the sham and inactive creams. The control group showed no evidence of habituation to the laser stimulus. The results indicate that the reduction in pain during experimental placebo response is unlikely to be due to sensory habituation or compliance with the experimental instructions.

The Effectiveness of Hypnosis Intervention for Labor: An Experimental Study.

PubMed

Beevi, Zuhrah; Low, Wah Yun; Hassan, Jamiyah

2017-10-01

Hypnosis has been shown to help pregnant women experience improved labor and postpartum periods. The present study compares the differences between experimental (n = 23) and control groups (n = 22) on specific variables measured both during labor and 24 hr postpartum. The participants in the experimental group received the hypnosis intervention at weeks 16, 20, 28, and 36 of pregnancy, while those in the control group received only routine antenatal care. The data collected at the labor stage describe the length of the labor stage, pain relief used during labor, the method of delivery, and the type of assisted vaginal delivery. Within 24 hr of delivery, data on neonatal birth weight, neonatal Apgar scores, and self-reported pain were obtained. The labor stage results showed no significant differences in the length of the second and third stages of labor. Although the participants in the experimental group reported higher pain levels immediately prior to, during, and immediately after delivery, their use of pethidine during labor was significantly lower than the control group participants. None of the experimental group participants opted for an epidural, and they had a greater number of assisted vaginal deliveries than the control group participants. The 24 hr postpartum results showed that the neonates of the experimental group participants had nonsignificantly higher Apgar scores than those of the women in the control group. Group differences in neonatal weight were not significant. The results of the present study indicate that hypnosis is useful for assisting pregnant women during labor and the postpartum period.

[Experimental study of the effects of impulse-electric discharge on chemotaxis and cytoadhesion of urinary infection pathogens].

PubMed

Kuderinov, S K; Azizov, I S; Turgunov, E M; Shambilova, N A

2006-01-01

The aim of the experimental study was to evaluate effects of impulse-electric discharge in liquid on chemotaxis and cytoadhesion of urinary infection pathogens. Chemotaxis was determined in respect to the lung, liver, spleen, kidney, ureter, urinary bladder, urethra of white mice by S. Likholetov's modified method. Cytoadhesion was assessed by V. Brilis. The experiments show that the impulse-electric discharge holds promise for urological practice.

Bulk photovoltaic effect in epitaxial (K, Nb) substituted BiFeO3 thin films

NASA Astrophysics Data System (ADS)

Agarwal, Radhe; Zheng, Fan; Sharma, Yogesh; Hong, Seungbum; Rappe, Andrew; Katiyar, Ram

We studied the bulk photovoltaic effect in epitaxial (K, Nb) modified BiFeO3 (BKFNO) thin films using theoretical and experimental methods. Epitaxial BKFNO thin films were grown by pulsed laser deposition (PLD). First, we have performed first principles density function theory (DFT) using DFT +U method to calculate electronic band structure, including Hubbard-Ueff (Ueff =U-J) correction into Hamiltonian. The electronic band structure calculations showed a direct band gap at 1.9 eV and a defect level at 1.7 eV (in a 40 atom BKFNO supercell), sufficiently lower in comparison to the experimentally observed values. Furthermore, the piezoforce microscopy (PFM) measurements indicated the presence of striped polydomains in BKFNO thin films. Angle-resolved PFM measurements were also performed to find domain orientation and net polarization directions in these films. The experimental studies of photovoltaic effect in BKNFO films showed a short circuit current of 59 micro amp/cm2 and open circuit voltage of 0.78 V. We compared our experimental results with first principles shift current theory calculations of bulk photovoltaic effect (BPVE).The synergy between theory and experimental results provided a realization of significant role of BPVE in order to understand the photovoltaic mechanism in ferroelectrics.

Spatial encoding using the nonlinear field perturbations from magnetic materials.

PubMed

Karimi, Hirad; Dominguez-Viqueira, William; Cunningham, Charles H

2014-08-01

A proof-of-concept study was performed to assess the technical feasibility of using magnetic materials to generate spatial encoding fields. Spatially varying magnetic fields were generated by the placement of markers with different volume susceptibilities within the imaging volume. No linear gradients were used for spatial encoding during the signal acquisition. A signal-encoding model is described for reconstructing the images encoded with these field perturbations. Simulation and proof-of-concept experimental results are presented. Experiments were performed using field perturbations from a cylindrical marker as an example of the new encoding fields. Based on this experimental setup, annular rings were reconstructed from signals encoded with the new fields. Simulation results were presented for different acquisition parameters. Proof-of-concept was supported by the correspondence of regions in an image reconstructed from experimental data compared to those in a conventional gradient-echo image. Experimental results showed that inclusions of dimensions 1.5 mm in size could be resolved with the experimental setup. This study shows the technical feasibility of using magnetic markers to produce encoding fields. Magnetic materials will allow generating spatial encoding fields, which can be tailored to an imaging application with less complexity and at lower cost compared to the use of gradient inserts. Copyright © 2013 Wiley Periodicals, Inc.

Histopathological study of experimental and natural infections by Trypanosoma cruzi in Didelphis marsupialis.

PubMed

Araujo Carreira, J C; Jansen, A M; Deane, M P; Lenzi, H L

1996-01-01

Didelphis marsupialis, the most important sylvatic reservoir of Trypanosoma cruzi, can also maintain in their anal scent glands the multiplicative forms only described in the intestinal tract of triatomine bugs. A study of 21 experimentally and 10 naturally infected opossums with T. cruzi was undertaken in order to establish the histopathological pattern under different conditions. Our results showed that the inflammation was predominantly lymphomacrophagic and more severe in the naturally infected animals but never as intense as those described in Chagas' disease or in other animal models. The parasitism in both groups was always mild with very scarce amastigote nests in the tissues. In the experimentally infected animals, the inflammation was directly related to the presence of amastigotes nests. Four 24 days-old animals, still in embryonic stage, showed multiple amastigotes nests and moderate inflammatory reactions, but even so they survived longer and presented less severe lesions than experimentally infected adult mice. Parasites were found in smooth, cardiac and/or predominantly striated muscles, as well as in nerve cells. Differing from the experimentally infected opossums parasitism in the naturally infected animals predominated in the heart, esophagus and stomach. Parasitism of the scent glands did not affect the histopathological pattern observed in extraglandular tissues.

Reducing variation in a rabbit vaccine safety study with particular emphasis on housing conditions and handling.

PubMed

Verwer, Cynthia M; van der Ark, Arno; van Amerongen, Geert; van den Bos, Ruud; Hendriksen, Coenraad F M

2009-04-01

This paper describes the results of a study of the effects of modified housing conditions, conditioning and habituation on humans using a rabbit model for monitoring whole-cell pertussis vaccine (pWCV)-induced adverse effects. The study has been performed with reference to previous vaccine safety studies of pWCV in rabbits in which results were difficult to interpret due to the large variation in experimental outcome, especially in the key parameter deep-body temperature (T(b)). Certain stressful laboratory conditions, as well as procedures involving humans, e.g. blood sampling, inoculation and cage-cleaning, were hypothesized to cause this large variation. The results of this study show that under modified housing conditions rabbits have normal circadian body temperatures. This allowed discrimination of pWCV-induced adverse effects in which handled rabbits tended to show a dose-related increase in temperature after inoculation with little variance, whereas non-handled rabbits did not. Effects of experimental and routine procedures on body temperature were significantly reduced under modified conditions and were within the normal T(b) range. Handled animals reacted less strongly and with less variance to experimental procedures, such as blood sampling, injection and cage-cleaning, than non-handled rabbits. Overall, handling had a positive effect on the behaviour of the animals. Data show that the housing modifications have provided a more robust model for monitoring pWCV adverse effects. Furthermore, conditioning and habituation of rabbits to humans reduce the variation in experimental outcome, which might allow for a reduction in the number of animals used. In addition, this also reduces distress and thus contributes to refining this animal model.

Early Orthographic Influences on Phonemic Awareness Tasks: Evidence from a Preschool Training Study

ERIC Educational Resources Information Center

Castles, Anne; Wilson, Katherine; Coltheart, Max

2011-01-01

Experienced readers show influences of orthographic knowledge on tasks ostensibly tapping phonemic awareness. Here we draw on data from an experimental training study to demonstrate that even preschoolers show influences of their emerging orthographic abilities in such tasks. A total of 40 children were taught some letter-sound correspondences but…

Experimental study and empirical prediction of fuel flow parameters under air evolution conditions

NASA Astrophysics Data System (ADS)

Kitanina, E. E.; Kitanin, E. L.; Bondarenko, D. A.; Kravtsov, P. A.; Peganova, M. M.; Stepanov, S. G.; Zherebzov, V. L.

2017-11-01

Air evolution in kerosene under the effect of gravity flow with various hydraulic resistances in the pipeline was studied experimentally. The study was conducted at pressure ranging from 0.2 to 1.0 bar and temperature varying between -20°C and +20°C. Through these experiments, the oversaturation limit beyond which dissolved air starts evolving intensively from the fuel was established and the correlations for the calculation of pressure losses and air evolution on local loss elements were obtained. A method of calculating two-phase flow behaviour in a titled pipeline segment with very low mass flow quality and fairly high volume flow quality was developed. The complete set of empirical correlations obtained by experimental analysis was implemented in the engineering code. The software simulation results were repeatedly verified against our experimental findings and Airbus test data to show that the two-phase flow simulation agrees quite well with the experimental results obtained in the complex branched pipelines.

Thermo-selective Tm(x)Ti(1-x)O(2-x/2) nanoparticles: from Tm-doped anatase TiO2 to a rutile/pyrochlore Tm2Ti2O7 mixture. An experimental and theoretical study with a photocatalytic application.

PubMed

Navas, Javier; Sánchez-Coronilla, Antonio; Aguilar, Teresa; De los Santos, Desireé M; Hernández, Norge C; Alcántara, Rodrigo; Fernández-Lorenzo, Concha; Martín-Calleja, Joaquín

2014-11-07

This is an experimental and theoretical study of thulium doped TiO2 nanoparticles. From an experimental perspective, a method was used to synthesize thulium-doped TiO2 nanoparticles in which Tm(3+) replaces Ti(4+) in the lattice, which to our knowledge has neither been reported nor studied theoretically so far. Different proportions of anatase and rutile phases were obtained at different annealing temperatures, and XRD and Raman spectroscopy also revealed the presence of a pyrochlore phase (Tm2Ti2O7) at 1173 K. Thus, the structure of the Tm-doped nanoparticles was thermally-controlled. Furthermore, XPS showed the presence of Tm(3+) in the samples synthesized, which produces oxygen vacancies to maintain the local neutrality in the lattice. The presence of Tm(3+) in the samples led to changes in the UV-Vis absorption spectra, so they showed photoluminescence properties and new states in the band gap, which produce a new lower energy electronic transition than the main TiO2 one. Periodic DFT calculations were performed to understand the experimentally produced structures. The production of oxygen vacancies was analysed and the changes generated in the structure were fully detailed. The DOS and PDOS analyses confirmed the experimental results obtained using UV-Vis spectroscopy, and showed that the new electronic states in the band gap are due to interactions of the f state of Tm and the p state of O. Likewise, the charge study and the ELF analysis indicate that when Tm is introduced into the TiO2 structure, the Ti-O bond around the oxygen vacancy is strengthened. Finally, an example of a photocatalytic application was developed to show the high efficiency of the samples due to the heterojunction in the interfaces of the phases in the samples, which improved the charge separation and the good charge carrier mobility due to the presence of the pyrochlore phase, as was also shown theoretically.

Experimental pretesting of public health campaigns: a case study.

PubMed

Whittingham, Jill; Ruiter, Robert A C; Zimbile, Filippo; Kok, Gerjo

2008-01-01

The aim of the present study is to demonstrate the merits of evaluating new public health campaign materials in the developmental phase using an experimental design. This is referred to as experimental pretesting. In practice, most new materials are tested only after they have been distributed using nonexperimental or quasiexperimental designs. In cases where materials are pretested prior to distribution, pretesting is usually done using qualitative research methods such as focus groups. Although these methods are useful, they cannot reliably predict the effectiveness of new campaign materials in a developmental phase. Therefore, we suggest when pretesting new materials, not only qualitative research methods but also experimental research methods must be used. The present study discusses an experimental pretest study of new campaign materials intended for distribution in a national sexually transmitted infection (STI) AIDS prevention campaign in the Netherlands. The campaign material tested was the storyline of a planned television commercial on safe sex. A storyboard that consisted of drawings and text was presented to members of the target population, namely, students between the ages of 14 and 16 enrolled in vocational schools. Results showed positive effects on targeted determinants of safe sexual behavior. The advantages, practical implications, and limitations of experimental pretesting are discussed.

The effects of overhead transparency design on retention, recall, and application of data analysis content.

PubMed

Van Hoozer, H; Brink, P J; Oppliger, R

1989-04-01

This experimental study tested the effects of overhead transparency design in conjunction with live lecture on retention, recall, and application of data analysis content over three occasions using a Solomon Four-Group, pretest-posttest design. Pretested subjects showed significant (p less than .001) gains in test scores from pre to posttest. No significant differences were found in pretest scores between control and experimental treatment groups or among the posttest scores of either the experimental or control groups.

Effect of mirror therapy with tDCS on functional recovery of the upper extremity of stroke patients.

PubMed

Cho, Hyuk-Shin; Cha, Hyun-Gyu

2015-04-01

[Purpose] This study aimed to determine the effect of mirror therapy (MT) with transcranial direct current stimulation (tDCS) on the recovery of the upper extremity function of chronic stroke patients. [Subjects] Twenty-seven patients at least 6 months after stroke onset were divided randomly into an experimental group (14 patients) and a control group (13 patients). [Methods] All subjects received tDCS for 20 min followed by a 5 min rest. Then the experimental group received MT while the control group conducted the same exercises as the experimental group using a mirror that did not show the non-paretic upper extremity. The groups performed the same exercises for 20 min. All subjects received this intervention for 45-min three times a week for 6 weeks. [Results] After the intervention, the experimental group showed significant improvements in the box and block test (BBT), grip strength, and the Fugl-Meyer assessment (FMA), and a significant decrease in the Jebsen-Taylor test. The control group showed a significant increase in grip strength after the intervention, and a significant decrease in the Jebsen-Taylor test. Comparison of the result after the intervention revealed that the experimental group showed more significant increases in the BBT and grip strength than the control group. [Conclusion] These results show that MT with tDCS has a positive effect on the functional recovery of the upper extremity of stroke patients, through activating motor regions in the brain, and thus plays an important role in recovery of neuroplasticity.

Generating Students' Information Seeking Questions in the Scholar Lab: What Benefits Can We Expect from Inquiry Teaching Approaches?

ERIC Educational Resources Information Center

Torres, Tarcilo; Milicic, Beatriz; Soto, Carlos; Sanjose, Vicente

2013-01-01

Physics teachers use experimental devices to show students how scientific concepts, principles, and laws are applied to understand the real world. This paper studies question generation of secondary and under-graduate university students when they are confronted with experimental devices in different but usual teaching situations: reading about…

Does Negative Mood Influence Self-Report Assessment of Individual and Relational Measures? An Experimental Analysis

ERIC Educational Resources Information Center

Heene, Els; De Raedt, Rudi; Buysse, Ann; Van Oost, Paulette

2007-01-01

The present study was designed to test the influence of negative mood on the self-report of individual and relational correlates of depression and marital distress. The authors applied a combined experimental mood induction procedure, based on music, autobiographical recall, and environmental manipulation. Results showed that the mood manipulation…

[Trends in nursing research in Korea: research trends for studies published from the inaugural issue to 2010 in the Journal of Korean Academy of Nursing and the journals published by member societies under Korean Academy of Nursing Science].

PubMed

Choe, Myoung Ae; Kim, Nam Cho; Kim, Kyung Mi; Kim, Sung Jae; Park, Kyung Sook; Byeon, Young Soon; Shin, Sung Rae; Yang, Soo; Lee, Kyung Sook; Lee, Eun Hyun; Lee, In Sook; Lee, Tae Wha; Cho, Myung Ok; Kim, Jin Hak

2014-10-01

The purpose of this study was to identify trends for studies published in the Journal of Korean Academy of Nursing and journals published by member societies from inaugural issues to 2010. A total of 6890 studies were analyzed using descriptive statistics. Quantitative studies accounted for 83.6% while qualitative studies accounted for 14.4%. Most frequently used research designs were quasi-experimental (91.1%) for experimental research and survey (85.2%) for non-experimental research. Most frequent study participants were healthy people (35.8%), most frequent nursing interventions, nursing skills (53.5%), and 39.8% used knowledge, attitude and behavior outcomes for dependent variables. Most frequently used keyword was elderly. Survey studies decreased from 1991 to 2010 by approximately 50%, while qualitative studies increased by about 20%. True experimental research (1.2%) showed no significant changes. Studies focusing on healthy populations increased from 2001-2005 (37.5%) to 2006-2010 (41.0%). From 1970 to 2010, studies using questionnaire accounted for over 50% whereas physiological measurement, approximately 5% only. Experimental studies using nursing skill interventions increased from 1970-1980 (30.4%) to 2006-2010 (64.0%). No significant changes were noted in studies using knowledge, attitude and behavior (39.9%) as dependent variables. The results suggest that further expansion of true experimental, qualitative studies and physiological measurements are needed.

Experimental Study of Damage Evolution in Circular Stirrup-Confined Concrete

PubMed Central

Li, Zuohua; Peng, Zhihan; Teng, Jun; Wang, Ying

2016-01-01

This paper presents an experimental study on circular stirrup-confined concrete specimens under uniaxial and monotonic load. The effects of stirrup volume ratio, stirrup yield strength and concrete strength on damage evolution of stirrup-confined concrete were investigated. The experimental results showed that the strength and ductility of concrete are improved by appropriate arrangement of the stirrup confinement. Firstly, the concrete damage evolution can be relatively restrained with the increase of the stirrup volume ratio. Secondly, higher stirrup yield strength usually causes larger confining pressures and slower concrete damage evolution. In contrast, higher concrete strength leads to higher brittleness, which accelerates the concrete damage evolution. A plastic strain expression is obtained through curve fitting, and a damage evolution equation for circular stirrup-confined concrete is proposed by introducing a confinement factor (C) based on the experimental data. The comparison results demonstrate that the proposed damage evolution model can accurately describe the experimental results. PMID:28773402

Experimental Study of Damage Evolution in Circular Stirrup-Confined Concrete.

PubMed

Li, Zuohua; Peng, Zhihan; Teng, Jun; Wang, Ying

2016-04-08

This paper presents an experimental study on circular stirrup-confined concrete specimens under uniaxial and monotonic load. The effects of stirrup volume ratio, stirrup yield strength and concrete strength on damage evolution of stirrup-confined concrete were investigated. The experimental results showed that the strength and ductility of concrete are improved by appropriate arrangement of the stirrup confinement. Firstly, the concrete damage evolution can be relatively restrained with the increase of the stirrup volume ratio. Secondly, higher stirrup yield strength usually causes larger confining pressures and slower concrete damage evolution. In contrast, higher concrete strength leads to higher brittleness, which accelerates the concrete damage evolution. A plastic strain expression is obtained through curve fitting, and a damage evolution equation for circular stirrup-confined concrete is proposed by introducing a confinement factor ( C ) based on the experimental data. The comparison results demonstrate that the proposed damage evolution model can accurately describe the experimental results.

Spectroscopic and theoretical investigation of oxali-palladium interactions with β-lactoglobulin.

PubMed

Ghalandari, Behafarid; Divsalar, Adeleh; Saboury, Ali Akbar; Haertlé, Thomas; Parivar, Kazem; Bazl, Roya; Eslami-Moghadam, Mahbube; Amanlou, Massoud

2014-01-24

The possibility of using a small cheap dairy protein, β-lactoglobulin (β-LG), as a carrier for oxali-palladium for drug delivery was studied. Their binding in an aqueous solution at two temperatures of 25 and 37°C was investigated using spectroscopic techniques in combination with a molecular docking study. Fluorescence intensity changes showed combined static and dynamic quenching during β-LG oxali-palladium binding, with the static mode being predominant in the quenching mechanism. The binding and thermodynamic parameters were determined by analyzing the results of quenching and those of the van't Hoff equation. According to obtained results the binding constants at two temperatures of 25 and 37°C are 3.3×10(9) M(-1) and 18.4×10(6) M(-1) respectively. Fluorescence resonance energy transfer (FRET) showed that the experimental results and the molecular docking results were coherent. An absence change of β-LG secondary structure was confirmed by the CD results. Molecular docking results agreed fully with the experimental results since the fluorescence studies also revealed the presence of two binding sites with a negative value for the Gibbs free energy of binding of oxali-palladium to β-LG. Furthermore, molecular docking and experimental results suggest that the hydrophobic effect plays a critical role in the formation of the oxali-palladium complex with β-LG. This agreement between molecular docking and experimental results implies that docking studies may be a suitable method for predicting and confirming experimental results, as shown in this study. Hence, the combination of molecular docking and spectroscopy methods is an effective innovative approach for binding studies, particularly for pharmacophores. Copyright © 2013 Elsevier B.V. All rights reserved.

[An experimental study of effects of active-heating-system for extravehicular spacesuit gloves on working performance].

PubMed

Ding, Li; Han, Long-zhu; Yang, Chun-xin; Yang, Feng; Yuan, Xiu-gan

2005-02-01

To observe the effects of active heating system for spacesuit gloves on extravehicular working performance. After analyzing the factors with gloves influence on the working performance, the effects of active heating system for gloves were studied experimentally with aspects to fatigue, hand strength, dexterity and tactile sensing. 1) Heating-system had not influence to grip; 2) Heating-system had 17% influence to fatigue except specific person; 3) Nut assembly and nipping pin showed that heating-system had little influence to dexterity; 4) Apperceiving shape of object and two-point distance showed heating-system had little influence to tactility. The active heating method is rational and has little influence on working performance.

Correlation between expression of CatSper family and sperm profiles in the adult mouse testis following Iranian Kerack abuse.

PubMed

Amini, M; Shirinbayan, P; Behnam, B; Roghani, M; Farhoudian, A; Joghataei, M T; Koruji, M

2014-05-01

Illicit drug use can be an important cause of male infertility. The aim of this study was to investigate the effects of an Iranian illicit drug, Kerack, on sperm parameters, testicular structure and CatSper genes expression of mice. In this study, 25 male mice were divided into five groups consisting of control, sham and three experimental groups. All animal in experimental groups were addicted to Kerack for 7 days. These experimental groups include experimental I which was given Kerack at a dose of 5 mg/kg, experimental II, 35 mg/kg and experimental III, 70 mg/kg, intraperitoneally twice a day for a period of 35 days. Mice were then sacrificed and spermatozoas were removed from cauda epididymis and analyzed for count, motility, morphology (normal/abnormal) and viability. Right testes were removed, weighed and processed for light microscopic studies whereas left testes removed were subjected to total mRNA extraction for using in real-time PCR (RT-PCR). The results were analyzed by performing anova (Tukey's tests) and Pearson correlation coefficient. Sperm parameters and seminiferous epithelium thickness were decreased in experimental groups (dose-dependently) vs. sham and control groups (p < 0.05). RT-PCR results showed that CatSper 2, 3, 4 genes expressions were reduced with 35 and 70 mg/kg injected Kerack when compared with control testes (p ≤ 0.05). However, CatSper1 expression was only reduced with high dose injected Kerack (70 mg/kg) in comparison to control testes (p ≤ 0.05). This study shows the deleterious effects of Kerack used in Iran on testis structure and sperm parameters in general, and particularly sperm morphology in adult mouse. It could down-regulate the expression of CatSper genes, resulting in depression of sperm motility. © 2014 American Society of Andrology and European Academy of Andrology.

[Experimental study of the collagen matrix for increase the gums using a 3D-modeling].

PubMed

Baulin, I M; Badalyan, V A; Ryakhovsky, A N

2015-01-01

In an experimental study on mini-pigs demonstrated that the use of collagen matrix Mucograft open method leads to the formation of mature connective tissue around the implants, more pronounced after 70 days, and the width of attached mucosa already 45th day (from 4.4 ± 0.3 to 7.7 ± 0.5 mm) is comparable to that of free gingival graft. Three-dimensional computer modeling of jaws experimental animals showed the soft tissue augmentation by 0.8 ± 0.1 cm3 after use of collagen matrix Mucograft and 1.1 ± 0.12 cm3 after free gingival graft.

IR-IR Conformation Specific Spectroscopy of Na+(Glucose) Adducts

NASA Astrophysics Data System (ADS)

Voss, Jonathan M.; Kregel, Steven J.; Fischer, Kaitlyn C.; Garand, Etienne

2018-01-01

We report an IR-IR double resonance study of the structural landscape present in the Na+(glucose) complex. Our experimental approach involves minimal modifications to a typical IR predissociation setup, and can be carried out via ion-dip or isomer-burning methods, providing additional flexibility to suit different experimental needs. In the current study, the single-laser IR predissociation spectrum of Na+(glucose), which clearly indicates contributions from multiple structures, was experimentally disentangled to reveal the presence of three α-conformers and five β-conformers. Comparisons with calculations show that these eight conformations correspond to the lowest energy gas-phase structures with distinctive Na+ coordination. [Figure not available: see fulltext.

[A preliminary study for the effect of nano hydroxyapatite on human adipose-derived mesenchymal stem cells mixture 3D bio-printing].

PubMed

Song, Y; Wang, X F; Wang, Y G; Dong, F; Lv, P J

2016-10-18

To study the effect of nano hydroxyapatite on human adipose-derived mesenchymal stem cells(hASCs) mixture 3D bio-printing for cells' proliferation and osteogenesis. P5 hASCs were used as seed cells, 10 g/L nano hydroxyapatite was added into the cell-sodium alginate-gelatin mixture (concentration: 20 g/L sodium alginate, 80 g/L gelatin; cell density: 1×10 6 /mL), then the mixture was printed by 3D bio-printer as the experimental group. And the cell-sodium alginate-gelatin mixture without nano hydroxyapatite was printed as the control group. Respectively, both the experimental and control groups were detected by microscope, CCK-8, Western blot and PCR at certain time pointsafter being printed, whose cells' proliferation and osteogenic differentiation were analyzed. The microscopic observation and CCK-8 results showed that the cells of the experimental group and the control group both had a good proliferation 24 h and 7 d after being printed. The Western blot results showed that 14 d after printing, the expression of Runt-related transcription factor 2 (RUNX2) had no statistical difference between the experimental group and control group. The PCR results showed that 14 d after printing, the expression of osteogenesis-related genes (RUNX2, osterix, and osteocalcin) was significantly higher in the experimental group than in the control group. Nano hydroxyapatite can increase osteogenic differentiation of the hASCs mixture after bio-printing, in which the cells still have a good proliferation.

Experimental and numerical analysis on noise reduction in a multi-blade centrifugal fan

NASA Astrophysics Data System (ADS)

Chen, X. J.; Y Cao, T.; Su, J.; Qin, G. L.

2013-12-01

In this work, analysis on noise source and reduction in a multi-blade centrifugal fan used for air-conditioners was carried out by experimental and numerical methods. Firstly, an experimental system using microphone mounted on volute surface for measuring surface pressure fluctuations of volute was designed and introduced, then surface pressure fluctuations of the whole volute for a multi-blade centrifugal fan were measured by this system, and the inlet noise for this fan was also obtained. And then, based on the experimental results, the aerodynamic noise source of the studied fan was analysed. The surface pressure fluctuations of the volute showed that there were largest surface pressure fluctuations near the volute tongue, and peaks appeared at the Blade Passing Frequency (BPF). The spectra of fan inlet noise showed that the peaks also appeared at BPF, and noise levels in a wide range of frequency were also larger. Secondly, the internal flow of the fan was simulated by commercial software under the same conditions with the experiment, and then the fluid flow and acoustic power field were obtained and discussed. The contours of acoustic power level showed that the larger noise was generated at the impeller area close to the outlet of scroll and at the volute tongue, which is same as that from experiment. Based on all of the results, we can find that the vortex noise is an important part of fan noise for the studied fan, and the rotation noise also cannot be neglected. Finally, several reduction methods that are thought to be effective based on experimental and numerical results were suggested.

Experimental Errors in QSAR Modeling Sets: What We Can Do and What We Cannot Do.

PubMed

Zhao, Linlin; Wang, Wenyi; Sedykh, Alexander; Zhu, Hao

2017-06-30

Numerous chemical data sets have become available for quantitative structure-activity relationship (QSAR) modeling studies. However, the quality of different data sources may be different based on the nature of experimental protocols. Therefore, potential experimental errors in the modeling sets may lead to the development of poor QSAR models and further affect the predictions of new compounds. In this study, we explored the relationship between the ratio of questionable data in the modeling sets, which was obtained by simulating experimental errors, and the QSAR modeling performance. To this end, we used eight data sets (four continuous endpoints and four categorical endpoints) that have been extensively curated both in-house and by our collaborators to create over 1800 various QSAR models. Each data set was duplicated to create several new modeling sets with different ratios of simulated experimental errors (i.e., randomizing the activities of part of the compounds) in the modeling process. A fivefold cross-validation process was used to evaluate the modeling performance, which deteriorates when the ratio of experimental errors increases. All of the resulting models were also used to predict external sets of new compounds, which were excluded at the beginning of the modeling process. The modeling results showed that the compounds with relatively large prediction errors in cross-validation processes are likely to be those with simulated experimental errors. However, after removing a certain number of compounds with large prediction errors in the cross-validation process, the external predictions of new compounds did not show improvement. Our conclusion is that the QSAR predictions, especially consensus predictions, can identify compounds with potential experimental errors. But removing those compounds by the cross-validation procedure is not a reasonable means to improve model predictivity due to overfitting.

Experimental Errors in QSAR Modeling Sets: What We Can Do and What We Cannot Do

PubMed Central

2017-01-01

Numerous chemical data sets have become available for quantitative structure–activity relationship (QSAR) modeling studies. However, the quality of different data sources may be different based on the nature of experimental protocols. Therefore, potential experimental errors in the modeling sets may lead to the development of poor QSAR models and further affect the predictions of new compounds. In this study, we explored the relationship between the ratio of questionable data in the modeling sets, which was obtained by simulating experimental errors, and the QSAR modeling performance. To this end, we used eight data sets (four continuous endpoints and four categorical endpoints) that have been extensively curated both in-house and by our collaborators to create over 1800 various QSAR models. Each data set was duplicated to create several new modeling sets with different ratios of simulated experimental errors (i.e., randomizing the activities of part of the compounds) in the modeling process. A fivefold cross-validation process was used to evaluate the modeling performance, which deteriorates when the ratio of experimental errors increases. All of the resulting models were also used to predict external sets of new compounds, which were excluded at the beginning of the modeling process. The modeling results showed that the compounds with relatively large prediction errors in cross-validation processes are likely to be those with simulated experimental errors. However, after removing a certain number of compounds with large prediction errors in the cross-validation process, the external predictions of new compounds did not show improvement. Our conclusion is that the QSAR predictions, especially consensus predictions, can identify compounds with potential experimental errors. But removing those compounds by the cross-validation procedure is not a reasonable means to improve model predictivity due to overfitting. PMID:28691113

Study of Surface Wave Propagation in Fluid-Saturated Porous Solids.

NASA Astrophysics Data System (ADS)

Azcuaga, Valery Francisco Godinez

1995-01-01

This study addresses the surface wave propagation phenomena on fluid-saturated porous solids. The analytical method for calculation of surface wave velocities (Feng and Johnson, JASA, 74, 906, 1983) is extended to the case of a porous solid saturated with a wetting fluid in contact with a non-wetting fluid, in order to study a material combination suitable for experimental investigation. The analytical method is further extended to the case of a non-wetting fluid/wetting fluid-saturated porous solid interface with an arbitrary finite surface stiffness. These extensions of the analytical method allows to theoretically study surface wave propagation phenomena during the saturation process. A modification to the 2-D space-time reflection Green's function (Feng and Johnson, JASA, 74, 915, 1983) is introduced in order to simulate the behavior of surface wave signals detected during the experimental investigation of surface wave propagation on fluid-saturated porous solids (Nagy, Appl. Phys. Lett., 60, 2735, 1992). This modification, together with the introduction of an excess attenuation for the Rayleigh surface mode, makes it possible to explain the apparent velocity changes observed on the surface wave signals during saturation. Experimental results concerning the propagation of surface waves on an alcohol-saturated porous glass are presented. These experiments were performed at frequencies of 500 and 800 kHz and show the simultaneous propagation of the two surface modes predicted by the extended analytical method. Finally an analysis of the displacements associated with the different surface modes is presented. This analysis reveals that it is possible to favor the generation of the Rayleigh surface mode or of the slow surface mode, simply by changing the type of transducer used in the generation of surface waves. Calculations show that a shear transducer couples more energy into the Rayleigh mode, whereas a longitudinal transducer couples more energy into the slow surface mode. Experimental results obtained with the modified experimental system show a qualitative agreement with the theoretical predictions.

Debonding of Stitched Composite Joints: Testing and Analysis

NASA Technical Reports Server (NTRS)

Glaessgen, E. H.; Raju, I. S.; Poe, C. C., Jr.

1999-01-01

The effect of stitches on the failure of a single lap joint configuration was determined in a combined experimental and analytical study. The experimental study was conducted to determine debond growth under static monotonic loading. The stitches were shown to delay the initiation ofthe debond and provide load transfer beyond the load necessary to completely debond the stitched lap joint. The strain energy release rates at the debond front were calculated using a finite element-based technique. Models of the unstitched configuration showed significant values of modes I and II across the width of the joint and showed that mode III is zero at the centerline but increases near the free edge. Models of the stitched configuration showed that the stitches effectively reduced mode I to zero, but had less of an effect on modes II and III.

Experimental investigation of convective heat transfer agumentation using Al2O3/water nanofluid in circular pipe

NASA Astrophysics Data System (ADS)

Chavan, Durgeshkumar; Pise, Ashok T.

2015-09-01

In the present paper, experimental study is performed to investigate convective heat transfer and flow characteristics of nanofluids through a circular tube. The heat transfer coefficient and friction factor of the γ-Al2O3-water nanofluid flowing through a pipe of 10 mm inner ID and 1 m in length, with constant wall temperature under turbulent flow conditions are investigated. Experiments are conducted with 30 nm size γ-Al2O3 nanoparticle with a volume fraction between 0.1 and to 1.0 and Reynolds number between 8,000 and 14,000. Experimental results emphasize the heat transfer enhancement with the increase in a Reynolds number or nanoparticle volume fraction. The maximum enhancement of 36 % in the heat transfer coefficient for a Reynolds number of 8,550, by using nanofluid with 1.0 vol% was observed compared with base fluid. Experimental measurement also shows the considerable increase in the pressure drop with small addition of nanoparticles in base fluid. Experimental results of nanofluids were compared with existing convective heat transfer correlations in the turbulent regime. Comparison shows that Maiga's correlation has close agreement with experimental results in comparison with Dittus Boelter correlation.

A study of the thermoregulatory characteristics of a liquid-cooled garment with automatic temperature control based on sweat rate: Experimental investigation and biothermal man-model development

NASA Technical Reports Server (NTRS)

Chambers, A. B.; Blackaby, J. R.; Miles, J. B.

1973-01-01

Experimental results for three subjects walking on a treadmill at exercise rates of up to 590 watts showed that thermal comfort could be maintained in a liquid cooled garment by using an automatic temperature controller based on sweat rate. The addition of head- and neck-cooling to an Apollo type liquid cooled garment increased its effectiveness and resulted in greater subjective comfort. The biothermal model of man developed in the second portion of the study utilized heat rates and exchange coefficients based on the experimental data, and included the cooling provisions of a liquid-cooled garment with automatic temperature control based on sweat rate. Simulation results were good approximations of the experimental results.

Nonlinear analysis of concrete beams strengthened by date palm fibers

NASA Astrophysics Data System (ADS)

Bouzouaid, Samia; Kriker, Abdelouahed

2017-02-01

The behaviour of concrete beams strengthened with date palm fibers was studied by Nonlinear Finite Element Analysis using ANSYS software. Five beams that were experimentally tested in a previous research were considered. The results obtained from the ANSYS finite element analysis are compared with the experimental data for the five beams with different amounts of fibres, ranging from 0.2% to 0.5% by a step equal to 0.1% and with a fibre length of 0.04 m. The results obtained by FEA showed good agreement with those obtained by the experimental program. This research demonstrates the ability of FEA in predicting the behaviour of beams strengthened with Date Palm fibers. It will help researchers in studying beams with different configurations without the need to go through the lengthy experimental testing programs.

Comparison between project-based learning and discovery learning toward students' metacognitive strategies on global warming concept

NASA Astrophysics Data System (ADS)

Tumewu, Widya Anjelia; Wulan, Ana Ratna; Sanjaya, Yayan

2017-05-01

The purpose of this study was to know comparing the effectiveness of learning using Project-based learning (PjBL) and Discovery Learning (DL) toward students metacognitive strategies on global warming concept. A quasi-experimental research design with a The Matching-Only Pretest-Posttest Control Group Design was used in this study. The subjects were students of two classes 7th grade of one of junior high school in Bandung City, West Java of 2015/2016 academic year. The study was conducted on two experimental class, that were project-based learning treatment on the experimental class I and discovery learning treatment was done on the experimental class II. The data was collected through questionnaire to know students metacognitive strategies. The statistical analysis showed that there were statistically significant differences in students metacognitive strategies between project-based learning and discovery learning.

Promoting middle school students’ abstract-thinking ability through cognitive apprenticeship instruction in mathematics learning

NASA Astrophysics Data System (ADS)

Yusepa, B. G. P.; Kusumah, Y. S.; Kartasasmita, B. G.

2018-01-01

The aim of this study is to get an in-depth understanding of students’ abstract-thinking ability in mathematics learning. This study was an experimental research with pre-test and post-test control group design. The subject of this study was eighth-grade students from two junior high schools in Bandung. In each schools, two parallel groups were selected and assigned into control and experimental groups. The experimental group was exposed to Cognitive Apprenticeship Instruction (CAI) treatment, whereas the control group was exposed to conventional learning. The results showed that abstract-thinking ability of students in experimental group was better than that of those in control group in which it could be observed from the overall and school level. It could be concluded that CAI could be a good alternative learning model to enhance students’ abstract-thinking ability.

Effectiveness of constructivist approach on students achievement in mathematics: A case study at primary school in Kuantan, Pahang

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.

Carbon Isotopes of Alkanes in Hydrothermal Abiotic Organic Synthesis Processes at High Temperatures and Pressures: An Experimental Study

NASA Technical Reports Server (NTRS)

Fu, Qi; Socki, Richard A.; Niles, Paul B.

2010-01-01

Observation of methane in the Martian atmosphere has been reported by different detection techniques [1-4]. With more evidence showing extensive water-rock interaction in Martian history [5-7], abiotic formation by Fischer-Tropsch Type (FTT) synthesis during serpentization reactions may be one possible process responsible for methane generation on Mars [8, 9]. While the experimental studies performed to date leave little doubt that chemical reactions exist for the abiotic synthesis of organic compounds by mineral surface-catalyzed reactions [10-12], little is known about the reaction pathways by which CO2 and/or CO are reduced under hydrothermal conditions. Carbon and hydrogen isotope measurements of alkanes have been used as an effective tool to constrain the origin and reaction pathways of hydrocarbon formation. Alkanes generated by thermal breakdown of high molecular weight organic compounds have carbon and hydrogen isotopic signatures completely distinct from those formed abiotically [13-15]. Recent experimental studies, however, showed that different abiogenic hydrocarbon formation processes (e.g., polymerization vs. depolymerization) may have different carbon and hydrogen isotopic patterns [16]. Results from previous experiments studying decomposition of higher molecular weight organic compounds (lignite) also suggested that pressure could be a crucial factor affecting fractionation of carbon isotopes [17]. Under high pressure conditions, no experimental data are available describing fractionation of carbon isotope during mineral catalyzed FTT synthesis. Thus, hydrothermal experiments present an excellent opportunity to provide the requisite carbon isotope data. Such data can also be used to identify reaction pathways of abiotic organic synthesis under experimental conditions.

Experimental studies of the near threshold production of K{sup +}K{sup -} pairs at COSY-11

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

Gil, Damian; Smyrski, Jerzy

2007-11-07

This paper sums up experimental studies of the near threshold production of K{sup +}K{sup -} pairs at COSY-11. The total cross section of the reaction pp{yields}ppK{sup +}K{sup -} has been measured at five excess energies below the {phi} production threshold with the magnetic spectrometer COSY-11. The new data show a significant enhancement of the total cross section compared to pure phase space expectations.

Core stabilization exercise with real-time feedback for chronic hemiparetic stroke: a pilot randomized controlled trials.

PubMed

Chung, Eunjung; Lee, Byoung-Hee; Hwang, Sujin

2014-01-01

The purpose of this study was to examine the feasibility of core stabilization exercise with real-time feedback on balance and gait function in patients with chronic hemiparetic stroke. Nineteen stroke subjects were enrolled in this study. The patients were randomly divided into the experimental (n = 10) and control groups (n = 9). Subjects in the experimental group performed core stabilization exercise with real-time feedback training for 30 minutes per day during a period of six weeks. Subjects in the control group performed core stabilization exercise during the same period. This study assessed the kinematic parameters using a portable walkway system, and timed up-and-go test. Gait velocity showed significantly greater improvement in the experimental group (7.3 ± 5.0 sec) than in the control group (-0.7 ± 10.6). Stride length showed significantly greater increase in the experimental group (13.2 ± 7.9 on the affected side and 12.6 ± 8.0 on the less affected side) than the control group (3.5 ± 8.7 on the affected side and 3.4 ± 8.5 on the less affected side). After training, change in results on the timed up and go test was significantly greater in the experimental group than in the control group. Core stabilization exercise using real-time feedback produces greater improvement in gait performance in chronic hemiparetic stroke patients than core stabilization exercise only.

Robert Dicke and the naissance of experimental gravity physics, 1957-1967

NASA Astrophysics Data System (ADS)

Peebles, Phillip James Edwin

2017-06-01

The experimental study of gravity became much more active in the late 1950s, a change pronounced enough be termed the birth, or naissance, of experimental gravity physics. I present a review of developments in this subject since 1915, through the broad range of new approaches that commenced in the late 1950s, and up to the transition of experimental gravity physics to what might be termed a normal and accepted part of physical science in the late 1960s. This review shows the importance of advances in technology, here as in all branches of natural science. The role of contingency is illustrated by Robert Dicke's decision in the mid-1950s to change directions in mid-career, to lead a research group dedicated to the experimental study of gravity. The review also shows the power of nonempirical evidence. Some in the 1950s felt that general relativity theory is so logically sound as to be scarcely worth the testing. But Dicke and others argued that a poorly tested theory is only that, and that other nonempirical arguments, based on Mach's Principle and Dirac's Large Numbers hypothesis, suggested it would be worth looking for a better theory of gravity. I conclude by offering lessons from this history, some peculiar to the study of gravity physics during the naissance, some of more general relevance. The central lesson, which is familiar but not always well advertised, is that physical theories can be empirically established, sometimes with surprising results.

Logo therapy effect on anxiety and depression in mothers of children with cancer

PubMed Central

Delavari, H; Nasirian, M; Baezegar bafrooei, K

2014-01-01

Background Cancer diagnosis among children can cause high stress and anxiety in parents, and they may lose their life expectancy. The present study investigated the effectiveness of Logo therapy on anxiety and depression among mothers of children with cancer. Materials and Methods This study was conducted by a semi-pilot method using pre-test and post-test with a control experimental group. Therapy sessions were held during 9 sessions of Logo therapy training for 90 minutes. The participants of this study were selected among 30 mothers of children with cancer and using sampling method in Yazd hospitals. The participants divided randomly into two groups: experimental and control. Participants in both experimental and control group completed questionnaires on Beck Anxiety Inventory and Beck Depression Inventory before and after training. Results The results showed that the index of depression and anxiety in control and experimental groups are 32.3, 6.63, 7.4 and 6.75, respectively. So, the level among the experimental group has been decreased after intervention of Logotherapy training and a significant difference occurred in the pre-post test stages. The results showed that Logo Therapy has a significant effect in reducing anxiety and depression among mothers of children with cancer (p<0.05). Conclusion Regarding the efficiency of this approach to reduce anxiety and depression among mothers, this treatment is recommended to be practiced beside other cancer therapies, so they can practice the treatment process with a better mood and mentality. PMID:25002923

Toxic myopathy and acute hepatic necrosis in cattle caused by ingestion of Senna obtusifolia (sicklepod; coffee senna) in Brazil.

PubMed

Furlan, Fernando Henrique; Zanata, Carina; Damasceno, Everson Dos Santos; de Oliveira, Leonardo Pintar; da Silva, Leilane Aparecida; Colodel, Edson Moleta; Riet-Correa, Franklin

2014-12-15

The epidemiological, clinical and pathological findings of field and experimental Senna obtusifolia (sicklepod; coffee senna) poisoning in cattle are described. The low availability of good quality forage and high rate of infestation of pastures by S. obtusifolia were the factors that led to poisonous plant ingestion. In this study, the morbidity ranged between 2% and 27.9%, and the lethality was 100%. For the experimental study, six cattle were fed with the aerial parts of S. obtusifolia collected in three different seasons at 9%-38% of the animal's body weight. The experimental and field diseases were similar. The main clinical signs were diarrhea, reluctance to move, muscular weakness and recumbency. The gross findings included pale discoloration of the skeletal muscle. Microscopically, the affected cattle showed degeneration and necrosis of the skeletal muscles and occasionally of the cardiac muscles. Additionally, two cattle showed centrilobular hepatic necrosis. In this study, S. obtusifolia collected from the same farm showed seasonal variation in toxicity. Poisoning by S. obtusifolia is an important cause of death of cattle in the Central Western region of Brazil. The toxicosis caused by this plant is similar to S. occidentalis poisoning; however, in S. obtusifolia poisoning, acute hepatic necrosis is sometimes present. Copyright © 2014 Elsevier Ltd. All rights reserved.

Finite element strategies to satisfy clinical and engineering requirements in the field of percutaneous valves.

PubMed

Capelli, Claudio; Biglino, Giovanni; Petrini, Lorenza; Migliavacca, Francesco; Cosentino, Daria; Bonhoeffer, Philipp; Taylor, Andrew M; Schievano, Silvia

2012-12-01

Finite element (FE) modelling can be a very resourceful tool in the field of cardiovascular devices. To ensure result reliability, FE models must be validated experimentally against physical data. Their clinical application (e.g., patients' suitability, morphological evaluation) also requires fast simulation process and access to results, while engineering applications need highly accurate results. This study shows how FE models with different mesh discretisations can suit clinical and engineering requirements for studying a novel device designed for percutaneous valve implantation. Following sensitivity analysis and experimental characterisation of the materials, the stent-graft was first studied in a simplified geometry (i.e., compliant cylinder) and validated against in vitro data, and then in a patient-specific implantation site (i.e., distensible right ventricular outflow tract). Different meshing strategies using solid, beam and shell elements were tested. Results showed excellent agreement between computational and experimental data in the simplified implantation site. Beam elements were found to be convenient for clinical applications, providing reliable results in less than one hour in a patient-specific anatomical model. Solid elements remain the FE choice for engineering applications, albeit more computationally expensive (>100 times). This work also showed how information on device mechanical behaviour differs when acquired in a simplified model as opposed to a patient-specific model.

Angiotensin II Moderately Decreases Plasmodium Infection and Experimental Cerebral Malaria in Mice.

PubMed

Gallego-Delgado, Julio; Baravian, Charlotte; Edagha, Innocent; Ty, Maureen C; Ruiz-Ortega, Marta; Xu, Wenyue; Rodriguez, Ana

2015-01-01

Angiotensin II, a peptide hormone that regulates blood pressure, has been proposed as a protective factor against cerebral malaria based on a genetic analysis. In vitro studies have documented an inhibitory effect of angiotensin II on Plasmodium growth, while studies using chemical inhibitors of angiotensin II in mice showed protection against experimental cerebral malaria but not major effects on parasite growth. To determine whether the level of angiotensin II affects Plasmodium growth and/or disease outcome in malaria, elevated levels of angiotensin II were induced in mice by intradermal implantation of osmotic mini-pumps providing constant release of this hormone. Mice were then infected with P. berghei and monitored for parasitemia and incidence of cerebral malaria. Mice infused with angiotensin II showed decreased parasitemia seven days after infection. The development of experimental cerebral malaria was delayed and a moderate increase in survival was observed in mice with elevated angiotensin II, as confirmed by decreased number of cerebral hemorrhages compared to controls. The results presented here show for the first time the effect of elevated levels of angiotensin II in an in vivo model of malaria. The decreased pathogenesis observed in mice complements a previous human genetic study, reinforcing the hypothesis of a beneficial effect of angiotensin II in malaria.

Experimental and numerical analysis of penetration/removal response of endodontic instrument made of single crystal Cu-based SMA: comparison with NiTi SMA instruments

NASA Astrophysics Data System (ADS)

Vincent, M.; Xolin, P.; Gevrey, A.-M.; Thiebaud, F.; Engels-Deutsch, M.; Ben Zineb, T.

2017-04-01

This paper presents an experimental and numerical study showing that single crystal shape memory alloy (SMA) Cu-based endodontic instruments can lead to equivalent mechanical performances compared to NiTi-based instruments besides their interesting biological properties. Following a previous finite element analysis (FEA) of single crystal CuAlBe endodontic instruments (Vincent et al 2015 J. Mater. Eng. Perform. 24 4128-39), prototypes with the determined geometrical parameters were machined and experimentally characterized in continuous rotation during a penetration/removal (P/R) protocol in artificial canals. The obtained mechanical responses were compared to responses of NiTi endodontic files in the same conditions. In addition, FEA was conducted and compared with the experimental results to validate the adopted modeling and to evaluate the local quantities inside the instrument as the stress state and the distribution of volume fraction of martensite. The obtained results highlight that single crystal CuAlBe SMA prototypes show equivalent mechanical responses to its NiTi homologous prototypes in the same P/R experimental conditions.

ASSESSMENT OF THE POTENTIAL FOR TRANSPORT OF ...

EPA Pesticide Factsheets

Dioxins are very toxic contaminants and warrant study under a variety of experimental conditions. Studies were performed to evaluate the mobility of several of the dioxins in both soil columns as well as in batch experiments. The studies showed that the amount of chlorination did not necessarily control the partitioning of the dioxins, as expected, but also suggested that the structure or location where the Cl ion was attached to the benzene ring modified the hydrophobicity of the compound. Studies were performed with a variety of cosolvents which might mediate the movement of the Dioxin. The observed modification in mobility was consistent with existing theory for enhanced mobility with truly miscible solvents. Experimental data appears to show reversibility in the sorption process, but significantly limited by kinetics with 30 to 50 days reguired to release 50-90% of the contaminant. present information

Advanced electric propulsion research, 1989

NASA Technical Reports Server (NTRS)

Wilbur, Paul J.

1990-01-01

Results of an experimental study of the characteristics of ion thruster hollow cathodes operating at high discharge currents (up to 60 A) are presented in a companion report. This work shows that ions produced near the cathode orifice can acquire sufficient energy to induce the high sputter erosion rates on cathode potential surfaces that have been observed in ion thrusters. A mechanism by which these ions could be produced is also described. A second, brief study showing how a discharge chamber model developed previously can be applied to determine optimal values for one or more discharge chamber design parameters is presented. The experimental approach being used to study the plasma potential field and charge-exchange ion production rate downstream of the accelerator grid of an ion thruster is discussed and preliminary results are presented.

Bilateral increase in expression and concentration of tachykinin in a unilateral rabbit muscle overuse model that leads to myositis

PubMed Central

2013-01-01

Background Tachykinins can have pro-inflammatory as well as healing effects during tissue reorganization and inflammation. Recent studies report an up-regulation in the expression of the substance P (SP)-preferred receptor, the neurokinin-1 receptor, in marked muscle inflammation (myositis). There is, however, only very little information on the expression patterns and levels of tachykinins in this situation. Methods The tachykinin system was analyzed using a rabbit experimental model of muscle overuse, whereby unilateral muscle exercise in combination with electrical stimulation led to muscle derangement and myositis in the triceps surae muscle (experimental length 1–6 weeks). Evaluations were made for both parts of the muscle (soleus and gastrocnemius muscles) in experimental and non-experimental (contralateral) sides. Morphologic evaluation, immunohistochemistry, in situ hybridization and enzyme immunoassay (EIA) analyses were applied. Results Myositis and muscle derangement occurred focally not only in the experimental side but also in the non-experimental side. In the inflammatory areas (focal myositis areas), there were frequent nerve fibers showing tachykinin-like immunoreactivity and which were parts of nerve fascicles and which were freely dispersed in the tissue. Cells in the inflammatory infiltrates showed tachykinin-like immunoreactivity and tachykinin mRNA expression. Specific immunoreactivity and mRNA expression were noted in blood vessel walls of both sides, especially in focally affected areas. With increasing experimental length, we observed an increase in the degree of immunoreactivity in the vessel walls. The EIA analyses showed that the concentration of tachykinin in the tissue on both sides increased in a time-dependent manner. There was a statistical correlation in the concentration of tachykinin and the level of tachykinin immunoreactivity in the blood vessel walls between experimental and non-experimental sides. Conclusions The observations show an up-regulation of the tachykinin system bilaterally during muscle derangement/myositis in response to pronounced unilateral muscle overuse. This up-regulation occurred in inflammatory areas and was related not only to increased tachykinin innervation but also to tachykinin expression in blood vessel walls and inflammatory cells. Importantly, the tachykinin system appears to be an important factor not only ipsilaterally but also contralaterally in these processes. PMID:23587295

Bilateral increase in expression and concentration of tachykinin in a unilateral rabbit muscle overuse model that leads to myositis.

PubMed

Song, Yafeng; Stål, Per S; Yu, Ji-Guo; Forsgren, Sture

2013-04-12

Tachykinins can have pro-inflammatory as well as healing effects during tissue reorganization and inflammation. Recent studies report an up-regulation in the expression of the substance P (SP)-preferred receptor, the neurokinin-1 receptor, in marked muscle inflammation (myositis). There is, however, only very little information on the expression patterns and levels of tachykinins in this situation. The tachykinin system was analyzed using a rabbit experimental model of muscle overuse, whereby unilateral muscle exercise in combination with electrical stimulation led to muscle derangement and myositis in the triceps surae muscle (experimental length 1-6 weeks). Evaluations were made for both parts of the muscle (soleus and gastrocnemius muscles) in experimental and non-experimental (contralateral) sides. Morphologic evaluation, immunohistochemistry, in situ hybridization and enzyme immunoassay (EIA) analyses were applied. Myositis and muscle derangement occurred focally not only in the experimental side but also in the non-experimental side. In the inflammatory areas (focal myositis areas), there were frequent nerve fibers showing tachykinin-like immunoreactivity and which were parts of nerve fascicles and which were freely dispersed in the tissue. Cells in the inflammatory infiltrates showed tachykinin-like immunoreactivity and tachykinin mRNA expression. Specific immunoreactivity and mRNA expression were noted in blood vessel walls of both sides, especially in focally affected areas. With increasing experimental length, we observed an increase in the degree of immunoreactivity in the vessel walls. The EIA analyses showed that the concentration of tachykinin in the tissue on both sides increased in a time-dependent manner. There was a statistical correlation in the concentration of tachykinin and the level of tachykinin immunoreactivity in the blood vessel walls between experimental and non-experimental sides. The observations show an up-regulation of the tachykinin system bilaterally during muscle derangement/myositis in response to pronounced unilateral muscle overuse. This up-regulation occurred in inflammatory areas and was related not only to increased tachykinin innervation but also to tachykinin expression in blood vessel walls and inflammatory cells. Importantly, the tachykinin system appears to be an important factor not only ipsilaterally but also contralaterally in these processes.

Scleral fibroblast response to experimental glaucoma in mice

PubMed Central

Tezel, Gülgün; Cone-Kimball, Elizabeth; Steinhart, Matthew R.; Jefferys, Joan; Pease, Mary E.; Quigley, Harry A.

2016-01-01

Purpose To study the detailed cellular and molecular changes in the mouse sclera subjected to experimental glaucoma. Methods Three strains of mice underwent experimental bead-injection glaucoma and were euthanized at 3 days and 1, 3, and 6 weeks. Scleral protein expression was analyzed with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) using 16O/18O labeling for quantification in 1- and 6-week tissues. Sclera protein samples were also analyzed with immunoblotting with specific antibodies to selected proteins. The proportion of proliferating scleral fibroblasts was quantified with Ki67 and 4’,6-diamidino-2-phenylindole (DAPI) labeling, and selected proteins were studied with immunohistochemistry. Results Proteomic analysis showed increases in molecules involved in integrin-linked kinase signaling and actin cytoskeleton signaling pathways at 1 and 6 weeks after experimental glaucoma. The peripapillary scleral region had more fibroblasts than equatorial sclera (p=0.001, n=217, multivariable regression models). There was a sixfold increase in proliferating fibroblasts in the experimental glaucoma sclera at 1 week and a threefold rise at 3 and 6 weeks (p=0.0005, univariate regression). Immunoblots confirmed increases for myosin, spectrin, and actinin at 1 week after glaucoma. Thrombospondin-1 (TSP-1), HINT1, vimentin, actinin, and α-smooth muscle actin were increased according to immunohistochemistry. Conclusions Scleral fibroblasts in experimental mouse glaucoma show increases in actin cytoskeleton and integrin-related signaling, increases in cell division, and features compatible with myofibroblast transition. PMID:26900327

Risk-taking behaviors and prefrontal cortex activity of male adolescents in the presence of peer passengers during simulated driving : a functional near-infrared spectroscopy (fNIRS) study.

DOT National Transportation Integrated Search

2015-09-01

Crash statistics show that adolescent drivers are more likely to be involved in motor-vehicle crashes than adults and that the : presence of peer passengers pose an additional risk factor for crashes. Experimental and observational studies show that ...

Review article: coffee consumption, the metabolic syndrome and non-alcoholic fatty liver disease.

PubMed

Yesil, A; Yilmaz, Y

2013-11-01

Coffee consumption may modulate the risk of the metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD). To review the experimental, epidemiological and clinical studies investigating the association between coffee consumption and the risk of MetS and NAFLD. A literature search was conducted with the aim of finding original experimental, epidemiological and clinical articles on the association between coffee consumption, MetS and NAFLD. The following databases were used: PubMed, Embase, Scopus and Science Direct. We included articles written in English and published up to July 2013. Three experimental animal studies investigated the effects of coffee in the MetS, whereas five examined whether experimental coffee intake may modulate the risk of fatty liver infiltration. All of the animal studies showed a protective effect of coffee towards the development of MetS and NAFLD. Moreover, we identified eleven epidemiological and clinical studies that met the inclusion criteria. Of them, six were carried out on the risk of the MetS and five on the risk of NAFLD. Four of the six studies reported an inverse association between coffee consumption and the risk of MetS. The two studies showing negative results were from the same study cohort consisting of young persons with a low prevalence of the MetS. All of the epidemiological and clinical studies on NAFLD reported a protective effect of coffee intake. Coffee intake can reduce the risk of NAFLD. Whether this effect may be mediated by certain components of the MetS deserves further investigation. © 2013 John Wiley & Sons Ltd.

Effect of surface roughness on substrate-tuned gold nanoparticle gap plasmon resonances.

PubMed

Lumdee, Chatdanai; Yun, Binfeng; Kik, Pieter G

2015-03-07

The effect of nanoscale surface roughness on the gap plasmon resonance of gold nanoparticles on thermally evaporated gold films is investigated experimentally and numerically. Single-particle scattering spectra obtained from 80 nm diameter gold particles on a gold film show significant particle-to-particle variation of the peak scattering wavelength of ±28 nm. The experimental results are compared with numerical simulations of gold nanoparticles positioned on representative rough gold surfaces, modeled based on atomic force microscopy measurements. The predicted spectral variation and average resonance wavelength show good agreement with the measured data. The study shows that nanometer scale surface roughness can significantly affect the performance of gap plasmon-based devices.

Optical properties of electrically connected plasmonic nanoantenna dimer arrays

NASA Astrophysics Data System (ADS)

Zimmerman, Darin T.; Borst, Benjamin D.; Carrick, Cassandra J.; Lent, Joseph M.; Wambold, Raymond A.; Weisel, Gary J.; Willis, Brian G.

2018-02-01

We fabricate electrically connected gold nanoantenna arrays of homodimers and heterodimers on silica substrates and present a systematic study of their optical properties. Electrically connected arrays of plasmonic nanoantennas make possible the realization of novel photonic devices, including optical sensors and rectifiers. Although the plasmonic response of unconnected arrays has been studied extensively, the present study shows that the inclusion of nanowire connections modifies the device response significantly. After presenting experimental measurements of optical extinction for unconnected dimer arrays, we compare these to measurements of dimers that are interconnected by gold nanowire "busbars." The connected devices show the familiar dipole response associated with the unconnected dimers but also show a second localized surface plasmon resonance (LSPR) that we refer to as the "coupled-busbar mode." Our experimental study also demonstrates that the placement of the nanowire along the antenna modifies the LSPR. Using finite-difference time-domain simulations, we confirm the experimental results and investigate the variation of dimer gap and spacing. Changing the dimer gap in connected devices has a significantly smaller effect on the dipole response than it does in unconnected devices. On the other hand, both LSPR modes respond strongly to changing the spacing between devices in the direction along the interconnecting wires. We also give results for the variation of E-field strength in the dimer gap, which will be important for any working sensor or rectenna device.

Laserthermia on head and neck malignancies--experimental and clinical studies.

PubMed

Ohyama, M; Nobori, T; Moriyama, I; Furuta, S; Shima, T

1988-01-01

In recent years, remarkable progress has been made in thermotherapy. However, there is little information on localized laser hyperthermia (laserthermia) or on conventional hyperthermia technique applied to head and neck cancers. We have developed a ceramic probe to insert into tumor tissue and irradiate the Nd:YAG laser omnidirectionally. This probe can heat a spherical range of 1.5 cm to 43 degrees C. This paper concerns experimental and clinical studies on the effectiveness of laserthermia using our technique in the tumor of head and neck regions. The results obtained were as follows: histological findings and biochemical studies of arachidonic acid metabolites on normal rabbit tongue after laserthermia showed very slight effect and relatively short duration of the concomitant inflammation. The combination of laserthermia and CDDP chemotherapy was found to give a much better cytocidal effect on the tumor tissue in nude mice implanted with human thyroid cancer cells. In a clinical study on 21 cases with head and neck cancers, four cases showed complete and 13 cases showed partial remission after combined treatments of laserthermia and radiochemotherapy. Both basic experimental and clinical results have indicated a role for laserthermia in the treatment of head and neck cancer. Possible uses include the treatment of early cancer as well as advanced or recurrent cancer, where its therapeutic effect may be increased by combination with radiotherapy or chemotherapy.

Experimental testing and constitutive modeling of the mechanical properties of the swine skin tissue.

PubMed

Łagan, Sylwia D; Liber-Kneć, Aneta

2017-01-01

The aim of the study was an estimation of the possibility of using hyperelastic material models to fit experimental data obtained in the tensile test for the swine skin tissue. The uniaxial tensile tests of samples taken from the abdomen and back of a pig was carried out. The mechanical properties of the skin such as the mean Young's modulus, the mean maximum stress and the mean maximum elongation were calculated. The experimental data have been used to identify the parameters in specific strain-energy functions given in seven constitutive models of hyperelastic materials: neo-Hookean, Mooney-Rivlin, Ogden, Yeoh, Martins, Humphrey and Veronda-Westmann. An analysis of errors in fitting of theoretical and experimental data was done. Comparison of load -displacement curves for the back and abdomen regions of skin taken showed a different scope of both the mean maximum loading forces and the mean maximum elongation. Samples which have been prepared from the abdominal area had lower values of the mean maximum load compared to samples from the spine area. The reverse trend was observed during the analysis of the values of elongation. An analysis of the accuracy of model fitting to the experimental data showed that, the least accurate were the model of neo- -Hookean, model of Mooney-Rivlin for the abdominal region and model of Veronda-Westmann for the spine region. An analysis of seven hyperelastic material models showed good correlations between the experimental and the theoretical data for five models.

A study of the effects of an experimental spiral physics curriculum taught to sixth grade girls and boys

NASA Astrophysics Data System (ADS)

Davis, Edith G.

The pilot study compared the effectiveness of using an experimental spiral physics curriculum to a traditional linear physics curriculum for sixth through eighth grades. The study also surveyed students' parents and principals about students' academic history and background as well as identified resilient children's attributes for academic success. The pilot study was used to help validate the testing instrument as well as help refine the complete study. The purpose of the complete study was to compare the effectiveness of using an experimental spiral physics curriculum and a traditional linear curriculum with sixth graders only; seventh and eighth graders were dropped in the complete study. The study also surveyed students' parents, teachers, and principals about students' academic history and background as well as identified resilient children's attributes for academic success. Both the experimental spiral physics curriculum and the traditional linear physics curriculum increased physics achievement; however, there was no statistically significant difference in effectiveness of teaching experimental spiral physics curriculum in the aggregated sixth grade group compared to the traditional linear physics curriculum. It is important to note that the majority of the subgroups studied did show statistically significant differences in effectiveness for the experimental spiral physics curriculum compared to the traditional linear physics curriculum. The Grounded Theory analysis of resilient student characteristics resulted in categories for future studies including the empathy factor ("E" factor), the tenacity factor ("T" factor), the relational factor ("R" factor), and the spiritual factor ("S" factor).

Influence of culture and language sensitive physics on science attitude enhancement

NASA Astrophysics Data System (ADS)

Morales, Marie Paz E.

2015-12-01

The study critically explored how culture and language sensitive curriculum materials in physics improve Pangasinan learners' attitude towards science. Their cultural dimensions, epistemological beliefs, and views on integration of culture and language in the teaching and learning process determined their cultural preference or profile. Design and development of culture and language sensitive curriculum materials in physics were heavily influenced by these learners' cultural preference or profile. Pilot-study using interviews and focus group discussions with natives of Pangasinan and document analysis were conducted to identify the culture, practices, and traditions integrated in the lesson development. Comparison of experimental participants' pretest and posttest results on science attitude measure showed significant statistical difference. Appraisal of science attitude enhancement favored the experimental group over the control group. Qualitative data deduced from post implementation interviews, focus group discussions, and journal log entries showed the same trend in favor of the experimental participants. The study revealed that culture and language integration in the teaching and learning process of physics concepts enabled students to develop positive attitude to science, their culture, and native language.

The Use of Wiki in Teaching Programming: Effects upon Achievement, Attitudes, and Collaborative Programming Behaviors

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…

WMC Database Evaluation. Case Study Report

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

Palounek, Andrea P. T

The WMC Database is ultimately envisioned to hold a collection of experimental data, design information, and information from computational models. This project was a first attempt at using the Database to access experimental data and extract information from it. This evaluation shows that the Database concept is sound and robust, and that the Database, once fully populated, should remain eminently usable for future researchers.

Elastic solitons in delaminated bars: splitting leads to fission

NASA Astrophysics Data System (ADS)

Samsonov, A. M.; Dreiden, G. V.; Khusnutdinova, K. R.; Semenova, I. V.

2008-06-01

Recent theoretical and successful experimental studies confirmed existence and demonstrated main properties of bulk strain solitary waves in nonlinearly elastic solid wave guides. Our current research is devoted to nonlinear wave processes in layered elastic wave guides with inhomogeneities modelling delamination. We present first theoretical and experimental results showing the influence of delamination on the parameters of the longitudinal strain solitary wave.

Optimization of the ultrasonic assisted removal of methylene blue by gold nanoparticles loaded on activated carbon using experimental design methodology.

PubMed

Roosta, M; Ghaedi, M; Daneshfar, A; Sahraei, R; Asghari, A

2014-01-01

The present study was focused on the removal of methylene blue (MB) from aqueous solution by ultrasound-assisted adsorption onto the gold nanoparticles loaded on activated carbon (Au-NP-AC). This nanomaterial was characterized using different techniques such as SEM, XRD, and BET. The effects of variables such as pH, initial dye concentration, adsorbent dosage (g), temperature and sonication time (min) on MB removal were studied and using central composite design (CCD) and the optimum experimental conditions were found with desirability function (DF) combined response surface methodology (RSM). Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Analysis of experimental adsorption data to various kinetic models such as pseudo-first and second order, Elovich and intraparticle diffusion models show the applicability of the second-order equation model. The small amount of proposed adsorbent (0.01 g) is applicable for successful removal of MB (RE>95%) in short time (1.6 min) with high adsorption capacity (104-185 mg g(-1)). Copyright © 2013 Elsevier B.V. All rights reserved.

Correlation of current drop, filling gas pressure, and ion beam emission in a low energy Mather-type plasma focus device

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

Behbahani, R. A.; Aghamir, F. M.

The behavior of current drop and its correlation with ion beam emission during the radial phase of a high inductance low energy Mather type plasma focus device have been studied. The study includes two ranges of filling gas pressure, namely the low range of 0.2-0.8 mbar and the high range of 0.8-1.5 mbar. Two different current simulation processes were performed to aid the interpretation of the experimental results. Within the low range of operating pressure, an acceptable match between the computed and experimental current signals was achieved when the effects of anomalous resistances were contemplated. While in the high rangemore » of pressure, the computed and experimental current traces were in line even without considering the effects of anomalous resistances. The analysis shows that by decreasing the filling gas pressure the effects of instabilities are intensified. The computed and experimental current traces, along with ion beam signals gathered from a faraday cup, show that there is a strong correlation between the intensity of ion beam and its duration with the current drop during the radial phase.« less

Experimental Evaluation of Inlet Distortion on an Ejector Powered Hybrid Wing Body at Take-off and Landing Conditions

NASA Technical Reports Server (NTRS)

Carter, Melissa B.; Shea, Patrick R.; Flamm, Jeffrey D.; Schuh, Michael; James, Kevin D.; Sexton, Matthew R.; Tompkins, Daniel M.; Beyar, Michael D.

2016-01-01

As part of the NASA Environmentally Responsible Aircraft project, an ultra high bypass ratio engine integration on a hybrid wing body demonstration was planned. The goal was to include engine and airframe integration concepts that reduced fuel consumption by at least 50% while still reducing noise 42 db cumulative on the ground. Since the engines would be mounted on the upper surface of the aft body of the aircraft, the inlets may be susceptible to vortex ingestion from the wing leading edge at high angles of attack and sideslip, and separated wing/body flow. Consequently, experimental and computational studies were conducted to collect flow surveys useful for characterizing engine operability. The wind tunnel tests were conducted at two NASA facilities, the 14- by 22-foot at NASA Langley and the 40- by 80-foot at NASA Ames Research Center. The test results included in this paper show that the distortion and pressure recovery levels were acceptable for engine operability. The CFD studies conducted to compare to experimental data showed excellent agreement for the angle of attacks examined, although failed to match the low speed experimental data at high sideslip angles.

Adsorption characteristics of green 5-arylaminomethylene pyrimidine-2,4,6-triones on mild steel surface in acidic medium: Experimental and computational approach

NASA Astrophysics Data System (ADS)

Verma, Chandrabhan; Olasunkanmi, Lukman O.; Ebenso, Eno E.; Quraishi, M. A.

2018-03-01

The effect of electron withdrawing nitro (-NO2) and electron releasing hydroxyl (-OH) groups on corrosion inhibition potentials of 5-arylaminomethylenepyrimidine-2,4,6-trione (AMP) had been studied. Four AMPs tagged AMP-1, AMP-2, AMP-3 and AMP-4 were studied for their ability to inhibit mild steel corrosion in 1 M HCl using experimental and theoretical methods. Gravimetric results showed that inhibition efficiency of the studied inhibitors increases with increasing concentration. The results further revealed that that electron withdrawing nitro (-NO2) group decreases the inhibition efficiency of AMP, while electron donating hydroxyl (-OH) group increases the inhibition efficiency of AMP. SEM and AFM studies showed that the studied compounds inhibit mild steel corrosion by adsorbing at the metal/electrolyte interface and their adsorption obeyed the Temkin adsorption isotherm. Potentiodynamic polarization study revealed that studied inhibitors act as mixed type inhibitors with predominant effect on cathodic reaction. The inhibitive strength of the compounds might have direct relationship electron donating ability of the molecules as revealed by quantum chemical parameters. The order of interaction energies derived from Monte Carlo simulations is AMP-4 > AMP-3 > AMP-2 > AMP-1, which is in agreement with the order of inhibition efficiencies obtained from experimental measurements.

La-oxides as tracers for PuO{sub 2} to simulate contaminated aerosol behavior

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

Meyer, L.C.; Newton, G.J.; Cronenberg, A.W.

1994-04-01

An analytical and experimental study was performed on the use of lanthanide oxides (La-oxides) as surrogates for plutonium oxides (PuO{sub 2}) during simulated buried waste retrieval. This study determined how well the La-oxides move compared to PuO{sub 2} in aerosolized soils during retrieval scenarios. As part of the analytical study, physical properties of La-oxides and PuO{sub 2}, such as molecular diameter, diffusivity, density, and molecular weight are compared. In addition, an experimental study was performed in which Idaho National Engineering Laboratory (INEL) soil, INEL soil with lanthanides, and INEL soil with plutonium were aerosolized and collected in filters. Comparison ofmore » particle size distribution parameters from this experimental study show similarity between INEL soil, INEL soil with lanthanides, and INEL soil with plutonium.« less

Scattering, absorption and transmittance of experimental graphene dental nanocomposites

NASA Astrophysics Data System (ADS)

Pérez, María. M.; Salas, Marianne; Moldovan, Marionara; Dudea, Diana; Yebra, Ana; Ghinea, Razvan

2017-08-01

Optical properties of experimental graphene dental nanocomposites were studied. Spectral reflectance was measured and S and K coefficients as well as transmittance of samples were calculated using Kubelka-Munk's equations. The spectral behavior of S, K and T experimental graphene exhibited different trends compared with the commercial nanocomposites and they were statistically different. Experimental nanocomposites show higher scattering and lower transmittance when compared with commercial nanocomposite, probably, due to the shape, type and size of the filler. K for short wavelength of the pre-polymerized experimental nancomposites was very low. According to our results, hidroxypatite with graphene oxide used in dental nanocomposites needs to be improved to reproduce esthetic properties of natural dental tissues and to have potentially clinical applications.

An experimental study of the effect of mooring systems on the dynamics of a SPAR buoy-type floating offshore wind turbine

NASA Astrophysics Data System (ADS)

Hong, Sinpyo; Lee, Inwon; Park, Seong Hyeon; Lee, Cheolmin; Chun, Ho-Hwan; Lim, Hee Chang

2015-09-01

An experimental study of the effect of mooring systems on the dynamics of a SPAR buoy-type floating offshore wind turbine is presented. The effects of the Center of Gravity (COG), mooring line spring constant, and fair-lead location on the turbine's motion in response to regular waves are investigated. Experimental results show that for a typical mooring system of a SPAR buoy-type Floating Offshore Wind Turbine (FOWT), the effect of mooring systems on the dynamics of the turbine can be considered negligible. However, the pitch decreases notably as the COG increases. The COG and spring constant of the mooring line have a negligible effect on the fairlead displacement. Numerical simulation and sensitivity analysis show that the wind turbine motion and its sensitivity to changes in the mooring system and COG are very large near resonant frequencies. The test results can be used to validate numerical simulation tools for FOWTs.

"I feel fat": an experimental induction of body displacement in disordered eating.

PubMed

McFarlane, Traci; Urbszat, Dax; Olmsted, Marion P

2011-04-01

Body displacement, the theory that predicts that individuals with eating disorders will displace negative feelings about themselves onto their body, was tested experimentally in this study. Unrestrained eaters (n = 61), restrained eaters (n = 33), and individuals with eating disorders (n = 26) were randomly assigned to a control condition or an ineffectiveness induction. In the ineffectiveness condition participants were asked to recall and reflect on a past experience when they felt useless or incapable (i.e., ineffective). Results showed that individuals with eating disorders who were made to feel ineffective reported more implicit appearance/body concern than those in the control condition. Unrestrained and restrained eaters did not show this effect. This is the first experimental study to support body displacement theory. These data can be used clinically to educate and encourage patients with eating disorders to address thoughts and feelings related to ineffectiveness directly, instead of displacing this distress onto their body and potentially perpetuating their eating disorder. Copyright © 2011 Elsevier Ltd. All rights reserved.

An experimental study of flank wear in the end milling of AISI 316 stainless steel with coated carbide inserts

NASA Astrophysics Data System (ADS)

Odedeyi, P. B.; Abou-El-Hossein, K.; Liman, M.

2017-05-01

Stainless steel 316 is a difficult-to-machine iron-based alloys that contain minimum of about 12% of chromium commonly used in marine and aerospace industry. This paper presents an experimental study of the tool wear propagation variations in the end milling of stainless steel 316 with coated carbide inserts. The milling tests were conducted at three different cutting speeds while feed rate and depth of cut were at (0.02, 0.06 and 01) mm/rev and (1, 2 and 3) mm, respectively. The cutting tool used was TiAlN-PVD-multi-layered coated carbides. The effects of cutting speed, cutting tool coating top layer and workpiece material were investigated on the tool life. The results showed that cutting speed significantly affected the machined flank wears values. With increasing cutting speed, the flank wear values decreased. The experimental results showed that significant flank wear was the major and predominant failure mode affecting the tool life.

Studying light-harvesting models with superconducting circuits.

PubMed

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.

Statins and Thyroid Carcinoma: a Meta-Analysis.

PubMed

Zhao, Junyu; Xu, Chunmei; Yao, Jinming; Yu, Changzhen; Liao, Lin; Dong, Jianjun

2018-06-19

Experimental studies have reported the antineoplastic effects of statins in thyroid carcinoma; however, observational studies suggested that statins might increase the risk of thyroid carcinoma. Therefore, this study evaluated the antineoplastic effects of statins in both in vitro studies and animal models, as well as the epidemiological evidence. Databases-PubMed, Cochrane Library, SinoMed, CNKI, Wanfang, and clinical trial registries- were searched. A meta-analysis was performed with sufficiently homogeneous studies. Eighteen articles were involved. In in vitro studies, statins showed a concentration-dependent inhibition of cell line growth (weighted mean difference -34.68, 95% confidence interval -36.53 to -32.83). A significant efficacy of statin-induced apoptosis was observed (weighted mean difference [95% confidence interval]: 24 h, 57.50 [55.98-59.03]; 48 h, 23.43 [22.19-24.66]; 72 h, 51.29 [47.52-55.07]). Early apoptosis was increased in a dose- and time-dependent manner. In in vivo antitumor studies, lovastatin inhibited tumor growth, as shown by a reduction in tumor volume. However, two clinical studies showed discordant results from the experimental studies. Experimental studies revealed the antineoplastic efficacy of statins but statins were associated with thyroid carcinoma in clinical studies. This discrepancy may be due to the different concentrations of statins used and the effects of hyperlipidemia interventions, and thus further study is required. © 2018 The Author(s). Published by S. Karger AG, Basel.

Electromyographic analysis of the masseter and buccinator muscles with the pro-fono facial exerciser use in bruxers.

PubMed

Jardini, Renata S R; Ruiz, Lydia S R; Moysés, Maria A A

2006-01-01

The aim of this study was to evaluate the efficiency of the Pró-Fono Facial Exerciser (Pró-Fono Productos Especializados para Fonoaudiologia Ltda., Barueri/SP, Brazil) to decrease bruxism, as well as the correlation between the masseter and the buccinator muscles using electromyography (EMG). In this study, 39 individuals ranging from 23 to 48 years of age were selected from a dental school and then underwent surface EMG at three different periods of time: 0, 10, and 70 days. They were divided into a normal control group, a bruxer control group (without device), and an experimental bruxer group who used the device. The bruxer group showed a greater masseter EMG amplitude when compared to the normal group, while the experimental group had deceased activity with a reduction in symptoms. The buccinator EMG spectral analysis of the experimental bruxist group showed asynchronous contractions of the masseter muscle (during jaw opening) after using the Pró-Fono Facial Exerciser. The normal group also showed asynchronous contractions. Upon correlation of the data between these muscles, the inference is that there is a reduction in bruxism when activating the buccinator muscle.

Biases in the Experimental Annotations of Protein Function and Their Effect on Our Understanding of Protein Function Space

PubMed Central

Schnoes, Alexandra M.; Ream, David C.; Thorman, Alexander W.; Babbitt, Patricia C.; Friedberg, Iddo

2013-01-01

The ongoing functional annotation of proteins relies upon the work of curators to capture experimental findings from scientific literature and apply them to protein sequence and structure data. However, with the increasing use of high-throughput experimental assays, a small number of experimental studies dominate the functional protein annotations collected in databases. Here, we investigate just how prevalent is the “few articles - many proteins” phenomenon. We examine the experimentally validated annotation of proteins provided by several groups in the GO Consortium, and show that the distribution of proteins per published study is exponential, with 0.14% of articles providing the source of annotations for 25% of the proteins in the UniProt-GOA compilation. Since each of the dominant articles describes the use of an assay that can find only one function or a small group of functions, this leads to substantial biases in what we know about the function of many proteins. Mass-spectrometry, microscopy and RNAi experiments dominate high throughput experiments. Consequently, the functional information derived from these experiments is mostly of the subcellular location of proteins, and of the participation of proteins in embryonic developmental pathways. For some organisms, the information provided by different studies overlap by a large amount. We also show that the information provided by high throughput experiments is less specific than those provided by low throughput experiments. Given the experimental techniques available, certain biases in protein function annotation due to high-throughput experiments are unavoidable. Knowing that these biases exist and understanding their characteristics and extent is important for database curators, developers of function annotation programs, and anyone who uses protein function annotation data to plan experiments. PMID:23737737

Retention and wear behaviors of two implant overdenture stud-type attachments at different implant angulations.

PubMed

Choi, Jae-Won; Bae, Ji-Hyeon; Jeong, Chang-Mo; Huh, Jung-Bo

2017-05-01

Implant angulation should be considered when selecting an attachment. Some in vitro studies have investigated the relationship between implant angulation and changes in the retention force of the stud attachment, but few studies have evaluated the effect of cyclic loading and repeated cycles of insertion and removal on the stud attachment. The purpose of this in vitro study was to evaluate the effects of implant angulation on the retentive characteristics of overdentures with 2 different stud attachments, an experimental system and O-rings in red and orange, after cyclic loading and repeated insertion and removal cycles. The canine region of a mandibular experimental model was fitted with 2 implant fixtures with 2 different stud attachment systems at implant angulations of 0, 15, or 30 degrees. A mastication simulator was used to simulate cyclic loading, and a universal testing machine was used to evaluate retentive force changes after repeated insertion and removal cycles. To simulate the numbers of mastication and insertion and removal cycles per annum, 400000 cyclic loadings and 1080 insertion and removal cycles were performed. Wear patterns and attachment surface deformations were evaluated by scanning electron microscopy. Data were analyzed using the Kruskal-Wallis test, Mann-Whitney U test with Bonferroni correction (α=.05/3=.017), and the paired-sample Student t test (α=.05). When retentive forces before and after testing were compared, O-ring showed significant retention loss at all implant angulations (P<.001). In contrast, the experimental system showed little retention loss in the 0- and 15-degree models (P>.05), whereas the 30-degree model showed a significant increase in retentive force (P=.001). At all implant angulations, retention loss increased significantly for the orange O-ring, followed by the red O-ring, and the experimental system (P<.001). Scanning electron microscopy analysis showed more intense wear in the matrix than the patrix (abutment that matches to matrix) and more severe wear and deformation of the O-ring rubber matrix than of the experimental zirconia ball. Upon completion of the experiment, wear and deformation were found for all attachment systems. Even when implants are not installed in parallel, the experimental system can be used without involving great loss of retention. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Magneto-optic dynamics in a ferromagnetic nematic liquid crystal

NASA Astrophysics Data System (ADS)

Potisk, Tilen; Mertelj, Alenka; Sebastián, Nerea; Osterman, Natan; Lisjak, Darja; Brand, Helmut R.; Pleiner, Harald; Svenšek, Daniel

2018-01-01

We investigate dynamic magneto-optic effects in a ferromagnetic nematic liquid crystal experimentally and theoretically. Experimentally we measure the magnetization and the phase difference of the transmitted light when an external magnetic field is applied. As a model we study the coupled dynamics of the magnetization, M , and the director field, n , associated with the liquid crystalline orientational order. We demonstrate that the experimentally studied macroscopic dynamic behavior reveals the importance of a dynamic cross-coupling between M and n . The experimental data are used to extract the value of the dissipative cross-coupling coefficient. We also make concrete predictions about how reversible cross-coupling terms between the magnetization and the director could be detected experimentally by measurements of the transmitted light intensity as well as by analyzing the azimuthal angle of the magnetization and the director out of the plane spanned by the anchoring axis and the external magnetic field. We derive the eigenmodes of the coupled system and study their relaxation rates. We show that in the usual experimental setup used for measuring the relaxation rates of the splay-bend or twist-bend eigenmodes of a nematic liquid crystal one expects for a ferromagnetic nematic liquid crystal a mixture of at least two eigenmodes.

Micromagnetic study of auto-oscillation modes in spin-Hall nano-oscillators

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

Ulrichs, H., E-mail: henning.ulrichs@uni-muenster.de; Demidov, V. E.; Demokritov, S. O.

2014-01-27

We present a numerical study of magnetization dynamics in a recently introduced spin torque nano-oscillator, whose operational principle relies on the spin-Hall effect—spin-Hall nano-oscillators. Our numerical results show good agreement with the experimentally observed behaviors and provide detailed information about the features of the primary auto-oscillation mode observed in the experiments. They also clarify the physical nature of the secondary auto-oscillation mode, which was experimentally observed under certain conditions only.

Experimental simulation of aerosols evolution in Titan's ionosphere

NASA Astrophysics Data System (ADS)

Chatain, A.; Carrasco, N.; Guaitella, O.

2017-09-01

Many recent studies on Titan are concerned with aerosols. In particular, questions are asked on how these complex organic molecules are formed and evolve in Titan's atmosphere. Here for the first time we experimentally study how harsh plasma environment simulating Titan ionosphere can affect these aerosols. Titan tholins are placed in a N2-H2 plasma reactor and sample signatures are measured by infrared transmission spectroscopy. First results show an evolution of the absorption bands. Therefore, plasma conditions seem to change tholin chemical structure.

Marginalized Women in West Iran

PubMed

Malmir, Shabnam; Barati, Majid; Khani Jeihooni, Ali; Bashirian, Saeed; Hazavehei, Seyed Mohammad Mehdi

2018-03-27

Objective: This study aimed to determine the effectiveness of an educational intervention to prevent cervical cancer among marginalized Iranianwomen based on the Protection Motivation Theory (PMT) as a theoretical framework. Methods: This quasi-experimental study was carried out on 143 women of Kermanshah City in western Iran during 2017. Participants were recruited through cluster and simple random sampling and randomly divided into experimental (n=72) and control groups (n=71). All completed a self-administered questionnaire including PMT constructs and demographic variables. An intervention over six sessions was then applied to the experimental group. Reassessment was conducted three months after the intervention, with data was analyzed with SPSS-16 using chi-square, McNemar, paired T- and independent T-tests. Results: The mean scores for the constructs of PMT, and cervical cancer screening behavior showed no significant differences between the two groups before the intervention (P>0.05). The educational manipulation had significant effects on the experimental groups’ average response for perceived vulnerability, perceived severity, perceived reward, self-efficacy, response efficacy, response cost and protection motivation (all p < 0.001). Also, the prevalence of regular Pap smear testing and referral to health centers were significantly increased after 3 months in the experimental (P=0.048), but notthe control group (P>0.05). Conclusions: The results show that applying an educational intervention based on PMT might help prevent cervical cancer and improve regular Pap smear testing. Creative Commons Attribution License

Anti-ageing effects of dentifrices containing anti-oxidative, anti-inflammatory, and anti-bacterial agents (Tomarina®) on gingival collagen degradation in rats.

PubMed

Koichiro, Irie; Tomofuji, Takaaki; Ekuni, Daisuke; Endo, Yasumasa; Kasuyama, Kenta; Azuma, Tetsuji; Tamaki, Naofumi; Yoneda, Toshiki; Morita, Manabu

2014-01-01

Previous studies have demonstrated the relationship between ageing and oxidative stress. In this study, we examined the effects of topical application of a dentifrice containing anti-oxidative, anti-inflammatory, and anti-bacterial agents (Tomarina®) to the gingival surface on gingival collagen degradation in rats. Fischer 344 male rats (4 or 8 months old) were divided into two groups: experimental group and control group. Tomarina® (the experimental group) or control dentifrice (the control group) was applied 5 days per week for 2 months. In the control group, gingival collagen density decreased with ageing. In the experimental group, the collagen density did not change with ageing, and was greater than that in the control group at 10 months of age (p < 0.0083). In addition, the control group showed an increase in serum oxidative stress with ageing. The experimental group also showed increased serum oxidative stress, but the value was lower than the control group at 10 months of age (p < 0.0083). Furthermore, low expressions of protein oxidative damage in the periodontal tissue were observed in the experimental group, compared to the control group at 6 months and 10 months. These findings indicate that Tomarina® might suppress the effects of ageing on gingival collagen degradation, by decreasing oxidative stress in the rat model.

Characterization and compression of dissipative-soliton-resonance pulses in fiber lasers

PubMed Central

Li, Daojing; Li, Lei; Zhou, Junyu; Zhao, Luming; Tang, Dingyuan; Shen, Deyuan

2016-01-01

We report numerical and experimental studies of dissipative-soliton-resonance (DSR) in a fiber laser with a nonlinear optical loop mirror. The DSR pulse presents temporally a flat-top profile and a clamped peak power. Its spectrum has a rectangle profile with characteristic steep edges. It shows a unique behavior as pulse energy increases: The rectangle part of the spectrum is unchanged while the newly emerging spectrum sits on the center part and forms a peak. Experimental observations match well with the numerical results. Moreover, the detailed evolution of the DSR pulse compression is both numerically and experimentally demonstrated for the first time. An experimentally obtained DSR pulse of 63 ps duration is compressed down to 760 fs, with low-intensity pedestals using a grating pair. Before being compressed to its narrowest width, the pulse firstly evolves into a cat-ear profile, and the corresponding autocorrelation trace shows a crown shape, which distinguishes itself from properties of other solitons formed in fiber lasers. PMID:27025189

Improving flexible thinking in deaf and hard of hearing children with virtual reality technology.

PubMed

Passig, D; Eden, S

2000-07-01

The study investigated whether rotating three-dimensional (3-D) objects using virtual reality (VR) will affect flexible thinking in deaf and hard of hearing children. Deaf and hard of hearing subjects were distributed into experimental and control groups. The experimental group played virtual 3-D Tetris (a game using VR technology) individually, 15 minutes once weekly over 3 months. The control group played conventional two-dimensional (2-D) Tetris over the same period. Children with normal hearing participated as a second control group in order to establish whether deaf and hard of hearing children really are disadvantaged in flexible thinking. Before-and-after testing showed significantly improved flexible thinking in the experimental group; the deaf and hard of hearing control group showed no significant improvement. Also, before the experiment, the deaf and hard of hearing children scored lower in flexible thinking than the children with normal hearing. After the experiment, the difference between the experimental group and the control group of children with normal hearing was smaller.

An experimental approach in revisiting the magnetic orientation of cattle.

PubMed

Weijers, Debby; Hemerik, Lia; Heitkönig, Ignas M A

2018-01-01

In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations-excluding the hottest part of the day-of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals.

Finding Meaning in Written Emotional Expression by Family Caregivers of Persons With Dementia.

PubMed

Butcher, Howard K; Gordon, Jean K; Ko, Ji Woon; Perkhounkova, Yelena; Cho, Jun Young; Rinner, Andrew; Lutgendorf, Susan

2016-12-01

This study tested the effect of written emotional expression on the ability to find meaning in caregiving and the effects of finding meaning on emotional state and psychological burden in 91 dementia family caregivers. In a pretest-posttest design, participants were randomly assigned to either an experimental or a comparison group. Experimental caregivers (n = 57) wrote about their deepest thoughts and feelings about caring for a family member with dementia, whereas those in the comparison group (n = 34) wrote about nonemotional topics. Results showed enhanced meaning-making abilities in experimental participants relative to comparison participants, particularly for those who used more positive emotion words. Improved meaning-making ability was in turn associated with psychological benefits at posttest, but experimental participants did not show significantly more benefit than comparison participants. We explore the mediating roles of the meaning-making process as well as some of the background characteristics of the individual caregivers and their caregiving environments. © The Author(s) 2016.

Effect of wild strains used as starter cultures and adjunct cultures on the volatile compounds of the Pecorino Siciliano cheese.

PubMed

Randazzo, C L; Pitino, I; De Luca, S; Scifò, G O; Caggia, C

2008-03-20

The effect of six wild strains on the volatile profile of the PS cheese was investigated and compared to that generated from industrial starters generally used to produce PS cheese. All cheeses were subjected to microbiological, physicochemical, and volatile compounds analyses. The DGGE of the 16S rDNA analysis was also applied. The volatile compounds generated during ripening were studied through the SPME and the GC-MS methods. No difference was detected between the experimental and control cheeses throughout chemical and microbiological analyses, while the DGGE results showed the presence of Streptococcus thermophilus in all cheeses, and the dominance of Enterococcus durans, Lactobacillus rhamnosus, and Lactobacillus casei in most of the experimental cheeses. Moreover, the presence of Lactococcus lactis species as in the control and in the experimental P2 and P4 cheeses was also revealed. The SPME results showed more pronounced volatile compounds in the experimental cheese samples than in the control ones.

Broadband frequency and angular response of a sinusoidal bull’s eye antenna

NASA Astrophysics Data System (ADS)

Beaskoetxea, U.; Navarro-Cía, M.; Beruete, M.

2016-07-01

A thorough experimental study of the frequency and beaming angle response of a metallic leaky-wave bull’s eye antenna working at 77 GHz with a sinusoidally corrugated profile is presented. The beam scanning property of these antennas as frequency is varied is experimentally demonstrated and corroborated through theoretical and numerical results. From the experimental results the dispersion diagram of the n  =  -1 and n  =  -2 space harmonics is extracted, and the operation at different frequency regimes is identified and discussed. In order to show the contribution of each half of the antenna, numerical examples of the near-field behavior are also displayed. Overall, experimental results are in good qualitative and quantitative agreement with theoretical and numerical calculations. Finally, an analysis of the beamwidth as a function of frequency is performed, showing that it can achieve values below 1.5° in a fractional bandwidth of 4% around the operation frequency, which is an interesting frequency-stable broadside radiation.

Reducing teachers' psychological distress through a mindfulness training program.

PubMed

Franco, Clemente; Mañas, Israel; Cangas, Adolfo J; Moreno, Emilio; Gallego, José

2010-11-01

Teachers constitute one of the professional collectives most affected by psychological problems. The purpose of this quasi-experimental study is to examine the efficacy of a mindfulness training programme to reduce psychological distress in a group of teachers. The sample comprised 68 teachers of Secondary School Education, from various public schools; half of them formed the experimental group, and the another half the control group. The levels of psychological distress were measured, in both groups, by the Symptom Checklist-90-R (SCL-90-R) before and after the application of the programme. Statistical analysis shows the significant reduction of three general measures of psychological distress (Global Severity Index, Positive Symptom Distress Index, and Positive Symptom Total), as well in all its dimensions (somatization, obsessive-compulsive, interpersonal sensibility, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism), in the experimental group compared with the control group. Follow-up measures show that these results were maintained for four months after termination of the intervention in the experimental group.

Experimental studies of two-stage centrifugal dust concentrator

NASA Astrophysics Data System (ADS)

Vechkanova, M. V.; Fadin, Yu M.; Ovsyannikov, Yu G.

2018-03-01

The article presents data of experimental results of two-stage centrifugal dust concentrator, describes its design, and shows the development of a method of engineering calculation and laboratory investigations. For the experiments, the authors used quartz, ceramic dust and slag. Experimental dispersion analysis of dust particles was obtained by sedimentation method. To build a mathematical model of the process, dust collection was built using central composite rotatable design of the four factorial experiment. A sequence of experiments was conducted in accordance with the table of random numbers. Conclusion were made.

Experimental study of uncentralized squeeze film dampers

NASA Technical Reports Server (NTRS)

Quinn, R. D.

1983-01-01

The vibration response of a rotor system supported by a squeeze film damper (SFD) was experimentally investigated in order to provide experimental data in support of the Rotor/Stator Interactive Finite Element theoretical development. Part of the investigation required the designing and building of a rotor/SFD system that could operate with or without end seals in order to accommodate different SFD lengths. SFD variables investigated included clearance, eccentricity mass, fluid pressure, and viscosity and temperature. The results show inlet pressure, viscosity and clearance have significant influence on the damper performance and accompanying rotor response.

Excitation spectra of liquid iron up to superhigh temperatures

NASA Astrophysics Data System (ADS)

Fomin, Yu D.; Ryzhov, V. N.; Tsiok, E. N.; Brazhkin, V. V.

2017-08-01

Investigation of excitation spectra of liquids is one of the hot test topics nowadays. In particular, recent experimental works showed that liquid metals can demonstrate transverse excitations and positive sound dispersion. However, the theoretical description of these experimental observations is still missing. Here we report a molecular dynamics study of excitation spectra of liquid iron. We compare the results with available experimental data to justify the method. After that we perform calculations for high temperatures to find the location of the Frenkel line introduced in our previous works.

Thermally enhanced signal strength and SNR improvement of photoacoustic radar module

PubMed Central

Wang, Wei; Mandelis, Andreas

2014-01-01

A thermally enhanced method for improving photoacoustic imaging depth and signal-to-noise (SNR) ratio is presented in this paper. Experimental results showed that the maximum imaging depth increased by 20% through raising the temperature of absorbing biotissues (ex-vivo beef muscle) uniformly from 37 to 43°C, and the SNR was increased by 8%. The parameters making up the Gruneisen constant were investigated experimentally and theoretically. The studies showed that the Gruneisen constant of biotissues increases with temperature, and the results were found to be consistent with the photoacousitc radar theory. PMID:25136501

Modelling the average velocity of propagation of the flame front in a gasoline engine with hydrogen additives

NASA Astrophysics Data System (ADS)

Smolenskaya, N. M.; Smolenskii, V. V.

2018-01-01

The paper presents models for calculating the average velocity of propagation of the flame front, obtained from the results of experimental studies. Experimental studies were carried out on a single-cylinder gasoline engine UIT-85 with hydrogen additives up to 6% of the mass of fuel. The article shows the influence of hydrogen addition on the average velocity propagation of the flame front in the main combustion phase. The dependences of the turbulent propagation velocity of the flame front in the second combustion phase on the composition of the mixture and operating modes. The article shows the influence of the normal combustion rate on the average flame propagation velocity in the third combustion phase.

Study of a coronagraphic mask using evanescent waves.

PubMed

Buisset, Christophe; Rabbia, Yves; Lepine, Thierry; Alagao, Mary-Angelie; Ducrot, Elsa; Poshyachinda, Saran; Soonthornthum, Boonrucksar

2017-04-03

The evanescent wave coronagraph (EvWaCo) is a specific kind of band-limited coronagraph using the frustrated total internal reflection phenomenon to produce the coronagraphic effect (removing starlight from the image plane in order to make the stellar environment detectable). In this paper, we present a theoretical and experimental study of the EvWaCo coronagraphic mask. First, we calculate the theoretical transmission and we show that this mask is partially achromatic. Then, we present the experimental results obtained in unpolarized light at the wavelength λ≈900 nm and relative spectral bandwidth Δλ/λ≈6%. In particular, we show that the coronagraph provides a contrast down to a few 10^-6 at an angular distance of about ten Airy radii.

Studies on unsaturated flow in dual-scale fiber fabrics

NASA Astrophysics Data System (ADS)

Yan, Fei; Yan, Shilin; Li, Yongjing

2018-03-01

Fiber fabrics in liquid composite molding (LCM) can be recognized as a dual-scale structure. As sink theory developed, this unsaturated flow behavior has already been simulated successfully; however, most of simulated results based on a unit cell under ideal status, thus making results were not agreement with experiment. In this study, an experimental method to establish sink function was proposed. After compared the simulation results by this sink function, it shows high accuracy with the experimental data. Subsequently, the key influencing factors for unsaturated flow have been further investigated; results show that the filling time for unsaturated flow was much longer than saturated flow. In addition, the injection pressure and permeability were the key factors lead to unsaturated flow.

FT-IR, FT-Raman, and DFT computational studies of melaminium nitrate molecular-ionic crystal

NASA Astrophysics Data System (ADS)

Tanak, Hasan; Marchewka, Mariusz K.

2013-02-01

The experimental and theoretical vibrational spectra of melaminium nitrate were studied. The Raman and infrared (FT-IR) spectra of the melaminium nitrate and its deuterated analogue were recorded in the solid phase. Molecular geometry and vibrational frequency values of melaminium nitrate in the electronic ground state were calculated using the density functional method (B3LYP) with the 6-31++G(d,p) basis set. The calculated results show that the optimized geometry can well reproduce the crystal structure, and the theoretical vibrational frequency values show good agreement with experimental values. The NBO analysis reveals that the N-H···O and N-H···N intermolecular interactions significantly influence crystal packing in this molecule.

An experimental/computational study of sharp fin induced shock wave/turbulent boundary layer interactions at Mach 5 - Experimental results

NASA Technical Reports Server (NTRS)

Rodi, Patrick E.; Dolling, David S.

1992-01-01

A combined experimental/computational study has been performed of sharp fin induced shock wave/turbulent boundary layer interactions at Mach 5. The current paper focuses on the experiments and analysis of the results. The experimental data include mean surface heat transfer, mean surface pressure distributions and surface flow visualization for fin angles of attack of 6, 8, 10, 12, 14 and 16-degrees at Mach 5 under a moderately cooled wall condition. Comparisons between the results and correlations developed earlier show that Scuderi's correlation for the upstream influence angle (recast in a conical form) is superior to other such correlations in predicting the current results, that normal Mach number based correlations for peak pressure heat transfer are adequate and that the initial heat transfer peak can be predicted using pressure-interaction theory.

Efficacy of a footbath for post-partum fatigue in South Korea: A quasi-experimental study.

PubMed

Choi, Eunsun; Song, Eunju

2017-04-01

The purpose of this study was to identify the effects of a footbath on post-partum fatigue. This study used a quasi-experimental design by using an unequivalent control group, pre-post-test design. The participants were divided into experimental and control groups. Fifty post-partum women who were admitted to an obstetrics and gynecology ward of a general hospital were the experimental group and 50 post-partum women who were admitted to an obstetrics and gynecology ward of a women's hospital were the control group. Two hospitals were providing similar postnatal care to their patients and they were located in the same city. The experimental group received a footbath along with postnatal care at the hospital, while the control group received only postnatal care from the hospital. Each group completed the Fatigue Continuum Form at a specified time. The general characteristics and pretest dependent variables were homogenous between the two groups. The hypothesis was supported post-test as the Fatigue Continuum Form scores differed significantly between the experimental and the control groups. This study showed that a footbath helps to decrease fatigue among post-partum women. In addition, it is a good preventative strategy for post-partum women who should initiate it in the early post-partum period. © 2016 Japan Academy of Nursing Science.

Experimental study on beam for composite CES structural system

NASA Astrophysics Data System (ADS)

Matsui, Tomoya

2017-10-01

Development study on Concrete Encase Steel (CES) composite structure system has been continuously conducted toward the practical use. CES structure is composed of steel and fiber reinforced concrete. In previous study, it was found that CES structure has good seismic performance from experimental study of columns, beam - column joints, shear walls and a two story two span frame. However, as fundamental study on CES beam could be lacking, it is necessary to understand the structural performance of CES beam. In this study, static loading tests of CES beams were conducted with experimental valuable of steel size, the presence or absence of slab and thickness of slab. And restoring characteristics, failure behavior, deformation behavior, and strength evaluation method of CES beam were investigated. As the results, it was found that CES beam showed stable hysteresis behavior. Furthermore it was found that the flexural strength of the CES beam could be evaluated by superposition strength theory.

Probabilistic motor sequence learning in a virtual reality serial reaction time task.

PubMed

Sense, Florian; van Rijn, Hedderik

2018-01-01

The serial reaction time task is widely used to study learning and memory. The task is traditionally administered by showing target positions on a computer screen and collecting responses using a button box or keyboard. By comparing response times to random or sequenced items or by using different transition probabilities, various forms of learning can be studied. However, this traditional laboratory setting limits the number of possible experimental manipulations. Here, we present a virtual reality version of the serial reaction time task and show that learning effects emerge as expected despite the novel way in which responses are collected. We also show that response times are distributed as expected. The current experiment was conducted in a blank virtual reality room to verify these basic principles. For future applications, the technology can be used to modify the virtual reality environment in any conceivable way, permitting a wide range of previously impossible experimental manipulations.

CFD Analysis of Evaporation-Condensation Phenomenon In an Evaporation Chamber of Natural Vacuum Solar Desalination

NASA Astrophysics Data System (ADS)

Ambarita, H.; Ronowikarto, A. D.; Siregar, R. E. T.; Setyawan, E. Y.

2018-01-01

Desalination technologies is one of solutions for water scarcity. With using renewable energy, like solar energy, wind energy, and geothermal energy, expected will reduce the energy demand. This required study on the modeling and transport parameters determination of natural vacuum solar desalination by using computational fluid dynamics (CFD) method to simulate the model. A three-dimensional case, two-phase model was developed for evaporation-condensation phenomenon in natural vacuum solar desalination. The CFD simulation results were compared with the avalaible experimental data. The simulation results shows inthat there is a phenomenon of evaporation-condensation in an evaporation chamber. From the simulation, the fresh water productivity is 2.21 litre, and from the experimental is 2.1 litre. This study shows there’s an error of magnitude 0.4%. The CFD results also show that, vacuum pressure will degrade the saturation temperature of sea water.

Modeling the Influence of Stitching on Delamination Growth in Stitched Warp-Knit Composite Lap Joints

NASA Technical Reports Server (NTRS)

Glaessgen, E. H.; Raju, I. S.; Poe, C. C., Jr.

1999-01-01

The effect of stitches on the failure of a single lap joint configuration was determined in a combined experimental and analytical study. The experimental study was conducted to determine debond growth under static monotonic loading. The stitches were shown to delay the initiation of the debond and provide load transfer beyond the load necessary to completely debond the stitched lap joint. The strain energy release rates at the debond front were calculated using a finite element-based technique. Models of the unstitched configuration showed significant values of modes I and II across the width of the joint and showed that mode III is zero at the centerline but increases near the free edge. Models of the stitched configuration showed that the stitches effectively reduced mode I to zero, but had less of an effect on modes II and III.

Multi-gene genetic programming based predictive models for municipal solid waste gasification in a fluidized bed gasifier.

PubMed

Pandey, Daya Shankar; Pan, Indranil; Das, Saptarshi; Leahy, James J; Kwapinski, Witold

2015-03-01

A multi-gene genetic programming technique is proposed as a new method to predict syngas yield production and the lower heating value for municipal solid waste gasification in a fluidized bed gasifier. The study shows that the predicted outputs of the municipal solid waste gasification process are in good agreement with the experimental dataset and also generalise well to validation (untrained) data. Published experimental datasets are used for model training and validation purposes. The results show the effectiveness of the genetic programming technique for solving complex nonlinear regression problems. The multi-gene genetic programming are also compared with a single-gene genetic programming model to show the relative merits and demerits of the technique. This study demonstrates that the genetic programming based data-driven modelling strategy can be a good candidate for developing models for other types of fuels as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

IR-IR Conformation Specific Spectroscopy of Na +(Glucose) Adducts

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

Voss, Jonathan M.; Kregel, Steven J.; Fischer, Kaitlyn C.

Here in this paper we report an IR-IR double resonance study of the structural landscape present in the Na +(glucose) complex. Our experimental approach involves minimal modifications to a typical IR predissociation setup, and can be carried out via ion-dip or isomer-burning methods, providing additional flexibility to suit different experimental needs. In the current study, the single-laser IR predissociation spectrum of Na +(glucose), which clearly indicates contributions from multiple structures, was experimentally disentangled to reveal the presence of three α-conformers and five β-conformers. Comparisons with calculations show that these eight conformations correspond to the lowest energy gas-phase structures with distinctivemore » Na+ coordination.« less

IR-IR Conformation Specific Spectroscopy of Na +(Glucose) Adducts

DOE PAGES

Voss, Jonathan M.; Kregel, Steven J.; Fischer, Kaitlyn C.; ...

2017-09-27

Here in this paper we report an IR-IR double resonance study of the structural landscape present in the Na +(glucose) complex. Our experimental approach involves minimal modifications to a typical IR predissociation setup, and can be carried out via ion-dip or isomer-burning methods, providing additional flexibility to suit different experimental needs. In the current study, the single-laser IR predissociation spectrum of Na +(glucose), which clearly indicates contributions from multiple structures, was experimentally disentangled to reveal the presence of three α-conformers and five β-conformers. Comparisons with calculations show that these eight conformations correspond to the lowest energy gas-phase structures with distinctivemore » Na+ coordination.« less

Experimental study of directionally solidified ferromagnetic shape memory alloy under multi-field coupling

NASA Astrophysics Data System (ADS)

Zhu, Yuping; Chen, Tao; Teng, Yao; Liu, Bingfei; Xue, Lijun

2016-11-01

Directionally solidified, polycrystalline Ni-Mn-Ga is studied in this paper. The polycrystalline Ni-Mn-Ga samples were cut at different angles to solidification direction. The magnetic field induced strain under constant stress and the temperature-induced strain under constant magnetic field during the loading-unloading cycle were measured. The experimental results show that the mechanical behavior during the loading-unloading cycle of the material is nonlinear and anisotropic. Based on the experimental results, the effects of multi-field coupling factors, such as stress, magnetic field, temperature and cutting angle on the mechanical behaviors were analyzed. Some useful conclusions were obtained, which will provide guidance for practical applications.

Comparison of 20-, 23-, and 25-gauge air infusion forces.

PubMed

Machado, Leonardo Martins; Magalhães, Octaviano; Maia, Mauricio; Rodrigues, Eduardo B; Farah, Michel Eid; Ismail, Kamal A R; Molon, Leandro; Oliveira, Danilo A

2011-11-01

To determine and compare 20-, 23-, and 25-gauge retinal infusion air jet impact pressure (force per unit area) in an experimental setting. Experimental laboratory investigation. Infusion cannulas were connected to a compressed air system. A controlled valve mechanism was used to obtain increasing levels of infusion pressure. Each infusion tube was positioned in front of a manual transducer to measure force. Impact pressure was calculated using known formulas in fluid dynamics. The 20-gauge infusion jet showed similar impact pressure values compared with the 23-gauge infusion jet. Both showed higher levels than the 25-gauge infusion jet. This was because of the smaller jet force for the 25-gauge system. In this experimental study, both the 23- and the 20-gauge air infusion jet showed higher impact pressure values compared with the 25-gauge air infusion jet. This could be of concern regarding air infusion during 23-gauge vitrectomy since retinal damage has been shown in standard-gauge surgeries.

Brief daily exposures to Asian females reverses perceptual narrowing for Asian faces in Caucasian infants

PubMed Central

Anzures, Gizelle; Wheeler, Andrea; Quinn, Paul C.; Pascalis, Olivier; Slater, Alan M.; Heron-Delaney, Michelle; Tanaka, James W.; Lee, Kang

2012-01-01

Perceptual narrowing in the visual, auditory, and multisensory domains has its developmental origins in infancy. The present study shows that experimentally induced experience can reverse the effects of perceptual narrowing on infants’ visual recognition memory of other-race faces. Caucasian 8- to 10-month-olds who could not discriminate between novel and familiarized Asian faces at the beginning of testing were given brief daily experience with Asian female faces in the experimental condition and Caucasian female faces in the control condition. At the end of three weeks, only infants who received daily experience with Asian females showed above-chance recognition of novel Asian female and male faces. Further, infants in the experimental condition showed greater efficiency in learning novel Asian females compared to infants in the control condition. Thus, visual experience with a novel stimulus category can reverse the effects of perceptual narrowing in infancy via improved stimulus recognition and encoding. PMID:22625845

The Use of Concept Map as a Consolidation Phase Based STAD to Enhance Students’ Comprehension about Environmental Pollution

NASA Astrophysics Data System (ADS)

Nugroho, O. F.; Chandra, D. T.; Sanjaya, Y.; Pendidikan Indonesia, Universitas

2017-02-01

The purpose of this study was to improve students’ concept comprehension using concept map as a consolidation phase based STAD. This study was conducted by randomized control group pretest-posttest. Data was collected by using an instrument test to evaluate the effect of concept map as a consolidation phase based STAD on students’understanding about environmental pollution. Data was analyzed using normalized gain (n-gain) and independent t-test. The n-gain analysis shows the increased of students’s understanding about environmental pollution at experimental group arehigher than at the control group. The result of this study showed that students’ comprehension at the experimental class (0,53) higher compared to the control group (0,23). Whilst the t-test analysis shows that there is a significant effect of mapping concept as a consolidation phase based STAD towards students’ concept comprehension. It can be concluded that the implementation of mapping concept based STAD may improve the students’s understanding on science concept.

Anomalous T2 relaxation in normal and degraded cartilage.

PubMed

Reiter, David A; Magin, Richard L; Li, Weiguo; Trujillo, Juan J; Pilar Velasco, M; Spencer, Richard G

2016-09-01

To compare the ordinary monoexponential model with three anomalous relaxation models-the stretched Mittag-Leffler, stretched exponential, and biexponential functions-using both simulated and experimental cartilage relaxation data. Monte Carlo simulations were used to examine both the ability of identifying a given model under high signal-to-noise ratio (SNR) conditions and the accuracy and precision of parameter estimates under more modest SNR as would be encountered clinically. Experimental transverse relaxation data were analyzed from normal and enzymatically degraded cartilage samples under high SNR and rapid echo sampling to compare each model. Both simulation and experimental results showed improvement in signal representation with the anomalous relaxation models. The stretched exponential model consistently showed the lowest mean squared error in experimental data and closely represents the signal decay over multiple decades of the decay time (e.g., 1-10 ms, 10-100 ms, and >100 ms). The stretched exponential parameter αse showed an inverse correlation with biochemically derived cartilage proteoglycan content. Experimental results obtained at high field suggest potential application of αse as a measure of matrix integrity. Simulation reflecting more clinical imaging conditions, indicate the ability to robustly estimate αse and distinguish between normal and degraded tissue, highlighting its potential as a biomarker for human studies. Magn Reson Med 76:953-962, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Effects of long-term experimental diabetes on adrenal gland growth and phosphoribosyl pyrophosphate formation in growth hormone-deficient dwarf rats.

PubMed

Kunjara, Sirilaksana; Greenbaum, A Leslie; McLean, Patricia; Grønbaek, Henning; Flyvbjerg, Allan

2012-06-01

The availability of growth hormone (GH)-deficient dwarf rats with otherwise normal pituitary function provides a powerful tool to examine the relative role of hyperglycaemia and the reordering of hormonal factors in the hypertrophy-hyperfunction of the adrenal gland that is seen in experimental diabetes. Here, we examine the effects of long-term (6 months) experimental diabetes on the growth of the adrenal glands; their content of phosphoribosyl pyrophosphate (PRPP); and the activity of the PRPP synthetase, G6P dehydrogenase and 6PG dehydrogenase enzymes in GH-deficient dwarf rats compared to heterozygous controls. These parameters were selected in view of the known role of PRPP in both de novo and salvage pathways of purine and pyrimidine synthesis and in the formation of NAD, and in view of the role of the oxidative enzymes of the pentose phosphate pathway in both R5P formation and the generation of the NADPH that is required in reductive synthetic reactions. This study shows that GH deficiency prevents the increase in adrenal gland weight, PRPP synthetase, PRPP content and G6P dehydrogenase and 6PG dehydrogenase. This contrasts sharply with the heterozygous group that showed the expected increase in these parameters. The blood glucose levels of the groups of long-term diabetic rats, both GH-deficient and heterozygous, remained at an elevated level throughout the experiment. These results are fully in accord with earlier evidence from studies with somatostatin analogues which showed that the GH-insulin-like growth factor I (IGF-I)-axis plays a key role in the adrenal diabetic hypertrophy-hyperfunction syndrome. © 2012 The Authors. International Journal of Experimental Pathology © 2012 International Journal of Experimental Pathology.

Long-term integrated studies show complex and surprising effects of climate change in northern hardwood forests

Treesearch

Peter M. Groffman; Lindsey Rustad; Pamela H. Templer; John Campbell; Lynn M. Christenson; Nina K. Lany; Anne M. Socci; Matthew A. Vadeboncoeur; Paul Schaberg; Geoffrey F. Wilson; Charles T. Driscoll; Timothy J. Fahey; Melany C. Fisk; Christine L. Goodale; Mark B. Green; Steven P. Hamburg; Chris E. Johnson; Myron J. Mitchell; Jennifer L. Morse; Linda H. Pardo; Nicholas L. Rodenhouse

2012-01-01

Evaluations of the local effects of global change are often confounded by the interactions of natural and anthropogenic factors that overshadow the effects of climate changes on ecosystems. Long-term watershed and natural elevation gradient studies at the Hubbard Brook Experimental Forest and in the surrounding region show surprising results demonstrating the effects...

Study on the thermal distribution and thermal management of high average power fiber lasers

NASA Astrophysics Data System (ADS)

Zhang, Yongliang; Zhao, Lei; Liang, Xiaobao; Li, Chao; Zhou, Taidou; Wang, Shiwei; Deng, Ying; Wei, Xiaofeng

2015-02-01

The thermal problems of CPS and YDF were studied. And the thermal management technologies are developed separately to the problems. Experimental results showed that the thermal management technologies worked well.

Ultrasound as visual feedback in speech habilitation: exploring consultative use in rural British Columbia, Canada.

PubMed

Bernhardt, May B; Bacsfalvi, Penelope; Adler-Bock, Marcy; Shimizu, Reiko; Cheney, Audrey; Giesbrecht, Nathan; O'connell, Maureen; Sirianni, Jason; Radanov, Bosko

2008-02-01

Ultrasound has shown promise as a visual feedback tool in speech therapy. Rural clients, however, often have minimal access to new technologies. The purpose of the current study was to evaluate consultative treatment using ultrasound in rural communities. Two speech-language pathologists (SLPs) trained in ultrasound use provided consultation with ultrasound in rural British Columbia to 13 school-aged children with residual speech impairments. Local SLPs provided treatment without ultrasound before and after the consultation. Speech samples were transcribed phonetically by independent trained listeners. Eleven children showed greater gains in production of the principal target /[image omitted]/ after the ultrasound consultation. Four of the seven participants who received more consultation time with ultrasound showed greatest improvement. Individual client factors also affected outcomes. The current study was a quasi-experimental clinic-based study. Larger, controlled experimental studies are needed to provide ultimate evaluation of the consultative use of ultrasound in speech therapy.

Comparison of modeled estimates of inhalation exposure to aerosols during use of consumer spray products.

PubMed

Park, Jihoon; Yoon, Chungsik; Lee, Kiyoung

2018-05-30

In the field of exposure science, various exposure assessment models have been developed to complement experimental measurements; however, few studies have been published on their validity. This study compares the estimated inhaled aerosol doses of several inhalation exposure models to experimental measurements of aerosols released from consumer spray products, and then compares deposited doses within different parts of the human respiratory tract according to deposition models. Exposure models, including the European Center for Ecotoxicology of Chemicals Targeted Risk Assessment (ECETOC TRA), the Consumer Exposure Model (CEM), SprayExpo, ConsExpo Web and ConsExpo Nano, were used to estimate the inhaled dose under various exposure scenarios, and modeled and experimental estimates were compared. The deposited dose in different respiratory regions was estimated using the International Commission on Radiological Protection model and multiple-path particle dosimetry models under the assumption of polydispersed particles. The modeled estimates of the inhaled doses were accurate in the short term, i.e., within 10 min of the initial spraying, with a differences from experimental estimates ranging from 0 to 73% among the models. However, the estimates for long-term exposure, i.e., exposure times of several hours, deviated significantly from the experimental estimates in the absence of ventilation. The differences between the experimental and modeled estimates of particle number and surface area were constant over time under ventilated conditions. ConsExpo Nano, as a nano-scale model, showed stable estimates of short-term exposure, with a difference from the experimental estimates of less than 60% for all metrics. The deposited particle estimates were similar among the deposition models, particularly in the nanoparticle range for the head airway and alveolar regions. In conclusion, the results showed that the inhalation exposure models tested in this study are suitable for estimating short-term aerosol exposure (within half an hour), but not for estimating long-term exposure. Copyright © 2018 Elsevier GmbH. All rights reserved.

Maternal and fetal immune response patterns in heifers experimentally infected with Neospora caninum in the second trimester of pregnancy- A descriptive study

USDA-ARS?s Scientific Manuscript database

Fetal and maternal immune responses 3, 6 and 9 weeks post infection (wpi) were investigated in cows experimentally infected with Neospora caninum on day 110 of gestation. Descriptive analysis showed that the fetuses had lower percentages of spleen T cell subpopulations (CD3+, CD4+ and CD8+) at 6 wpi...

Experimental StudyHigh Altitude Forced Convective Cooling of Electromechanical Actuation Systems

DTIC Science & Technology

2016-01-01

experimental validation at altitudes above 16,000 feet, relevant to commercial and military aircraft. The convective heat transfer coefficient at altitudes...and natural occurring phenomena. Figure 1.3 also shows that a typical flight ceiling for commercial and military air breathing aircraft is about...However, they have not been extensively vetted in atmospheric conditions experienced by commercial and tactical military aircraft. 1.3 Purpose

The experimenters' regress reconsidered: Replication, tacit knowledge, and the dynamics of knowledge generation.

PubMed

Feest, Uljana

2016-08-01

This paper revisits the debate between Harry Collins and Allan Franklin, concerning the experimenters' regress. Focusing my attention on a case study from recent psychology (regarding experimental evidence for the existence of a Mozart Effect), I argue that Franklin is right to highlight the role of epistemological strategies in scientific practice, but that his account does not sufficiently appreciate Collins's point about the importance of tacit knowledge in experimental practice. In turn, Collins rightly highlights the epistemic uncertainty (and skepticism) surrounding much experimental research. However, I will argue that his analysis of tacit knowledge fails to elucidate the reasons why scientists often are (and should be) skeptical of other researchers' experimental results. I will present an analysis of tacit knowledge in experimental research that not only answers to this desideratum, but also shows how such skepticism can in fact be a vital enabling factor for the dynamic processes of experimental knowledge generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Latency correction of event-related potentials between different experimental protocols

NASA Astrophysics Data System (ADS)

Iturrate, I.; Chavarriaga, R.; Montesano, L.; Minguez, J.; Millán, JdR

2014-06-01

Objective. A fundamental issue in EEG event-related potentials (ERPs) studies is the amount of data required to have an accurate ERP model. This also impacts the time required to train a classifier for a brain-computer interface (BCI). This issue is mainly due to the poor signal-to-noise ratio and the large fluctuations of the EEG caused by several sources of variability. One of these sources is directly related to the experimental protocol or application designed, and may affect the amplitude or latency of ERPs. This usually prevents BCI classifiers from generalizing among different experimental protocols. In this paper, we analyze the effect of the amplitude and the latency variations among different experimental protocols based on the same type of ERP. Approach. We present a method to analyze and compensate for the latency variations in BCI applications. The algorithm has been tested on two widely used ERPs (P300 and observation error potentials), in three experimental protocols in each case. We report the ERP analysis and single-trial classification. Main results. The results obtained show that the designed experimental protocols significantly affect the latency of the recorded potentials but not the amplitudes. Significance. These results show how the use of latency-corrected data can be used to generalize the BCIs, reducing the calibration time when facing a new experimental protocol.

The effect of incorporating different concentrations of chlorhexidine digluconate on the degree of conversion of an experimental adhesive resin.

PubMed

Moharam, Lamiaa-Mahmoud; Salem, Haidy-Nabil; Elgamily, Hanaa-Mahmoud

2018-04-01

The aim of this study was to evaluate the effect of chlorhexidine digluconate incorporation on the degree of conversion of an experimental adhesive resin. The experimental resin was prepared from 70 wt% bisphenol A glycerolate dimethacrylate, 30 wt% hydroxyethyl methacrylate, silanized SiO2 nanofillers, 0.5% of camphorquinone and ethyl 4-dimethylaminebenzoate (binary photo-initiator system). Five chlorhexidine digluconate concentrations (0, 0.5, 1, 2 and 4 wt%) were then incorporated into the experimental resin. Thirty Potassium Bromide pellets were prepared then divided into six groups (n=5/group), repre¬senting the tested adhesive resins (Single Bond 2, 0, 0.5, 1, 2 and 4 wt% chlohexidine-incorporated experimental adhesive resins), that were applied to the pellets without light-curing (uncured specimens). Another 30 pellets were prepared and treated with the previous materials then light-cured using LED light-curing device (cured specimens). Degree of conversion of the uncured and the cured specimens were evaluated using FTIR analysis. Adper Single Bond 2 showed the highest degree of conversion mean values followed by 0.5 wt% chlorhexidine concentration then 2 wt% followed by 4 wt% then 1 wt% concentrations, while 0 wt% concentration showed the lowest mean values. Chlorhexidine digluconate had slight significant influence on the efficiency of polymerization of the experimental adhesive resin. Key words: Chlorhexidine digluconate, different concentrations, degree of conversion, experimental adhesive resin.

A Comparative Study of Collagen Matrix Density Effect on Endothelial Sprout Formation Using Experimental and Computational Approaches.

PubMed

Shamloo, Amir; Mohammadaliha, Negar; Heilshorn, Sarah C; Bauer, Amy L

2016-04-01

A thorough understanding of determining factors in angiogenesis is a necessary step to control the development of new blood vessels. Extracellular matrix density is known to have a significant influence on cellular behaviors and consequently can regulate vessel formation. The utilization of experimental platforms in combination with numerical models can be a powerful method to explore the mechanisms of new capillary sprout formation. In this study, using an integrative method, the interplay between the matrix density and angiogenesis was investigated. Owing the fact that the extracellular matrix density is a global parameter that can affect other parameters such as pore size, stiffness, cell-matrix adhesion and cross-linking, deeper understanding of the most important biomechanical or biochemical properties of the ECM causing changes in sprout morphogenesis is crucial. Here, we implemented both computational and experimental methods to analyze the mechanisms responsible for the influence of ECM density on the sprout formation that is difficult to be investigated comprehensively using each of these single methods. For this purpose, we first utilized an innovative approach to quantify the correspondence of the simulated collagen fibril density to the collagen density in the experimental part. Comparing the results of the experimental study and computational model led to some considerable achievements. First, we verified the results of the computational model using the experimental results. Then, we reported parameters such as the ratio of proliferating cells to migrating cells that was difficult to obtain from experimental study. Finally, this integrative system led to gain an understanding of the possible mechanisms responsible for the effect of ECM density on angiogenesis. The results showed that stable and long sprouts were observed at an intermediate collagen matrix density of 1.2 and 1.9 mg/ml due to a balance between the number of migrating and proliferating cells. As a result of weaker connections between the cells and matrix, a lower collagen matrix density (0.7 mg/ml) led to unstable and broken sprouts. However, higher matrix density (2.7 mg/ml) suppressed sprout formation due to the high level of matrix entanglement, which inhibited cell migration. This study also showed that extracellular matrix density can influence sprout branching. Our experimental results support this finding.

Comparison between Different Methods for Biomechanical Assessment of Ex Vivo Fracture Callus Stiffness in Small Animal Bone Healing Studies

PubMed Central

Steiner, Malte; Volkheimer, David; Meyers, Nicholaus; Wehner, Tim; Wilke, Hans-Joachim; Claes, Lutz; Ignatius, Anita

2015-01-01

For ex vivo measurements of fracture callus stiffness in small animals, different test methods, such as torsion or bending tests, are established. Each method provides advantages and disadvantages, and it is still debated which of those is most sensitive to experimental conditions (i.e. specimen alignment, directional dependency, asymmetric behavior). The aim of this study was to experimentally compare six different testing methods regarding their robustness against experimental errors. Therefore, standardized specimens were created by selective laser sintering (SLS), mimicking size, directional behavior, and embedding variations of respective rat long bone specimens. For the latter, five different geometries were created which show shifted or tilted specimen alignments. The mechanical tests included three-point bending, four-point bending, cantilever bending, axial compression, constrained torsion, and unconstrained torsion. All three different bending tests showed the same principal behavior. They were highly dependent on the rotational direction of the maximum fracture callus expansion relative to the loading direction (creating experimental errors of more than 60%), however small angular deviations (<15°) were negligible. Differences in the experimental results between the bending tests originate in their respective location of maximal bending moment induction. Compared to four-point bending, three-point bending is easier to apply on small rat and mouse bones under realistic testing conditions and yields robust measurements, provided low variation of the callus shape among the tested specimens. Axial compressive testing was highly sensitive to embedding variations, and therefore cannot be recommended. Although it is experimentally difficult to realize, unconstrained torsion testing was found to be the most robust method, since it was independent of both rotational alignment and embedding uncertainties. Constrained torsional testing showed small errors (up to 16.8%, compared to corresponding alignment under unconstrained torsion) due to a parallel offset between the specimens’ axis of gravity and the torsional axis of rotation. PMID:25781027

Experimental Lung Cancer Drug Shows Early Promise | Frederick National Laboratory for Cancer Research

Cancer.gov

A first-of-its-kind drug is showing early promise in attacking certain lung cancers that are hard to treat because they build up resistance to conventional chemotherapy. The drug, CO-1686, performed well in a preclinical study involving xenograft and

On the relationship between justice and forgiveness: are all forms of justice made equal?

PubMed

Wenzel, Michael; Okimoto, Tyler G

2014-09-01

This research investigates whether, following a wrongdoing, the restoration of justice promotes forgiveness. Three studies - one correlational recall study and two experimental scenario studies - provide evidence that while a restored sense of justice is overall positively related to forgiveness, forgiveness is highly dependent on the means of justice restoration being retributive (punitive) versus restorative (consensus-seeking) in nature. The findings showed that, overall, restorative but not retributive responses led to greater forgiveness. Although both retributive and restorative responses appeared to increase forgiveness indirectly through increased feelings of justice, for retributive responses these effects were counteracted by direct effects on forgiveness. Moreover, the experimental evidence showed that, while feelings of justice derived from restorative responses were positively related to forgiveness, feelings of justice derived from retributive responses were not. © 2013 The British Psychological Society.

The perception of animal experimentation ethics among Indian teenage school pupils.

PubMed

Kim, Justin Namuk; Choi, Eun Hee; Kim, Soo-Ki

2017-03-01

To promote awareness of animal experimentation ethics among teenagers, we created an educational pamphlet and an accompanying questionnaire. One hundred Indian teenage school pupils were given the pamphlet and subsequently surveyed with the questionnaire, to evaluate: a) their perception of animal experimentation ethics; and b) their opinion on the effectiveness of the pamphlet, according to gender and school grade/age. There was a significant correlation between grade/age and support for animal experimentation, i.e. senior students were more inclined to show support for animal experimentation. There was also a significant correlation between gender and perception of the need to learn about animal experimentation ethics, with girls more likely to feel the need to learn about ethics than boys. In addition, the four questions relating to the usefulness of the pamphlet, and student satisfaction with its content, received positive responses from the majority of the students. Even though the pamphlet was concise, it was apparent that three quarters of the students were satisfied with its content. Gender and age did not influence this level of satisfaction. Overall, our study shows that there is a significant correlation between a pupil`s school grade/age and their support for animal experimentation, and that there is also a significant correlation between gender and the perceived need to learn about animal experimentation ethics. This pilot scheme involving an educational pamphlet and questionnaire could be beneficial in helping to formulate basic strategies for educating teenage school pupils about animal ethics. 2017 FRAME.

Pharmacological inhibition of PAR2 with the pepducin P2pal-18S protects mice against acute experimental biliary pancreatitis.

PubMed

Michael, E S; Kuliopulos, A; Covic, L; Steer, M L; Perides, G

2013-03-01

Pancreatic acinar cells express proteinase-activated receptor-2 (PAR2) that is activated by trypsin-like serine proteases and has been shown to exert model-specific effects on the severity of experimental pancreatitis, i.e., PAR2(-/-) mice are protected from experimental acute biliary pancreatitis but develop more severe secretagogue-induced pancreatitis. P2pal-18S is a novel pepducin lipopeptide that targets and inhibits PAR2. In studies monitoring PAR2-stimulated intracellular Ca(2+) concentration changes, we show that P2pal-18S is a full PAR2 inhibitor in acinar cells. Our in vivo studies show that P2pal-18S significantly reduces the severity of experimental biliary pancreatitis induced by retrograde intraductal bile acid infusion, which mimics injury induced by endoscopic retrograde cholangiopancreatography (ERCP). This reduction in pancreatitis severity is observed when the pepducin is given before or 2 h after bile acid infusion but not when it is given 5 h after bile acid infusion. Conversely, P2pal-18S increases the severity of secretagogue-induced pancreatitis. In vitro studies indicate that P2pal-18S protects acinar cells against bile acid-induced injury/death, but it does not alter bile acid-induced intracellular zymogen activation. These studies are the first to report the effects of an effective PAR2 pharmacological inhibitor on pancreatic acinar cells and on the severity of experimental pancreatitis. They raise the possibility that a pepducin such as P2pal-18S might prove useful in the clinical management of patients at risk for developing severe biliary pancreatitis such as occurs following ERCP.

On the mechanical stability of porous coated press fit titanium implants: a finite element study of a pushout test.

PubMed

Helgason, Benedikt; Viceconti, Marco; Rúnarsson, Tómas P; Brynjólfsson, Sigurour

2008-01-01

Pushout tests can be used to estimate the shear strength of the bone implant interface. Numerous such experimental studies have been published in the literature. Despite this researchers are still some way off with respect to the development of accurate numerical models to simulate implant stability. In the present work a specific experimental pushout study from the literature was simulated using two different bones implant interface models. The implant was a porous coated Ti-6Al-4V retrieved 4 weeks postoperatively from a dog model. The purpose was to find out which of the interface models could replicate the experimental results using physically meaningful input parameters. The results showed that a model based on partial bone ingrowth (ingrowth stability) is superior to an interface model based on friction and prestressing due to press fit (initial stability). Even though the present study is limited to a single experimental setup, the authors suggest that the presented methodology can be used to investigate implant stability from other experimental pushout models. This would eventually enhance the much needed understanding of the mechanical response of the bone implant interface and help to quantify how implant stability evolves with time.

Development and Validation of Computational Fluid Dynamics Models for Prediction of Heat Transfer and Thermal Microenvironments of Corals

PubMed Central

Ong, Robert H.; King, Andrew J. C.; Mullins, Benjamin J.; Cooper, Timothy F.; Caley, M. Julian

2012-01-01

We present Computational Fluid Dynamics (CFD) models of the coupled dynamics of water flow, heat transfer and irradiance in and around corals to predict temperatures experienced by corals. These models were validated against controlled laboratory experiments, under constant and transient irradiance, for hemispherical and branching corals. Our CFD models agree very well with experimental studies. A linear relationship between irradiance and coral surface warming was evident in both the simulation and experimental result agreeing with heat transfer theory. However, CFD models for the steady state simulation produced a better fit to the linear relationship than the experimental data, likely due to experimental error in the empirical measurements. The consistency of our modelling results with experimental observations demonstrates the applicability of CFD simulations, such as the models developed here, to coral bleaching studies. A study of the influence of coral skeletal porosity and skeletal bulk density on surface warming was also undertaken, demonstrating boundary layer behaviour, and interstitial flow magnitude and temperature profiles in coral cross sections. Our models compliment recent studies showing systematic changes in these parameters in some coral colonies and have utility in the prediction of coral bleaching. PMID:22701582

Analytical and experimental analysis of solute transport in heterogeneous porous media.

PubMed

Wu, Lei; Gao, Bin; Tian, Yuan; Muñoz-Carpena, Rafael

2014-01-01

Knowledge of solute transport in heterogeneous porous media is crucial to monitor contaminant fate and transport in soil and groundwater systems. In this study, we present new findings from experimental and mathematical analysis to improve current understanding of solute transport in structured heterogeneous porous media. Three saturated columns packed with different sand combinations were used to examine the breakthrough behavior of bromide, a conservative tracer. Experimental results showed that bromide had different breakthrough responses in the three types of sand combinations, indicating that heterogeneity in hydraulic conductivity has a significant effect on the solute transport in structured heterogeneous porous media. Simulations from analytical solutions of a two-domain solute transport model matched experimental breakthrough data well for all the experimental conditions tested. Experimental and model results show that under saturated flow conditions, advection dominates solute transport in both fast-flow and slow-flow domains. The sand with larger hydraulic conductivity provided a preferential flow path for solute transport (fast-flow domain) that dominates the mass transfer in the heterogeneous porous media. Importantly, the transport in the slow-flow domain and mass exchange between the domains also contribute to the flow and solute transport processes and thus must be considered when investigating contaminant transport in heterogeneous porous media.

Ectopic bone formation during tissue-engineered cartilage repair using autologous chondrocytes and novel plasma-derived albumin scaffolds.

PubMed

Robla Costales, David; Junquera, Luis; García Pérez, Eva; Gómez Llames, Sara; Álvarez-Viejo, María; Meana-Infiesta, Álvaro

2016-10-01

The aims of this study were twofold: first, to evaluate the production of cartilaginous tissue in vitro and in vivo using a novel plasma-derived scaffold, and second, to test the repair of experimental defects made on ears of New Zealand rabbits (NZr) using this approach. Scaffolds were seeded with chondrocytes and cultured in vitro for 3 months to check in vitro cartilage production. To evaluate in vivo cartilage production, a chondrocyte-seeded scaffold was transplanted subcutaneously to a nude mouse. To check in vivo repair, experimental defects made in the ears of five New Zealand rabbits (NZr) were filled with chondrocyte-seeded scaffolds. In vitro culture produced mature chondrocytes with no extracellular matrix (ECM). Histological examination of redifferentiated in vitro cultures showed differentiated chondrocytes adhered to scaffold pores. Subcutaneous transplantation of these constructs to a nude mouse produced cartilage, confirmed by histological study. Experimental cartilage repair in five NZr showed cartilaginous tissue repairing the defects, mixed with calcified areas of bone formation. It is possible to produce cartilaginous tissue in vivo and to repair experimental auricular defects by means of chondrocyte cultures and the novel plasma-derived scaffold. Further studies are needed to determine the significance of bone formation in the samples. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

The Perspective Structure of Visual Space

PubMed Central

2015-01-01

Luneburg’s model has been the reference for experimental studies of visual space for almost seventy years. His claim for a curved visual space has been a source of inspiration for visual scientists as well as philosophers. The conclusion of many experimental studies has been that Luneburg’s model does not describe visual space in various tasks and conditions. Remarkably, no alternative model has been suggested. The current study explores perspective transformations of Euclidean space as a model for visual space. Computations show that the geometry of perspective spaces is considerably different from that of Euclidean space. Collinearity but not parallelism is preserved in perspective space and angles are not invariant under translation and rotation. Similar relationships have shown to be properties of visual space. Alley experiments performed early in the nineteenth century have been instrumental in hypothesizing curved visual spaces. Alleys were computed in perspective space and compared with reconstructed alleys of Blumenfeld. Parallel alleys were accurately described by perspective geometry. Accurate distance alleys were derived from parallel alleys by adjusting the interstimulus distances according to the size-distance invariance hypothesis. Agreement between computed and experimental alleys and accommodation of experimental results that rejected Luneburg’s model show that perspective space is an appropriate model for how we perceive orientations and angles. The model is also appropriate for perceived distance ratios between stimuli but fails to predict perceived distances. PMID:27648222

Improving Middle School Students’ Quantitative Literacy through Inquiry Lab and Group Investigation

NASA Astrophysics Data System (ADS)

Aisya, N. S. M.; Supriatno, B.; Saefudin; Anggraeni, S.

2017-02-01

The purpose of this study was to analyze the application of metacognitive strategies learning based Vee Diagram through Inquiry Lab and Group Investigation toward students’ quantitative literacy. This study compared two treatments on learning activity in middle school. The metacognitive strategies have applied to the content of environmental pollution at 7th grade. This study used a quantitative approach with quasi-experimental method. The research sample were the 7th grade students, involves 27 students in the experimental through Inquiry Lab and 27 students in the experimental through Group Investigation. The instruments that used in this research were pretest and posttest quantitative literacy skills, learning step observation sheets, and the questionnaire of teachers and students responses. As the result, N-gain average of pretest and posttest increased in both experimental groups. The average of posttest score was 61,11 for the Inquiry Lab and 54,01 to the Group Investigation. The average score of N-gain quantitative literacy skill of Inquiry Lab class was 0,492 and Group Investigation class was 0,426. Both classes of experiments showed an average N-gain in the medium category. The data has been analyzed statistically by using SPSS ver.23 and the results showed that although both the learning model can develop quantitative literacy, but there is not significantly different of improving students’ quantitative literacy between Inquiry Lab and Group Investigation in environmental pollution material.

Study of a variable mass Atwood's machine using a smartphone

NASA Astrophysics Data System (ADS)

Lopez, Dany; Caprile, Isidora; Corvacho, Fernando; Reyes, Orfa

2018-03-01

The Atwood machine was invented in 1784 by George Atwood and this system has been widely studied both theoretically and experimentally over the years. Nowadays, it is commonplace that many experimental physics courses include both Atwood's machine and variable mass to introduce more complex concepts in physics. To study the dynamics of the masses that compose the variable Atwood's machine, laboratories typically use a smart pulley. Now, the first work that introduced a smartphone as data acquisition equipment to study the acceleration in the Atwood's machine was the one by M. Monteiro et al. Since then, there has been no further information available on the usage of smartphones in variable mass systems. This prompted us to do a study of this kind of system by means of data obtained with a smartphone and to show the practicality of using smartphones in complex experimental situations.

Influence of Problem Based Learning on Critical Thinking Skills and Competence Class VIII SMPN 1 Gunuang Omeh, 2016/2017

NASA Astrophysics Data System (ADS)

Aswan, D. M.; Lufri, L.; Sumarmin, R.

2018-04-01

This research intends to determine the effect of Problem Based Learning models on students' critical thinking skills and competences. This study was a quasi-experimental research. The population of the study was the students of class VIII SMPN 1 Subdistrict Gunuang Omeh. Random sample selection is done by randomizing the class. Sample class that was chosen VIII3 as an experimental class given that treatment study based on problems and class VIII1 as control class that treatment usually given study. Instrument that used to consist of critical thinking test, cognitive tests, observation sheet of affective and psychomotor. Independent t-test and Mann Whitney U test was used for the analysis. Results showed that there was significant difference (sig <0.05) between control and experimental group. The conclusion of this study was Problem Based Learning models affected the students’ critical thinking skills and competences.

USM3D Predictions of Supersonic Nozzle Flow

NASA Technical Reports Server (NTRS)

Carter, Melissa B.; Elmiligui, Alaa A.; Campbell, Richard L.; Nayani, Sudheer N.

2014-01-01

This study focused on the NASA Tetrahedral Unstructured Software System CFD code (USM3D) capability to predict supersonic plume flow. Previous studies, published in 2004 and 2009, investigated USM3D's results versus historical experimental data. This current study continued that comparison however focusing on the use of the volume souring to capture the shear layers and internal shock structure of the plume. This study was conducted using two benchmark axisymmetric supersonic jet experimental data sets. The study showed that with the use of volume sourcing, USM3D was able to capture and model a jet plume's shear layer and internal shock structure.

Combining experimental evolution with next-generation sequencing: a powerful tool to study adaptation from standing genetic variation.

PubMed

Schlötterer, C; Kofler, R; Versace, E; Tobler, R; Franssen, S U

2015-05-01

Evolve and resequence (E&R) is a new approach to investigate the genomic responses to selection during experimental evolution. By using whole genome sequencing of pools of individuals (Pool-Seq), this method can identify selected variants in controlled and replicable experimental settings. Reviewing the current state of the field, we show that E&R can be powerful enough to identify causative genes and possibly even single-nucleotide polymorphisms. We also discuss how the experimental design and the complexity of the trait could result in a large number of false positive candidates. We suggest experimental and analytical strategies to maximize the power of E&R to uncover the genotype-phenotype link and serve as an important research tool for a broad range of evolutionary questions.

Towards ethically improved animal experimentation in the study of animal reproduction.

PubMed

Blache, D; Martin, G B; Maloney, S K

2008-07-01

The ethics of animal-based research is a continuing area of debate, but ethical research protocols do not prevent scientific progress. In this paper, we argue that our current knowledge of the factors that affect reproductive processes provides researchers with a solid foundation upon which they can conduct more ethical research and simultaneously produce data of higher quality. We support this argument by showing how a deep understanding of the genetics, nutrition and temperament of our experimental animals can improve compliance with two of the '3 Rs', reduction and refinement, simply by offering better control over the variance in our experimental model. The outcome is a better experimental design, on both ethical and scientific grounds.

Experimental pragmatics: a Gricean turn in the study of language.

PubMed

Noveck, Ira A; Reboul, Anne

2008-11-01

Discerning the meaning of an utterance requires not only mastering grammar and knowing the meanings of words but also understanding the communicative (i.e., pragmatic) features of language. Although it has been an ever present aspect of linguistic analyses and discussions, it is only over the last ten years or so that cognitive scientists have been investigating--in a concerted fashion--the pragmatic features of language experimentally. We begin by highlighting Paul Grice's contributions to ordinary language philosophy and show how it has led to this active area of experimental investigation. We then focus on two exemplary phenomena--'scalar inference' and 'reference resolution'--before considering other topics that fit into the paradigm known as 'experimental pragmatics'.

Atomic bonding effects in annular dark field scanning transmission electron microscopy. II. Experiments

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

Odlyzko, Michael L.; Held, Jacob T.; Mkhoyan, K. Andre, E-mail: mkhoyan@umn.edu

2016-07-15

Quantitatively calibrated annular dark field scanning transmission electron microscopy (ADF-STEM) imaging experiments were compared to frozen phonon multislice simulations adapted to include chemical bonding effects. Having carefully matched simulation parameters to experimental conditions, a depth-dependent bonding effect was observed for high-angle ADF-STEM imaging of aluminum nitride. This result is explained by computational predictions, systematically examined in the preceding portion of this study, showing the propagation of the converged STEM beam to be highly sensitive to net interatomic charge transfer. Thus, although uncertainties in experimental conditions and simulation accuracy remain, the computationally predicted experimental bonding effect withstands the experimental testing reportedmore » here.« less

Impact of finite rate chemistry on the hydrodynamic stability of shear flows in turbulent lean premixed combustion

NASA Astrophysics Data System (ADS)

Dagan, Yuval; Ghoniem, Ahmed

2017-11-01

Recent experimental observations show that the dynamic response of a reactive flow is strongly impacted by the fuel chemistry. In order to gain insight into some of the underlying mechanisms we formulate a new linear stability model that incorporates the impact of finite rate chemistry on the hydrodynamic stability of shear flows. Contrary to previous studies which typically assume that the velocity field is independent of the kinetic rates, the velocity field in our study is coupled with the temperature field. Using this formulation, we reproduce previous results, e.g., most unstable global modes, obtained for non-reacting shear flow. Moreover, we show that these modes are significantly altered in frequency and gain by the presence of a reaction region within the shear layer. This qualitatively agrees with results of our recent experimental and numerical studies, which show that the flame surface location relative to the shear layer influences the stability characteristics in combustion tunnels. This study suggests a physical explanation for the observed impact of finite rate chemistry on shear flow stability.

Emotion Regulation as the Foundation of Political Attitudes: Does Reappraisal Decrease Support for Conservative Policies?

PubMed Central

Lee, Jooa Julia; Sohn, Yunkyu; Fowler, James H.

2013-01-01

Cognitive scientists, behavior geneticists, and political scientists have identified several ways in which emotions influence political attitudes, and psychologists have shown that emotion regulation can have an important causal effect on physiology, cognition, and subjective experience. However, no work to date explores the possibility that emotion regulation may shape political ideology and attitudes toward policies. Here, we conduct four studies that investigate the role of a particular emotion regulation strategy – reappraisal in particular. Two observational studies show that individual differences in emotion regulation styles predict variation in political orientations and support for conservative policies. In the third study, we experimentally induce disgust as the target emotion to be regulated and show that use of reappraisal reduces the experience of disgust, thereby decreasing moral concerns associated with conservatism. In the final experimental study, we show that use of reappraisal successfully attenuates the relationship between trait-level disgust sensitivity and support for conservative policies. Our findings provide the first evidence of a critical link between emotion regulation and political attitudes. PMID:24367583

Fusion and Sense Making of Heterogeneous Sensor Network and Other Sources

DTIC Science & Technology

2017-03-16

multimodal fusion framework that uses both training data and web resources for scene classification, the experimental results on the benchmark datasets...show that the proposed text-aided scene classification framework could significantly improve classification performance. Experimental results also show...human whose adaptability is achieved by reliability- dependent weighting of different sensory modalities. Experimental results show that the proposed

Influence of abutment design on the success of immediately loaded dental implants: experimental and numerical studies.

PubMed

Hasan, I; Röger, B; Heinemann, F; Keilig, L; Bourauel, C

2012-09-01

The aim of the present study was to investigate experimentally and numerically the influence of a fine threaded- against a roughened-cervical region of immediately loaded dental implants in combination with straight and 20°-angled abutments on the implant primary stability. A total of 30 implants were inserted in bovine rib-segments, 14 cervically roughened implants and 16 implants with fine cervical threads. Each implant system received two abutments, straight and 20°-angled. Implant displacements and rotations were measured using a biomechanical measurement system. Subsequently, eight samples were selected for geometrical reconstruction and numerical investigation of stress and strain distributions in the bone by means of the finite element method. Experimentally, both implant systems showed similar behaviour with the straight abutments concerning displacements and rotations. However, fine threaded implants showed much less displacement and rotation against roughened implants when angled abutments were considered. Numerically, stresses were within 35-45 MPa in the cortical bone for both implant systems. The strains showed highest values within the spongious bone with the roughened implants connected to angled abutments. The results indicate that implants with fine cervical threads could be recommended in particular with angled abutments. The outcomes of this study are currently confirmed by long-term clinical investigations. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Effect of Cefotaxime on the CAT Activities and GSH Contents of Zebrafish

NASA Astrophysics Data System (ADS)

Wang, Yaxue; Shen, Hong-Yan

2018-05-01

In order to define eco-toxicity effect of cefotaxime on zebrafish, the indoor exposure method was used to study the impact of cefotaxime on zebrafish. In this study, zebrafish was exposed to cefotaxime of 1mg/L, 5mg/L, 25mg/L and 125mg/L for 15 days to study the effect of Catalase (CAT) activities and Glutathione (GSH) contents. According to the experimental data, the CAT activities and GSH contents in zebrafish muscle tissue had changed significantly during the period of exposure. The experimental results show that the activities of CAT in four concentration groups were significantly inhibited (P<0.01). The CAT activities in the 1 mg/L and 5 mg/L groups showed the "Λ" type change, inhibited first and induced later. But in the 25 mg/L and 125 mg/L groups, the CAT activities were inhibited all the time. Cefotaxime had a significant effect on GSH content in the muscle tissue of the zebrafish at the early stage of exposure, rapidly increase to the maximum at the early stage and rapidly decrease to the minimum on the 6th day. During 6th day to 15th day, the contents of GSH in the zebrafish were basically stable at the level of control. The experimental results show that the CAT activities and GSH contents in zebrafish muscle tissue had changed significantly.

Experimental and theoretical studies of 3-benzyloxy-2-nitropyridine

NASA Astrophysics Data System (ADS)

Sun, Wenting; Cui, Yu; Liu, Huimin; Zhao, Haitao; Zhang, Wenqin

2012-10-01

The structure of 3-benzyloxy-2-nitropyridine has been investigated both experimentally and theoretically. The X-ray crystallography results show that the nitro group is tilted out of the pyridine ring plane by 66.4(4)°, which is mainly attributed to the electron-electron repulsions of the lone pairs in O atom of the 3-benzyloxy moiety with O atom in nitro group. An interesting centrosymmetric π-stacking molecular pair has been found in the crystalline state, which results in the approximate coplanarity of the pyridine ring with the benzene ring. The calculated results show that the dihedral angle between the nitro group and pyridine ring from the X3LYP method is much closer to the experimental data than that from the M06-2X one. The existing two conformational isomers of 3-benzyloxy-2-nitropyridine with equal energy explain well the disorder of the nitro group at room temperature. In addition, the vibrational frequencies are also calculated by the X3LYP and M06-2X methods and compared with the experimental results. The prediction from the X3LYP method coincides with the locations of the experimental frequencies well.

Utilization of variation theory in the classroom: Effect on students' algebraic achievement and motivation

NASA Astrophysics Data System (ADS)

Jing, Ting Jing; Tarmizi, Rohani Ahmad; Bakar, Kamariah Abu; Aralas, Dalia

2017-01-01

This study investigates the effect of utilizing Variation Theory Based Strategy on students' algebraic achievement and motivation in learning algebra. The study used quasi-experimental non-equivalent control group research design and involved 56 Form Two (Secondary Two) students in two classes (28 in experimental group, 28 in control group) in Malaysia The first class of students went through algebra class taught with Variation Theory Based Strategy (VTBS) while the second class of students experienced conventional teaching strategy. The instruments used for the study were a 24-item Algebra Test and 36-item Instructional Materials Motivation Survey. Result from analysis of Covariance indicated that experimental group students achieved significantly better test scores than control group. Result of Multivariate Analysis of Variance also shows evidences of significant effect of VTBS on experimental students' overall motivation in all the five subscales; attention, relevance, confidence, and satisfaction. These results suggested the utilization of VTBS would improve students' learning in algebra.

Inflammasomes make the case for littermate-controlled experimental design in studying host-microbiota interactions.

PubMed

Mamantopoulos, Michail; Ronchi, Francesca; McCoy, Kathy D; Wullaert, Andy

2018-04-19

Several human diseases are thought to evolve due to a combination of host genetic mutations and environmental factors that include alterations in intestinal microbiota composition termed dysbiosis. Although in some cases, host genetics may shape the gut microbiota and enable it to provoke disease, experimentally disentangling cause and consequence in such host-microbe interactions requires strict control over non-genetic confounding factors. Mouse genetic studies previously proposed Nlrp6/ASC inflammasomes as innate immunity regulators of the intestinal ecosystem. In contrast, using littermate-controlled experimental setups, we recently showed that Nlrp6/ASC inflammasomes do not alter the gut microbiota composition. Our analyses indicated that maternal inheritance and long-term separate housing are non-genetic confounders that preclude the use of non-littermate mice when analyzing host genetic effects on intestinal ecology. Here, we summarize and discuss our gut microbiota analyses in inflammasome-deficient mice for illustrating the importance of littermate experimental design in studying host-microbiota interactions.

Experimental evaluation of automotive air-conditioning using HFC-134a and HC-134a

NASA Astrophysics Data System (ADS)

Nasution, Henry; Zainudin, Muhammad Amir; Aziz, Azhar Abdul; Latiff, Zulkarnain Abdul; Perang, Mohd Rozi Mohd; Rahman, Abd Halim Abdul

2012-06-01

An experimental study to evaluate the energy consumption of an automotive air conditioning is presented. In this study, these refrigerants will be tested using the experimental rig which simulated the actual cars as a cabin complete with a cooling system component of the actual car that is as the blower, evaporator, condenser, radiators, electric motor, which acts as a vehicle engine, and then the electric motor will operate the compressor using a belt and pulley system, as well as to the alternator will recharge the battery. The compressor working with the fluids HFC-134a and HC-134a and has been tested varying the speed in the range 1000, 1500, 2000 and 2500 rpm. The measurements taken during the one hour experimental periods at 2-minutes interval times for temperature setpoint of 20°C with internal heat loads 0, 500, 700 and 1000 W. The final results of this study show an overall better energy consumption of the HFC-134a compared with the HC-134a.

Experimental panic provocation in healthy man—a translational role in anti-panic drug development?

PubMed Central

Kellner, Michael

2011-01-01

Experimental neurochemical provocation of panic attacks in susceptible human subjects has considerably expanded our knowledge of the pathophysiology and psychopharmacology of panic disorder. Some panicogens also elicit short-lived panic-like states in healthy man. This offers the opportunity to assess the anti-panic action of drugs in proof-of-concept studies. However, from current data it is still unclear whether experimental panic in healthy man is a valid translational model. Most such studies in healthy volunteers have been performed using a cholecystokinin tetrapeptide (CCK-4) challenge. While CCK-4 panic was blocked by alprazolam pretreatment, escitalopram showed negative results in healthy man. Preliminary findings on novel investigational drugs and a few problematic results will be reviewed. Small sample sizes in many panic provocation studies, lack of dose-response aspects, and still-insufficient knowledge about the biological underpinning of experimental and spontaneous panic limit the interpretation of existing findings and should inspire further research. PMID:22275853

Experimental challenge of pregnant cattle with the putative abortifacient Waddlia chondrophila.

PubMed

Wheelhouse, Nicholas; Flockhart, Allen; Aitchison, Kevin; Livingstone, Morag; Finlayson, Jeanie; Flachon, Virginie; Sellal, Eric; Dagleish, Mark P; Longbottom, David

2016-11-14

Waddlia chondrophila is a Gram-negative intracellular bacterial organism that is related to classical chlamydial species and has been implicated as a cause of abortion in cattle. Despite an increasing number of observational studies linking W. chondrophila infection to cattle abortion, little direct experimental evidence exists. Given this paucity of direct evidence the current study was carried out to investigate whether experimental challenge of pregnant cattle with W. chondrophila would result in infection and abortion. Nine pregnant Friesian-Holstein heifers received 2 × 10 8 inclusion forming units (IFU) W. chondrophila intravenously on day 105-110 of pregnancy, while four negative-control animals underwent mock challenge. Only one of the challenged animals showed pathogen-associated lesions, with the organism being detected in the diseased placenta. Importantly, the organism was re-isolated and its identity confirmed by whole genome sequencing, confirming Koch's third and fourth postulates. However, while infection of the placenta was observed, the experimental challenge in this study did not confirm the abortifacient potential of the organism.

Synthesis, structural, DFT studies, docking and antibacterial activity of a xanthene based hydrazone ligand

NASA Astrophysics Data System (ADS)

Naseem, Saira; Khalid, Muhammad; Tahir, Muhammad Nawaz; Halim, Mohammad A.; Braga, Ataualpa A. C.; Naseer, Muhammad Moazzam; Shafiq, Zahid

2017-09-01

Herein, we present the synthesis of novel xanthene-based hydrazone (1). The chemical structure of 1 was resolved using spectroscopic techniques such as NMR, FT-IR, UV-VIS and X-ray crystallographic approaches. X-ray diffraction analysis shows that the compound (1) crystallizes in triclinic crystal lattice with the Pbar1 space group and diffused to form multi-layered structure due to non-covalent interactions such as intramolecular hydrogen bonding (H.B). In addition to experimental investigation, density functional theory (DFT) calculation with M06-2X/6-31G(d,p) and B3LYP/6-31G(d,p) level of theories was performed on compound (1) to obtain optimized geometry, spectroscopic and electronic properties. DFT optimized geometry shows good agreement with the experimental XRD structure. The hyper conjugative interactions and hydrogen bonding network are responsible for the stability of compound (1) as revealed by natural bond orbital (NBO) calculation. Moreover, hydrogen bonding network in the dimer is confirmed by FT-IR and thermodynamic studies showing excellent agreement with XRD and NBO findings. TD-DFT/UV-VIS analysis provides insight that maximum excitation is found in 1 which shows good agreement with experimental UV-VIS result. The global reactivity parameters are calculated using the energies of frontier molecular orbitals also disclosed that the compound is more stable might be due to hydrogen bonding network. Experimental and molecular docking studies indicated that this compound has anti-bacterial and anti-diabetic properties. The binding affinity of this compound against the multidrug efflux pump subunit AcrB OS=Escherichia coli (strain K12) and Human Pancreatic Alpha-Amylase is -9.2 and -10.00 kcal/mol which are higher than the control drugs. Pi-Pi, Pi-anaion, amide-pi and pi-alkyl bonds play key role in drug-protein complexes.

The flaws and human harms of animal experimentation.

PubMed

Akhtar, Aysha

2015-10-01

Nonhuman animal ("animal") experimentation is typically defended by arguments that it is reliable, that animals provide sufficiently good models of human biology and diseases to yield relevant information, and that, consequently, its use provides major human health benefits. I demonstrate that a growing body of scientific literature critically assessing the validity of animal experimentation generally (and animal modeling specifically) raises important concerns about its reliability and predictive value for human outcomes and for understanding human physiology. The unreliability of animal experimentation across a wide range of areas undermines scientific arguments in favor of the practice. Additionally, I show how animal experimentation often significantly harms humans through misleading safety studies, potential abandonment of effective therapeutics, and direction of resources away from more effective testing methods. The resulting evidence suggests that the collective harms and costs to humans from animal experimentation outweigh potential benefits and that resources would be better invested in developing human-based testing methods.

Audio Motor Training at the Foot Level Improves Space Representation.

PubMed

Aggius-Vella, Elena; Campus, Claudio; Finocchietti, Sara; Gori, Monica

2017-01-01

Spatial representation is developed thanks to the integration of visual signals with the other senses. It has been shown that the lack of vision compromises the development of some spatial representations. In this study we tested the effect of a new rehabilitation device called ABBI (Audio Bracelet for Blind Interaction) to improve space representation. ABBI produces an audio feedback linked to body movement. Previous studies from our group showed that this device improves the spatial representation of space in early blind adults around the upper part of the body. Here we evaluate whether the audio motor feedback produced by ABBI can also improve audio spatial representation of sighted individuals in the space around the legs. Forty five blindfolded sighted subjects participated in the study, subdivided into three experimental groups. An audio space localization (front-back discrimination) task was performed twice by all groups of subjects before and after different kind of training conditions. A group (experimental) performed an audio-motor training with the ABBI device placed on their foot. Another group (control) performed a free motor activity without audio feedback associated with body movement. The other group (control) passively listened to the ABBI sound moved at foot level by the experimenter without producing any body movement. Results showed that only the experimental group, which performed the training with the audio-motor feedback, showed an improvement in accuracy for sound discrimination. No improvement was observed for the two control groups. These findings suggest that the audio-motor training with ABBI improves audio space perception also in the space around the legs in sighted individuals. This result provides important inputs for the rehabilitation of the space representations in the lower part of the body.

Audio Motor Training at the Foot Level Improves Space Representation

PubMed Central

Aggius-Vella, Elena; Campus, Claudio; Finocchietti, Sara; Gori, Monica

2017-01-01

Spatial representation is developed thanks to the integration of visual signals with the other senses. It has been shown that the lack of vision compromises the development of some spatial representations. In this study we tested the effect of a new rehabilitation device called ABBI (Audio Bracelet for Blind Interaction) to improve space representation. ABBI produces an audio feedback linked to body movement. Previous studies from our group showed that this device improves the spatial representation of space in early blind adults around the upper part of the body. Here we evaluate whether the audio motor feedback produced by ABBI can also improve audio spatial representation of sighted individuals in the space around the legs. Forty five blindfolded sighted subjects participated in the study, subdivided into three experimental groups. An audio space localization (front-back discrimination) task was performed twice by all groups of subjects before and after different kind of training conditions. A group (experimental) performed an audio-motor training with the ABBI device placed on their foot. Another group (control) performed a free motor activity without audio feedback associated with body movement. The other group (control) passively listened to the ABBI sound moved at foot level by the experimenter without producing any body movement. Results showed that only the experimental group, which performed the training with the audio-motor feedback, showed an improvement in accuracy for sound discrimination. No improvement was observed for the two control groups. These findings suggest that the audio-motor training with ABBI improves audio space perception also in the space around the legs in sighted individuals. This result provides important inputs for the rehabilitation of the space representations in the lower part of the body. PMID:29326564

Carbon Nanotubes' Effect on Mitochondrial Oxygen Flux Dynamics: Polarography Experimental Study and Machine Learning Models using Star Graph Trace Invariants of Raman Spectra.

PubMed

González-Durruthy, Michael; Monserrat, Jose M; Rasulev, Bakhtiyor; Casañola-Martín, Gerardo M; Barreiro Sorrivas, José María; Paraíso-Medina, Sergio; Maojo, Víctor; González-Díaz, Humberto; Pazos, Alejandro; Munteanu, Cristian R

2017-11-11

This study presents the impact of carbon nanotubes (CNTs) on mitochondrial oxygen mass flux ( J m ) under three experimental conditions. New experimental results and a new methodology are reported for the first time and they are based on CNT Raman spectra star graph transform (spectral moments) and perturbation theory. The experimental measures of J m showed that no tested CNT family can inhibit the oxygen consumption profiles of mitochondria. The best model for the prediction of J m for other CNTs was provided by random forest using eight features, obtaining test R-squared ( R ²) of 0.863 and test root-mean-square error (RMSE) of 0.0461. The results demonstrate the capability of encoding CNT information into spectral moments of the Raman star graphs (SG) transform with a potential applicability as predictive tools in nanotechnology and material risk assessments.

Experimental and Numerical Investigation of Losses in Low-Pressure Turbine Blade Rows

NASA Technical Reports Server (NTRS)

Dorney, Daniel J.; Lake, James P.; King, Paul I.; Ashpis, David E.

2000-01-01

Experimental data and numerical simulations of low-pressure turbines have shown that unsteady blade row interactions and separation can have a significant impact on the turbine efficiency. Measured turbine efficiencies at takeoff can be as much as two points higher than those at cruise conditions. Several recent studies have revealed that the performance of low-pressure turbine blades is a strong function of the Reynolds number. In the current investigation, experiments and simulations have been performed to study the behavior of a low-pressure turbine blade at several Reynolds numbers. Both the predicted and experimental results indicate increased cascade losses as the Reynolds number is reduced to the values associated with aircraft cruise conditions. In addition, both sets of data show that tripping the boundary layer helps reduce the losses at lower Reynolds numbers. Overall, the predicted aerodynamic and performance results exhibit fair agreement with experimental data.

Experimental study on flow boiling heat transfer of LNG in a vertical smooth tube

NASA Astrophysics Data System (ADS)

Chen, Dongsheng; Shi, Yumei

2013-10-01

An experimental apparatus is set up in this work to study the upward flow boiling heat transfer characteristics of LNG (liquefied natural gas) in vertical smooth tubes with inner diameters of 8 mm and 14 mm. The experiments were performed at various inlet pressures from 0.3 to 0.7 MPa. The results were obtained over the mass flux range from 16 to 200 kg m-2 s-1 and heat fluxes ranging from 8.0 to 32 kW m-2. The influences of quality, heat flux and mass flux, tube diameter on the heat transfer characteristic are examined and discussed. The comparisons of the experimental heat transfer coefficients with the predicted values from the existing correlations are analyzed. The correlation by Zou et al. [16] shows the best accuracy with the RMS deviation of 31.7% in comparison with the experimental data.

In vivo Expression of Inducible Nitric Oxide Synthase in Experimentally Induced Neurologic Diseases

NASA Astrophysics Data System (ADS)

Koprowski, Hilary; Zheng, Yong Mu; Heber-Katz, Ellen; Fraser, Nigel; Rorke, Lucy; Fu, Zhen Fang; Hanlon, Cathleen; Dietzschold, Bernhard

1993-04-01

The purpose of this study was to investigate the induction of inducible nitric oxide synthase (iNOS) mRNA in the brain tissue of rats and mice under the following experimental conditions: in rats infected with borna disease virus and rabies virus, in mice infected with herpes simplex virus, and in rats after the induction of experimental allergic encephalitis. The results showed that iNOS mRNA, normally nondetectable in the brain, was present in animals after viral infection or after induction of experimental allergic encephalitis. The induction of iNOS mRNA coincided with the severity of clinical signs and in some cases with the presence of inflammatory cells in the brain. The results indicate that nitric oxide produced by cells induced by iNOS may be the toxic factor accounting for cell damage and this may open the door to approaches to the study of the pathogenesis of neurological diseases.

Change of electric dipole moment in charge transfer transitions of ferrocene oligomers studied by ultrafast two-photon absorption

NASA Astrophysics Data System (ADS)

Mikhaylov, Alexander; Arias, Eduardo; Moggio, Ivana; Ziolo, Ronald; Uudsemaa, Merle; Trummal, Aleksander; Cooper, Thomas; Rebane, Aleksander

2017-02-01

Change of permanent electric dipole moment in the lower-energy charge transfer transitions for a series of symmetrical and non-symmetrical ferrocene-phenyleneethynylene oligomers were studied by measuring the corresponding femtosecond two-photon absorption cross section spectra, and were determined to be in the range Δμ = 3 - 10 D. Quantum-chemical calculations of Δμ for the non-symmetrical oligomers show good quantitative agreement with the experimental results, thus validating two-photon absorption spectroscopy as a viable experimental approach to study electrostatic properties of organometallics and other charge transfer systems.

Favorable results from the use of herbal and plant products in inflammatory bowel disease: evidence from experimental animal studies

PubMed Central

Triantafillidis, John K.; Triantafyllidi, Aikaterini; Vagianos, Constantinos; Papalois, Apostolos

2016-01-01

The use of herbal therapy for inflammatory bowel disease is increasing worldwide. The aim of this study was to review the available literature on the efficacy of herbal therapy in experimental colitis. All relevant studies published in Medline and Embase up to June 2015 have been reviewed. The results of bowel histology and serum parameters have been recorded. A satisfactory number of published experimental studies, and a quite large one of both herbal and plant products tested in different studies have been reported. The results showed that in the majority of the studies, herbal therapy reduced the inflammatory activity of experimental colitis and diminished the levels of many inflammatory indices, including serum cytokines and indices of oxidative stress. The most promising plant and herbal products were tormentil extracts, wormwoodherb, Aloe vera, germinated barley foodstuff, curcumin, Boswellia serrata, Panax notoginseng, Ixeris dentata, green tea, Cordia dichotoma, Plantago lanceolata, Iridoidglycosides, and mastic gum. Herbal therapies exert their therapeutic benefit via various mechanisms, including immune regulation, anti-oxidant activity, inhibition of leukotriene B4 and nuclear factor-κB, and antiplatelet activity. Large, double-blind clinical studies assessing these natural substances should be urgently conducted. PMID:27366027

The influence of diet consistence, drinking water and bedding on periodontal disease in Sprague-Dawley rats.

PubMed

Björnsson, Magnús Jón; Velschow, Sten; Stoltze, Kaj; Havemose-Poulsen, Anne; Schou, Søren; Holmstrup, Palle

2003-12-01

Although rats have been extensively used in periodontal research, pre-experimental periodontal inspection has not been given high priority in previous studies of experimental periodontal disease in rats. An inspection of 50 Sprague-Dawley rats, which were to be used in a model of experimental periodontal disease, revealed signs of periodontal disease in a considerable proportion of the animals. The objectives of the present study were to describe disease progression, identify factors responsible for induction of periodontal disease and test a method for breeding of healthy rats. A longitudinal study revealed that 33% of rats, bred under the same conditions, showed signs of periodontal disease during, or shortly after, eruption of the molars. Regular diet caused significantly more horizontal bone loss (P = 0.0001) and significantly less periodontal bone support (P < 0.0001) than the same kind of diet with a smaller grain size. Wood chip bedding in the rats' cages significantly reduced periodontal bone support (P < 0.0001) compared to a wire mesh floor and a simultaneous use of regular diet and bedding decreased it even further (P = 0.0023). Finally, by using finely milled diet, a wire mesh floor and tap water, instead of conventional breeding methods of regular diet, bedding and acidic water, it was possible to breed rats with minimal signs of periodontal disease. The results of the present study emphasize the need for pre- experimental examination of rats. They also show that diet and bedding conditions have the potential of seriously influencing outcomes of studies of periodontal disease in rats.

In vitro experimental environments lacking or containing soil disparately affect competition experiments of Aspergillus flavus and co-occurring fungi in maize grains.

PubMed

Falade, Titilayo D O; Syed Mohdhamdan, Sharifah H; Sultanbawa, Yasmina; Fletcher, Mary T; Harvey, Jagger J W; Chaliha, Mridusmita; Fox, Glen P

2016-07-01

In vitro experimental environments are used to study interactions between microorganisms, and to predict dynamics in natural ecosystems. This study highlights that experimental in vitro environments should be selected to match closely the natural environment of interest during in vitro studies to strengthen extrapolations about aflatoxin production by Aspergillus and competing organisms. Fungal competition and aflatoxin accumulation were studied in soil, cotton wool or tube (water-only) environments, for Aspergillus flavus competition with Penicillium purpurogenum, Fusarium oxysporum or Sarocladium zeae within maize grains. Inoculated grains were incubated in each environment at two temperature regimes (25 and 30°C). Competition experiments showed interaction between the main effects of aflatoxin accumulation and the environment at 25°C, but not so at 30°C. However, competition experiments showed fungal populations were always interacting with their environments. Fungal survival differed after the 72-h incubation in different experimental environments. Whereas all fungi incubated within the soil environment survived, in the cotton wool environment none of the competitors of A. flavus survived at 30°C. With aflatoxin accumulation, F. oxysporum was the only fungus able to interdict aflatoxin production at both temperatures. This occurred only in the soil environment and fumonisins accumulated instead. Smallholder farmers in developing countries face serious mycotoxin contamination of their grains, and soil is a natural reservoir for the associated fungal propagules, and a drying and storage surface for grains on these farms. Studying fungal dynamics in the soil environment and other environments in vitro can provide insights into aflatoxin accumulation post-harvest.

Effects of Aggression Replacement Training on Problem Solving, Anger and Aggressive Behaviour among Adolescents with Criminal Attempts in Turkey: A Quasi-Experimental Study.

PubMed

Kaya, Fadime; Buzlu, Sevim

2016-12-01

The research was conducted by a pretest and post-test conducted in a quasi-experimental design which aimed to determine effectiveness of Aggression Replacement Training (ART) on problem solving, anger and aggressive behaviour among adolescents with criminal attempts in Turkey. The study included 65 adolescents with criminal attempts (32 intervention, 33 control). There was no difference between the groups in terms of average age (16.13±1.10 in the experimental group and 16.21±0.89 in the control group). After the intervention, the experimental group showed significantly decreased Trait Anger levels (t=1.906; P=0.033), increased Anger Control scores (t=2.522; P=0.008), decreased Physical Aggression scores (t=1.925; P=0.031), decreased Hostility scores (t=2.496; P=0.009), increased Social Problem Solving total scores (t=2.937; P=0.005). Increased Anger Control scores were found to be significant when compared with the control group (t=2.273, P=0.026). These results showed that ART was effective on problem solving, anger and aggressive behaviour and can be used to develop positive behaviours among adolescents with criminal attempts. Copyright © 2016 Elsevier Inc. All rights reserved.

The Development of Experimentation and Evidence Evaluation Skills at Preschool Age

NASA Astrophysics Data System (ADS)

Piekny, Jeanette; Grube, Dietmar; Maehler, Claudia

2014-01-01

Researchers taking a domain-general approach to the development of scientific reasoning long thought that the ability to engage in scientific reasoning did not develop until adolescence. However, more recent studies have shown that preschool children already have a basic ability to evaluate evidence and a basic understanding of experimentation. Data providing insights into when exactly in the preschool years significant gains in these abilities occur are scarce. Drawing on a sample of 138 preschool children, this longitudinal study therefore examined how children's ability to evaluate evidence and their understanding of experimentation develop between the ages of four and six. Findings showed that the ability to evaluate evidence was already well developed at age four and increased steadily and significantly over time as long as the pattern of covariation was perfect. In the case of imperfect covariation, the proportion of correct answers was low over the period of observation, but showed a significant increase between the ages of four and five. If the data did not allow relationship between variables to be inferred, the proportion of correct answers was low, with a significant increase between the ages of five and six. The children's understanding of experimentation increased significantly between the ages of five and six. The implications of these findings for age-appropriate science programs in preschool are discussed.

Arnica montana experimental studies: confounders and biases?

PubMed

Bellavite, Paolo; Marzotto, Marta; Bonafini, Clara

2018-03-01

Arnica montana is a popular traditional remedy widely used in complementary and alternative medicine, in part for its wound-healing properties. The authors recently showed that this plant extract and several of its homeopathic dilutions are able to modify the expression of a series of genes involved in inflammation and connective tissue regeneration. Their studies opened a debate, including criticisms to the "errors" in the methods used and the "confounders and biases". Here the authors show that the criticisms raised on methodology and statistics are not consistent and cannot be considered pertinent. The present comment also updates and reviews information concerning the action of A. montana dilutions in human macrophage cells while summarizing the major experimental advances reported on this interesting medicinal plant. Copyright © 2018. Published by Elsevier B.V.

[Clinical and experimental study of treating aplastic anemia with fetal liver cell suspension and fetal liver cell-free suspension].

PubMed

Han, J R; Yuan, S W; Ren, Q F

1990-06-01

Fresh fetal liver obtained from 3- to 6-month fetus was prepared. Fetal liver cell suspension (FLC) or fetal liver cell-free suspension (FLCF) were then transfused into two groups of patient of aplastic anemia. 15 of 21 patients of aplastic anemia treated with FLC showed reconstitution of haemopoietic function or improvement of peripheral blood pictures, while 27 of 30 patients treated with FLCF showed reconstitution or improvement. It is verified that there is a stimulating factor for CFU-CM, BFU-E, and CFU-E and also a immunologic stimulant for improving the nonspecific immunologic function of the organism as shown by clinical analysis and experimental study. It is obvious that the therapeutic effect of FLCF is much better than that of the FLC.

Investigation of non-linear contact for a clearance-fit bolt in a graphite/epoxy laminate

NASA Technical Reports Server (NTRS)

Prabhakaran, R.; Naik, R. A.

1986-01-01

Numerous analytical studies have been published for the nonlinear load-contact variations in clearance-fit bolted joints. In these studies, stress distributions have been obtained and failure predictions have been made. However, very little experimental work has been reported regarding the contact or the stresses. This paper describes a fiber-optic technique for measuring the angle of contact in a clearance-fit bolt-loaded hole. Measurements of the contact angle have been made in a quasi-isotropic graphite-epoxy laminate by the optical as well as an electrical technique, and the results have been compared with those obtained from a finite-element analysis. The results from the two experimental techniques show excellent agreement; the finite-element results show some discrepancy, probably due to the interfacial frictions.

Stimulus meanings alter illusory self-motion (vection)--experimental examination of the train illusion.

PubMed

Seno, Takeharu; Fukuda, Haruaki

2012-01-01

Over the last 100 years, numerous studies have examined the effective visual stimulus properties for inducing illusory self-motion (known as vection). This vection is often experienced more strongly in daily life than under controlled experimental conditions. One well-known example of vection in real life is the so-called 'train illusion'. In the present study, we showed that this train illusion can also be generated in the laboratory using virtual computer graphics-based motion stimuli. We also demonstrated that this vection can be modified by altering the meaning of the visual stimuli (i.e., top down effects). Importantly, we show that the semantic meaning of a stimulus can inhibit or facilitate vection, even when there is no physical change to the stimulus.

An analytical study of the effect of coolant flow variables on the kinetic energy output of a cooled turbine blade flow

NASA Technical Reports Server (NTRS)

Prust, H. W., Jr.

1971-01-01

The results of an analytical study to determine the effect of changes in the amount, velocity, injection location, injection angle, and temperature of coolant flow on blade row performance are presented. The results show that the change in output of a cooled turbine blade row relative to the specific output of the uncooled blade row can be positive, negative, or zero. Comparisons between the analytical results and experimental results for four different cases of coolant discharge, all at a coolant temperature ratio of unity, show good agreement for three cases and rather poor agreement for the other. To further test the validity of the method, more experimental data is needed, particularly at different coolant temperature ratios.

Experimental study of cryogen spray properties for application in dermatologic laser surgery.

PubMed

Aguilar, Guillermo; Majaron, Boris; Karapetian, Emil; Lavernia, Enrique J; Nelson, J Stuart

2003-07-01

Cryogenic sprays are used for cooling human skin during laser dermatologic surgery. In this paper, six straight-tube nozzles are characterized by photographs of cryogenic spray shapes, as well as measurements of average droplet diameter, velocity, and temperature. A single-droplet evaporation model to predict average spray droplet diameter and temperature is tested using the experimental data presented here. The results show two distinct spray patterns--sprays for 1.4-mm-diameter nozzles (wide nozzles) show significantly larger average droplet diameters and higher temperatures as a function of distance from the nozzle compared with those for 0.5-0.8-mm-diameter nozzles (narrow nozzles). These results complement and support previously reported studies, indicating that wide nozzles induce more efficient heat extraction than the narrow nozzles.

Experimental and theoretical study on THz spectrum artesunate

NASA Astrophysics Data System (ADS)

Zhang, Ai-Bing; Kong, Ling-Gao; Wang, Shi-Jin; Li, Lei; Zheng, Xiang-Zhi

2008-10-01

Artesunate is a very effective drug to treat malaria. They are studied experimentally by Terahertz (THz) time-domain spectroscopy (THz-TDS), and the characteristic absorption spectra are obtained in the range of 0.2 to 2.6 THz. The vibrational frequencies are calculated using the density functional theory (DFT). Theoretical results show that 0.71, 1.94 and 2.46 THz are significant agreement with the experimental results in 0.87, 1.82 and 2.46THz, and identification of vibrational modes are given. The calculated results further confirm that the characteristic frequencies come from the collective vibrational modes. The results suggest that the use of the THz-TDS technique can be an effective way to inspect for Chinese medicine.

A study of air-to-ground sound propagation using an instrumented meteorological tower

NASA Technical Reports Server (NTRS)

Kasper, P. K.; Pappa, R. S.; Keefe, L. R.; Sutherland, L. C.

1975-01-01

The results of an exploratory NASA study, leading to a better understanding of the effects of meteorological conditions on the propagation of aircraft noise, are reported. The experimental program utilized a known sound source fixed atop an instrumented meteorological tower. The basic experimental scheme consisted of measuring the amplitude of sound radiated toward the ground along a line of microphones fixed to a tower guy wire. Experimental results show the feasibility of this approach in the acquisition of data indicating the variations encountered in the time-averaged and instantaneous amplitudes of propagated sound. The investigation included a consideration of ground reflections, a comparison of measured attenuations with predicted atmospheric absorption losses, and an evaluation of the amplitude fluctuations of recorded sound pressures.

Electron impact ionization of metastable 2P-state hydrogen atoms in the coplanar geometry

NASA Astrophysics Data System (ADS)

Dhar, S.; Nahar, N.

Triple differential cross sections (TDCS) for the ionization of metastable 2P-state hydrogen atoms by electrons are calculated for various kinematic conditions in the asymmetric coplanar geometry. In this calculation, the final state is described by a multiple-scattering theory for ionization of hydrogen atoms by electrons. Results show qualitative agreement with the available experimental data and those of other theoretical computational results for ionization of hydrogen atoms from ground state, and our first Born results. There is no available other theoretical results and experimental data for ionization of hydrogen atoms from the 2P state. The present study offers a wide scope for the experimental study for ionization of hydrogen atoms from the metastable 2P state.

The efficacy of focus group discussion in teaching ESP speaking skill for prospective vocational school teacher

NASA Astrophysics Data System (ADS)

Nurmasitah, Sita; Faridi, Abdurrachman; Utomo, Aryo Baskoro; Astuti, Pudji

2018-03-01

The aims of the study were to implement the focus group discussion in teaching English for Specific Purposes (ESP) speaking skill for prospective Vocational School teacher and also to find out its effectiveness in improving their English speaking skill in ESP course. Quasi-experimental design was employed in this research. Thirty students of Family Welfare Vocational Education Study Program who were taking ESP course, were divided into two classes; experimental and control class. The research data were collected through interview, observation and the students' speaking assessment. The result showed that the implementation of focus group discussion method in the experimental class effectively increased the students' speaking skill compared to the control class.

Three phase heat and mass transfer model for unsaturated soil freezing process: Part 2 - model validation

NASA Astrophysics Data System (ADS)

Zhang, Yaning; Xu, Fei; Li, Bingxi; Kim, Yong-Song; Zhao, Wenke; Xie, Gongnan; Fu, Zhongbin

2018-04-01

This study aims to validate the three-phase heat and mass transfer model developed in the first part (Three phase heat and mass transfer model for unsaturated soil freezing process: Part 1 - model development). Experimental results from studies and experiments were used for the validation. The results showed that the correlation coefficients for the simulated and experimental water contents at different soil depths were between 0.83 and 0.92. The correlation coefficients for the simulated and experimental liquid water contents at different soil temperatures were between 0.95 and 0.99. With these high accuracies, the developed model can be well used to predict the water contents at different soil depths and temperatures.

Arguments, contradictions, resistances, and conceptual change in students' understanding of atomic structure

NASA Astrophysics Data System (ADS)

Niaz, Mansoor; Aguilera, Damarys; Maza, Arelys; Liendo, Gustavo

2002-07-01

Most general chemistry courses and textbooks emphasize experimental details and lack a history and philosophy of science perspective. The objective of this study is to facilitate freshman general chemistry students' understanding of atomic structure based on the work of Thomson, Rutherford, and Bohr. It is hypothesized that classroom discussions based on arguments/counterarguments of the heuristic principles, on which these scientists based their atomic models, can facilitate students' conceptual understanding. This study is based on 160 freshman students enrolled in six sections of General Chemistry I (three sections formed part of the experimental group). All three models (Thomson, Rutherford, and Bohr) were presented to the experimental and control group students in the traditional manner, as found in most textbooks. After this, the three sections of the experimental group participated in the discussion of six items with alternative responses. Students were first asked to select a response and then participate in classroom discussions leading to arguments in favor or against the selected response and finally select a new response. Three weeks after having discussed the six items, both the experimental and control groups presented a monthly exam (based on the three models) and after another 3 weeks a semester exam. Results obtained show that given the opportunity to argue and discuss, students' understanding can go beyond the simple regurgitation of experimental details. Performance of the experimental group showed contradictions, resistances, and progressive conceptual change with considerable and consistent improvement in the last item. It is concluded that if we want our students to understand scientific progress and practice, then it is important that we include the experimental details not as a rhetoric of conclusions (Schwab, 1962, The teaching of science as enquiry, Cambridge, MA, Harward University Press; Schwab, 1974, Conflicting conceptions of curriculum, Berkeley, CA, McCutchan) but as heuristic principles (Lakatos, 1970, Criticism and the growth of knowledge, Cambridge, UK, Cambridge University Press, pp. 91-195), which were based on arguments, controversies, and interpretations of the scientists.

Remediation of saturated soil contaminated with petroleum products using air sparging with thermal enhancement.

PubMed

Mohamed, A M I; El-menshawy, Nabil; Saif, Amany M

2007-05-01

Pollutants in the form of non-aqueous phase liquids (NAPLs), such as petroleum products, pose a serious threat to the soil and groundwater. A mathematical model was derived to study the unsteady pollutant concentrations through water saturated contaminated soil under air sparging conditions for different NAPLs and soil properties. The comparison between the numerical model results and the published experimental results showed acceptable agreement. Furthermore, an experimental study was conducted to remove NAPLs from the contaminated soil using the sparging air technique, considering the sparging air velocity, air temperature, soil grain size and different contaminant properties. This study showed that sparging air at ambient temperature through the contaminated soil can remove NAPLs, however, employing hot air sparging can provide higher contaminant removal efficiency, by about 9%. An empirical correlation for the volatilization mass transfer coefficient was developed from the experimental results. The dimensionless numbers used were Sherwood number (Sh), Peclet number (Pe), Schmidt number (Sc) and several physical-chemical properties of VOCs and porous media. Finally, the estimated volatilization mass transfer coefficient was used for calculation of the influence of heated sparging air on the spreading of the NAPL plume through the contaminated soil.

Investigating axial diffusion in cylindrical pores using confocal single-particle fluorescence correlation spectroscopy.

PubMed

Chen, Fang; Neupane, Bhanu; Li, Peiyuan; Su, Wei; Wang, Gufeng

2016-08-01

We explored the feasibility of using confocal fluorescence correlation spectroscopy to study small nanoparticle diffusion in hundred-nanometer-sized cylindrical pores. By modeling single particle diffusion in tube-like confined three-dimensional space aligned parallel to the confocal optical axis, we showed that two diffusion dynamics can be observed in both original intensity traces and the autocorrelation functions (ACFs): the confined two-dimensional lateral diffusion and the unconfined one-dimensional (1D) axial diffusion. The separation of the axial and confined lateral diffusion dynamics provides an opportunity to study diffusions in different dimensions separately. We further experimentally studied 45 nm carboxylated polystyrene particles diffusing in 300 nm alumina pores. The experimental data showed consistency with the simulation. To extract the accurate axial diffusion coefficient, we found that a 1D diffusion model with a Lorentzian axial collection profile needs to be used to analyze the experimental ACFs. The diffusion of the 45 nm nanoparticles in polyethyleneglycol-passivated 300 nm pores slowed down by a factor of ∼2, which can be satisfactorily explained by hydrodynamic frictions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effects of acute inflammation on cognitive functioning and emotional processing in humans: A systematic review of experimental studies.

PubMed

Bollen, Jessica; Trick, Leanne; Llewellyn, David; Dickens, Chris

2017-03-01

The cognitive neuropsychological model of depression proposes that negative biases in the processing of emotionally salient information have a central role in the development and maintenance of depression. We have conducted a systematic review to determine whether acute experimental inflammation is associated with changes to cognitive and emotional processing that are thought to cause and maintain depression. We identified experimental studies in which healthy individuals were administered an acute inflammatory challenge (bacterial endotoxin/vaccination) and standardised tests of cognitive function were performed. Fourteen references were identified, reporting findings from 12 independent studies on 345 participants. Methodological quality was rated strong or moderate for 11 studies. Acute experimental inflammation was triggered using a variety of agents (including endotoxin from E. coli, S. typhi, S. abortus Equi and Hepatitis B vaccine) and cognition was assessed over hours to months, using cognitive tests of i) attention/executive functioning, ii) memory and iii) social/emotional processing. Studies found mixed evidence that acute experimental inflammation caused changes to attention/executive functioning (2 of 6 studies showed improvements in attention executive function compared to control), changes in memory (3 of 5 studies; improved reaction time: reduced memory for object proximity: poorer immediate and delayed memory) and changes to social/emotional processing (4 of 5 studies; reduced perception of emotions, increased avoidance of punishment/loss experiences, and increased social disconnectedness). Acute experimental inflammation causes negative biases in social and emotional processing that could explain observed associations between inflammation and depression. Copyright © 2017 Elsevier Inc. All rights reserved.

Ab initio study of H + + H 2 collisions: Elastic/inelastic and charge transfer processes

NASA Astrophysics Data System (ADS)

Saieswari, A.; Kumar, Sanjay

2007-12-01

An ab initio full configuration interaction study has been undertaken to obtain the global potential energy surfaces for the ground and the first excited electronic state of the H + + H 2 system employing Dunning's cc-pVQZ basis set. Using the ab initio approach the corresponding quasi-diabatic potential energy surfaces and coupling potentials have been obtained. A time-independent quantum mechanical study has been also undertaken for both the inelastic and charge transfer processes at the experimental collision energy Ec.m. = 20.0 eV and the preliminary results show better agreement with the experimental data as compared to the earlier available theoretical studies.

An experimental test of the effects of gender constancy on sex typing.

PubMed

Arthur, Andrea E; Bigler, Rebecca S; Ruble, Diane N

2009-12-01

This study provides an experimental test of the hypothesis that level of gender constancy understanding affects children's sex typing. Preschool-age children (N=62, mean age=47 months) were randomly assigned to experimental lessons that taught that biological traits (including gender) are either fixed (pro-constancy condition) or mutable (anti-constancy condition). Posttests revealed that the lessons were effective; children in the pro-constancy condition showed higher gender constancy and appearance-reality distinction scores than did children in the anti-constancy condition. Sex typing did not, however, differ between treatment conditions at immediate and 3-month posttesting.

Calculation with MCNP of capture photon flux in VVER-1000 experimental reactor.

PubMed

Töre, Candan; Ortego, Pedro

2005-01-01

The aim of this study is to obtain by Monte Carlo method the high energy photon flux due to neutron capture in the internals and vessel layers of the experimental reactor LR-0 located in REZ, Czech Republic, and loaded with VVER-1000 fuel. The calclated neutron, photon and photon to neutron flux ratio are compared with experimental measurements performed with a multi-parameter stilbene detector. The results show clear underestimation of photon flux in downcomer and some overestimation at vessel surface and 1/4 thickness but a good fitting for deeper points in vessel.

Focus on Quantum Memory

NASA Astrophysics Data System (ADS)

Brennen, Gavin; Giacobino, Elisabeth; Simon, Christoph

2015-05-01

Quantum memories are essential for quantum information processing and long-distance quantum communication. The field has recently seen a lot of progress, and the present focus issue offers a glimpse of these developments, showing both experimental and theoretical results from many of the leading groups around the world. On the experimental side, it shows work on cold gases, warm vapors, rare-earth ion doped crystals and single atoms. On the theoretical side there are in-depth studies of existing memory protocols, proposals for new protocols including approaches based on quantum error correction, and proposals for new applications of quantum storage. Looking forward, we anticipate many more exciting results in this area.

1-Formyl-3-phenyl-5-(4-isopropylphenyl)-2-pyrazoline: Synthesis, characterization, antimicrobial activity and DFT studies

NASA Astrophysics Data System (ADS)

Sid, Assia; Messai, Amel; Parlak, Cemal; Kazancı, Nadide; Luneau, Dominique; Keşan, Gürkan; Rhyman, Lydia; Alswaidan, Ibrahim A.; Ramasami, Ponnadurai

2016-10-01

The structure of 1-formyl-3-phenyl-5-(4-isopropylphenyl)-2-pyrazoline synthesized as single crystal was investigated by FTIR, NMR, XRD. Experimental data were complemented by quantum mechanical calculations. XRD data show that the compound crystallizes in the triclinic system (P-1) via trans isomer (a = 6.4267(4) Å, b = 10.9259(12) Å, c = 12.4628(9) Å and α = 102.894(8)°, β = 102.535(6)°, γ = 101.633(7)°). Anti-microbial screening results indicate that the compound shows promising activity. The theoretically predicted and experimentally obtained parameters reveal further insight into pyrazoline systems.

Estimation of Organic Vapor Breakthrough in Humidified Activated Carbon Beds: -Application of Wheeler-Jonas Equation, NIOSH MultiVapor™ and RBT (Relative Breakthrough Time)

PubMed Central

Abiko, Hironobu; Furuse, Mitsuya; Takano, Tsuguo

2016-01-01

Objectives: In the use of activated carbon beds as adsorbents for various types of organic vapor in respirator gas filters, water adsorption of the bed and test gas humidity are expected to alter the accuracy in the estimation of breakthrough data. There is increasing interest in the effects of moisture on estimation methods, and this study has investigated the effects with actual breakthrough data. Methods: We prepared several activated carbon beds preconditioned by equilibration with moisture at different relative humidities (RH=40%-70%) and a constant temperature of 20°C. Then, we measured breakthrough curves in the early region of breakthrough time for 10 types of organic vapor, and investigated the effects of moisture on estimation using the Wheeler-Jonas equation, the simulation software NIOSH MultiVapor™ 2.2.3, and RBT (Relative Breakthrough Time) proposed by Tanaka et al. Results: The Wheeler-Jonas equation showed good accordance with breakthrough curves at all RH in this study. However, the correlation coefficient decreased gradually with increasing RH regardless of type of organic vapor. Estimation of breakthrough time by MultiVapor showed good accordance with experimental data at RH=50%. In contrast, it showed discordance at high RH (>50%). RBTs reported previously were consistent with experimental data at RH=50%. On the other hand, the values of RBT changed markedly with increasing RH. Conclusions: The results of each estimation method showed good accordance with experimental data under comparatively dry conditions (RH≤50%). However, there were discrepancies under high humidified conditions, and further studies are warranted. PMID:27725483

Direct and indirect reputation formation in nonhuman great apes (Pan paniscus, Pan troglodytes, Gorilla gorilla, Pongo pygmaeus) and human children (Homo sapiens).

PubMed

Herrmann, Esther; Keupp, Stefanie; Hare, Brian; Vaish, Amrisha; Tomasello, Michael

2013-02-01

Humans make decisions about when and with whom to cooperate based on their reputations. People either learn about others by direct interaction or by observing third-party interactions or gossip. An important question is whether other animal species, especially our closest living relatives, the nonhuman great apes, also form reputations of others. In Study 1, chimpanzees, bonobos, orangutans, and 2.5-year-old human children experienced a nice experimenter who tried to give food/toys to the subject and a mean experimenter who interrupted the food/toy giving. In studies 2 and 3, nonhuman great apes and human children could only passively observe a similar interaction, in which a nice experimenter and a mean experimenter interacted with a third party. Orangutans and 2.5-year-old human children preferred to approach the nice experimenter rather than the mean one after having directly experienced their respective behaviors. Orangutans, chimpanzees, and 2.5-year-old human children also took into account experimenter actions toward third parties in forming reputations. These studies show that the human ability to form direct and indirect reputation judgment is already present in young children and shared with at least some of the other great apes. PsycINFO Database Record (c) 2013 APA, all rights reserved

Active music therapy approach for stroke patients in the post-acute rehabilitation.

PubMed

Raglio, Alfredo; Zaliani, Alberto; Baiardi, Paola; Bossi, Daniela; Sguazzin, Cinzia; Capodaglio, Edda; Imbriani, Chiara; Gontero, Giulia; Imbriani, Marcello

2017-05-01

Guidelines in stroke rehabilitation recommend the use of a multidisciplinary approach. Different approaches and techniques with music are used in the stroke rehabilitation to improve motor and cognitive functions but also psychological outcomes. In this randomized controlled pilot trial, relational active music therapy approaches were tested in the post-acute phase of disease. Thirty-eight hospitalized patients with ischemic and hemorrhagic stroke were recruited and allocated in two groups. The experimental group underwent the standard of care (physiotherapy and occupational therapy daily sessions) and relational active music therapy treatments. The control group underwent the standard of care only. Motor functions and psychological aspects were assessed before and after treatments. Music therapy process was also evaluated using a specific rating scale. All groups showed a positive trend in quality of life, functional and disability levels, and gross mobility. The experimental group showed a decrease of anxiety and, in particular, of depression (p = 0.016). In addition, the strength of non-dominant hand (grip) significantly increased in the experimental group (p = 0.041). Music therapy assessment showed a significant improvement over time of non-verbal and sonorous-music relationships. Future studies, including a greater number of patients and follow-up evaluations, are needed to confirm promising results of this study.

Bite force measurement system using pressure-sensitive sheet and silicone impression material.

PubMed

Ando, Katsuya; Fuwa, Yuji; Kurosawa, Masahiro; Kondo, Takamasa; Goto, Shigemi

2009-03-01

This study was conducted to reduce the bias in measured values caused by the thickness of materials used in occlusal examinations. To this end, a silicone impression material for bite force measurement and an experimental model of a simplified stomatognathic system were employed in this study. By means of this experimental model, results showed that the effect of bias toward the posterior arch could be reduced in the anterior-posterior distribution of bite forces and in the occlusal contact areas due to the thickness of the materials used in occlusal examinations.

A new cannulation method for isolated mitral valve surgery--"apicoaortic-pa" cannulation.

PubMed

Wada, J; Komatsu, S; Nakae, S; Kazui, T

1976-06-01

The present paper describes experimental and clinical studies of a new method "Apicoaortic-PA" cannulation for mitral valve surgery. Our experimental study showed that this method was more rapid and more physiological for cardiopulmonary bypass. We used this technique in 55 cases of isolated mitral valve surgery with successful results. Our general philosophy of surgical approach to the mitral valve diseases is also discussed. We advocate the utilization of the "Apicoaortic Pulmonary Artery" cannulation method for clinical use in isolated mitral valve surgery through the left thoracotomy.

Vibration of middle ear with shape memory prosthesis - Experimental and numerical study

NASA Astrophysics Data System (ADS)

Rafal, Rusinek; Szymanski, Marcin; Lajmert, Pawel

2018-01-01

The paper presents experimental investigations of ossicular chain vibrations using a Laser Doppler Vibrometer (LDV) for the intact middle ear and a reconstructed one by means of the new designed shape memory prosthesis. Vibrations of the round window are measured with the Laser Doppler vibrometer and studied classically by the transfer function analysis. Moreover, the recurrence plot technique and the Hilbert vibration decomposition method are used to extend the classical analysis. The new methods show additional vibrations components and provide more information about middle ear behaviour.

Mechanistic insights into the rhenium-catalyzed alcohol-to-olefin dehydration reaction.

PubMed

Korstanje, Ties J; Jastrzebski, Johann T B H; Klein Gebbink, Robertus J M

2013-09-23

Rhenium-based complexes are powerful catalysts for the dehydration of various alcohols to the corresponding olefins. Here, we report on both experimental and theoretical (DFT) studies into the mechanism of the rhenium-catalyzed dehydration of alcohols to olefins in general, and the methyltrioxorhenium-catalyzed dehydration of 1-phenylethanol to styrene in particular. The experimental and theoretical studies are in good agreement, both showing the involvement of several proton transfers, and of a carbenium ion intermediate in the catalytic cycle. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mitochondrial protection by low doses of insulin-like growth factor- I in experimental cirrhosis.

PubMed

Pérez, Raquel; García-Fernández, María; Díaz-Sánchez, Matías; Puche, Juan E; Delgado, Gloria; Conchillo, Marian; Muntané, Jordi; Castilla-Cortázar, Inma

2008-05-07

To characterize the mitochondrial dysfunction in experimental cirrhosis and to study whether insulin-like growth factor-I (IGF- I) therapy (4 wk) is able to induce beneficial effects on damaged mitochondria leading to cellular protection. Wistar rats were divided into three groups: Control group, untreated cirrhotic rats and cirrhotic rats treated with IGF- I treatment (2 microg/100 g bw/d). Mitochondrial function was analyzed by flow cytometry in isolated hepatic mitochondria, caspase 3 activation was assessed by Western blot and apoptosis by TUNEL in the three experimental groups. Untreated cirrhotic rats showed a mitochondrial dysfunction characterized by a significant reduction of mitochondrial membrane potential (in status 4 and 3); an increase of intramitochondrial reactive oxigen species (ROS) generation and a significant reduction of ATPase activity. IGF- I therapy normalized mitochondrial function by increasing the membrane potential and ATPase activity and reducing the intramitochondrial free radical production. Activity of the electron transport complexes I and III was increased in both cirrhotic groups. In addition, untreated cirrhotic rats showed an increase of caspase 3 activation and apoptosis. IGF- I therapy reduced the expression of the active peptide of caspase 3 and resulted in reduced apoptosis. These results show that IGF- I exerts a mitochondrial protection in experimental cirrhosis leading to reduced apoptosis and increased ATP production.

Mitochondrial protection by low doses of insulin-like growth factor-Iin experimental cirrhosis

PubMed Central

Pérez, Raquel; García-Fernández, María; Díaz-Sánchez, Matías; Puche, Juan E; Delgado, Gloria; Conchillo, Marian; Muntané, Jordi; Castilla-Cortázar, Inma

2008-01-01

AIM: To characterize the mitochondrial dysfunction in experimental cirrhosis and to study whether insulin-like growth factor-I(IGF-I) therapy (4 wk) is able to induce beneficial effects on damaged mitochondria leading to cellular protection. METHODS: Wistar rats were divided into three groups: Control group, untreated cirrhotic rats and cirrhotic rats treated with IGF-Itreatment (2 μg/100 g bw/d). Mitochondrial function was analyzed by flow cytometry in isolated hepatic mitochondria, caspase 3 activation was assessed by Western blot and apoptosis by TUNEL in the three experimental groups. RESULTS: Untreated cirrhotic rats showed a mitochondrial dysfunction characterized by a significant reduction of mitochondrial membrane potential (in status 4 and 3); an increase of intramitochondrial reactive oxigen species (ROS) generation and a significant reduction of ATPase activity. IGF-Itherapy normalized mitochondrial function by increasing the membrane potential and ATPase activity and reducing the intramitochondrial free radical production. Activity of the electron transport complexes Iand III was increased in both cirrhotic groups. In addition, untreated cirrhotic rats showed an increase of caspase 3 activation and apoptosis. IGF-Itherapy reduced the expression of the active peptide of caspase 3 and resulted in reduced apoptosis. CONCLUSION: These results show that IGF-Iexerts a mitochondrial protection in experimental cirrhosis leading to reduced apoptosis and increased ATP production. PMID:18461658

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.

Theoretical study of liquid droplet dispersion in a venturi scrubber.

PubMed

Fathikalajahi, J; Talaie, M R; Taheri, M

1995-03-01

The droplet concentration distribution in an atomizing scrubber was calculated based on droplet eddy diffusion by a three-dimensional dispersion model. This model is also capable of predicting the liquid flowing on the wall. The theoretical distribution of droplet concentration agrees well with experimental data given by Viswanathan et al. for droplet concentration distribution in a venturi-type scrubber. The results obtained by the model show a non-uniform distribution of drops over the cross section of the scrubber, as noted by the experimental data. While the maximum of droplet concentration distribution may depend on many operating parameters of the scrubber, the results of this study show that the highest uniformity of drop distribution will be reached when penetration length is approximately equal to one-fourth of the depth of the scrubber. The results of this study can be applied to evaluate the removal efficiency of a venturi scrubber.

Pressure Distribution on Inner Wall of Parabolic Nozzle in Laser Propulsion with Single Pulse

NASA Astrophysics Data System (ADS)

Cui, Cunyan; Hong, Yanji; Wen, Ming; Song, Junling; Fang, Juan

2011-11-01

A system based of dynamic pressure sensors was established to study the time resolved pressure distribution on the inner wall of a parabolic nozzle in laser propulsion. Dynamic calibration and static calibration of the test system were made and the results showed that frequency response was up to 412 kHz and linear error was less than 10%. Experimental model was a parabolic nozzle and three test points were preset along one generating line. This study showed that experimental results agreed well with those obtained by numerical calculation way in pressure evolution tendency. The peak value of the calculation was higher than that of the experiment at each tested orifice because of the limitation of the numerical models. The results of this study were very useful for analyzing the energy deposition in laser propulsion and modifying numerical models.

[Effects of a Customized Birth Control Program for Married Immigrant Postpartum Mothers].

PubMed

Kim, So Young; Choi, So Young

2016-12-01

This study was conducted to develop a customized birth control program and identify its effects on attitude, subjective norm, behavioral control, intention, and behavior of contraception among immigrant postpartum mothers. In this experimental study, Vietnamese, Filipino or Cambodian married immigrant postpartum mothers were recruited. They were assigned to the experiment group (n=21) or control group (n=21). The customized birth control program was provided to the experimental group for 4 weeks. The experimental group showed a significant increase in the score of attitude, subjective norm, behavioral control, intention, and behavior of contraception. Findings in this study indicate that the customized postpartum birth control program, a systematic and integrative intervention program composed of customized health education, counseling and telephone monitoring, is able to provide effective planning for postpartum health promotion and birth control behavior practice in married immigrant women.

Theoretical and experimental studies of turbo product code with time diversity in free space optical communication.

PubMed

Han, Yaoqiang; Dang, Anhong; Ren, Yongxiong; Tang, Junxiong; Guo, Hong

2010-12-20

In free space optical communication (FSOC) systems, channel fading caused by atmospheric turbulence degrades the system performance seriously. However, channel coding combined with diversity techniques can be exploited to mitigate channel fading. In this paper, based on the experimental study of the channel fading effects, we propose to use turbo product code (TPC) as the channel coding scheme, which features good resistance to burst errors and no error floor. However, only channel coding cannot cope with burst errors caused by channel fading, interleaving is also used. We investigate the efficiency of interleaving for different interleaving depths, and then the optimum interleaving depth for TPC is also determined. Finally, an experimental study of TPC with interleaving is demonstrated, and we show that TPC with interleaving can significantly mitigate channel fading in FSOC systems.

Computational and Experimental Study of Supersonic Nozzle Flow and Aft-Deck Interactions

NASA Technical Reports Server (NTRS)

Bruce, Walter E., IV; Carter, Melissa B.; Elmiligui, Alaa A.; Winski, Courtney S.; Nayani, Sudheer N.; Castner, Raymond S.

2016-01-01

NASA has been conducting research into reducing sonic boom and changing FAA regulations to allow for supersonic commercial transport over land in the United States. This particular study looks at a plume passing through a shock generated from an aft deck on a nacelle; the aft deck is meant to represent the trailing edge of a wing. NASA Langley Research Center USM3D CFD code results are compared to the experimental data taken at the NASA Glenn Research Center 1-foot by 1-foot Supersonic Wind Tunnel. This study included examining two turbulence models along with different volume sourcing methods for grid generation. The results show that using the k-epsilon turbulence model within USM3D produced shock signatures that closely follow the experimental data at a variety of nozzle pressure ratio settings.

Experimental study of the quasi 1d motion of a ``robot bacterium'' within a tube

NASA Astrophysics Data System (ADS)

Liu, Kai; Jiao, Yusheng; Li, Shutong; Ding, Yang; Xu, Xinliang; Complex Fluids Team

2017-11-01

Understanding how solid boundary influences the motion of a micro-swimmer can be quite important. Here we experimentally study the problem with a system of centi-meter size ``robot bacterium'' immersed in the solvent silicon oil. Equipped with build-in battery and motor, the robot mimics a free swimmer and the overall Reynolds number of the system is kept very small as we use silicon oil with very high viscosity. The motion of centi-meter size ``robot bacterium'' within cylindrical tube is experimentally studied in detail. Our results show that robot bacteria with different shapes respond very different to the solid boundary. For certain shapes the swimmers actually swim much faster within a tube, when compared to their motions without any confinement, in good agreement with our numerical evaluations of the hydrodynamics of the system.

A Brief Mindfulness Meditation Training Increases Pain Threshold and Accelerates Modulation of Response to Tonic Pain in an Experimental Study.

PubMed

Reiner, Keren; Granot, Michal; Soffer, Eliran; Lipsitz, Joshua Dan

2016-04-01

Research shows that mindfulness meditation (MM) affects pain perception; however, studies have yet to measure patterns of change over time. We examined effects of MM on perception of experimental heat pain using multiple psychophysical indices, including pattern of change in response to tonic painful stimuli. We also tested the potential moderating role of baseline mindfulness. Forty participants were randomly assigned to a brief MM training or control group. We assessed: a) heat pain threshold (HPT), b) temperature which induces pain at a fixed, target intensity level, and c) response pattern over time to tonic heat pain. Compared to control group, the MM group showed increased HPT and more rapid attenuation of pain intensity for tonic pain stimuli. Moderation analyses indicated that baseline mindfulness moderated effects of MM on HPT. A brief MM intervention appears to affect perception of experimental pain both by increasing pain threshold and accelerating modulation of response. Findings may help elucidate mechanisms of MM for chronic pain. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

ANTIPLAQUE AND ANTIGINGIVITIS EFFECT OF LIPPIA SIDOIDES. A DOUBLE-BLIND CLINICAL STUDY IN HUMANS

PubMed Central

Rodrigues, Ítalo Sarto Carvalho; Tavares, Vinícius Nascimento; Pereira, Sérgio Luís da Silva; da Costa, Flávio Nogueira

2009-01-01

Objectives: The antiplaque and antigingivitis effect of Lippia Sidoides (LS) was evaluated in this in vivo investigation. Material and Methods: Twenty-three subjects participated in a cross-over, double-blind clinical study, using 21-day partial-mouth experimental model of gingivitis. A toothshield was constructed for each volunteer, avoiding the brushing of the 4 experimental posterior teeth in the lower left quadrant. The subjects were randomly assigned initially to use either the placebo gel (control group) or the test gel, containing 10% LS (test group). Results: The clinical results showed statistically significant differences for plaque index (PLI) (p<0.01) between days 0 and 21 in both groups, however only the control group showed statistically significant difference (p<0.01) for the bleeding (IB) and gingival (GI) index within the experimental period of 21 days. On day 21, the test group presented significantly better results than the control group with regard to the GI (p<0.05). Conclusions: The test gel containing 10% LS was effective in the control of gingivitis. PMID:19936516

Evidence of forward-backward multiplicity correlation at SPS energy

NASA Astrophysics Data System (ADS)

Bhoumik, Gopa; Bhattacharyya, Swarnapratim; Deb, Argha; Ghosh, Dipak

In this paper, a detailed study of two-particle rapidity correlation has been presented by measuring the dynamical fluctuation variable σc2 in forward and backward pseudo-rapidity window of shower particles produced in the relativistic heavy ion collision, 16O-AgBr interactions at 60AGeV and 32S-AgBr interactions at 200AGeV. Variations of σc2 with rapidity gap between forward and backward zones and with the width of each zone have been studied. For both cases, σc2 increase with increasing either width of the zone or gap between the zones. Our findings show the presence of strong long-range correlation. Comparison of experimental results with MC-RAND events confirms the present correlation to be dynamical in nature. We have also compared our results with FRITIOF and UrQMD events. Such events also show the presence of correlation, but found to fail to reproduce the experimental results both quantitatively and qualitatively. Strength of correlation is dependent on the centrality of collision for experimental events, it decreases with centrality.

CFD study on NACA 4415 airfoil implementing spherical and sinusoidal Tubercle Leading Edge

PubMed Central

2017-01-01

The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c), the wavelength (0.25c) is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil. PMID:28850622

CFD study on NACA 4415 airfoil implementing spherical and sinusoidal Tubercle Leading Edge.

PubMed

Aftab, S M A; Ahmad, K A

2017-01-01

The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c), the wavelength (0.25c) is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.

One-year dog toxicity study of D-002, a mixture of aliphatic alcohols.

PubMed

Alemán, C; Rodeiro, I; Noa, M; Menéndez, R; Gaméz, R; Hernandez, C; Más, R

2001-01-01

D-002 is a mixture of high-molecular-weight aliphatic alcohols, obtained from bees wax (Apis mellifera), with mild anti-inflammatory properties and effective anti-ulcer activities demonstrated in experimental models. This study investigated the oral toxicity of D-002 administered for 1 year to beagle dogs. Twenty-four beagle dogs (12 males and 12 females) were distributed randomly in three experimental groups (four animals per group): a control and two treated groups received D-002 at 50 and 250 mg kg(-1) (7 days/week) by gastric gavage. Overall, D-002 was well tolerated throughout the study. No signs or symptoms of toxicity were observed, and no mortality occurred during the study. All groups showed similar weight gain and food consumption. No hematological, blood biochemical or histopathological disturbances attributable to treatment were observed. This study shows no drug-related toxicity induced by long-term administration of up to 250 mg kg(-1) D-002 to beagle dogs. Copyright 2001 John Wiley & Sons, Ltd.

First- and second-language phonological representations in the mental lexicon.

PubMed

Sebastian-Gallés, Núria; Rodríguez-Fornells, Antoni; de Diego-Balaguer, Ruth; Díaz, Begoña

2006-08-01

Performance-based studies on the psychological nature of linguistic competence can conceal significant differences in the brain processes that underlie native versus nonnative knowledge of language. Here we report results from the brain activity of very proficient early bilinguals making a lexical decision task that illustrates this point. Two groups of Spanish-Catalan early bilinguals (Spanish-dominant and Catalan-dominant) were asked to decide whether a given form was a Catalan word or not. The nonwords were based on real words, with one vowel changed. In the experimental stimuli, the vowel change involved a Catalan-specific contrast that previous research had shown to be difficult for Spanish natives to perceive. In the control stimuli, the vowel switch involved contrasts common to Spanish and Catalan. The results indicated that the groups of bilinguals did not differ in their behavioral and event-related brain potential measurements for the control stimuli; both groups made very few errors and showed a larger N400 component for control nonwords than for control words. However, significant differences were observed for the experimental stimuli across groups: Specifically, Spanish-dominant bilinguals showed great difficulty in rejecting experimental nonwords. Indeed, these participants not only showed very high error rates for these stimuli, but also did not show an error-related negativity effect in their erroneous nonword decisions. However, both groups of bilinguals showed a larger correct-related negativity when making correct decisions about the experimental nonwords. The results suggest that although some aspects of a second language system may show a remarkable lack of plasticity (like the acquisition of some foreign contrasts), first-language representations seem to be more dynamic in their capacity of adapting and incorporating new information.

Comprehensive DFT study on molecular structures of Lewisites in support of the Chemical Weapons Convention

NASA Astrophysics Data System (ADS)

Saeidian, Hamid; Sahandi, Morteza

2015-11-01

The structure of all of Lewisite's stereoisomers has been examined by B3LYP/6-311++G(3df,3pd) calculations. The geometry analysis for trans Lewisite L1-1 shows that the calculated bond angles, bond distances and dipole moment have a satisfactory relation compared with experimental values. HOMO-LUMO analysis of Lewisites reveals that L1-2 and L3-7 have the maximum and minimum electrophilicity index, respectively. The calculated chemical shifts were compared with experimental data, showing a very good agreement both for 1H and 13C. The vibrational and Raman frequencies of Lewisites have been precisely assigned and theoretical data were compared with the experimental vibrations. The bonding trends and Mulliken and atomic polar tensor charge distribution in Lewisites can be explained by the Bent's rule and the donor-acceptor interaction, respectively.

Mechanical evaluation of a tissue-engineered zone of calcification in a bone–hydrogel osteochondral construct

PubMed Central

Hollenstein, Jérôme; Terrier, Alexandre; Cory, Esther; Chen, Albert C.; Sah, Robert L.; Pioletti, Dominique P.

2016-01-01

The objective of this study was to test the hypothesis that mechanical properties of artificial osteochondral constructs can be improved by a tissue-engineered zone of calcification (teZCC) at the bone–hydrogel interface. Experimental push-off tests were performed on osteochondral constructs with or without a teZCC. In parallel, a numerical model of the osteochondral defect treatment was developed and validated against experimental results. Experimental results showed that the shear strength at the bone–hydrogel interface increased by 100% with the teZCC. Numerical predictions of the osteochondral defect treatment showed that the shear stress at the bone–hydrogel interface was reduced with the teZCC. We conclude that a teZCC in osteochondral constructs can provide two improvements. First, it increases the strength of the bone–hydrogel interface and second, it reduces the stress at this interface. PMID:23706035

Experimental Identification and Characterization of Multirotor UAV Propulsion

NASA Astrophysics Data System (ADS)

Kotarski, Denis; Krznar, Matija; Piljek, Petar; Simunic, Nikola

2017-07-01

In this paper, an experimental procedure for the identification and characterization of multirotor Unmanned Aerial Vehicle (UAV) propulsion is presented. Propulsion configuration needs to be defined precisely in order to achieve required flight performance. Based on the accurate dynamic model and empirical measurements of multirotor propulsion physical parameters, it is possible to design diverse configurations with different characteristics for various purposes. As a case study, we investigated design considerations for a micro indoor multirotor which is suitable for control algorithm implementation in structured environment. It consists of open source autopilot, sensors for indoor flight, “take off the shelf” propulsion components and frame. The series of experiments were conducted to show the process of parameters identification and the procedure for analysis and propulsion characterization. Additionally, we explore battery performance in terms of mass and specific energy. Experimental results show identified and estimated propulsion parameters through which blade element theory is verified.

Propriomuscular coding of kinaesthetic sensation. Experimental approach and mathematical modelling.

PubMed

Gilhodes, J C; Coiton, Y; Roll, J P; Ans, B

1993-01-01

The role of propriomuscular information in kinaesthetic sensation was studied. Experiments were carried out on human subjects in whom kinaesthetic illusions were induced by applying tendon vibration with a variable frequency. Six patterns of frequency modulation were used, four of which had an arbitrary form and the other two mimicked natural Ia discharges. The results show that the shape of the illusory movements recorded depended on the type of vibratory pattern used. A mathematical model for the propriomuscular information decoding process is proposed. It takes into account both the agonist and antagonist muscle spindle populations as sources of kinaesthetic information and is based on the assumption that position and velocity information are additively combined. The experimental data show a good fit with the theoretical data obtained by means of model simulation, thus validating our initial hypothesis. Various aspects of the experimental results and the hypotheses involved in the model are discussed.

Role of codeposited impurities during growth. I. Explaining distinctive experimental morphology on Cu(0 0 1)

NASA Astrophysics Data System (ADS)

Hamouda, Ajmi Bh.; Sathiyanarayanan, Rajesh; Pimpinelli, Alberto; Einstein, T. L.

2011-01-01

A unified explanation of the physics underlying all the distinctive features of the growth instabilities observed on Cu vicinals has long eluded theorists. Recently, kinetic Monte Carlo studies showed that codeposition of impurities during growth could account for the key distinctive experimental observations [Hamouda , Phys. Rev. BPLRBAQ0556-280510.1103/PhysRevB.77.245430 77, 245430 (2008)]. To identify the responsible impurity atom, we compute the nearest-neighbor binding energies (ENN) and terrace diffusion barriers (Ed) for several candidate impurity atoms on Cu(0 0 1) using DFT-based VASP. Our calculations show that codeposition (with Cu) of midtransition elements, such as Fe, Mn, and W, could—in conjunction with substantial Ehrlich-Schwoebel barriers—cause the observed instabilities; when the experimental setup is considered, W emerges to be the most likely candidate. We discuss the role of impurities in nanostructuring of surfaces.

Electronic and vibrational spectra of matrix isolated anthracene radical cations - Experimental and theoretical aspects

NASA Technical Reports Server (NTRS)

Szczepanski, Jan; Vala, Martin; Talbi, Dahbia; Parisel, Olivier; Ellinger, Yves

1993-01-01

The IR vibrational and visible/UV electronic absorption spectra of the anthracene cation, An(+), were studied experimentally, in argon matrices at 12 K, as well as theoretically, using ab initio calculations for the vibrational modes and enhanced semiempirical methods with configuration interaction for the electronic spectra. It was found that both approaches predicted well the observed photoelectron spectrum. The theoretical IR intensities showed some remarkable differences between neutral and ionized species (for example, the CH in-plane bending modes and CC in-plane stretching vibrations were predicted to increase by several orders of magnitude upon ionization). Likewise, estimated experimental IR intensities showed a significant increase in the cation band intensities over the neutrals. The implication of these findings for the hypothesis that polycyclic aromatic hydrocarbon cations are responsible for the unidentified IR emission bands from interstellar space is discussed.

Glutamine Randomized Studies in Early Life: The Unsolved Riddle of Experimental and Clinical Studies

PubMed Central

Briassouli, Efrossini; Briassoulis, George

2012-01-01

Glutamine may have benefits during immaturity or critical illness in early life but its effects on outcome end hardpoints are controversial. Our aim was to review randomized studies on glutamine supplementation in pups, infants, and children examining whether glutamine affects outcome. Experimental work has proposed various mechanisms of glutamine action but none of the randomized studies in early life showed any effect on mortality and only a few showed some effect on inflammatory response, organ function, and a trend for infection control. Although apparently safe in animal models (pups), premature infants, and critically ill children, glutamine supplementation does not reduce mortality or late onset sepsis, and its routine use cannot be recommended in these sensitive populations. Large prospectively stratified trials are needed to better define the crucial interrelations of “glutamine-heat shock proteins-stress response” in critical illness and to identify the specific subgroups of premature neonates and critically ill infants or children who may have a greater need for glutamine and who may eventually benefit from its supplementation. The methodological problems noted in the reviewed randomized experimental and clinical trials should be seriously considered in any future well-designed large blinded randomized controlled trial involving glutamine supplementation in critical illness. PMID:23019424

[Experimental study on acid mine drainage treatment using mine tailings of Xiangsi Valley, Tongling, China].

PubMed

Zhang, Nan; Chen, Tian-Hu; Zhou, Yue-Fei; Li, Shao-Jie; Jin, Jie; Wang, Yan-Ming

2012-04-01

Mine tailings in Xiangsi Valley, Tongling, China, is a typical skarn-type tailing with high contents of carbonates. This study designed dynamic leaching experiments to investigate the efficiency of this tailing under the acid mine drainage treatment. During 80 d trial period, the physical and chemical properties of influents were fixed and the effluents were monitored. After the trial, the speciation of Fe, Cu and Zn in solid was analyzed. The results showed that during the trial period, pH value maintained above 7.5. Moreover, the concentrations of Cu, Zn, Fe ions in effluents kept below 0.1, 0.4 and 1 mg x L(-1), respectively. In addition, the permeability coefficient of experimental column kept decreasing during the experimental period (from 0.23 cm x s(-1) to 0.10 cm x s(-1)). Five-step sequential extraction method was employed to study the distribution of elements at different depths. The results showed that Cu2+, Zn2+ were removed mainly through sorption and precipitation. This study indicates that Tongling skarn mine tailings have strong acid neutralization as well as heavy metal binding capacities. Therefore, the authors suggest that this mine tailing, which used to be waste, has a potential in AMD control and treatment.

[Improving the teaching quality by multiple tools and technology in oral histopathology experimental course].

PubMed

Tian, Zhen; Wang, Li-Zhen; Hu, Yu-Hua; Zhang, Chun-Ye; Li, Jiang

2017-04-01

Oral histopathology is a course which needs to be combined with theory and practice closely. Experimental course plays an important role in teaching oral histopathology. Here, we aim to explore a series of effective measures to improve the teaching quality of experimental course and tried to train observation, thinking, analysis and problem solving skills of dental students. We re-edited and updated the experimental textbook "guidelines of experimental course of oral histopathology", and published the reference book for experimental course--"color pocket atlas of oral histopathology: experiment and diadactic teaching". The number of clinicopathological cases for presentation and class discussion was increased, and high-quality teaching slides were added and replaced the poor-quality or worn out slides. We established a variety of teaching methods based on the internet, which provided an environment of self-directed learning for dental students. Instead of simple slice-reading examination, a new evaluation system based on computer was established. The questionnaire survey showed that the students spoke positively on the teaching reform for experimental course. They thought that the reform played a significant role in enriching the teaching content, motivating learning interest and promoting self-study. Compared with traditional examination, computer-based examination showed a great advantage on mastering professional knowledge systematically and comprehensively. The measures adopted in our teaching reform not only effectively improve the teaching quality of experimental course of oral histopathology, but also help the students to have a clear, logical thinking when facing complicated diseases and have the ability to apply theoretical knowledge into clinical practice.

Mechanisms of Günther Tulip filter tilting during transfemoral placement.

PubMed

Matsui, Y; Horikawa, M; Ohta, K; Jahangiri Noudeh, Y; Kaufman, J A; Farsad, K

The purpose of this study was to characterize the mechanisms of Günther Tulip filter (GTF) tilting during transfemoral placement in an experimental model with further validation in a clinical series. In an experimental study, 120 GTF placements in an inferior vena cava (IVC) model were performed using 6 configurations of pre-deployment filter position. The angle between the pre-deployment filter axis and IVC axis, and the proximity of the constrained filter legs to IVC wall prior to deployment were evaluated. The association of those pre-deployment factors with post-deployment filter tilting was analyzed. The association noted in the experimental study was then evaluated in a retrospective clinical series of 21 patients. In the experimental study, there was a significant association between the pre-deployment angle and post-deployment filter tilting (P<0.0001). With a low pre-deployment angle (≤5°), a significant association was noted between filter tilting and the proximity of the constrained filter legs to the far IVC wall (P=0.001). In a retrospective clinical study, a significant association between the pre-deployment angle and post-deployment filter tilting was also noted with a linear regression model (P=0.026). Significant association of the pre-deployment angle with post-deployment GTF tilting was shown in both the experimental and clinical studies. The experimental study also showed that proximity of filter legs is relevant when pre-deployment angle is small. Addressing these factors may result in a lower incidence of filter tilting. Copyright © 2017 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Ab initio study of the structure and dynamics of bulk liquid Fe

NASA Astrophysics Data System (ADS)

Marqués, M.; González, L. E.; González, D. J.

2015-10-01

Several static and dynamic properties of bulk liquid Fe at a thermodynamic state near its triple point have been evaluated by ab initio molecular dynamics simulations. The calculated static structure shows very good agreement with the available experimental data, including an asymmetric second peak in the structure factor which underlines a substantial local icosahedral short-range order in the liquid. The dynamical structure reveals propagating density fluctuations, with an associated dispersion relation which closely follows the experimental data. The dynamic structure factors S (q ,ω ) show a good agreement with their experimental counterparts which have been recently measured by an inelastic x-ray scattering experiment. The dynamical processes behind the S (q ,ω ) have been analyzed by using a model with two decay channels (a fast and a slow) associated with the relaxations of the collective excitations. The recent finding of transverselike excitation modes in the IXS data is analyzed by using the present ab initio simulation results. Several transport coefficients have been evaluated and the results are compared with the available experimental data.

Experimental investigation on no-vent fill process using tetrafluoromethane (CF4)

NASA Astrophysics Data System (ADS)

Kim, Youngcheol; Lee, Cheonkyu; Park, Jiho; Seo, Mansu; Jeong, Sangkwon

2016-03-01

This paper investigates the transfer of liquid cryogens using a no-vent fill (NVF) process experimentally to identify the dominant NVF parameters. The experimental apparatus has been fabricated with extensive instrumentations to precisely study the effects of each NVF parameter. Liquid tetrafluoromethane (CF4) is selected as the working fluid due to its similar molecular structures and similar normal boiling point and triple point with liquid methane which has been considered as an attractive future cryogenic propellant. The experimental results show that the initial receiver tank wall temperature and the incoming liquid temperature are the primary factors that characterize the (non-equilibrium) thermodynamic state at the start of a NVF transfer. The supply pressure is also critical as it indicates the ability to condense vapor in the receiver tank. A non-dimensional map based on energy balance is proposed to find acceptable initial conditions of the filling volume at the desired final tank pressure. The non-dimensional map shows good agreement with the NVF data not only in this paper but also in the previous research.

An experimental approach in revisiting the magnetic orientation of cattle

PubMed Central

Weijers, Debby; Hemerik, Lia; Heitkönig, Ignas M. A.

2018-01-01

In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations—excluding the hottest part of the day—of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals. PMID:29641517

Dissection Videos Do Not Improve Anatomy Examination Scores

ERIC Educational Resources Information Center

Mahmud, Waqas; Hyder, Omar; Butt, Jamaal; Aftab, Arsalan

2011-01-01

In this quasi-experimental study, we describe the effect of showing dissection videos on first-year medical students' performance in terms of test scores during a gross anatomy course. We also surveyed students' perception regarding the showing of dissection videos. Two hundred eighty-seven first-year medical students at Rawalpindi Medical College…

Induced Pathogen Resistance in Bean Plants: A Model for Studying "Vaccination" in the Classroom.

ERIC Educational Resources Information Center

Goetsch, Emily; Mathias, Christine; Mosley, Sydnie; Shull, Meredith; Brock, David L.

2002-01-01

Shows how the tobacco mosaic virus can be used in conjunction with the common bean plant Phaseolus vulgaris to provide a discernable, experimental model that students can use to study induced resistance. (Contains 17 references.) (DDR)

The Role of Lad Magazines in Priming Men's Chronic and Temporary Appearance-Related Schemata: An Investigation of Longitudinal and Experimental Findings

ERIC Educational Resources Information Center

Aubrey, Jennifer Stevens; Taylor, Laramie D.

2009-01-01

We present a program of research investigating the effects of lad magazines on male body self-consciousness and appearance anxiety. Study 1, based on panel data from undergraduate men, showed that lad magazine exposure in Year 1 predicted body self-consciousness in Year 2. Study 2 was an experiment that showed that men assigned to view objectified…

The teacher benefits from giving autonomy support during physical education instruction.

PubMed

Cheon, Sung Hyeon; Reeve, Johnmarshall; Yu, Tae Ho; Jang, Hue Ryen

2014-08-01

Recognizing that students benefit when they receive autonomy-supportive teaching, the current study tested the parallel hypothesis that teachers themselves would benefit from giving autonomy support. Twenty-seven elementary, middle, and high school physical education teachers (20 males, 7 females) were randomly assigned either to participate in an autonomy-supportive intervention program (experimental group) or to teach their physical education course with their existing style (control group) within a three-wave longitudinal research design. Manipulation checks showed that the intervention was successful, as students perceived and raters scored teachers in the experimental group as displaying a more autonomy-supportive and less controlling motivating style. In the main analyses, ANCOVA-based repeated-measures analyses showed large and consistent benefits for teachers in the experimental group, including greater teaching motivation (psychological need satisfaction, autonomous motivation, and intrinsic goals), teaching skill (teaching efficacy), and teaching well-being (vitality, job satisfaction, and lesser emotional and physical exhaustion). These findings show that giving autonomy support benefits teachers in much the same way that receiving it benefits their students.

Delamination and Stitched Failure in Stitched Composite Joints

NASA Technical Reports Server (NTRS)

Glaessgen, E. H.; Raju, I. S.; Poe, C. C., Jr.

1999-01-01

The effect of stitches on the failure of a single lap joint configuration was determined in a combined experimental and finite element study. The experimental program was conducted to determine debond growth under static monotonic loading. The stitches were shown to delay the initiation of the debond and provide load transfer beyond the load necessary to completely debond the stitched lap joint. The experimentally determined debond length vs. applied load was used as an input parameter in the finite element analysis of both configurations. The strain energy release rates at the debond from were calculated using plate finite elements. Nonlinear fastener elements were used to model the stitches and multipoint constraints were used to model the contact problem. Models of the unstitched configuration showed significant values of modes I and II across the width of the joint and showed that mode III is zero at the centerline but increases near the free edge. Models of the stitched configuration showed that the stitches were effective in reducing mode I to zero, but had less of an effect on modes II and III.

Interactions between environmental aversiveness and the anxiolytic effects of enhanced cannabinoid signaling by FAAH inhibition in rats.

PubMed

Haller, J; Barna, I; Barsvari, B; Gyimesi Pelczer, K; Yasar, S; Panlilio, L V; Goldberg, S

2009-07-01

Since the discovery of endogenous cannabinoid signaling, the number of studies exploring its role in health and disease has increased exponentially. Fatty acid amide hydrolase (FAAH), the enzyme responsible for degradation of the endocannabinoid anandamide, has emerged as a promising target for anxiety-related disorders. FAAH inhibitors (e.g., URB597) increase brain levels of anandamide and induce anxiolytic-like effects in rodents. Recent findings, however, questioned the efficacy of URB597 as an anxiolytic. We tested here the hypothesis that conflicting findings are due to variations in the stressfulness of experimental conditions employed in various studies. We found that URB597 (0.1-0.3 mg/kg) did not produce anxiolytic effects when the aversiveness of testing procedures was minimized by handling rats daily before experimentation, by habituating them to the experimental room, or by employing low illumination during testing. In contrast, URB597 had robust anxiolytic effects when the aversiveness of the testing environment was increased by eliminating habituation to the experimental room or by employing bright lighting conditions. Unlike URB597, the benzodiazepine chlordiazepoxide (5 mg/kg) had anxiolytic effects under all testing conditions. The anxiolytic effects of URB597 were abolished by the cannabinoid CB1-receptor antagonist AM251, showing that they were mediated by CB1 receptors. Close inspection of experimental conditions employed in earlier reports suggests that conflicting findings with URB597 can be explained by different testing conditions, such as those manipulated in the present study. Our findings show that FAAH inhibition does not affect anxiety under mildly stressful circumstances but protects against the anxiogenic effects of aversive stimuli.

ASSESSMENT OF THE POTENTIAL FOR TRANSPORT OF DIOXINS AND CODISPOSED MATERIALS TO GROUNDWATER

EPA Science Inventory

Dioxins are very toxic contaminants and warrant study under a variety of experimental conditions. Studies were performed to evaluate the mobility of several of the dioxins in both soil columns as well as in batch experiments. The studies showed that the amount of chlorination did...

Oxidative and proteolysis-related parameters of skeletal muscle from hamsters with experimental pulmonary emphysema: a comparison between papain and elastase induction.

PubMed

Brunnquell, Cláudia R; Vieira, Nichelle A; Sábio, Laís R; Sczepanski, Felipe; Cecchini, Alessandra L; Cecchini, Rubens; Guarnier, Flávia A

2015-06-01

The objective of this study was to investigate whether emphysema induced by elastase or papain triggers the same effects on skeletal muscle, related to oxidative stress and proteolysis, in hamsters. For this purpose, we evaluated pulmonary lesions, body weight, muscle loss, oxidative stress (thiobarbituric acid-reactive substances, total and oxidized glutathiones, chemiluminescence stimulated by tert-butyl hydroperoxide and carbonyl proteins), chymotrypsin-like and calpain-like proteolytic activities and muscle fibre cross-sectional area in the gastrocnemius muscles of emphysemic hamsters. Two groups of animals received different intratracheal inductions of experimental emphysema: by 40 mg/ml papain (EP) or 5.2 IU/100 g animal (EE) elastase (n = 10 animals/group). The control group received intratracheal instillation of 300 μl sterile NaCl 0.9%. Compared with the control group, the EP group had reduced muscle weight (18.34%) and the EE group had increased muscle weight (8.37%). Additionally, tert-butyl hydroperoxide-initiated chemiluminescence, carbonylated proteins and chymotrypsin-like proteolytic activity were all elevated in the EP group compared to the CS group, while total glutathione was decreased compared to the EE group. The EE group showed more fibres with increased cross-sectional areas and increased calpain-like activity. Together, these data show that elastase and papain, when used to induce experimental models of emphysema, lead to different speeds and types of adaptation. These findings provide more information on choosing a suitable experimental model for studying skeletal muscle adaptations in emphysema. © 2015 The Authors. International Journal of Experimental Pathology © 2015 International Journal of Experimental Pathology.

Repair of experimental plaque-induced periodontal disease in dogs.

PubMed

Shoukry, M; Ben Ali, L; Abdel Naby, M; Soliman, A

2007-09-01

Forty mongrel dogs were used in this study for induction of periodontal disease by placing subgingival silk ligatures affecting maxillary and mandibular premolar teeth during a 12-month period. Experimental premolar teeth received monthly clinical, radiographic, and histometric/pathologic assessments. The results demonstrated significant increases in scores and values of periodontal disease parameters associated with variable degrees of alveolar bone loss. The experimental maxillary premolar teeth exhibited more severe and rapid rates of periodontal disease compared with mandibular premolar teeth. Histometric analysis showed significant reduction in free and attached gingiva of the experimental teeth. Histopathological examination of buccolingual sections from experimental premolar teeth showed the presence of rete pegs within the sulcular epithelium with acanthosis and erosive changes, widening of the periodontal ligament, and alveolar bone resorption. Various methods for periodontal repair were studied in 194 experimental premolar teeth exhibiting different degrees of periodontal disease. The treatment plan comprised non-surgical (teeth scaling, root planing, and oral hygiene) and surgical methods (closed gingival curettage, modified Widman flap, and reconstructive surgery using autogenous bone marrow graft and canine amniotic membrane). The initial non-surgical treatment resulted in a periodontal recovery rate of 37.6% and was found effective for treatment of early periodontal disease based on resolution of gingivitis and reduction of periodontal probing depths. Surgical treatment by closed gingival curettage to eliminate the diseased pocket lining resulted in a recovery rate of 48.8% and proved effective in substantially reducing deep periodontal pockets. Open root planing following flap elevation resulted in a recovery rate of 85.4% and was effective for deep and refractory periodontal pockets. Autogenous bone graft implantation combined with canine amniotic membrane as a biodegradable membrane was used in 18 premolar teeth and failed to improve advanced furcation defects in most teeth.

Numerical and experimental investigation of the effect of geometry on combustion characteristics of solid-fuel ramjet

NASA Astrophysics Data System (ADS)

Gong, Lunkun; Chen, Xiong; Musa, Omer; Yang, Haitao; Zhou, Changsheng

2017-12-01

Numerical and experimental investigation on the solid-fuel ramjet was carried out to study the effect of geometry on combustion characteristics. The two-dimensional axisymmetric program developed in the present study adopted finite rate chemistry and second-order moment turbulence-chemistry models, together with k-ω shear stress transport (SST) turbulence model. Experimental data were obtained by burning cylindrical polyethylene using a connected pipe facility. The simulation results show that a fuel-rich zone near the solid fuel surface and an air-rich zone in the core exist in the chamber, and the chemical reactions occur mainly in the interface of this two regions; The physical reasons for the effect of geometry on regression rate is the variation of turbulent viscosity due to the geometry change. Port-to-inlet diameter ratio is the main parameter influencing the turbulent viscosity, and a linear relationship between port-to-inlet diameter and regression rate were obtained. The air mass flow rate and air-fuel ratio are the main influencing factors on ramjet performances. Based on the simulation results, the correlations between geometry and air-fuel ratio were obtained, and the effect of geometry on ramjet performances was analyzed according to the correlation. Three-dimensional regression rate contour obtained experimentally indicates that the regression rate which shows axisymmetric distribution due to the symmetry structure increases sharply, followed by slow decrease in axial direction. The radiation heat transfer in recirculation zone cannot be ignored. Compared with the experimental results, the deviations of calculated average regression rate and characteristic velocity are about 5%. Concerning the effect of geometry on air-fuel ratio, the deviations between experimental and theoretical results are less than 10%.

Experimental Modeling of a Formula Student Carbon Composite Nose Cone

PubMed Central

Fellows, Neil A.

2017-01-01

A numerical impact study is presented on a Formula Student (FS) racing car carbon composite nose cone. The effect of material model and model parameter selection on the numerical deceleration curves is discussed in light of the experimental deceleration data. The models show reasonable correlation in terms of the shape of the deceleration-displacement curves but do not match the peak deceleration values with errors greater that 30%. PMID:28772982

Peregrine soliton generation and breakup in standard telecommunications fiber.

PubMed

Hammani, Kamal; Kibler, Bertrand; Finot, Christophe; Morin, Philippe; Fatome, Julien; Dudley, John M; Millot, Guy

2011-01-15

We present experimental and numerical results showing the generation and breakup of the Peregrine soliton in standard telecommunications fiber. The impact of nonideal initial conditions is studied through direct cutback measurements of the longitudinal evolution of the emerging soliton dynamics and is shown to be associated with the splitting of the Peregrine soliton into two subpulses, with each subpulse itself exhibiting Peregrine soliton characteristics. Experimental results are in good agreement with simulations.

Effects of momentary self-monitoring on empowerment in a randomized controlled trial in patients with depression.

PubMed

Simons, C J P; Hartmann, J A; Kramer, I; Menne-Lothmann, C; Höhn, P; van Bemmel, A L; Myin-Germeys, I; Delespaul, P; van Os, J; Wichers, M

2015-11-01

Interventions based on the experience sampling method (ESM) are ideally suited to provide insight into personal, contextualized affective patterns in the flow of daily life. Recently, we showed that an ESM-intervention focusing on positive affect was associated with a decrease in symptoms in patients with depression. The aim of the present study was to examine whether ESM-intervention increased patient empowerment. Depressed out-patients (n=102) receiving psychopharmacological treatment who had participated in a randomized controlled trial with three arms: (i) an experimental group receiving six weeks of ESM self-monitoring combined with weekly feedback sessions, (ii) a pseudo-experimental group participating in six weeks of ESM self-monitoring without feedback, and (iii) a control group (treatment as usual only). Patients were recruited in the Netherlands between January 2010 and February 2012. Self-report empowerment scores were obtained pre- and post-intervention. There was an effect of group×assessment period, indicating that the experimental (B=7.26, P=0.061, d=0.44, statistically imprecise) and pseudo-experimental group (B=11.19, P=0.003, d=0.76) increased more in reported empowerment compared to the control group. In the pseudo-experimental group, 29% of the participants showed a statistically reliable increase in empowerment score and 0% reliable decrease compared to 17% reliable increase and 21% reliable decrease in the control group. The experimental group showed 19% reliable increase and 4% reliable decrease. These findings tentatively suggest that self-monitoring to complement standard antidepressant treatment may increase patients' feelings of empowerment. Further research is necessary to investigate long-term empowering effects of self-monitoring in combination with person-tailored feedback. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

A Perspective on Research on Dishonesty: Limited External Validity Due to the Lack of Possibility of Self-Selection in Experimental Designs.

PubMed

Houdek, Petr

2017-01-01

The aim of this perspective article is to show that current experimental evidence on factors influencing dishonesty has limited external validity. Most of experimental studies is built on random assignments, in which control/experimental groups of subjects face varied sizes of the expected reward for behaving dishonestly, opportunities for cheating, means of rationalizing dishonest behavior etc., and mean groups' reactions are observed. The studies have internal validity in assessing the causal influence of these and other factors, but they lack external validity in organizational, market and other environments. If people can opt into or out of diverse real-world environments, an experiment aimed at studying factors influencing real-life degree of dishonesty should permit for such an option. The behavior of such self-selected groups of marginal subjects would probably contain a larger level of (non)deception than the behavior of average people. The article warns that there are not many studies that would enable self-selection or sorting of participants into varying environments, and that limits current knowledge of the extent and dynamics of dishonest and fraudulent behavior. The article focuses on suggestions how to improve dishonesty research, especially how to avoid the experimenter demand bias.

A Perspective on Research on Dishonesty: Limited External Validity Due to the Lack of Possibility of Self-Selection in Experimental Designs

PubMed Central

Houdek, Petr

2017-01-01

The aim of this perspective article is to show that current experimental evidence on factors influencing dishonesty has limited external validity. Most of experimental studies is built on random assignments, in which control/experimental groups of subjects face varied sizes of the expected reward for behaving dishonestly, opportunities for cheating, means of rationalizing dishonest behavior etc., and mean groups’ reactions are observed. The studies have internal validity in assessing the causal influence of these and other factors, but they lack external validity in organizational, market and other environments. If people can opt into or out of diverse real-world environments, an experiment aimed at studying factors influencing real-life degree of dishonesty should permit for such an option. The behavior of such self-selected groups of marginal subjects would probably contain a larger level of (non)deception than the behavior of average people. The article warns that there are not many studies that would enable self-selection or sorting of participants into varying environments, and that limits current knowledge of the extent and dynamics of dishonest and fraudulent behavior. The article focuses on suggestions how to improve dishonesty research, especially how to avoid the experimenter demand bias. PMID:28955279

Using experimental design to define boundary manikins.

PubMed

Bertilsson, Erik; Högberg, Dan; Hanson, Lars

2012-01-01

When evaluating human-machine interaction it is central to consider anthropometric diversity to ensure intended accommodation levels. A well-known method is the use of boundary cases where manikins with extreme but likely measurement combinations are derived by mathematical treatment of anthropometric data. The supposition by that method is that the use of these manikins will facilitate accommodation of the expected part of the total, less extreme, population. In literature sources there are differences in how many and in what way these manikins should be defined. A similar field to the boundary case method is the use of experimental design in where relationships between affecting factors of a process is studied by a systematic approach. This paper examines the possibilities to adopt methodology used in experimental design to define a group of manikins. Different experimental designs were adopted to be used together with a confidence region and its axes. The result from the study shows that it is possible to adapt the methodology of experimental design when creating groups of manikins. The size of these groups of manikins depends heavily on the number of key measurements but also on the type of chosen experimental design.

Numerical model updating technique for structures using firefly algorithm

NASA Astrophysics Data System (ADS)

Sai Kubair, K.; Mohan, S. C.

2018-03-01

Numerical model updating is a technique used for updating the existing experimental models for any structures related to civil, mechanical, automobiles, marine, aerospace engineering, etc. The basic concept behind this technique is updating the numerical models to closely match with experimental data obtained from real or prototype test structures. The present work involves the development of numerical model using MATLAB as a computational tool and with mathematical equations that define the experimental model. Firefly algorithm is used as an optimization tool in this study. In this updating process a response parameter of the structure has to be chosen, which helps to correlate the numerical model developed with the experimental results obtained. The variables for the updating can be either material or geometrical properties of the model or both. In this study, to verify the proposed technique, a cantilever beam is analyzed for its tip deflection and a space frame has been analyzed for its natural frequencies. Both the models are updated with their respective response values obtained from experimental results. The numerical results after updating show that there is a close relationship that can be brought between the experimental and the numerical models.

Embodiment: A New Perspective for Evaluating Physicality in Learning

ERIC Educational Resources Information Center

Han, Insook

2013-01-01

The purpose of this study is to provide a new perspective for evaluating physicality in learning with a preliminary experimental study based on embodied cognition. While there are studies showing no superiority of physical manipulation over virtual manipulation, there are also studies that seem to advocate adding more physicality in simulations…

Liquid chromatography tandem-mass spectrometry (LC-MS/MS) and dried blood spot sampling applied to pharmacokinetics studies in animals: Correlation of classic and block design.

PubMed

Baldo, Matías N; Angeli, Emmanuel; Gareis, Natalia C; Hunzicker, Gabriel A; Murguía, Marcelo C; Ortega, Hugo H; Hein, Gustavo J

2018-04-01

A relative bioavailability study (RBA) of two phenytoin (PHT) formulations was conducted in rabbits, in order to compare the results obtained from different matrices (plasma and blood from dried blood spot (DBS) sampling) and different experimental designs (classic and block). The method was developed by liquid chromatography tandem-mass spectrometry (LC-MS/MS) in plasma and blood samples. The different sample preparation techniques, plasma protein precipitation and DBS, were validated according to international requirements. The analytical method was validated with ranges 0.20-50.80 and 0.12-20.32 µg ml -1 , r > 0.999 for plasma and blood, respectively. Accuracy and precision were within acceptance criteria for bioanalytical assay validation (< 15 for bias and CV% and < 20 for limit of quantification (LOQ)). PHT showed long-term stability, both for plasma and blood, and under refrigerated and room temperature conditions. Haematocrit values were measured during the validation process and RBA study. Finally, the pharmacokinetic parameters (C max , T max and AUC 0-t ) obtained from the RBA study were tested. Results were highly comparable for matrices and experimental designs. A matrix correlation higher than 0.975 and a ratio of (PHT blood) = 1.158 (PHT plasma) were obtained. The results obtained herein show that the use of classic experimental design and DBS sampling for animal pharmacokinetic studies should be encouraged as they could help to prevent the use of a large number of animals and also animal euthanasia. Finally, the combination of DBS sampling with LC-MS/MS technology showed to be an excellent tool not only for therapeutic drug monitoring but also for RBA studies.

Pen Devices for Insulin Self-Administration Compared With Needle and Vial: Systematic Review of the Literature and Meta-Analysis.

PubMed

Lasalvia, Pieralessandro; Barahona-Correa, Julián Esteban; Romero-Alvernia, Diana Marcela; Gil-Tamayo, Sebastián; Castañeda-Cardona, Camilo; Bayona, Juan Gabriel; Triana, Juan José; Laserna, Andrés Felipe; Mejía-Torres, Miguel; Restrepo-Jimenez, Paula; Jimenez-Zapata, Juliana; Rosselli, Diego

2016-07-01

Pen devices offer advantages compared with vial and syringe (VaS). The purpose of this article was to evaluate efficacy of pen devices compared to VaS. A systematic review of literature was performed in 8 different databases. References were independently screened and selected. Primary observational or experimental studies comparing pen devices with VaS for insulin administrations were included. Studies on specific populations were excluded. Risk of bias was evaluated using appropriate tools. Data on glycosylated hemoglobin (HbA1c), hypoglycemia, adherence, persistence, patient preference, and quality of life (QOL) were collected. Meta-analysis was performed when appropriate. Heterogeneity and risk of publication bias were evaluated. Otherwise, descriptive analyses of the available data was done. In all, 10 348 articles were screened. A total of 17 studies were finally selected: 7 experimental and 10 analytical. The populations of the included articles were mainly composed of adults with type 2 diabetes mellitus. Important risk of bias was found in all of the articles, particularly experimental studies. Meta-analyses were performed for HbA1c, hypoglycemia, adherence and persistence. Pen device showed better results in mean HbA1c change, patients with hypoglycemia, adherence and persistence compared to VaS. No difference was observed in number of patients achieving <7% HbA1c. Preference studies showed a tendency favoring pen devices, however nonvalidated tools were used. One QoL study showed improvements in some subscales of SF-36. There is evidence that pen devices offer benefits in clinical and, less clearly, patient-reported outcomes compared to VaS for insulin administration. However, these results should be taken with caution. © 2016 Diabetes Technology Society.

Teaching science for public understanding: Developing decision-making abilities

NASA Astrophysics Data System (ADS)

Siegel, Marcelle A.

One of the most important challenges educators have is teaching students how to make decisions about complex issues. In this study, methods designed to enhance students' decision-making skills and attitudes were investigated. An issue-oriented science curriculum was partly replaced with activities designed by the experimenter. The first objective of the study was to examine the effects of an instructional method to increase students' use of relevant scientific evidence in their decisions. The second goal of the research was to test whether the instructional activities could promote students' beliefs that science is relevant to them, because attitudes have been shown to affect students' performance and persistence (Schommer, 1994). Third, the study was designed to determine whether the instructional activities would affect students' beliefs that their intelligence is not fixed but can grow; this question is based on Dweck and Leggett's (1988) definition of two orientations toward intelligence---entity theorists and incremental theorists (Dweck & Leggett, 1988; Dweck & Henderson, 1989). Two urban high-school classrooms participated in this study. Tenth graders examined scientific materials about current issues involving technology and society. Instructional materials on decision making were prepared for one class of students to enhance their regular issue-oriented course, Science and Sustainability. A computer program, called Convince Me (Schank, Ranney & Hoadley, 1996), provided scaffolding for making an evidence-based decision. The experimental group's activities also included pen-and-paper lessons on decision making and the effect of experience on the structure of the brain. The control class continued to engage in Science and Sustainability decision-making activities during the time the experimental class completed the treatment. The control group did not show significant improvement on decision-making tasks, and the experimental group showed marginally significant gains (p = .06) according to the Rasch analysis. A measure of students' understanding of coherent argumentation was correlated with higher decision posttest scores. Over time, both classes significantly regarded science as being more relevant to everyday life. Students' attitudes about ability showed insignificant changes.

The Effect of Problem-Solving Instruction on the Programming Self-efficacy and Achievement of Introductory Computer Science Students

NASA Astrophysics Data System (ADS)

Maddrey, Elizabeth

Research in academia and industry continues to identify a decline in enrollment in computer science. One major component of this decline in enrollment is a shortage of female students. The primary reasons for the gender gap presented in the research include lack of computer experience prior to their first year in college, misconceptions about the field, negative cultural stereotypes, lack of female mentors and role models, subtle discriminations in the classroom, and lack of self-confidence (Pollock, McCoy, Carberry, Hundigopal, & You, 2004). Male students are also leaving the field due to misconceptions about the field, negative cultural stereotypes, and a lack of self-confidence. Analysis of first year attrition revealed that one of the major challenges faced by students of both genders is a lack of problem-solving skills (Beaubouef, Lucas & Howatt, 2001; Olsen, 2005; Paxton & Mumey, 2001). The purpose of this study was to investigate whether specific, non-mathematical problem-solving instruction as part of introductory programming courses significantly increased computer programming self-efficacy and achievement of students. The results of this study showed that students in the experimental group had significantly higher achievement than students in the control group. While this shows statistical significance, due to the effect size and disordinal nature of the data between groups, care has to be taken in its interpretation. The study did not show significantly higher programming self-efficacy among the experimental students. There was not enough data collected to statistically analyze the effect of the treatment on self-efficacy and achievement by gender. However, differences in means were observed between the gender groups, with females in the experimental group demonstrating a higher than average degree of self-efficacy when compared with males in the experimental group and both genders in the control group. These results suggest that the treatment from this study may provide a gender-based increase in self-efficacy and future research should focus on exploring this possibility.

The influence of two imidazolium-based ionic liquids on the structure and activity of glucose oxidase: Experimental and theoretical studies.

PubMed

Janati-Fard, Fatemeh; Housaindokht, Mohammad Reza; Monhemi, Hassan; Esmaeili, Abbas Ali; Nakhaei Pour, Ali

2018-07-15

The search for ionic liquids (ILs) with biochemical and biomedical applications has recently gained great attention. IL containing solvents can change the structure, stability and function of proteins. The study of protein conformation in ILs is important to understand enzymatic activity. In this work, conformational stability and activity of the enzyme in two imidazolium-based ILs (1-butyl 3-methyl-imidozolium and 1-hexyl 3-methyl-imidozoliumbromides) were investigated. We treated glucose oxidase as dimer-active enzyme in different IL concentration and seen that GOx activity was inhibited in the presence of ILs. Our experimental data showed that inhibition of activity and reduction of enzyme tertiary structure are more for hexyl than butyl derivative. These experimental results are in agreement with foregoing observations. To find a possible mechanism, a series of molecular dynamics simulation of the enzyme were performed at different IL concentration. The structure parameters obtained from MD simulation showed that conformational changes at the active site and FAD-binding site support the hypothesis of enzyme inhibition at the presence of ILs. Root mean square deviation and fluctuation calculations indicated that the enzyme has stable conformation at higher IL concentration, in agreement with experimental observation. But hexyl derivative has a much stronger stabilization effect on the protein structure. In summary, the present study could improve our understanding of the molecular mechanism about the ionic liquid effects on the structure and activity of proteins. Copyright © 2018 Elsevier B.V. All rights reserved.

Using experimental studies and theoretical calculations to analyze the molecular mechanism of coumarin, p-hydroxybenzoic acid, and cinnamic acid

NASA Astrophysics Data System (ADS)

Hsieh, Tiane-Jye; Su, Chia-Ching; Chen, Chung-Yi; Liou, Chyong-Huey; Lu, Li-Hwa

2005-05-01

Three natural products, Coumarin ( 1), p-hydroxybenzoic acid ( 2), trans-cinnamic acid ( 3) were isolated from the natural plant of indigenous cinnamon and the structures including relative stereochemistry were elucidated on the basis of spectroscopic data and theoretical calculations. Their sterochemical structures were determined by NMR spectroscopy, mass spectroscopy, and X-ray crystallography. The p-hydroxybenzoic acid complex with water is reported to show the existence of two hydrogen bonds. The two hydrogen bonds are formed in the water molecule of two hydrogen-accepting oxygen of carbonyl group of the p-hydroxybenzoic acid. The intermolecular interaction two hydrogen bond of the model system of the water- p-hydroxybenzoic acid was investigated. An experimental study and a theoretical analysis using the B3LYP/6-31G* method in the GAUSSIAN-03 package program were conducted on the three natural products. The theoretical results are supplemented by experimental data. Optimal geometric structures of three compounds were also determined. The calculated molecular mechanics compared quite well with those obtained from the experimental data. The ionization potentials, highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy, energy gaps, heat of formation, atomization energies, and vibration frequencies of the compounds were also calculated. The results of the calculations show that three natural products are stable molecules with high reactive and various other physical properties. The study also provided an explicit understanding of the sterochemical structure and thermodynamic properties of the three natural products.

Osteointegration of porous absorbable bone substitutes: A systematic review of the literature.

PubMed

Paulo, Maria Júlia Escanhoela; Dos Santos, Mariana Avelino; Cimatti, Bruno; Gava, Nelson Fabrício; Riberto, Marcelo; Engel, Edgard Eduard

2017-07-01

Biomaterials' structural characteristics and the addition of osteoinductors influence the osteointegration capacity of bone substitutes. This study aims to identify the characteristics of porous and resorbable bone substitutes that influence new bone formation. An Internet search for studies reporting new bone formation rates in bone defects filled with porous and resorbable substitutes was performed in duplicate using the PubMed, Web of Science, Scielo, and University of São Paulo Digital Library databases. Metaphyseal or calvarial bone defects 4 to 10 mm in diameter from various animal models were selected. New bone formation rates were collected from the histomorphometry or micro-CT data. The following variables were analyzed: animal model, bone region, defect diameter, follow-up time after implantation, basic substitute material, osteoinductor addition, pore size and porosity. Of 3,266 initially identified articles, 15 articles describing 32 experimental groups met the inclusion criteria. There were no differences between the groups in the experimental model characteristics, except for the follow-up time, which showed a very weak to moderate correlation with the rate of new bone formation. In terms of the biomaterial and structural characteristics, only porosity showed a significant influence on the rate of new bone formation. Higher porosity is related to higher new bone formation rates. The influence of other characteristics could not be identified, possibly due to the large variety of experimental models and methodologies used to estimate new bone formation rates. We suggest the inclusion of standard control groups in future experimental studies to compare biomaterials.

Fluid dynamics during Random Positioning Machine micro-gravity experiments

NASA Astrophysics Data System (ADS)

Leguy, Carole A. D.; Delfos, René; Pourquie, Mathieu J. B. M.; Poelma, Christian; Westerweel, Jerry; van Loon, Jack J. W. A.

2017-06-01

A Random Positioning Machine (RPM) is a device used to study the role of gravity on biological systems. This is accomplished through continuous reorientation of the sample such that the net influence of gravity is randomized over time. The aim of this study is to predict fluid flow behavior during such RPM simulated microgravity studies, which may explain differences found between RPM and space flight experiments. An analytical solution is given for a cylinder as a model for an experimental container. Then, a dual-axis rotating frame is used to mimic the motion characteristics of an RPM with sinusoidal rotation frequencies of 0.2 Hz and 0.1 Hz while Particle Image Velocimetry is used to measure the velocity field inside a flask. To reproduce the same experiment numerically, a Direct Numerical Simulation model is used. The analytical model predicts that an increase in the Womersley number leads to higher shear stresses at the cylinder wall and decrease in fluid angular velocity inside the cylinder. The experimental results show that periodic single-axis rotation induces a fluid motion parallel to the wall and that a complex flow is observed for two-axis rotation with a maximum wall shear stress of 8.0 mPa (80 mdyne /cm2). The experimental and numerical results show that oscillatory motion inside an RPM induces flow motion that can, depending on the experimental samples, reduce the quality of the simulated microgravity. Thus, it is crucial to determine the appropriate oscillatory frequency of the axes to design biological experiments.

An experimental study of high-pressure droplet combustion

NASA Technical Reports Server (NTRS)

Norton, Chris M.; Litchford, Ron J.; Jeng, San-Mou

1990-01-01

The results are presented of an experimental study on suspended n-heptane droplet combustion in air for reduced pressures up to P(r) = 2.305. Transition to fully transient heat-up through the critical state is demonstrated above a threshold pressure corresponding to P(r) of roughly 1.4. A silhouette imaging technique resolves the droplet surface for reduced pressures up to about P(r) roughly 0.63, but soot formation conceals the surface at higher pressures. Images of the soot plumes do not show any sudden change in behavior indicative of critical transition. Mean burning rate constants are computed from the d-squared variation law using measured effective droplet diameters at ignition and measured burn times, and corrected burning times are computed for an effective initial droplet diameter. The results show that the burning rates increase as the fuel critical pressure is approached and decrease as the pressure exceeds the fuel critical pressure. Corrected burning times show inverse behavior.

Immediate effects of atlanto-occipital joint manipulation on active mouth opening and pressure pain sensitivity in women with mechanical neck pain.

PubMed

Mansilla-Ferragut, Pilar; Fernández-de-Las Peñas, César; Alburquerque-Sendín, Francisco; Cleland, Joshua A; Boscá-Gandía, Juan José

2009-02-01

The purpose of this study was to investigate the effects of a spinal thrust manipulation directed to the upper cervical segments (atlanto-occipital joint) on active mouth opening and pressure pain sensitivity in a trigeminal nerve innervated region (sphenoid bone) in women with mechanical neck pain. Thirty-seven women, ages 21 to 50 years old (mean age, 35 +/- 8 years) with mechanical neck pain were recruited for this study. Participants were randomly assigned into 1 of 2 groups as follows: an experimental group that received a spinal manipulation of the atlanto-occipital joint and a control group that received a manual contact placebo intervention. Outcomes collected were assessed pretreatment and 5 minutes posttreatment by an assessor blinded to the treatment allocation and included active mouth opening and pressure pain thresholds (PPTs) over both sides of the sphenoid bone. A 2-way repeated measures analysis of variance (ANOVA) with time (pre-post) as the within subjects variable and group (control, experimental) as the between subjects variable was used to examine the effects of the intervention. The hypothesis of interest was group-time interaction. The ANOVA showed a significant effect for time (F = 23.1; P < .001) and an interaction between group and time (F = 37.7; P < .001) for active mouth opening as follows: the experimental group showed a greater improvement when compared to the control group. A large positive within-group effect size (d > 1.5) for the experimental group, whereas a negative medium within-group effect size (d = -0.5) for the control group were identified. The ANOVA showed a significant interaction between group and time (F = 14.4; P < .001) for PPT levels at the sphenoid bone as follows: the experimental group showed a greater improvement when compared to the control group. A medium positive within-group effect size (d = -0.5) for the experimental group, whereas a negative medium within-group effect size (d = -0.5) for the control group was found. Our findings suggest that the application of an atlantoaxial joint thrust manipulation resulted in an increase in active mouth opening and PPT over a trigeminal nerve distribution area (sphenoid bone) in women with mechanical neck pain.

Experimental and Numerical Study of Wind and Turbulence in a Near-Field Dispersion Campaign at an Inhomogeneous Site

NASA Astrophysics Data System (ADS)

Wei, Xiao; Dupont, Eric; Gilbert, Eric; Musson-Genon, Luc; Carissimo, Bertrand

2016-09-01

We present a detailed experimental and numerical study of the local flow field for a pollutant dispersion experimental program conducted at SIRTA (Site Instrumental de Recherche par Télédétection Atmosphérique), a complex and intensively instrumented site in a southern suburb of Paris. Global analysis of continuous measurements over 2 years highlights the impact of terrain heterogeneity on wind and turbulence. It shows that the forest to the north of the experimental field induces strong directional shear and wind deceleration below the forest canopy height. This directional shear is stronger with decreasing height and decreasing distance from the forest edge. Numerical simulations are carried out using Code_Saturne, a computational fluid dynamics code, in Reynolds-averaged Navier-Stokes mode with a standard k{-}ɛ closure and a canopy model, in neutral and stable stratifications. These simulations are shown to reproduce globally well the characteristics of the mean flow, especially the directional wind shear in northeasterly and northwesterly cases and the turbulent kinetic energy increase induced by the forest. However, they slightly underestimate wind speed and the directional shear of the flow below the forest canopy height. Sensitivity studies are performed to investigate the influence of leaf area density, inlet stability condition, and roughness length. These studies show that the typical features of the canopy flow become more pronounced as canopy density increases. Performance statistics indicate that the impact of the forest and adequate inlet profiles are the most important factors in the accurate reproduction of flow at the site, especially under stable stratification.

Inquiry-Based Integrated Science Education: Implementation of Local Content “Soil Washing” Project To Improve Junior High School Students’ Environmental Literacy

NASA Astrophysics Data System (ADS)

Syifahayu

2017-02-01

The study was conducted based on teaching and learning problems led by conventional method that had been done in the process of learning science. It gave students lack opportunities to develop their competence and thinking skills. Consequently, the process of learning science was neglected. Students did not have opportunity to improve their critical attitude and creative thinking skills. To cope this problem, the study was conducted using Project-Based Learning model through inquiry-based science education about environment. The study also used an approach called Sains Lingkungan and Teknologi masyarakat - “Saling Temas” (Environmental science and Technology in Society) which promoted the local content in Lampung as a theme in integrated science teaching and learning. The study was a quasi-experimental with pretest-posttest control group design. Initially, the subjects were given a pre-test. The experimental group was given inquiry learning method while the control group was given conventional learning. After the learning process, the subjects of both groups were given post-test. Quantitative analysis was performed using the Mann-Whitney U-test and also a qualitative descriptive. Based on the result, environmental literacy skills of students who get inquiry learning strategy, with project-based learning model on the theme soil washing, showed significant differences. The experimental group is better than the control group. Data analysis showed the p-value or sig. (2-tailed) is 0.000 <α = 0.05 with the average N-gain of experimental group is 34.72 and control group is 16.40. Besides, the learning process becomes more meaningful.

Human environmental and occupational exposures to boric acid: reconciliation with experimental reproductive toxicity data.

PubMed

Bolt, Hermann M; Başaran, Nurşen; Duydu, Yalçın

2012-01-01

The reproductive toxicity of boric acid and borates is a matter of current regulatory concern. Based on experimental studies in rats, no-observed-adverse-effect levels (NOAELs) were found to be 17.5 mg boron (B)/kg body weight (b.w.) for male fertility and 9.6 mg B/kg b.w. for developmental toxicity. Recently, occupational human field studies in highly exposed cohorts were reported from China and Turkey, with both studies showing negative results regarding male reproduction. A comparison of the conditions of these studies with the experimental NOAEL conditions are based on reported B blood levels, which is clearly superior to a scaling according to estimated B exposures. A comparison of estimated daily B exposure levels and measured B blood levels confirms the preference of biomonitoring data for a comparison of human field studies. In general, it appears that high environmental exposures to B are lower than possible high occupational exposures. The comparison reveals no contradiction between human and experimental reproductive toxicity data. It clearly appears that human B exposures, even in the highest exposed cohorts, are too low to reach the blood (and target tissue) concentrations that would be required to exert adverse effects on reproductive functions.

Cyber bullying prevention: intervention in Taiwan.

PubMed

Lee, Ming-Shinn; Zi-Pei, Wu; Svanström, Leif; Dalal, Koustuv

2013-01-01

This study aimed to explore the effectiveness of the cyber bullying prevention WebQuest course implementation. The study adopted the quasi-experimental design with two classes made up of a total of 61 junior high school students of seventh grade. The study subjects comprised of 30 students from the experimental group and 31 students from the control group. The experimental group received eight sessions (total 360 minutes) of the teaching intervention for four consecutive weeks, while the control group did not engage in any related courses. The self-compiled questionnaire for the student's knowledge, attitudes, and intentions toward cyber bullying prevention was adopted. Data were analysed through generalized estimating equations to understand the immediate results on the student's knowledge, attitudes, and intentions after the intervention. The results show that the WebQuest course immediately and effectively enhanced the knowledge of cyber bullying, reduced the intentions, and retained the effects after the learning. But it produced no significant impact on the attitude toward cyber bullying. The intervention through this pilot study was effective and positive for cyber bulling prevention. It was with small number of students. Therefore, studies with large number of students and long experimental times, in different areas and countries are warranted.

Experimental study of the oscillation of spheres in an acoustic levitator.

PubMed

Andrade, Marco A B; Pérez, Nicolás; Adamowski, Julio C

2014-10-01

The spontaneous oscillation of solid spheres in a single-axis acoustic levitator is experimentally investigated by using a high speed camera to record the position of the levitated sphere as a function of time. The oscillations in the axial and radial directions are systematically studied by changing the sphere density and the acoustic pressure amplitude. In order to interpret the experimental results, a simple model based on a spring-mass system is applied in the analysis of the sphere oscillatory behavior. This model requires the knowledge of the acoustic pressure distribution, which was obtained numerically by using a linear finite element method (FEM). Additionally, the linear acoustic pressure distribution obtained by FEM was compared with that measured with a laser Doppler vibrometer. The comparison between numerical and experimental pressure distributions shows good agreement for low values of pressure amplitude. When the pressure amplitude is increased, the acoustic pressure distribution becomes nonlinear, producing harmonics of the fundamental frequency. The experimental results of the spheres oscillations for low pressure amplitudes are consistent with the results predicted by the simple model based on a spring-mass system.

Crowdsourcing for Cognitive Science – The Utility of Smartphones

PubMed Central

Brown, Harriet R.; Zeidman, Peter; Smittenaar, Peter; Adams, Rick A.; McNab, Fiona; Rutledge, Robb B.; Dolan, Raymond J.

2014-01-01

By 2015, there will be an estimated two billion smartphone users worldwide. This technology presents exciting opportunities for cognitive science as a medium for rapid, large-scale experimentation and data collection. At present, cost and logistics limit most study populations to small samples, restricting the experimental questions that can be addressed. In this study we investigated whether the mass collection of experimental data using smartphone technology is valid, given the variability of data collection outside of a laboratory setting. We presented four classic experimental paradigms as short games, available as a free app and over the first month 20,800 users submitted data. We found that the large sample size vastly outweighed the noise inherent in collecting data outside a controlled laboratory setting, and show that for all four games canonical results were reproduced. For the first time, we provide experimental validation for the use of smartphones for data collection in cognitive science, which can lead to the collection of richer data sets and a significant cost reduction as well as provide an opportunity for efficient phenotypic screening of large populations. PMID:25025865

Crowdsourcing for cognitive science--the utility of smartphones.

PubMed

Brown, Harriet R; Zeidman, Peter; Smittenaar, Peter; Adams, Rick A; McNab, Fiona; Rutledge, Robb B; Dolan, Raymond J

2014-01-01

By 2015, there will be an estimated two billion smartphone users worldwide. This technology presents exciting opportunities for cognitive science as a medium for rapid, large-scale experimentation and data collection. At present, cost and logistics limit most study populations to small samples, restricting the experimental questions that can be addressed. In this study we investigated whether the mass collection of experimental data using smartphone technology is valid, given the variability of data collection outside of a laboratory setting. We presented four classic experimental paradigms as short games, available as a free app and over the first month 20,800 users submitted data. We found that the large sample size vastly outweighed the noise inherent in collecting data outside a controlled laboratory setting, and show that for all four games canonical results were reproduced. For the first time, we provide experimental validation for the use of smartphones for data collection in cognitive science, which can lead to the collection of richer data sets and a significant cost reduction as well as provide an opportunity for efficient phenotypic screening of large populations.

Neural Network Models of Simple Mechanical Systems Illustrating the Feasibility of Accelerated Life Testing

NASA Technical Reports Server (NTRS)

Fusaro, Robert L.; Jones, Steven P.; Jansen, Ralph

1996-01-01

A complete evaluation of the tribological characteristics of a given material/mechanical system is a time-consuming operation since the friction and wear process is extremely systems sensitive. As a result, experimental designs (i.e., Latin Square, Taguchi) have been implemented in an attempt to not only reduce the total number of experimental combinations needed to fully characterize a material/mechanical system, but also to acquire life data for a system without having to perform an actual life test. Unfortunately, these experimental designs still require a great deal of experimental testing and the output does not always produce meaningful information. In order to further reduce the amount of experimental testing required, this study employs a computer neural network model to investigate different material/mechanical systems. The work focuses on the modeling of the wear behavior, while showing the feasibility of using neural networks to predict life data. The model is capable of defining which input variables will influence the tribological behavior of the particular material/mechanical system being studied based on the specifications of the overall system.

An environmental friendly animal waste disposal process with ammonia recovery and energy production: Experimental study and economic analysis.

PubMed

Shen, Ye; Tan, Michelle Ting Ting; Chong, Clive; Xiao, Wende; Wang, Chi-Hwa

2017-10-01

Animal manure waste is considered as an environmental challenge especially in farming areas mainly because of gaseous emission and water pollution. Among all the pollutants emitted from manure waste, ammonia is of greatest concern as it could contribute to formation of aerosols in the air and could hardly be controlled by traditional disposal methods like landfill or composting. On the other hand, manure waste is also a renewable source for energy production. In this work, an environmental friendly animal waste disposal process with combined ammonia recovery and energy production was proposed and investigated both experimentally and economically. Lab-scale feasibility study results showed that 70% of ammonia in the manure waste could be converted to struvite as fertilizer, while solid manure waste was successfully gasified in a 10kW downdraft fixed-bed gasifier producing syngas with the higher heating value of 4.9MJ/(Nm 3 ). Based on experimental results, economic study for the system was carried out using a cost-benefit analysis to investigate the financial feasibility based on a Singapore case study. In addition, for comparison, schemes of gasification without ammonia removal and incineration were also studied for manure waste disposal. The results showed that the proposed gasification-based manure waste treatment process integrated with ammonia recovery was most financially viable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Research on the Microstructures and Mechanical Properties of Ti Micro-Alloyed Cold Rolled Hot-Dip Galvanizing DP980 Steel

NASA Astrophysics Data System (ADS)

Han, Yun; Kuang, Shuang; Qi, Xiumei; Xie, Chunqian; Liu, Guanghui

Effects of galvanizing simulation parameters on microstructures and mechanical properties of Ti-microalloyed cold rolled hot-dip galvanizing DP980 steel were investigated in this study by optical microscopy (OM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and tensile test. Moreover, the precipitation behavior of Ti in the experimental steel was also studied. The results show that, as the heating temperature increases, the tensile strength of experimental galvanizing DP980 steel decreases while the yield ratio and elongation of the steel are enhanced. The microstructures of experimental steels exhibit typical dual phase steel character and the volume fractions of MA islands are almost 30%. In addition, lots of nano-sized TiC precipitates can be found in the ferrite grains.

An experimental study on the effect of temperature on piezoelectric sensors for impedance-based structural health monitoring.

PubMed

Baptista, Fabricio G; Budoya, Danilo E; de Almeida, Vinicius A D; Ulson, Jose Alfredo C

2014-01-10

The electromechanical impedance (EMI) technique is considered to be one of the most promising methods for developing structural health monitoring (SHM) systems. This technique is simple to implement and uses small and inexpensive piezoelectric sensors. However, practical problems have hindered its application to real-world structures, and temperature effects have been cited in the literature as critical problems. In this paper, we present an experimental study of the effect of temperature on the electrical impedance of the piezoelectric sensors used in the EMI technique. We used 5H PZT (lead zirconate titanate) ceramic sensors, which are commonly used in the EMI technique. The experimental results showed that the temperature effects were strongly frequency-dependent, which may motivate future research in the SHM field.

Experimental Study on Ice Forming Process of Cryogenic Liquid Releasing underwater

NASA Astrophysics Data System (ADS)

Zhang, Bin; Wu, Wanqing; Zhang, Xingdong; Zhang, Yi; Zhang, Chuanlin; Zhang, Haoran; Wang, Peng

2017-11-01

Cryogenic liquid releasing into water would be a process combines hyperactive boiling with ice forming. There are still few researches on the experimental study on the environmental conditions for deciding ice forming speed and liquid surviving state. In this paper, to advance our understanding of ice forming deciding factors in the process of LN2 releasing underwater, a visualization experimental system is built. The results show that the pressure difference significantly influences the ice forming speed and liquid surviving distance, which is observed by the experiment and theoretically analysed by Kelvin-Helmholtz instability. Adding nucleating agent is helpful to provide ice nucleus which can accelerate the ice forming speed. Water flowing has some effect on changing pressure difference, which can affect the ice forming speed and liquid surviving distance.

Numerical and experimental study of actuator performance on piezoelectric microelectromechanical inkjet print head.

PubMed

Van So, Pham; Jun, Hyun Woo; Lee, Jaichan

2013-12-01

We have investigated the actuator performance of a piezoelectrically actuated inkjet print head via the numerical and experimental analysis. The actuator consisting of multi-layer membranes, such as piezoelectric, elastic and other buffer layers, and ink chamber was fabricated by MEMS processing. The maximum displacement of the actuator membrane obtained in the experiment is explained by numerical analysis. A simulation of the actuator performance with fluidic damping shows that the resonant frequency of the membrane in liquid is reduced from its resonant frequency in air by a factor of three, which was also verified in the experiment. These simulation and experimental studies demonstrate how much "dynamic force," in terms of a membrane's maximum displacement, maximum force and driving frequency, can be produced by an actuator membrane interacting with fluid.

Experimental and Theoretical Study on Supramolecular Ionic Liquid (IL)-Asphaltene Complex Interactions and Their Effects on the Flow Properties of Heavy Crude Oils.

PubMed

Hernández-Bravo, R; Miranda, A D; Martínez-Magadán, J-M; Domínguez, J M

2018-04-19

A combined study for understanding the molecular interactions of asphaltenes with molecular species such as ionic liquids (ILs) comprised experimental measurements and computational numerical simulation calculations, using density-functional theory (DFT) with dispersion corrections, molecular dynamics (MD) calculations, and experimental rheological characterization of the heavy crude oils (HCOs), before and after doping with ILs, respectively. The main results show that ILs influence the asphaltenic dimer association by forming supramolecular complexes that modify the properties of crude oils such as viscosity and interfacial tension. The IL-cation and asphaltene-π ligand molecular interactions seem to dominate the interactions between ionic liquids and asphaltenes, where ILs' high aromaticity index induces a strong interaction with the aromatic hard core of asphaltenes.

Study of the high-pressure helium phase diagram using molecular dynamics

NASA Astrophysics Data System (ADS)

Koci, L.; Ahuja, R.; Belonoshko, A. B.; Johansson, B.

2007-01-01

The rich occurrence of helium and hydrogen in space makes their properties highly interesting. By means of molecular dynamics (MD), we have examined two interatomic potentials for 4He. Both potentials are demonstrated to reproduce high-pressure solid and liquid equation of state (EOS) data. The EOS, solid-solid transitions and melting at high pressures (P) were studied using a two-phase method. The Buckingham potential shows a good agreement with theoretical and experimental EOS, but does not reproduce experimental melting data. The Aziz potential shows a perfect match with theoretical melting data. We conclude that there is a stable body-centred-cubic (bcc) phase for 4He at temperatures (T) above 340 K and pressures above 22 GPa for the Buckingham potential, whereas no bcc phase is found for the Aziz potential in the applied PT range.

[Modeling and experimental study on frequency-domain electricity properties of biological materials].

PubMed

Tian, Hua; Luo, Shiqiang; Zhang, Rui; Yang, Gang; Huang, Hua

2009-12-01

Frequency-domain electricity properties of four objects, including bullfrog skin, bullfrog muscle, triply distilled water and 0.9% NaCl, were tested in the range of 100Hz-10MHz using home-made electrode and measuring system. The experimental results showed that the resistance of 0.9% NaCl decreased dramatically, that the amplitude frequency characteristics of bullfrog's muscle and skin were similar, but that of triply distilled water did not change significantly. The frequency dependence of 0.9% NaCl showed that the electrode had great influence on the measuring system, so a new equivalent circuit model based on the electrode system was needed. These findings suggest that the new five-parameter equivalent circuit model, which embodies considerations on the interaction between electrodes and tissues, is a reasonable equivalent circuit for studying the electrical characteristics of biological materials.

Gas-Phase Reactions of Dimethyl Disulfide with Aliphatic Carbanions - A Mass Spectrometry and Computational Study

NASA Astrophysics Data System (ADS)

Franczuk, Barbara; Danikiewicz, Witold

2018-03-01

Ion-molecule reactions of Me2S2 with a wide range of aliphatic carbanions differing by structure and proton affinity values have been studied in the gas phase using mass spectrometry techniques and DFT calculations. The analysis of the spectra shows a variety of product ions formed via different reaction mechanisms, depending on the structure and proton affinity of the carbanion. Product ions of thiophilic reaction ( m/z 47), SN2 ( m/z 79), and E2 elimination - addition sequence of reactions ( m/z 93) can be observed. Primary products of thiophilic reaction can undergo subsequent SN2 and proton transfer reactions. Gibbs free energy profiles calculated for experimentally observed reactions using PBE0/6-311+G(2d,p) method show good agreement with experimental results. [Figure not available: see fulltext.

[Experimental study on spectra of compressed air microwave plasma].

PubMed

Liu, Yong-Xi; Zhang, Gui-Xin; Wang, Qiang; Hou, Ling-Yun

2013-03-01

Using a microwave plasma generator, compressed air microwave plasma was excited under 1 - 5 atm pressures. Under different pressures and different incident microwave power, the emission spectra of compressed air microwave plasma were studied with a spectra measuring system. The results show that continuum is significant at atmospheric pressure and the characteristic will be weakened as the pressure increases. The band spectra intensity will be reduced with the falling of the incident microwave power and the band spectra were still significant. The experimental results are valuable to studying the characteristics of compressed air microwave plasma and the generating conditions of NO active groups.

Experimental investigation of non-planar sheared outboard wing planforms

NASA Technical Reports Server (NTRS)

Naik, D. A.; Ostowari, C.

1988-01-01

The outboard planforms of wings have been found to be of prime importance in studies of induced drag reduction. This conclusion is based on an experimental and theoretical study of the aerodynamic characteristics of planar and nonplanar outboard wing forms. Six different configurations; baseline rectangular, planar sheared, sheared with dihedral, sheared with anhedral, rising arc, and drooping arc were investigated for two different spans. Span efficiencies as much as 20 percent greater than baseline can be realized with nonplanar wing forms. Optimization studies show that this advantage can be achieved along with a bending moment benefit. Parasite drag and lateral stability estimations were not included in the analysis.

Is Affect Aversive to Young Children with Autism: Behavioral and Cardiac Responses to Experimenter Distress.

ERIC Educational Resources Information Center

Corona, Rosalie; Dissanayake, Cheryl; Arbelle, Shoshana; Wellington, Peter; Sigman, Marian

1998-01-01

Compared attention, behavioral reaction, facial affect, and cardiac responses of 22 autistic and 22 mentally retarded preschoolers to emotional displays. Found that both groups looked more at the experimenter and displayed more interest and concern when the experimenter showed strong distress than when she showed neutral affect. Autistic…

Using Complementary Learning Clusters in Studying Literature to Enhance Students' Medical Humanities Literacy, Critical Thinking, and English Proficiency.

PubMed

Liao, Hung-Chang; Wang, Ya-Huei

2016-04-01

This study examined whether students studying literature in complementary learning clusters would show more improvement in medical humanities literacy, critical thinking skills, and English proficiency compared to those in conventional learning clusters. Ninety-three students participated in the study (M age = 18.2 years, SD = 0.4; 36 men, 57 women). A quasi-experimental design was used over 16 weeks, with the control group (n = 47) working in conventional learning clusters and the experimental group (n = 46) working in complementary learning clusters. Complementary learning clusters were those in which individuals had complementary strengths enabling them to learn from and offer assistance to other cluster members, hypothetically facilitating the learning process. Measures included the Medical Humanities Literacy Scale, Critical Thinking Disposition Assessment, English proficiency tests, and Analytic Critical Thinking Scoring Rubric. The results showed that complementary learning clusters have the potential to improve students' medical humanities literacy, critical thinking skills, and English proficiency. © The Author(s) 2016.

Molecular binding of toxic phenothiazinium derivatives, azures to bovine serum albumin: A comparative spectroscopic, calorimetric, and in silico study.

PubMed

Das, Somnath; Islam, Md Maidul; Jana, Gopal Chandra; Patra, Anirudha; Jha, Pradeep K; Hossain, Maidul

2017-07-01

In this paper, the comparative binding behavior of antimalarial drug azure A, azure B and azure C with bovine serum albumin (BSA) has been studied. The interaction has been confirmed by multispectroscopic (UV, fluorescence, Fourier transform infrared (FT-IR), and circular dichroism) and molecular docking techniques. The experimental results show that azure B has the highest BSA binding affinity followed by azure A and azure C. The experimental evidence of binding showed a static quenching mechanism in the interaction azures with BSA. The isothermal titration calorimetry result reveals that the binding was exothermic with positive entropy contribution in each case. The thermodynamic parameters ΔH, ΔG, and ΔS at 25°C were calculated, which indicates that the weak van der Waals forces and hydrogen bonding rather than the hydrophobic effect played an important role in the interaction. According to the theory of Förster nonradiative energy transfer, the distance (r) between the donor (BSA) and acceptor azures found to be <7 nm in all the case. The circular dichroism and FT-IR studies show that the content of α-helix structure has increased for the azures-BSA system. Overall, experimental studies characterize the interaction dynamics and energetics of the binding of three toxic analogs towards the physiologically relevant serum albumins. We hope, the outcome of this work will be most helpful for synthesizing a new type of phenothiazinium derivatives of the better therapeutic application. Copyright © 2017 John Wiley & Sons, Ltd.

Structural characterization, spectroscopic signatures, nonlinear optical response, and antioxidant property of 4-benzyloxybenzaldehyde and its binding activity with microtubule-associated tau protein

NASA Astrophysics Data System (ADS)

Anbu, V.; Vijayalakshmi, K. A.; Karthick, T.; Tandon, Poonam; Narayana, B.

2017-09-01

In the proposed work, the non-linear optical response, spectroscopic signature and binding activity of 4-Benzyloxybenzaldehyde (4BB) has been investigated. In order to find the vibrational contribution of functional groups in mixed or coupled modes in the experimental FT-IR and FT-Raman spectra, the potential energy distribution (PED) based on the internal coordinates have been computed. Since the molecule exists in the form of dimer in solid state, the electronic structure of dimer has been proposed in order to explain the intermolecular hydrogen bonding interactions via aldehyde group. The experimental and simulated powder X-ray diffraction data was compared and the miller indices which define the crystallographic planes in the crystal lattices were identified. Optical transmittance and absorbance measurement were taken at ambient temperature in order to investigate the transparency and optical band gap. For screening the material for nonlinear applications, theoretical second order hyperpolarizability studies were performed and compared with the standard reference urea. To validate the theoretical results, powder second harmonic generation (SHG) studies were carried out using Kurtz and Perry technique. The results show that the molecule studied in this work exhibit considerable non-linear optical (NLO) response. In addition to the characterization and NLO studies, we also claimed based on the experimental and theoretical data that the molecule shows antioxidant property and inhibition capability. Since the title molecule shows significant binding with Tau protein that helps to stabilize microtubules in the nervous system, the molecular docking investigation was performed to find the inhibition constant, binding affinity and active binding residues.

[The effect of osteogenic inducer on healing of tooth extraction sockets].

PubMed

Chen, Junliang; Shan, Chuncheng; He, Yun; Xia, Delin

2012-06-01

To study the effect of osteogenic inducer (dexamethasone, beta-sodium glycerophosphate and Vitamin C) carried by gelatin sponge on healing and remodeling of tooth extraction sockets. Fifty rabbits were selected. After extracting the first premolars of bilateral maxillary, the right side tooth extraction sockets were filled with gelatin sponge containing osteogenic inducer as experimental side, tooth extraction sockets on left side were filled with gelatin sponge as control. Every ten rabbits were executed at the end of 1, 2, 4, 8, 12 weeks after tooth extraction. Bone density was measured through digital X-ray images. The specimens were examined by histology. The absorption height of alveolar bone at 12 weeks was measured. X-ray measurement showed that the bone density of experimental side was higher than that of control side at 2, 4, 8, 12 weeks, the difference had statistical significance (P<0.01). The histology examination showed that new bone formation in tooth extraction sockets of experimental side was earlier than that in control side. The absorptional height of alveolar bone had significant difference between experimental side and control side (P<0.01), of which experimental side was less. Filling the osteogenic inducer in tooth extraction sockets can promote the healing and new bone formation and prevent from alveolar bone absorption.

Experimental Infection with Sporulated Oocysts of Eimeria maxima (Apicomplexa: Eimeriidae) in Broiler

PubMed Central

Brito, Luciana da S.; Pereira, Elder N.; da Silva, Augusta A.; Bentivóglio Costa Silva, Vinícius; Freitas, Fagner L. da C.

2014-01-01

Through this study we assessed the metabolic and pathological changes in broilers experimentally infected with oocysts of Eimeria maxima. To perform the experiment, we used 150 broiler strain cooB males, with ten days of age, were randomized according to weight and randomly assigned to two experimental groups: the control group was inoculated with 0.5 mL of distilled water; the infected group inoculated with 0.5 mL of solution containing 5 × 104 sporulated oocysts of Eimeria maxima. The live performance was evaluated on day 0 (day of inoculation), 5°, 10°, 15°, 25°, and 35° dpi, being slaughtered by cervical dislocation, fifteen birds/group. Although the sum in meat production was higher in the control group, the weight of the heart and gizzard of the experimental animals showed no significant difference, while the liver had difference on day 5°, 15°, and 35° dpi. The pathologic evaluation showed congested mucosa and presence of large amounts of mucus at 6 dpi. Therefore, it is concluded that the dose of 5 × 104  E. maxima inoculated in the experimental group was enough to cause harm to the animal organism. PMID:26464925

The effect of rehearsal training on working memory span of children with fetal alcohol spectrum disorder.

PubMed

Loomes, Carly; Rasmussen, Carmen; Pei, Jacqueline; Manji, Shazeen; Andrew, Gail

2008-01-01

A key area of weakness in individuals with fetal alcohol spectrum disorder (FASD) is working memory, thus the goal of this study was to determine whether teaching children (aged 4-11) with FASD verbal rehearsal would increase their memory. Rehearsal training has been effective in other populations with working memory difficulties, so we hypothesized that children with FASD would also benefit from rehearsal training. Children were divided into an Experimental group, who received rehearsal training and a Control group, who did not receive training. All children were tested on digit span tasks over three sessions: a pretest (baseline) and then post-test 1 and post-test 2 (where only the Experimental group received rehearsal training). The Experimental group showed a significant increase in performance across session but the Control group did not. Children in the Experimental group performed significantly higher than the Control group on post-test 2 but not on the pretest or post-test 1. More children in the Experimental group showed behavioral evidence and self-report of rehearsal after training. Rehearsal training was successful at increasing the memory for numbers among children with FASD and may help to ameliorate working memory difficulties in FASD, ultimately supporting academic and developmental growth of children with FASD.

Factorial experimental design intended for the optimization of the alumina purification conditions

NASA Astrophysics Data System (ADS)

Brahmi, Mounaouer; Ba, Mohamedou; Hidri, Yassine; Hassen, Abdennaceur

2018-04-01

The objective of this study was to determine the optimal conditions by using the experimental design methodology for the removal of some impurities associated with the alumina. So, three alumina qualities of different origins were investigated under the same conditions. The application of full-factorial designs on the samples of different qualities of alumina has followed the removal rates of the sodium oxide. However, a factorial experimental design was developed to describe the elimination of sodium oxide associated with the alumina. The experimental results showed that chemical analyze followed by XRF prior treatment of the samples, provided a primary idea concerning these prevailing impurities. Therefore, it appeared that the sodium oxide constituted the largest amount among all impurities. After the application of experimental design, analysis of the effectors different factors and their interactions showed that to have a better result, we should reduce the alumina quantity investigated and by against increase the stirring time for the first two samples, whereas, it was necessary to increase the alumina quantity in the case of the third sample. To expand and improve this research, we should take into account all existing impurities, since we found during this investigation that the levels of partial impurities increased after the treatment.

Performance metrics for Inertial Confinement Fusion implosions: aspects of the technical framework for measuring progress in the National Ignition Campaign

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

Spears, B K; Glenzer, S; Edwards, M J

The National Ignition Campaign (NIC) uses non-igniting 'THD' capsules to study and optimize the hydrodynamic assembly of the fuel without burn. These capsules are designed to simultaneously reduce DT neutron yield and to maintain hydrodynamic similarity with the DT ignition capsule. We will discuss nominal THD performance and the associated experimental observables. We will show the results of large ensembles of numerical simulations of THD and DT implosions and their simulated diagnostic outputs. These simulations cover a broad range of both nominal and off nominal implosions. We will focus on the development of an experimental implosion performance metric called themore » experimental ignition threshold factor (ITFX). We will discuss the relationship between ITFX and other integrated performance metrics, including the ignition threshold factor (ITF), the generalized Lawson criterion (GLC), and the hot spot pressure (HSP). We will then consider the experimental results of the recent NIC THD campaign. We will show that we can observe the key quantities for producing a measured ITFX and for inferring the other performance metrics. We will discuss trends in the experimental data, improvement in ITFX, and briefly the upcoming tuning campaign aimed at taking the next steps in performance improvement on the path to ignition on NIF.« less

Performance metrics for inertial confinement fusion implosions: Aspects of the technical framework for measuring progress in the National Ignition Campaign

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

Spears, Brian K.; Glenzer, S.; Edwards, M. J.

The National Ignition Campaign (NIC) uses non-igniting 'tritium hydrogen deuterium (THD)' capsules to study and optimize the hydrodynamic assembly of the fuel without burn. These capsules are designed to simultaneously reduce DT neutron yield and to maintain hydrodynamic similarity with the DT ignition capsule. We will discuss nominal THD performance and the associated experimental observables. We will show the results of large ensembles of numerical simulations of THD and DT implosions and their simulated diagnostic outputs. These simulations cover a broad range of both nominal and off-nominal implosions. We will focus on the development of an experimental implosion performance metricmore » called the experimental ignition threshold factor (ITFX). We will discuss the relationship between ITFX and other integrated performance metrics, including the ignition threshold factor (ITF), the generalized Lawson criterion (GLC), and the hot spot pressure (HSP). We will then consider the experimental results of the recent NIC THD campaign. We will show that we can observe the key quantities for producing a measured ITFX and for inferring the other performance metrics. We will discuss trends in the experimental data, improvement in ITFX, and briefly the upcoming tuning campaign aimed at taking the next steps in performance improvement on the path to ignition on NIF.« less

Geometry of thin liquid sheet flows

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

1994-01-01

Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

The enhancement of students’ mathematical representation in junior high school using cognitive apprenticeship instruction (CAI)

NASA Astrophysics Data System (ADS)

Yusepa, B. G. P.; Kusumah, Y. S.; Kartasasmita, B. G.

2018-03-01

This study aims to get an in-depth understanding of the enhancement of students’ mathematical representation. This study is experimental research with pretest-posttest control group design. The subject of this study is the students’ of the eighth grade from junior high schools in Bandung: high-level and middle-level. In each school, two parallel groups were chosen as a control group and an experimental group. The experimental group was given cognitive apprenticeship instruction (CAI) treatment while the control group was given conventional learning. The results show that the enhancement of students’ mathematical representation who obtained CAI treatment was better than the conventional one, viewed which can be observed from the overall, mathematical prior knowledge (MPK), and school level. It can be concluded that CAI can be used as a good alternative learning model to enhance students’ mathematical representation.

Challenging Density Functional Theory Calculations with Hemes and Porphyrins.

PubMed

de Visser, Sam P; Stillman, Martin J

2016-04-07

In this paper we review recent advances in computational chemistry and specifically focus on the chemical description of heme proteins and synthetic porphyrins that act as both mimics of natural processes and technological uses. These are challenging biochemical systems involved in electron transfer as well as biocatalysis processes. In recent years computational tools have improved considerably and now can reproduce experimental spectroscopic and reactivity studies within a reasonable error margin (several kcal·mol(-1)). This paper gives recent examples from our groups, where we investigated heme and synthetic metal-porphyrin systems. The four case studies highlight how computational modelling can correctly reproduce experimental product distributions, predicted reactivity trends and guide interpretation of electronic structures of complex systems. The case studies focus on the calculations of a variety of spectroscopic features of porphyrins and show how computational modelling gives important insight that explains the experimental spectra and can lead to the design of porphyrins with tuned properties.

Mechanical properties of experimental composites with different calcium phosphates fillers.

PubMed

Okulus, Zuzanna; Voelkel, Adam

2017-09-01

Calcium phosphates (CaPs)-containing composites have already shown good properties from the point of view of dental restorative materials. The purpose of this study was to examine the crucial mechanical properties of twelve hydroxyapatite- or tricalcium phosphate-filled composites. The raw and surface-treated forms of both CaP fillers were applied. As a reference materials two experimental glass-containing composites and one commercial dental restorative composite were applied. Nano-hardness, elastic modulus, compressive, flexural and diametral tensile strength of all studied materials were determined. Application of statistical methods (one-way analysis of variance and cluster agglomerative analysis) allowed for assessing the similarities between examined materials according to the values of studied parameters. The obtained results show that in almost all cases the mechanical properties of experimental CaPs-composites are comparable or even better than mechanical properties of examined reference materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental realization of dynamo action: present status and prospects

NASA Astrophysics Data System (ADS)

Giesecke, André; Stefani, Frank; Gundrum, Thomas; Gerbeth, Gunter; Nore, Caroline; Léorat, Jacques

2013-07-01

In the last decades, the experimental study of dynamo action has made great progress. However, after the dynamo experiments in Karlsruhe and Riga, the von-Kármán-Sodium (VKS) dynamo is only the third facility that has been able to demonstrate fluid flow driven self-generation of magnetic fields in a laboratory experiment. Further progress in the experimental examination of dynamo action is expected from the planned precession driven dynamo experiment that will be designed in the framework of the liquid sodium facility DRESDYN (DREsden Sodium facility for DYNamo and thermohydraulic studies). In this paper, we briefly present numerical models of the VKS dynamo that demonstrate the close relation between the axisymmetric field observed in that experiment and the soft iron material used for the flow driving impellers. We further show recent results of preparatory water experiments and design studies related to the precession dynamo and delineate the scientific prospects for the final set-up.

Experimental Investigation into the Radar Anomalies on the Surface of Venus

NASA Technical Reports Server (NTRS)

Kohler, E.; Gavin, P.; Chevrier, V.; Johnson, Natasha M.

2012-01-01

Radar mapping of thc surface of Venus shows areas of high reflectivity (low emissivity) in the Venusian highlands at altitudes between 2.5-4.75 kilometers. The origin of the radar anomalies found in the Venusian highlands remains unclear. Most explanations of the potential causes for these radar anomalies come from theoretical work. Previous studies suggest increased surface roughness or materials with higher dielectric constants as well as surface atmospheric interactions. Several possible candidates of high-dielectric materials are tellurium) ferroelectric materials, and lead or bismuth sulfides. While previous studies have been influential in determining possible sources for the Venus anomalies, only a very few hypotheses have been verified via experimentation. This work intends to experimentally constrain the source of the radar anomalies on Venus. This study proposes to investigate four possible materials that could potentially cause the high reflectivities on the surface of Venus and tests their behavior under simulated Venusian conditions.

Morphological Study of Langmuir Polymer Films by means of Atomic Force Microscopy and MD Simulations

NASA Astrophysics Data System (ADS)

Reiter, Renate; Knecht, Volker; Chandran, Sivasurender; Reiter, Günter

In general it is difficult to reproduce well defined morphologies of Langmuir polymer films (LPFs) because they have a high propensity to form non-equilibrium states. We present a systematic study based on different compression protocols designed to allow for relaxations of LPFs under well defined conditions. The homo peptide poly-?-benzyl-L-glutamate (PBLG) was chosen for this study because it is a well investigated system that represents the relaxational behaviour of rod-like molecules which is expected to show less complexity than coiled polymer molecules. Our results demonstrate that experimentally manipulating the course of relaxations in LPFs has tremendous impact on the ordering of the molecules. Coarse grain molecular dynamics simulations were performed under comparable conditions. The results match the experimental observations reasonably well and allow to zoom into molecular details which are not resolved experimentally.

Investigation of heat transfer and material flow of P-FSSW: Experimental and numerical study

NASA Astrophysics Data System (ADS)

Rezazadeh, Niki; Mosavizadeh, Seyed Mostafa; Azizi, Hamed

2018-02-01

Friction stir spot welding (FSSW) is the joining process which utilizes a rotating tool consisting of a shoulder and/or a probe. In this study, the novel method of FSSW, which is called protrusion friction stir spot welding (P-FSSW), has been presented and effect of shoulder diameter parameter has been studied numerically and experimentally on the weld quality including temperature field, velocity contour, material flow, bonding length, and the depth of the stirred area. The results show that the numerical findings are in good agreement with experimental measurements. The present model could well predict the temperature distribution, velocity contour, depth of the stirred area, and the bonding length. As the shoulder diameter increases, the amount of temperature rises which leads to a rise in stirred area depth, bonding length and temperatures and velocities. Therefore, a weld of higher quality will be performed.

Thermal conductivity improvement in carbon nanoparticle doped PAO oil: An experimental study

NASA Astrophysics Data System (ADS)

Shaikh, S.; Lafdi, K.; Ponnappan, R.

2007-03-01

The present work involves a study on the thermal conductivity of nanoparticle-oil suspensions for three types of nanoparticles, namely, carbon nanotubes (CNTs), exfoliated graphite (EXG), and heat treated nanofibers (HTT) with PAO oil as the base fluid. To accomplish the above task, an experimental analysis is performed using a modern light flash technique (LFA 447) for measuring the thermal conductivity of the three types of nanofluids, for different loading of nanoparticles. The experimental results show a similar trend as observed in literature for nanofluids with a maximum enhancement of approximately 161% obtained for the CNT-PAO oil suspension. The overall percent enhancements for different volume fractions of the nanoparticles are highest for the CNT-based nanofluid, followed by the EXG and the HTT. The findings from this study for the three different types of carbon nanoparticles can have great potential in the field of thermal management.

Experimental parametric study of servers cooling management in data centers buildings

NASA Astrophysics Data System (ADS)

Nada, S. A.; Elfeky, K. E.; Attia, Ali M. A.; Alshaer, W. G.

2017-06-01

A parametric study of air flow and cooling management of data centers servers is experimentally conducted for different design conditions. A physical scale model of data center accommodating one rack of four servers was designed and constructed for testing purposes. Front and rear rack and server's temperatures distributions and supply/return heat indices (SHI/RHI) are used to evaluate data center thermal performance. Experiments were conducted to parametrically study the effects of perforated tiles opening ratio, servers power load variation and rack power density. The results showed that (1) perforated tile of 25% opening ratio provides the best results among the other opening ratios, (2) optimum benefit of cold air in servers cooling is obtained at uniformly power loading of servers (3) increasing power density decrease air re-circulation but increase air bypass and servers temperature. The present results are compared with previous experimental and CFD results and fair agreement was found.

Modelling of the UV Index on vertical and 40° tilted planes for different orientations.

PubMed

Serrano, D; Marín, M J; Utrillas, M P; Tena, F; Martínez-Lozano, J A

2012-02-01

In this study, estimated data of the UV Index on vertical planes are presented for the latitude of Valencia, Spain. For that purpose, the UVER values have been generated on vertical planes by means of four different geometrical models a) isotropic, b) Perez, c) Gueymard, d) Muneer, based on values of the global horizontal UVER and the diffuse horizontal UVER, measured experimentally. The UVER values, obtained by any model, overestimate the experimental values for all orientations, with the exception of the Perez model for the East plane. The results show statistical values of the MAD parameter (Mean Absolute Deviation) between 10% and 25%, the Perez model being the one that obtained a lower MAD for all levels. As for the statistic RMSD parameter (Root Mean Square Deviation), the results show values between 17% and 32%, and again the Perez model provides the best results in all vertical planes. The difference between the estimated UV Index and the experimental UV Index, for vertical and 40° tilted planes, was also calculated. 40° is an angle close to the latitude of Burjassot, Valencia, (39.5°), which, according to various studies, is the optimum angle to capture maximum radiation on tilted planes. We conclude that the models provide a good estimate of the UV Index, as they coincide or differ in one unit compared to the experimental values in 99% of cases, and this is valid for all orientations. Finally, we examined the relation between the UV Index on vertical and 40° tilted planes, both the experimental and estimated by the Perez model, and the experimental UV Index on a horizontal plane at 12 GMT. Based on the results, we can conclude that it is possible to estimate with a good approximation the UV Index on vertical and 40° tilted planes in different directions on the basis of the experimental horizontal UVI value, thus justifying the interest of this study. This journal is © The Royal Society of Chemistry and Owner Societies 2012

The essential value of long-term experimental data for hydrology and water management

NASA Astrophysics Data System (ADS)

Tetzlaff, Doerthe; Carey, Sean K.; McNamara, James P.; Laudon, Hjalmar; Soulsby, Chris

2017-04-01

Observations and data from long-term experimental watersheds are the foundation of hydrology as a geoscience. They allow us to benchmark process understanding, observe trends and natural cycles, and are prerequisites for testing predictive models. Long-term experimental watersheds also are places where new measurement technologies are developed. These studies offer a crucial evidence base for understanding and managing the provision of clean water supplies, predicting and mitigating the effects of floods, and protecting ecosystem services provided by rivers and wetlands. They also show how to manage land and water in an integrated, sustainable way that reduces environmental and economic costs.

Quantum Interference Effects in Resonant Raman Spectroscopy of Single- and Triple-Layer MoTe2 from First-Principles

NASA Astrophysics Data System (ADS)

Miranda, Henrique P. C.; Reichardt, Sven; Froehlicher, Guillaume; Molina-Sánchez, Alejandro; Berciaud, Stéphane; Wirtz, Ludger

2017-04-01

We present a combined experimental and theoretical study of resonant Raman spectroscopy in single- and triple-layer MoTe$_2$. Raman intensities are computed entirely from first principles by calculating finite differences of the dielectric susceptibility. In our analysis, we investigate the role of quantum interference effects and the electron-phonon coupling. With this method, we explain the experimentally observed intensity inversion of the $A^\\prime_1$ vibrational modes in triple-layer MoTe2 with increasing laser photon energy. Finally, we show that a quantitative comparison with experimental data requires the proper inclusion of excitonic effects.

X-Phi and Carnapian Explication.

PubMed

Shepherd, Joshua; Justus, James

2015-04-01

The rise of experimental philosophy (x-phi) has placed metaphilosophical questions, particularly those concerning concepts, at the center of philosophical attention. X-phi offers empirically rigorous methods for identifying conceptual content, but what exactly it contributes towards evaluating conceptual content remains unclear. We show how x-phi complements Rudolf Carnap's underappreciated methodology for concept determination, explication. This clarifies and extends x-phi's positive philosophical import, and also exhibits explication's broad appeal. But there is a potential problem: Carnap's account of explication was limited to empirical and logical concepts, but many concepts of interest to philosophers (experimental and otherwise) are essentially normative. With formal epistemology as a case study, we show how x-phi assisted explication can apply to normative domains.

Experimental Research into Noise Emission of A Gear Micropump with Plastic Rotor

NASA Astrophysics Data System (ADS)

Rodionov, L. V.; Rekadze, P. D.

2018-01-01

The previous researches show that it’s possible to replace several parts of gear pump to plastic ones. This substitution leads to cost and noise reduction of the pump. Therefore, the series of acoustic experiments on a test bench were carry-out. Sound pressure levels were recorded with microphone, located in a pipe made of a vacuum rubber. Conducted experiment shows that acoustic characteristics of the micropump depend on the different material of driven rotor. Experimental result indicates that the proposed measures for replacing metal rotor to plastic one reduce micropump noise on the studied modes. The maximum achieved acoustic efficiency on equivalent level is 11 dB.

Utilization of aloe vera extract as electrolyte for an accumulator

NASA Astrophysics Data System (ADS)

Azmi, F.; Sispriatna, D.; Ikhsan, K.; Masrura, M.; Azzahra, S. S.; Mahidin; Supardan, M. D.

2018-03-01

Aloe vera contains acid, which has the potential to generate electric current. The objective of this research is to study the potency of aloe vera extract as electrolyte for an accumulator. Experimental results showed that aloe vera extract has no a stable value of voltage and currency. The voltage and currency of aloe vera extract were reduced more than 50% for 60 minutes. Then, aloe vera extract was mixed with accu zuur to produce electrolyte solution. The mixture composition of aloe vera extract to accu zuur of 50:50 (v/v) generated stable voltage and currency. The experimental results showed the potential use of aloe vera extract to reduce the chemicals used in a conventional electrolyte solution.

Flexural properties of three kinds of experimental fiber-reinforced composite posts.

PubMed

Kim, Mi-Joo; Jung, Won-Chang; Oh, Seunghan; Hattori, Masayuki; Yoshinari, Masao; Kawada, Eiji; Oda, Yutaka; Bae, Ji-Myung

2011-01-01

The aim of this study was to estimate the flexural properties of three kinds of experimental fiber-reinforced composite (FRC) posts and to evaluate their potential use as posts. Experimental FRC posts were fabricated with glass, aramid, and UHMWP fibers. Commercial FRC posts were used for comparison. A three-point bending test was performed at a crosshead speed of 1 mm/min. Experimental glass fiber posts showed significantly higher flexural strengths and moduli than aramid and UHMWP posts. Experimental UHMWP posts demonstrated superior toughness to the commercial posts. The glass fiber posts displayed stiff, strong and brittle features, while the UHMWP posts were flexible, weak and ductile. The flexural properties of the aramid posts fell between those of the glass and UHMWP posts. In conclusion, the glass fiber posts proved excellent in flexural strengths and moduli. However, the superior toughness of UHMWP fibers suggests the possibility of their use as posts in combination with glass fibers.

Hybrid test on building structures using electrodynamic fatigue test machine

NASA Astrophysics Data System (ADS)

Xu, Zhao-Dong; Wang, Kai-Yang; Guo, Ying-Qing; Wu, Min-Dong; Xu, Meng

2017-01-01

Hybrid simulation is an advanced structural dynamic experimental method that combines experimental physical models with analytical numerical models. It has increasingly been recognised as a powerful methodology to evaluate structural nonlinear components and systems under realistic operating conditions. One of the barriers for this advanced testing is the lack of flexible software for hybrid simulation using heterogeneous experimental equipment. In this study, an electrodynamic fatigue test machine is made and a MATLAB program is developed for hybrid simulation. Compared with the servo-hydraulic system, electrodynamic fatigue test machine has the advantages of small volume, easy operation and fast response. A hybrid simulation is conducted to verify the flexibility and capability of the whole system whose experimental substructure is one spring brace and numerical substructure is a two-storey steel frame structure. Experimental and numerical results show the feasibility and applicability of the whole system.

Analytical and experimental investigation of microstructural alterations in bearing steel in rolling contact fatigue

NASA Astrophysics Data System (ADS)

Mobasher Moghaddam, Sina

Rolling Contact Fatigue (RCF) is one the most common failure modes in bearings. RCF is usually associated with particular microstructural alterations. Such alterations (i.e. white etching cracks, butterflies, etc.) which lead to RCF failure are known to be among the most concerning matters to bearing industry. In the current work, an analytical as well as experimental approaches are used to investigate "butterfly wing" formation, crack initiation and propagation from inclusions. A new damage evolution equation coupled with a FE model is employed to account for the effect of mean stresses and alternating stresses simultaneously to investigate butterfly formation. The proposed damage evolution law matches experimentally observed butterfly orientation, shape, and size successfully. The model is used to obtain S-N results for butterfly formation at different Hertzian load levels. The results corroborate well with the experimental data available in the open literature. The model is used to predict debonding at the inclusion/matrix interface and the most vulnerable regions for crack initiation on butterfly/matrix interface. A new variable called butterfly formation index (BFI) is introduced to manifest the dependence of wing formation on depth. The value of critical damage inside the butterfly wings was obtained experimentally and was then used to simulate damage evolution. Voronoi tessellation was used to develop the FEM domains to capture the effect of microstructural randomness on butterfly wing formation, crack initiation and propagation. Then, the effects of different inclusion characteristics such as size, depth, and stiffness on RCF life are studied. The results show that stiffness of an inclusion and its location has a significant effect on the RCF life: stiffer inclusions and inclusions located at the depth of maximum shear stress reversal are more detrimental to the RCF life. Stress concentrations are not significantly affected by inclusion size for the cases investigated; however, a stereology study showed that larger inclusions have a higher chance to be located at the critical depth and cause failure. Crack maps were recorded and compared to spall geometries observed experimentally. The results show that crack initiation locations and final spall shapes are similar to what has been observed in failed bearings.

[The experimental surgery and your relation with the university: an experience report].

PubMed

Yamaki, Vitor Nagai; Teixeira, Renan Kleber Costa; Feijo, Daniel Haber; Silva, José Antonio Cordero da; Botelho, Nara Macedo; Henriques, Marcus Vinicius

2014-01-01

The laboratory of experimental surgery represents one of the key points for the university, especially in the biomedical area. This focuses on the university's tripod of primary structure that are teaching, research and extension, which are essential for formation of humanistic and practice of a good doctor that is based, first of all, on scientific evidence and critical knowledge. The importance of a laboratory of experimental surgery centers for medical education was regulated from the new curriculum guidelines of the Ministério da Educação e Cultura, establishing a mandatory laboratory within college centers. Therefore, it is of great importance to the contribution of the laboratories of experimental surgery in the curriculum, both in the discipline of surgical technics and experimental surgery, and an incentive for basic research. Thus, the study presents the experience of 15 years of the Laboratory of Experimental Surgery from Universidade do Estado do Pará, with the goal show the importance of this to medical graduation and the university.

Mechanical Behaviour of 3D Multi-layer Braided Composites: Experimental, Numerical and Theoretical Study

NASA Astrophysics Data System (ADS)

Deng, Jian; Zhou, Guangming; Ji, Le; Wang, Xiaopei

2017-12-01

Mechanical properties and failure mechanisms of a newly designed 3D multi-layer braided composites are evaluated by experimental, numerical and theoretical studies. The microstructure of the composites is introduced. The unit cell technique is employed to address the periodic arrangement of the structure. The volume averaging method is used in theoretical solutions while FEM with reasonable periodic boundary conditions and meshing technique in numerical simulations. Experimental studies are also conducted to verify the feasibility of the proposed models. Predicted elastic properties agree well with the experimental data, indicating the feasibility of the proposed models. Numerical evaluation is more accurate than theoretical assessment. Deformations and stress distributions of the unit cell under tension shows displacement and traction continuity, guaranteeing the rationality of the applied periodic boundary conditions. Although compression and tension modulus are close, the compressive strength only reaches 70% of the tension strength. This indicates that the composites can be weakened in compressive loading. Additionally, by analysing the micrograph of fracture faces and strain-stress curves, a brittle failure mechanism is observed both in composites under tension and compression.

[Development and evaluation of "Hospice Smart Patient" service program].

PubMed

Park, Chai-Soon; Yoo, Yang-Sook; Choi, Dong-Won; Park, Hyun-Jeong; Kim, Ji-In

2011-02-01

The purpose of this study was to develop and implement the Hospice Smart Patient Program and to evaluate its effectiveness. It was quasi-experimental non-equivalent pre-post study. Breast cancer patients who underwent surgery, chemotherapy or radiotherapy, or who needed palliative care, participated in the study. Participants were divided into two groups, experimental and control groups based on their preferences. The program was developed after literature review and discussion among experts on hospice and palliative care. Participants who were in the experimental group received either face-to-face or phone "Hospice Smart Patient" Service at least once a week for 5 months. There was a significant difference in quality of life and communication skill between the two groups after the service was provided. In addition, participants in experimental group showed improved decision making skills, mastery sense, and understanding of hospice and palliative care, which would be beneficial in improving their quality of life. We have concluded that the "Hospice Smart Patient" Program is useful for cancer patients in decision making, improving self-control and choosing hospice care to improve their quality of life.

The Effect of Live Interpretation with Theater on Attitudes and Learning of Children in the Mythbusters Exhibit

ERIC Educational Resources Information Center

Price, C. Aaron; Gean, Katherine; Barnes, Heather

2015-01-01

"Mythbusters: The Explosive Exhibition" is a traveling exhibit based on the popular television show. When housed at the Museum of Science and Industry, Chicago, it included a traditional, interactive free flow exhibition space followed by a live facilitated show. This paper describes results from an experimental study about the effects…

Communication: Anion-specific response of mesoscopic organization in ionic liquids upon pressurization

NASA Astrophysics Data System (ADS)

Lo Celso, Fabrizio; Triolo, Alessandro; Gontrani, Lorenzo; Russina, Olga

2018-06-01

One of the outstanding features of ionic liquids is their inherently hierarchical structural organization at mesoscopic spatial scales. Recently experimental and computational studies showed the fading of this feature when pressurising. Here we use simulations to show that this effect is not general: appropriate anion choice leads to an obstinate resistance against pressurization.

Heat transfer augmentation of a car radiator using nanofluids

NASA Astrophysics Data System (ADS)

Hussein, Adnan M.; Bakar, R. A.; Kadirgama, K.; Sharma, K. V.

2014-05-01

The car radiator heat transfer enhancement by using TiO2 and SiO2 nanoparticles dispersed in water as a base fluid was studied experimentally. The test rig is setup as a car radiator with tubes and container. The range of Reynolds number and volume fraction are (250-1,750) and (1.0-2.5 %) respectively. Results showed that the heat transfer increases with increasing of nanofluid volume fraction. The experimental data is agreed with other investigator.

Experimental studies of toroidal correlations of plasma density fluctuations along the magnetic field lines in the T-10 tokamak and first results of numerical modeling

NASA Astrophysics Data System (ADS)

Buldakov, M. A.; Vershkov, V. A.; Isaev, M. Yu; Shelukhin, D. A.

2017-10-01

The antenna system of reflectometry diagnostics at the T-10 tokamak allows to study long-range toroidal correlations of plasma density fluctuations along the magnetic field lines. The antenna systems are installed in two poloidal cross-sections of the vacuum chamber separated by a 90° angle in the toroidal direction. The experiments, which were conducted at the low field side, showed that the high level of toroidal correlations is observed only for quasi-coherent fluctuations. However, broadband and stochastic low frequency fluctuations are not correlated. Numerical modeling of the plasma turbulence structure in the T-10 tokamak was conducted to interpret the experimental results and take into account non-locality of reflectometry measurements. In the model used, it was assumed that the magnitudes of density fluctuations are constant along the magnetic field lines. The 2D full-wave Tamic-RTH code was used to model the reflectometry signals. High level of correlations for quasi-coherent fluctuations was obtained during the modeling, which agrees with the experimental observations. However, the performed modeling also predicts high level of correlations for broadband fluctuations, which contradicts the experimental data. The modeling showed that the effective reflection radius, from which the information on quasi-coherent plasma turbulence is obtained, is shifted outwards from the reflection radius by approximately 7 mm.

Treadmill sideways gait training with visual blocking for patients with brain lesions.

PubMed

Kim, Tea-Woo; Kim, Yong-Wook

2014-09-01

[Purpose] The aim of this study was to verify the effect of sideways treadmill training with and without visual blocking on the balance and gait function of patients with brain lesions. [Subjects] Twenty-four stroke and traumatic brain injury subjects participated in this study. They were divided into two groups: an experimental group (12 subjects) and a control group (12 subjects). [Methods] Each group executed a treadmill training session for 20 minutes, three times a week, for 6 weeks. The sideways gait training on the treadmill was performed with visual blocking by the experimental group and with normal vision by the control group. A Biodex Gait Trainer 2 was used to assess the gait function. It was used to measure walking speed, walking distance, step length, and stance time on each foot. The Five-Times-Sit-To-Stand test (FTSST) and Timed Up and Go test (TUG) were used as balance measures. [Results] The sideways gait training with visual blocking group showed significantly improved walking speed, walking distance, step length, and stance time on each foot after training; FTSST and TUG times also significantly improved after training in the experimental group. Compared to the control group, the experimental group showed significant increases in stance time on each foot. [Conclusion] Sideways gait training on a treadmill with visual blocking performed by patients with brain lesions significantly improved their balance and gait function.

Reach and speed of judgment propagation in the laboratory.

PubMed

Moussaïd, Mehdi; Herzog, Stefan M; Kämmer, Juliane E; Hertwig, Ralph

2017-04-18

In recent years, a large body of research has demonstrated that judgments and behaviors can propagate from person to person. Phenomena as diverse as political mobilization, health practices, altruism, and emotional states exhibit similar dynamics of social contagion. The precise mechanisms of judgment propagation are not well understood, however, because it is difficult to control for confounding factors such as homophily or dynamic network structures. We introduce an experimental design that renders possible the stringent study of judgment propagation. In this design, experimental chains of individuals can revise their initial judgment in a visual perception task after observing a predecessor's judgment. The positioning of a very good performer at the top of a chain created a performance gap, which triggered waves of judgment propagation down the chain. We evaluated the dynamics of judgment propagation experimentally. Despite strong social influence within pairs of individuals, the reach of judgment propagation across a chain rarely exceeded a social distance of three to four degrees of separation. Furthermore, computer simulations showed that the speed of judgment propagation decayed exponentially with the social distance from the source. We show that information distortion and the overweighting of other people's errors are two individual-level mechanisms hindering judgment propagation at the scale of the chain. Our results contribute to the understanding of social-contagion processes, and our experimental method offers numerous new opportunities to study judgment propagation in the laboratory.

Reach and speed of judgment propagation in the laboratory

PubMed Central

Herzog, Stefan M.; Kämmer, Juliane E.; Hertwig, Ralph

2017-01-01

In recent years, a large body of research has demonstrated that judgments and behaviors can propagate from person to person. Phenomena as diverse as political mobilization, health practices, altruism, and emotional states exhibit similar dynamics of social contagion. The precise mechanisms of judgment propagation are not well understood, however, because it is difficult to control for confounding factors such as homophily or dynamic network structures. We introduce an experimental design that renders possible the stringent study of judgment propagation. In this design, experimental chains of individuals can revise their initial judgment in a visual perception task after observing a predecessor’s judgment. The positioning of a very good performer at the top of a chain created a performance gap, which triggered waves of judgment propagation down the chain. We evaluated the dynamics of judgment propagation experimentally. Despite strong social influence within pairs of individuals, the reach of judgment propagation across a chain rarely exceeded a social distance of three to four degrees of separation. Furthermore, computer simulations showed that the speed of judgment propagation decayed exponentially with the social distance from the source. We show that information distortion and the overweighting of other people’s errors are two individual-level mechanisms hindering judgment propagation at the scale of the chain. Our results contribute to the understanding of social-contagion processes, and our experimental method offers numerous new opportunities to study judgment propagation in the laboratory. PMID:28373540

[Absorption Characteristics and Simulation of LLM-105 in the Terahertz Range].

PubMed

Meng, Zeng-rui; Shang, Li-ping; Du, Yu; Deng, Hu

2015-07-01

2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), a novel explosive with high energy and low sensibility. In order to study the molecular structure characteristics of the explosive, the absorption spectra of LLM-105 in the frequency range of 0.2-2.4 THz were detected by terahertz time-domain spectroscopy (THz-TDS). The results showed that a number of characteristic absorption peaks with different intensity located at 1.27, 1.59, 2.00, 2.08, 2.20, 2.29 THz. The article also simulated the absorption spectra of LLM-105 molecular crystal within 0.2-2.5 THz region by using Materials Studio 6.0 software based on density functional theory (DFT), and the simulated results agreed well with the experimental data except for the peak at 2.29 THz, which verified theoretically the accuracy of the experimental data. In addition, the vibrational modes of the characteristic peaks in the experimental absorption spectra were analyzed and identified, the results showed that the forming of the characteristic absorption peaks and the molecular vibration were closely related, which further provided important laboratory and technology support for the study of the transformation of molecule structure of LLM-105. There was no simulated frequency agreed with the experimental absorption peak at 2.29 THz, which may be caused by the vibration of the crystal lattice or other reasons.

Effect of Wii-intervention on balance of children with poor motor performance.

PubMed

Mombarg, Remo; Jelsma, Dorothee; Hartman, Esther

2013-09-01

The purpose of this study was to investigate the effects of training with the Wii-balance board on balance and balance-related skills of children with poor motor performance. Twenty-nine children (23 boys, 6 girls; aged 7-12 years) participated in this study and were randomly assigned to an experimental and control group. All children scored below the 16th percentile on a standardized test of motor ability and balance skills (Movement Assessment Battery for children (M-ABC-2)). Before and after a six-week Wii-intervention (M=8h, 22 min, SD=53 min), the balance skills of the experimental group and control group were measured with the M-ABC-2 and the Bruininks-Oseretsky test of motor proficiency (BOT-2). Both groups improved on all tests. The M-ABC-2 and the BOT-2 total balance-scores of the experimental group improved significantly from pre to post intervention, whereas those of the control group showed no significant progress. This resulted in significant interaction-effects, favoring the experimental children. No transfer-effects of the intervention on balance-related skills were demonstrated. Our findings showed that the Wii-balance board is an effective intervention for children with poor balance control. Further development and investigation of the intervention could be directed toward the implementation of the newly acquired balance-skills in daily life. Copyright © 2013 Elsevier Ltd. All rights reserved.

A new concept of a unified parameter management, experiment control, and data analysis in fMRI: application to real-time fMRI at 3T and 7T.

PubMed

Hollmann, M; Mönch, T; Mulla-Osman, S; Tempelmann, C; Stadler, J; Bernarding, J

2008-10-30

In functional MRI (fMRI) complex experiments and applications require increasingly complex parameter handling as the experimental setup usually consists of separated soft- and hardware systems. Advanced real-time applications such as neurofeedback-based training or brain computer interfaces (BCIs) may even require adaptive changes of the paradigms and experimental setup during the measurement. This would be facilitated by an automated management of the overall workflow and a control of the communication between all experimental components. We realized a concept based on an XML software framework called Experiment Description Language (EDL). All parameters relevant for real-time data acquisition, real-time fMRI (rtfMRI) statistical data analysis, stimulus presentation, and activation processing are stored in one central EDL file, and processed during the experiment. A usability study comparing the central EDL parameter management with traditional approaches showed an improvement of the complete experimental handling. Based on this concept, a feasibility study realizing a dynamic rtfMRI-based brain computer interface showed that the developed system in combination with EDL was able to reliably detect and evaluate activation patterns in real-time. The implementation of a centrally controlled communication between the subsystems involved in the rtfMRI experiments reduced potential inconsistencies, and will open new applications for adaptive BCIs.

Single laser based pump-probe technique to study plasma shielding during nanosecond laser ablation of copper thin films

NASA Astrophysics Data System (ADS)

Nammi, Srinagalakshmi; Vasa, Nilesh J.; Gurusamy, Balaganesan; Mathur, Anil C.

2017-09-01

A plasma shielding phenomenon and its influence on micromachining is studied experimentally and theoretically for laser wavelengths of 355 nm, 532 nm and 1064 nm. A time resolved pump-probe technique is proposed and demonstrated by splitting a single nanosecond Nd3+:YAG laser into an ablation laser (pump laser) and a probe laser to understand the influence of plasma shielding on laser ablation of copper (Cu) clad on polyimide thin films. The proposed nanosecond pump-probe technique allows simultaneous measurement of the absorption characteristics of plasma produced during Cu film ablation by the pump laser. Experimental measurements of the probe intensity distinctly show that the absorption by the ablated plume increases with increase in the pump intensity, as a result of plasma shielding. Theoretical estimation of the intensity of the transmitted pump beam based on the thermo-temporal modeling is in qualitative agreement with the pump-probe based experimental measurements. The theoretical estimate of the depth attained for a single pulse with high pump intensity value on a Cu thin film is limited by the plasma shielding of the incident laser beam, similar to that observed experimentally. Further, the depth of micro-channels produced shows a similar trend for all three wavelengths, however, the channel depth achieved is lesser at the wavelength of 1064 nm.

[Experimental study of multiple organ injuries after high-velocity missiles].

PubMed

Fu, X B

1990-06-01

Multiple organ injuries after high-velocity missiles shot were studied on the 8 pigs. The experimental results showed that (1) more than two organs (the maximum six organs) wounded could be seen in all the pigs; (2) the injuries were characterized by hemorrhage, tissue rupture and hematoma, etc., the pathologic changes were local edema and necrosis; (3) the marked increase of LPO on the vital organs indicates that multiple organ injuries can also occur at the molecular level; (4) they are due to direct effects of pressure waves and not to shock or infection.

SCDFT Study of High Tc Nitride Superconductors

NASA Astrophysics Data System (ADS)

Arita, R.

Based on the density functional theory for superconductors (SCDFT), we study the pairing mechanism of the layered nitride superconductors, β-LixMNCl (M=Zr, Hf). Recently, it has been shown that SCDFT reproduces experimental superconducting transition temperatures (Tc) of conventional superconductors very accurately. Here we use SCDFT as a "litmus paper" to determine whether the system is a conventional or unconventional superconductor. We show that Tc estimated by SCDFT is less than half of the experimental Tc and its doping dependence is opposite to that observed in the experiments. The present result suggests that β- LixMNCl is not a Migdal-Eliashberg type superconductor.

Techniques for video compression

NASA Technical Reports Server (NTRS)

Wu, Chwan-Hwa

1995-01-01

In this report, we present our study on multiprocessor implementation of a MPEG2 encoding algorithm. First, we compare two approaches to implementing video standards, VLSI technology and multiprocessor processing, in terms of design complexity, applications, and cost. Then we evaluate the functional modules of MPEG2 encoding process in terms of their computation time. Two crucial modules are identified based on this evaluation. Then we present our experimental study on the multiprocessor implementation of the two crucial modules. Data partitioning is used for job assignment. Experimental results show that high speedup ratio and good scalability can be achieved by using this kind of job assignment strategy.

Role of the vestibular end organs in experimental motion sickness - A primate model

NASA Technical Reports Server (NTRS)

Igarashi, Makoto

1990-01-01

Experimental studies of the role of vestibular end organs in motion sickness experienced by squirrel monkeys are reviewed. The first experiments in motion-sickness-susceptible squirrel monkeys were performed under a free-moving condition with horizontal rotation and vertical oscillation. In the following experiments, the vestibular-visual conflict in the pitch plane was given to the chair-restrained (upright position) squirrel monkeys. Results of this study showed that the existence of otolith afferents, which continually signal the directional change of gravity and linear acceleration vectors, was necessary for the elicitation of emesis by the sensory conflict in pitch.

Experimental evidence of the effect of nutrient enrichment on the zooplankton in a Brazilian coastal lagoon.

PubMed

Kozlowsky-Suzuki, B; Bozelli, R L

2002-11-01

Non-treated sewage disposal is one of the main impacts to which Imboassica Lagoon has been subjected. The aim of this study was to evaluate the effect of a potential increase in the artificial enrichment on the environmental conditions and zooplankton of this system. To this end, an experimental study was conducted in mesocosms where nutrients were added daily. Bacterial numbers, chlorophyll-a, and picoplanktonic cyanobacteria densities showed an increase with the availability of nutrients. Bacterio- and phytoplankton seemed to be regulated by the rotifers Brachionus rotundiformis and Hexarthra brandorffi.

Experimental Study on the Treatment of low C/N ratio disposal of sewage with BAF

NASA Astrophysics Data System (ADS)

Wang, W. J.; Ma, T.; Cheng, W.

2010-03-01

The Biological Aerated Filter (BAF) is a simple, high-efficient, low-consumptive for new biological membrane method correspond to the situation of china, will be one of the main technical measures to solve the progressive deterioration of water environment problem faced china especially medium and small towns. This paper focuses on the experimental study and mechanism analysis in which the up flow, cocurrent gas-water, single-stage BAF was adopted on treatment domestic wastewater, the results showed that BAF has good performance in treating domestic sewage, and it had steady treatment effect with different pollution loads.

A numerical and experimental study of confined swirling jets

NASA Technical Reports Server (NTRS)

Nikjooy, M.; Mongia, H. C.; Samuelsen, G. S.; Mcdonell, V. G.

1989-01-01

A numerical and experimental study of a confined strong swirling flow is presented. Detailed velocity measurements are made using a two-component laser Doppler velocimeter (LDV) technique. Computations are performed using a differential second-moment (DSM) closure. The effect of inlet dissipation rate on calculated mean and turbulence fields is investigated. Various model constants are employed in the pressure-strain model to demonstrate their influences on the predicted results. Finally, comparison of the DSM calculations with the algebraic second-monent (ASM) closure results shows that the DSM is better suited for complex swirling flow analysis.

Validation of reference genes for RT-qPCR studies of gene expression in banana fruit under different experimental conditions.

PubMed

Chen, Lei; Zhong, Hai-ying; Kuang, Jian-fei; Li, Jian-guo; Lu, Wang-jin; Chen, Jian-ye

2011-08-01

Reverse transcription quantitative real-time PCR (RT-qPCR) is a sensitive technique for quantifying gene expression, but its success depends on the stability of the reference gene(s) used for data normalization. Only a few studies on validation of reference genes have been conducted in fruit trees and none in banana yet. In the present work, 20 candidate reference genes were selected, and their expression stability in 144 banana samples were evaluated and analyzed using two algorithms, geNorm and NormFinder. The samples consisted of eight sample sets collected under different experimental conditions, including various tissues, developmental stages, postharvest ripening, stresses (chilling, high temperature, and pathogen), and hormone treatments. Our results showed that different suitable reference gene(s) or combination of reference genes for normalization should be selected depending on the experimental conditions. The RPS2 and UBQ2 genes were validated as the most suitable reference genes across all tested samples. More importantly, our data further showed that the widely used reference genes, ACT and GAPDH, were not the most suitable reference genes in many banana sample sets. In addition, the expression of MaEBF1, a gene of interest that plays an important role in regulating fruit ripening, under different experimental conditions was used to further confirm the validated reference genes. Taken together, our results provide guidelines for reference gene(s) selection under different experimental conditions and a foundation for more accurate and widespread use of RT-qPCR in banana.

Experimental far-field imaging properties of a ~5-μm diameter spherical lens.

PubMed

Ye, Ran; Ye, Yong-Hong; Ma, Hui Feng; Ma, Jun; Wang, Bin; Yao, Jie; Liu, Shuai; Cao, Lingling; Xu, Huanhuan; Zhang, Jia-Yu

2013-06-01

Microscale lenses are mostly used as near-sighted lenses. The far-field imaging properties of a microscale spherical lens, where the lens is spatially separated from the object, are experimentally studied. Our experimental results show that, for a blu-ray disc (an object) whose spacing is 300 nm, the lens can magnify the stripe patterns of the disc when the lens is spatially separated from the object. In the experimentally tested range (0-14 μm), all the magnified images are virtual images. When the distance is increased from 0 to 14 μm the magnification decreases from 1.47× to 1.20× and the field of view increases from 3.8 to 12.2 μm. The image magnification cannot be described by standard geometrical optics.

Study Casts Cold Water on Bonus Pay

ERIC Educational Resources Information Center

Sawchuk, Stephen

2010-01-01

The most rigorous experimental study of performance-based teacher compensation ever conducted in the United States shows that a nationally watched bonus-pay system had no overall impact on student achievement--results that are certain to set off a firestorm of debate. The study, known as POINT for the Project on Incentives in Teaching, was a…

An Experimental Study of Career Development in Cooperative and Non-Cooperative Education Liberal Arts Students.

ERIC Educational Resources Information Center

Martello, John S.; Shelton, Paul D.

1980-01-01

A study comparing cooperative and noncooperative education students across time on several variables related to career maturity, career choice, and major certainty showed that co-op students rate higher in career maturity, career planning and problem-solving abilities. (JOW)

The role of the affect and availability heuristics in risk communication.

PubMed

Keller, Carmen; Siegrist, Michael; Gutscher, Heinz

2006-06-01

Results of past research suggest that affect plays an important role in risk perception. Because affect may also increase the availability of risks, affect and availability are closely related concepts. Three studies tested the hypothesis that evoking negative affect (fear), either through past experience or through experimental manipulation, results in greater perceived risk. The present research focused on perception of flooding risk. Study 1 and Study 2 showed that participants who received risk information concerning a longer time period (e.g., 30 years) perceived more danger compared with participants who received risk information for one year. Study 2 showed that the interpretation of risk information was influenced by participants' own experiences with flooding. In Study 3, affect was experimentally manipulated. After looking at photographs depicting houses in a flooded region, participants perceived greater risk compared with participants in a control group. Taken together, the results of these three studies suggest that affect is important for successful risk communication. Results of the present research are in line with the affect heuristic proposed by Slovic and colleagues.

Protective effect of proanthocyanidins on endotoxin induced experimental periodontitis in rats.

PubMed

Govindaraj, Jayamathi; Emmadi, Pamela; Deepalakshmi; Rajaram, Vijayalakshmi; Prakash, Geetha; Puvanakrishnan, Rengarajulu

2010-02-01

The pathogenesis of periodontitis involves anaerobic oral bacteria as well as the host response to infection and several drugs have been developed which can curtail these deleterious effects. Proanthocyanidin, a novel flavanoid extracted from grape seeds, has been shown to provide a significant therapeutic effect on endotoxin (Escherichia coli) induced experimental periodontitis in rats. In this study, protective action of different doses of proanthocyanidins was investigated in blood by assaying the reactive oxygen species such as hydrogen peroxide, superoxide anion, myeloperoxidase and lipid peroxides, lysosomal enzyme activities such as cathepsin B, cathepsin D, beta-glucuronidase and acid phosphatase, nonenzymatic antioxidants such as ascorbic acid, alpha-tocopherol, ceruloplasmin, reduced glutathione and antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione-s-transferase. Experimental periodontitis rats showed a reduction in body weight and body weight gain could be noticed when they were administered proanthocyanidins. The levels of reactive oxygen species and lysosomal enzymes were found to increase whereas antioxidant levels were decreased significantly in experimental periodontitis. Proanthocyanidins at an effective dose of 30 mg/kg body weight, sc, for 30 days effected a decrease in serum reactive oxygen species, lipid peroxides, lysosomal enzymes, acute phase proteins and an increase in antioxidant levels. Histopathological evidence of experimental periodontitis showed cellular infiltration of inflammatory cells while proanthocyanidin treated groups demonstrated only scattered inflammatory cells and blood vessels. Thus, the results showed that dietary supplementation of proanthocyanidin enhanced the host resistance as well as the inhibition of the biological and mechanical irritants involved in the onset of gingivitis and the progression of periodontal disease.

[Experimental study on the transforming growth factor β3 combined with dental pulp stem cells in early bone integration of implant].

PubMed

Guzalinuer, Ababaikeli; Muhetaer, Huojia; Wu, H; Paerhati, Abudureheman

2018-04-09

Objective: To establish the experimental model of rabbit mandibular anterior implant repair and evaluate the effects of transforming growth factor (TGF)-β3 and dental pulp stem cells (DPSC) in promoting the bone integration of implant. Methods: The New Zealand rabbits were randomly divided into experimental group, control group and blank group (6 rabbits for each group) . In the experimental group, the implant area was filled with the mixture of TGF-β3, DPSC and Bio-oss powder. In the control group, the implant area was filled with the mixture of DPSC and Bio-oss powder. In the blank group, the implant area was filled with the mixture of phosphate buffer solution and Bio-oss powder. Eighteen New Zealand rabbits were sacrificed in 2 weeks after procedure. The treated alveolar bone tissue was observed. The bone tissue around the implant were estimated by HE staining, immunocytochemical staining and real-time quantitative PCR. Results: The implants were no shedding nor loose. HE staining shows the blank group had a sparse trabecular bone and a small amount of blood vessel around the implant and no obvious new bone formation. The control group showed that the bone trabecula around the implant was sparse and slender, the osteoblasts were arranged linearly around the trabecular bone, a small amount of new bone formation was found around the implant. In the experimental group, there were more thick and dense trabecular bone around the implant, the surrounding osteoblasts were arranged in clusters. The osteoblasts were active and many new bone formed. Typical bone lacunae, bone cells and a large number of new blood vessels can be observed. Immunohistochemistry showed that the proportion of average positive area in the experimental group, control group, blank group were (24.6±5.3) %, (11.3±2.8) % and (7.6±3.8) % respectively. The expression of bone sialoprotein in experimental group were significantly higher than the other 2 groups( P= 0.000). Real-time quantitative PCR results showed that the expression level of Runt-related transcription factor 2 (RUNX2), type Ⅰcollagen (COL-Ⅰ), alkaline phosphatase in the experimental group was higher than in the blank group. The expression level of RUNX2 and COL-Ⅰ in the experimental group was higher than that of the control group ( P= 0.023). Conclusions: TGF-β3 has potential to promote the transformation of DPSC into osteoblasts, which can promote the integration of bone around the implant.

Application of Taguchi L32 orthogonal array design to optimize copper biosorption by using Spaghnum moss.

PubMed

Ozdemir, Utkan; Ozbay, Bilge; Ozbay, Ismail; Veli, Sevil

2014-09-01

In this work, Taguchi L32 experimental design was applied to optimize biosorption of Cu(2+) ions by an easily available biosorbent, Spaghnum moss. With this aim, batch biosorption tests were performed to achieve targeted experimental design with five factors (concentration, pH, biosorbent dosage, temperature and agitation time) at two different levels. Optimal experimental conditions were determined by calculated signal-to-noise ratios. "Higher is better" approach was followed to calculate signal-to-noise ratios as it was aimed to obtain high metal removal efficiencies. The impact ratios of factors were determined by the model. Within the study, Cu(2+) biosorption efficiencies were also predicted by using Taguchi method. Results of the model showed that experimental and predicted values were close to each other demonstrating the success of Taguchi approach. Furthermore, thermodynamic, isotherm and kinetic studies were performed to explain the biosorption mechanism. Calculated thermodynamic parameters were in good accordance with the results of Taguchi model. Copyright © 2014 Elsevier Inc. All rights reserved.

An experimental and theoretical study of molecular structure and vibrational spectra of 2-methylphenyl boronic acid by density functional theory calculations

NASA Astrophysics Data System (ADS)

Hiremath, Sudhir M.; Hiremath, C. S.; Khemalapure, S. S.; Patil, N. R.

2018-05-01

This paper reports the experimental and theoretical study on the structure and vibrations of 2-Methylphenyl boronic acid (2MPBA). The different spectroscopic techniques such as FT-IR (4000-400 cm-1) and FT-Raman (4000-50 cm-1) of the title molecule in the solid phase were recorded. The geometry of the molecule was fully optimized using density functional theory (DFT) (B3LYP) with 6-311++G(d, p) basis set calculations. The vibrational wavenumbers were also corrected with scale factor to take better results for the calculated data. Vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the potential energy distribution (PED) of the vibrational modes obtained from VEDA 4 program. The calculated wavenumbers showed the best agreement with the experimental results. Whereas, it is observed that, the theoretical frequencies are more than the experimental one for O-H stretching vibration modes of the title molecule.

An Investigation of Effectiveness of Conceptual Change Text-oriented Instruction on Students' Understanding of Solution Concepts

NASA Astrophysics Data System (ADS)

Pinarbaşi; , Tacettin; Canpolat, Nurtaç; Bayrakçeken, Samih; Geban, Ömer

2006-12-01

This study investigated the effect of conceptual change text-oriented instruction over traditional instruction on students' understanding of solution concepts (e.g., dissolving, solubility, factors affecting solubility, concentrations of solutions, types of solutions, physical properties of solutions) and their attitudes towards chemistry. The sample of this study consisted of 87 undergraduate students from two classes enrolled in an introductory chemistry course. One of the classes was assigned randomly to the control group, and the other class were assigned randomly to the experimental group. During teaching the topic of solution concepts in the chemistry curriculum, a conceptual change text-oriented instruction was applied in the experimental group whereas traditional instruction was followed in the control group. The results showed that the students in the experimental group performed better with respect to solution concepts. In addition, it has been found that there was no significant difference between the attitudes of students in the experimental and control groups towards chemistry.

Emotional state talk and emotion understanding: a training study with preschool children.

PubMed

Gavazzi, Ilaria Grazzani; Ornaghi, Veronica

2011-11-01

ABSTRACTThe present study investigates whether training preschool children in the active use of emotional state talk plays a significant role in bringing about greater understanding of emotion terms and improved emotion comprehension. Participants were 100 preschool children (M=52 months; SD=9·9; range: 35-70 months), randomly assigned to experimental or control conditions. They were pre- and post-tested to assess their language comprehension, metacognitive language comprehension and emotion understanding. Analyses of pre-test data did not show any significant differences between experimental and control groups. During the intervention phase, the children were read stories enriched with emotional lexicon. After listening to the stories, children in the experimental group took part in conversational language games designed to stimulate use of the selected emotional terms. In contrast, the control group children did not take part in any special linguistic activities after the story readings. Analyses revealed that the experimental group outperformed the control group in the understanding of inner state language and in the comprehension of emotion.

Involvement of Cot/Tp12 in bone loss during periodontitis.

PubMed

Ohnishi, T; Okamoto, A; Kakimoto, K; Bandow, K; Chiba, N; Matsuguchi, T

2010-02-01

Periodontitis causes resorption of alveolar bone, in which RANKL induces osteoclastogenesis. The binding of lipopolysaccharide to Toll-like receptors causes phosphorylation of Cot/Tp12 to activate the MAPK cascade. Previous in vitro studies showed that Cot/Tp12 was essential for the induction of RANKL expression by lipopolysaccharide. In this study, we examined whether Cot/Tp12 deficiency reduced the progression of alveolar bone loss and osteoclastogenesis during experimental periodontitis. We found that the extent of alveolar bone loss and osteoclastogenesis induced by ligature-induced periodontitis was decreased in Cot/Tp12-deficient mice. In addition, reduction of RANKL expression was observed in periodontal tissues of Cot/Tp12-deficient mice with experimental periodontitis. Furthermore, we found that Cot/Tp12 was involved in the induction of TNF-alpha mRNA expression in gingiva of mice with experimental periodontitis. Our observations suggested that Cot/Tp12 is essential for the progression of alveolar bone loss and osteoclastogenesis in periodontal tissue during experimental periodontitis mediated through increased RANKL expression.

Induced sadness increases persistence in a simulated slot machine task among recreational gamblers.

PubMed

Devos, Gaëtan; Clark, Luke; Maurage, Pierre; Billieux, Joël

2018-05-01

Gambling may constitute a strategy for coping with depressive mood, but a direct influence of depressive mood on gambling behaviors has never been tested via realistic experimental designs in gamblers. The current study tested whether experimentally induced sadness increases persistence on a simulated slot machine task using real monetary reinforcement in recreational gamblers. Sixty participants were randomly assigned to an experimental (sadness induction) or control (no emotional induction) condition, and then performed a slot machine task consisting of a mandatory phase followed by a persistence phase. Potential confounding variables (problem gambling symptoms, impulsivity traits, gambling cognitions) were measured to ensure that the experimental and control groups were comparable. The study showed that participants in the sadness condition displayed greater gambling persistence than control participants (p = .011). These data support the causal role of negative affect in decisions to gamble and persistence, which bears important theoretical and clinical implications. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Evaluating the effectiveness of an intervention program to influence attitudes of students towards peers with disabilities.

PubMed

de Boer, Anke; Pijl, Sip Jan; Minnaert, Alexander; Post, Wendy

2014-03-01

In this study we examine the effectiveness of an intervention program to influence attitudes of elementary school students towards peers with intellectual, physical and severe physical and intellectual disabilities. A quasi-experimental longitudinal study was designed with an experimental group and a control group, both comprising two rural schools. An intervention program was developed for kindergarten (n(experimental) = 22, n(control) = 31) and elementary school students without disabilities (n(experimental) = 91, n(control) = 127) (age range 4-12 years old). This intervention consisted of a 3 weeks education project comprising six lessons about disabilities. The Acceptance Scale for Kindergarten-revised and the Attitude Survey to Inclusive Education were used to measure attitudes at three moments: prior to the start of the intervention, after the intervention and 1 year later. The outcomes of the multilevel analysis showed positive, immediate effects on attitudes of kindergarten students, but limited effects on elementary school students' attitudes.

Design, development, and evaluation of visual aids for communicating prescription drug instructions to nonliterate patients in rural Cameroon.

PubMed

Ngoh, L N; Shepherd, M D

1997-03-01

In this study, culturally sensitive visual aids designed to help convey drug information to nonliterate female adults who had a prescription for a solid oral dosage form of antibiotic medications were developed and evaluated. The researchers conceptualized the educational messages while a local artist produced the visual aids. Seventy-eight female ambulatory patients were evaluated for comprehension and compliance with antibiotic prescription instructions. The study was conducted in three health centers in Cameroon, West Africa and followed a pre-test, post-test, and follow-up format for three groups: two experimental, and one control. All participants were randomly assigned to either experimental or control groups, 26 patients to each group. Subjects in the experimental groups received visual aids alone or visual aids plus an Advanced Organizer. A comparison of the three groups showed that subjects in the experimental groups scored significantly higher than the control group in both the comprehension and compliance measures.

Development, implementation, and effects of an integrated web-based teaching model in a nursing ethics course.

PubMed

Chao, S-Y; Chang, Y-C; Yang, S C; Clark, M J

2017-08-01

Ethical competence, which is reflected in the ability to detect ethical challenges in clinical situations and engage in deliberate thinking on ethical actions, is one of the core competencies of nursing practice. The purpose of this study was to develop and implement an interactive situational e-learning system, integrating nursing ethical decisions into a nursing ethics course, and to evaluate the effects of this course on student nurses' ethical decision-making competence. The project was designed to be carried out in two phases. In the first phase, an interactive situated e-learning system was developed and integrated into the nursing ethics course. The second phase involved implementing the course and evaluating its effects in a quasi-experimental study. The course intervention was designed for 2h per week over one semester (18weeks). A total of 100 two-year technical college nursing students in their second year of the program participated in the study, with 51 in the experimental group and 49 in the control group. After completing the course, the students in the experimental group showed significant improvement in nursing ethical decision-making competence, including skills in "raising questions," "recognizing differences," "comparing differences," "self-dialogue," "taking action," and "identifying the implications of decisions made," compared to their performance prior to the class. After controlling for factors influencing learning effects, students in the experimental group showed superiority to those in the control group in the competency of "recognizing differences." The students in the experimental group reported that the course pushed them to search for and collect information needed to resolve the ethical dilemma. The interactive situational e-learning system developed by our project was helpful in developing the students' competence in ethical reasoning. The e-learning system and the situational teaching materials used in this study may be applicable in nursing and related professional ethics courses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study on the generation of a vortex laser beam by using phase-only liquid crystal spatial light modulator

NASA Astrophysics Data System (ADS)

Ma, Haotong; Hu, Haojun; Xie, Wenke; Xu, Xiaojun

2013-09-01

The generation of vortex laser beam by using phase-only liquid crystal spatial light modulator (LC-SLM) combined with the spiral phase screen is experimentally and theoretically studied. Results show that Gaussian and dark hollow vortex laser beams can be generated by using this method successfully. Differing with the Gaussian and dark hollow beams, far field intensities of the generated vortex laser beams still exhibit dark hollow distributions. The comparisons between the ideal generation and experimental generation of vortex laser beams with different optical topological charges by using phase only LC-SLM is investigated in detail. Compared with the ideal generated vortex laser beam, phase distribution of the experimental generated vortex laser beam contains many phase singularities, the number of which is the same as that of the optical topological charges. The corresponding near field and far field dark hollow intensity distributions of the generated vortex laser beams exhibit discontinuous in rotational direction. Detailed theoretical analysis show that the main reason for the physical phenomenon mentioned above is the response error of phase only LC-SLM. These studies can provide effective guide for the generation of vortex laser beam by using phase only LC-SLM for optical tweezers and free space optical communication.

Impaired down-regulation of negative emotion in self-referent social situations in bipolar disorder: A pilot study of a novel experimental paradigm.

PubMed

Kjærstad, Hanne L; Vinberg, Maj; Goldin, Philippe R; Køster, Nicolai; Støttrup, Mette Marie D; Knorr, Ulla; Kessing, Lars V; Miskowiak, Kamilla W

2016-04-30

Emotion dysregulation is a core feature of bipolar disorder (BD) that persists into periods of remission. Neuroimaging studies show aberrant neural responses during emotion regulation (ER) in patients with BD relative to healthy controls, but behavioural evidence for ER deficits is sparse and conflicting. This study aimed to explore ER in BD using a novel, personally relevant experimental paradigm. Twenty patients with BD and 20 patients with unipolar disorder (UD), in full or partial remission, and 20 healthy controls were given a novel computerised test. Participants were instructed to react naturally or dampen their emotional response to positive and negative social scenarios and associated self-beliefs. They were also given an established experimental task for comparison, involving reappraisal of negative affective picture stimuli, as well as a questionnaire of habitual ER strategies. BD patients showed reduced ability to down-regulate emotional responses in negative, but not positive, social scenarios relative to healthy controls and UD patients. In contrast, there were no between-group differences in the established ER task or in self-reported habitual reappraisal strategies. Findings highlight the novel social scenario paradigm as a sensitive test for detection of ER difficulties in BD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Adaptive Signal Recovery on Graphs via Harmonic Analysis for Experimental Design in Neuroimaging.

PubMed

Kim, Won Hwa; Hwang, Seong Jae; Adluru, Nagesh; Johnson, Sterling C; Singh, Vikas

2016-10-01

Consider an experimental design of a neuroimaging study, where we need to obtain p measurements for each participant in a setting where p ' (< p ) are cheaper and easier to acquire while the remaining ( p - p ') are expensive. For example, the p ' measurements may include demographics, cognitive scores or routinely offered imaging scans while the ( p - p ') measurements may correspond to more expensive types of brain image scans with a higher participant burden. In this scenario, it seems reasonable to seek an "adaptive" design for data acquisition so as to minimize the cost of the study without compromising statistical power. We show how this problem can be solved via harmonic analysis of a band-limited graph whose vertices correspond to participants and our goal is to fully recover a multi-variate signal on the nodes, given the full set of cheaper features and a partial set of more expensive measurements. This is accomplished using an adaptive query strategy derived from probing the properties of the graph in the frequency space. To demonstrate the benefits that this framework can provide, we present experimental evaluations on two independent neuroimaging studies and show that our proposed method can reliably recover the true signal with only partial observations directly yielding substantial financial savings.

Housekeeping gene expression during fetal brain development in the rat-validation by semi-quantitative RT-PCR.

PubMed

Al-Bader, Maie Dawoud; Al-Sarraf, Hameed Ali

2005-04-21

Mammalian gene expression is usually carried out at the level of mRNA where the amount of mRNA of interest is measured under different conditions such as growth and development. It is therefore important to use a "housekeeping gene", that does not change in relative abundance during the experimental conditions, as a standard or internal control. However, recent data suggest that expression of some housekeeping genes may vary with the extent of cell proliferation, differentiation and under various experimental conditions. In this study, the expression of various housekeeping genes (18S rRNA [18S], glyceraldehydes-3-phosphate dehydrogenase [G3PDH], beta-glucuronidase [BGLU], histone H4 [HH4], ribosomal protein L19 [RPL19] and cyclophilin [CY]) was investigated during fetal rat brain development using semi-quantitative RT-PCR at 16, 19 and 21 days gestation. It was found that all genes studied, with exception to G3PDH, did not show any change in their expression levels during development. G3PDH, on the other hand, showed increased expression with development. These results suggest that the choice of a housekeeping gene is critical to the interpretation of experimental results and should be modified according to the nature of the study.

Men, women…who cares? A population-based study on sex differences and gender roles in empathy and moral cognition.

PubMed

Baez, Sandra; Flichtentrei, Daniel; Prats, María; Mastandueno, Ricardo; García, Adolfo M; Cetkovich, Marcelo; Ibáñez, Agustín

2017-01-01

Research on sex differences in empathy has revealed mixed findings. Whereas experimental and neuropsychological measures show no consistent sex effect, self-report data consistently indicates greater empathy in women. However, available results mainly come from separate populations with relatively small samples, which may inflate effect sizes and hinder comparability between both empirical corpora. To elucidate the issue, we conducted two large-scale studies. First, we examined whether sex differences emerge in a large population-based sample (n = 10,802) when empathy is measured with an experimental empathy-for-pain paradigm. Moreover, we investigated the relationship between empathy and moral judgment. In the second study, a subsample (n = 334) completed a self-report empathy questionnaire. Results showed some sex differences in the experimental paradigm, but with minuscule effect sizes. Conversely, women did portray themselves as more empathic through self-reports. In addition, utilitarian responses to moral dilemmas were less frequent in women, although these differences also had small effect sizes. These findings suggest that sex differences in empathy are highly driven by the assessment measure. In particular, self-reports may induce biases leading individuals to assume gender-role stereotypes. Awareness of the role of measurement instruments in this field may hone our understanding of the links between empathy, sex differences, and gender roles.

Experimental and Numerical Investigations on the Mechanical Characteristics of Carbon Fiber Sensors

PubMed Central

Siddiqui, Mohammed

2017-01-01

Carbon fiber-based materials possess excellent mechanical properties and show linear piezoresistive behavior, which make them good candidate materials for strain measurements. They have the potential to be used as sensors for various applications such as damage detection, stress analysis and monitoring of manufacturing processes and quality. In this paper, carbon fiber sensors are prepared to perform reliable strain measurements. Both experimental and computational studies were carried out on commercially available carbon fibers in order to understand the response of the carbon fiber sensors due to changes in the axial strain. Effects of parameters such as diameter, length, and epoxy-hardener ratio are discussed. The developed numerical model was calibrated using laboratory-based experimental data. The results of the current study show that sensors with shorter lengths have relatively better sensitivity. This is due to the fact short fibers have low initial resistance, which will increase the change of resistance over initial resistance. Carbon fibers with low number of filaments exhibit linear behavior while nonlinear behavior due to transverse resistance is significant in fibers with large number of filaments. This study will allow researchers to predict the behavior of the carbon fiber sensor in real life and it will serve as a basis for designing carbon fiber sensors to be used in different applications. PMID:28869538

Combining density functional theory (DFT) and collision cross-section (CCS) calculations to analyze the gas-phase behaviour of small molecules and their protonation site isomers.

PubMed

Boschmans, Jasper; Jacobs, Sam; Williams, Jonathan P; Palmer, Martin; Richardson, Keith; Giles, Kevin; Lapthorn, Cris; Herrebout, Wouter A; Lemière, Filip; Sobott, Frank

2016-06-20

Electrospray ion mobility-mass spectrometry (IM-MS) data show that for some small molecules, two (or even more) ions with identical sum formula and mass, but distinct drift times are observed. In spite of showing their own unique and characteristic fragmentation spectra in MS/MS, no configurational or constitutional isomers are found to be present in solution. Instead the observation and separation of such ions appears to be inherent to their gas-phase behaviour during ion mobility experiments. The origin of multiple drift times is thought to be the result of protonation site isomers ('protomers'). Although some important properties of protomers have been highlighted by other studies, correlating the experimental collision cross-sections (CCSs) with calculated values has proven to be a major difficulty. As a model, this study uses the pharmaceutical compound melphalan and a number of related molecules with alternative (gas-phase) protonation sites. Our study combines density functional theory (DFT) calculations with modified MobCal methods (e.g. nitrogen-based Trajectory Method algorithm) for the calculation of theoretical CCS values. Calculated structures can be linked to experimentally observed signals, and a strong correlation is found between the difference of the calculated dipole moments of the protomer pairs and their experimental CCS separation.

On Leakage Current Measured at High Cell Voltages in Lithium-Ion Batteries

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

Vadivel, Nicole R.; Ha, Seungbum; He, Meinan

2017-01-01

In this study, parasitic side reactions in lithium-ion batteries were examined experimentally using a potentiostatic hold at high cell voltage. The experimental leakage current measured during the potentiostatic hold was compared to the Tafel expression and showed poor agreement with the expected transfer coefficient values, indicating that a more complicated expression could be needed to accurately capture the physics of this side reaction. Here we show that cross-talk between the electrodes is the primary contribution to the observed leakage current after the relaxation of concentration gradients has ceased. This cross-talk was confirmed with experiments using a lithium-ion conducting glass ceramicmore » (LICGC) separator, which has high conductance only for lithium cations. The cells with LICGC separators showed significantly less leakage current during the potentiostatic hold test compared to cells with standard microporous separators where cross-talk is present. In addition, direct-current pulse power tests show an impedance rise for cells held at high potentials and for cells held at high temperatures, which could be attributed to film formation from the parasitic side reaction. Based on the experimental findings, a phenomenological mechanism is proposed for the parasitic side reaction which accounts for cross-talk and mass transport of the decomposition products across the separator.« less

Texture development in naturally compacted and experimentally deformed silty clay sediments from the Nankai Trench and Forearc, Japan

NASA Astrophysics Data System (ADS)

Schumann, Kai; Stipp, Michael; Leiss, Bernd; Behrmann, Jan H.

2014-12-01

The petrophysical properties of fine-grained marine sediments to a large extent depend on the microstructure and crystallographic preferred orientations (CPOs). In this contribution we show that Rietveld-based synchrotron texture analysis is a new and valuable tool to quantify textures of water-saturated fine-grained phyllosilicate-rich sediments, and assess the effects of compaction and tectonic deformation. We studied the CPO of compositionally almost homogeneous silty clay drillcore samples from the Nankai Accretionary Prism slope and the incoming Philippine Sea plate, offshore SW Japan. Basal planes of phyllosilicates show bedding-parallel alignment increasing with drillhole depth, thus reflecting progressive burial and compaction. In some samples calcite and albite display a CPO due to crystallographically controlled non-isometric grain shapes, or nannofossil tests. Consolidated-undrained experimental deformation of a suite of thirteen samples from the prism slope shows that the CPOs of phyllosilicate and calcite basal planes develop normal to the experimental shortening axis. There is at least a qualitative relation between CPO intensity and strain magnitude. Scanning electron micrographs show concurrent evolution of preferred orientations of micropores and detrital illite flakes normal to axial shortening. This indicates that the microfabrics are sensitive strain gauges, and contribute to anisotropic physical properties along with the CPO.

[Analysis of healing in the Alba Linea with the use of Orbignya phalerata (babassu) water extract. Controlled study in rats].

PubMed

Brito Filho, Sebastião Barreto de; Matias, Jorge Eduardo F; Stahlke Júnior, Henrique Jorge; Torres, Orlando Jorge Martins; Timi, Jorge Rufino Ribas; Tenório, Sérgio Bernardo; Tâmbara, Elizabeth Milla; Carstens, Angelo G; Campos, Richard Vieira; Myamoto, Márcio

2006-01-01

The babassu mesocarp (Orbignya phalerata) has been used in experimental research studies focused on its antiinflammatory action. In state of Maranhão--Brazil it is widely used not only as food, but also as popular medicine in wound healing process. To evaluate the action of Orbignya phalerata extract in macroscopic, histologic and tensiometric aspects in the healing process of median laparotomy in rats. Forty male adult Wistar rats were submitted to an incision in the alba linea, sutured back in one plan with separated stitches of polypropylene 5-0. After regular procedure, the animals were divided into two groups of 20 rats each. To the group named control an intraperitoneal, dose of 1.0 ml of saline solution per kilogram of body weight was done. To the experimental group, the same thing was also done, but instead of saline solution it was injected water solution of babassu, in a dose of 50 mg/kg. The animals were observed in the following days. All of them were killed within a three and seven day post-operative period schedule, and then a histological and tensiometric analysis was carried out. On macroscopic examination no relevant adherence, between the alba linea and the abdominal organs in the study groups, was found. Histological evaluation presented marginal significant effects (p=0.86) to acute inflammation and significant effects (p=0.003) to giant cell reaction in both control and experimental three days groups. Significant difference was observed to acute inflammation in both seven days control and experimental groups. In the intragroup analysis (control three and seven) some marginal significant effect was in relationship to acute and chronic inflammation. In the inter-experimental groups analysis, only the giant cell reactions (0.002) and colagenization had significant results. The tensiometric evaluation showed in the seven day experimental group more resistance then others. The macroscopic and histological evaluation didn't show any significant difference between the experimental and control groups, but the tensiometric evaluation at the 7th day experimental group had significant difference compared to the control group, signaling that the use of the extract of babassu intraperitoneally injected can improve the healing process.

Assessing the Accuracy of Generalized Inferences From Comparison Group Studies Using a Within-Study Comparison Approach: The Methodology.

PubMed

Jaciw, Andrew P

2016-06-01

Various studies have examined bias in impact estimates from comparison group studies (CGSs) of job training programs, and in education, where results are benchmarked against experimental results. Such within-study comparison (WSC) approaches investigate levels of bias in CGS-based impact estimates, as well as the success of various design and analytic strategies for reducing bias. This article reviews past literature and summarizes conditions under which CGSs replicate experimental benchmark results. It extends the framework to, and develops the methodology for, situations where results from CGSs are generalized to untreated inference populations. Past research is summarized; methods are developed to examine bias in program impact estimates based on cross-site comparisons in a multisite trial that are evaluated against site-specific experimental benchmarks. Students in Grades K-3 in 79 schools in Tennessee; students in Grades 4-8 in 82 schools in Alabama. Grades K-3 Stanford Achievement Test (SAT) in reading and math scores; Grades 4-8 SAT10 reading scores. Past studies show that bias in CGS-based estimates can be limited through strong design, with local matching, and appropriate analysis involving pretest covariates and variables that represent selection processes. Extension of the methodology to investigate accuracy of generalized estimates from CGSs shows bias from confounders and effect moderators. CGS results, when extrapolated to untreated inference populations, may be biased due to variation in outcomes and impact. Accounting for effects of confounders or moderators may reduce bias. © The Author(s) 2016.

[Effects of a Positive Psychotherapy Program on Positive Affect, Interpersonal Relations, Resilience, and Mental Health Recovery in Community-Dwelling People with Schizophrenia].

PubMed

Kim, Jinhee; Na, Hyunjoo

2017-10-01

Recently, the interest in positive psychotherapy is growing, which can help to encourage positive relationships and develop strengths of people. This study was conducted to investigate the effects of a positive psychotherapy program on positive affect, interpersonal relations, resilience, and mental health recovery in community-dwelling people with schizophrenia. The research was conducted using a randomized control group pretest-posttest design. A total of 57 adults with schizophrenia participated in this study. The study participants in experimental group received a positive psychotherapy program (n=28) and the participants in control group received only the usual treatment in community centers (n=29). The positive psychotherapy program was provided for 5 weeks (of 10 sessions, held twice/week, for 60 minutes). The study outcomes included positive affect, interpersonal relations, resilience, and mental health recovery. The collected data were analyzed using repeated measures ANOVA for examining study hypothesis. Results showed that interpersonal relations (F=11.83, p=.001) and resilience (F=9.62, p=.003) significantly increased in the experimental group compared to the control group. Although experimental group showed a slight increase in positive affect, it was not significant. The study findings confirm that the positive psychotherapy program is effective for improving interpersonal relations and resilience of community-dwelling people with schizophrenia. Based on the findings, we believe that the positive psychotherapy program would be acceptable and helpful to improve recovery of mental health in schizophrenia. © 2017 Korean Society of Nursing Science

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.

Effects of long-term stimulation of textured insoles on postural control in health elderly.

PubMed

Annino, Giuseppe; Palazzo, Francesco; Alwardat, Mohammad S; Manzi, Vincenzo; Lebone, Pietro; Tancredi, Virginia; Sinibaldi Salimei, Paola; Caronti, Alfio; Panzarino, Michele; Padua, Elvira

2018-04-01

The aim of this study was to confirm the effects of long term (chronic) stimulating surface (textured insole) on body balance of elderly people. Twenty-four healthy elderly individuals were randomly distributed in two groups: control and experimental (67.75±6.04 years, 74.55±12.14 kg, 163.7±8.55 cm, 27.75±3.04 kg/m2). Over one month, control group (CG) used smooth insoles and the experimental group (ExG) used textured insoles every day. Velocity net (Vnet), anteroposterior (VA/P), mediolateral (VM/L) and sway path of CoP were assessed in different eye conditions before and after the experimental procedure. A mixed between-within subject ANOVA was conducted to assess the impact of soft and textured insoles and two visual conditions (vision vs. no vision) across two time periods (α≤0.05). The results showed any statistical difference between groups in each parameter assessed in this study. CoP, Vnet and VM/L in the experimental group showed a statistically significant effect of textured insoles only without vision (CoP: P=0.002; η2=0.35), Vnet P=0.02; η2=0.24, VM/L P=0.04; η2=0.177) whereas VA/P showed no statistically significant effect in the same group and condition. There was no significant effect in Vnet, VA/P, VM/L and COP in control group that used smooth insole for both eye conditions. The results confirm that postural stability improved in healthy elderly individuals, increasing somatosensory information's from feet plantar mechanoreceptors. Long term stimulation with textured insoles decreased CoP, Vnet and VM/L with eyes closed.

Increased Disease Activity is Associated with Altered Sleep Architecture in an Experimental Model of Systemic Lupus Erythematosus

PubMed Central

Palma, Beatriz Duarte; Tufik, Sergio

2010-01-01

Study Objectives: The aim of this study was to evaluate sleep patterns during the course of the disease in (NZB/NZW)F1 mice, an experimental model of systemic lupus erythematosus (SLE). Design: Female mice were implanted with electrodes for chronic recording of sleep-wake cycles during the entire experimental phase (9, 19, and 29 weeks of age). The disease course was also assessed. At each time-point, blood samples were collected from the orbital plexus to evaluate serum antinuclear antibodies (ANA), which are important serologic parameters of disease evolution. Pain perception was also evaluated. Measurements and Results: During the dark phase, (NZB/NZW)F1 mice aged 19 weeks spent more time in sleep, and, as a consequence, the total waking time was lower when compared with earlier periods. An augmented number of sleep-stage transitions and microarousals were observed at the 29th week of life in both light and dark phases. At this same time-point, the mice showed lower pain thresholds than they had at 9 weeks of life. The disease status was confirmed; the entire group of mice at 29 weeks of life showed positive ANA with high titer levels. Conclusions: The sleep-recording data showed that, during the progress and severe phases of the disease (19 and 29 wks of age, respectively), sleep architecture is altered. According to these results, increased sleep fragmentation, disease activity, and pain sensitivity are features observed in these mice, similar to symptoms of SLE. Citation: Palma BD; Tufik S. Increased disease activity is associated with altered sleep architecture in an experimental model of systemic lupus erythematosus. SLEEP 2010;33(9):1244-1248. PMID:20857872

Therapeutic effect of alkaloids and glycosides of colocynth seeds on liver injury, associated with metabolic syndrome in wistar rats, subject to nutritional stress.

PubMed

Tabani, Khadidja; Birem, Zahia; Halzoune, Hanane; Saiah, Wassila; Lahfa, Farid; Koceir, Elhadj Ahmed; Omari, Naima

2018-01-01

The Citrullus colocynthis, commonly called colocynth, is known because of its purgative effects and whose seeds are commonly used as certain diseases treatment, namely liver diseases, in the Mediterranean countries traditional medicine. This study aims to analyze the effect of two colocynth extracts « glycosides » and « alkaloids » on metabolic and histological disorders associated with liver function in Wistar rats (Rattus norvegicus). This pathology is due to an enriched oil palm diet. For this purpose, Wistar male rats n = 18, weighing between 130g and 150g, are divided into two lots. A control group (C) n = 6, receives a standard laboratory diet ; an experimental group (E) n = 12, receives a standard laboratory diet supplemented with palm oil. After seven months of experimentation, 8 experimental rats were sacrificed for the morphological study and the remaining 12 rats undergo a colocynth treatment (Tr) for eight weeks. They are subdivided into: The first six experimental rats receive a 70mg/kg single intraperitoneal injection of ethanol extract of cucurbitacin glycosides (Glc). The second lot receives a 70mg/kg single intraperitoneal injection of total alkaloids extract (Alc). The animals of (E) group showed hyperglycemia, hyperinsulinemia, hyperlipemia, dyslipoproteinemia, a significant increase of the enzymatic activity of transaminase (AST and ALT) and alkaline phosphatase (ALP). Histological examination of the liver gland shows major damages Non-alcoholic steatohepatitis [NASH]. Treatment with colocynth glycosides and alkaloids reveals a significant improvement at different levels in plasma as well as in tissue. Treatment with colocynth glycosides and alkaloids shows a hypoglycemic effect, lipid-lowering a well as a hepato-protective effect.

Chronic effect of static stretching on strength performance and basal serum IGF-1 levels.

PubMed

Borges Bastos, Carmen L; Miranda, Humberto; Vale, Rodrigo Gomes de Souza; Portal, Maria de Nazaré; Gomes, M Thiago; Novaes, Jefferson da Silva; Winchester, Jason B

2013-09-01

Improving the process of how physical performance is enhanced is one of the main topics evaluated by physiologists. This process often involves athletes and nonathletic populations. The purpose of this study was to assess the chronic response to 10 weeks of static stretching exercises carried out before and during a strength training program for 8 exercises on an 8 repetition maximum (8RM) test performance, and basal serum insulinlike growth factor (IGF-1) levels. Thirty recreationally trained volunteers were randomly assigned to 1 of 3 training groups: (a) SBST (performed a warm-up with a static stretching protocol before each strength training session); (b) SDST (before each training set, a static stretching exercise was performed); and (c) OST (entire session was performed without any type of stretching exercise). Strength and IGF-1 levels were collected at the beginning (pretest) and end (posttest) of the entire experimental procedure. All the exercises showed a significant increase in muscle strength for the OST group. However, the results revealed a significant increase in the muscle strength for only a few exercises in the SBST (LP, LE) and SDST (LP) experimental conditions. Significant statistical differences were found between SBST and SDST for all the exercises in the OST experimental condition. Furthermore, the IGF-1 expression showed no significant differences in the intragroup analysis. However, the OST group showed higher values (p < 0.05) in the posttest when compared with those of the other groups (increased significantly only in the OST experimental condition). It has been concluded that, although all the groups showed an increase in muscular strength, the strength training performed without any type of stretching exercise, regardless of whether the stretching is performed before or during the lifting session, can more effectively increase muscle strength and basal serum IGF-1 levels. It was concluded that strength training, with or without the use of stretching exercises, increased muscular strength in the studied groups, and can induce an increase in IGF-1 levels.

Using event-related fMRI to examine sustained attention processes and effects of APOE ε4 in young adults.

PubMed

Evans, Simon; Clarke, Devin; Dowell, Nicholas G; Tabet, Naji; King, Sarah L; Hutton, Samuel B; Rusted, Jennifer M

2018-01-01

In this study we investigated effects of the APOE ε4 allele (which confers an enhanced risk of poorer cognitive ageing, and Alzheimer's Disease) on sustained attention (vigilance) performance in young adults using the Rapid Visual Information Processing (RVIP) task and event-related fMRI. Previous fMRI work with this task has used block designs: this study is the first to image an extended (6-minute) RVIP task. Participants were 26 carriers of the APOE ε4 allele, and 26 non carriers (aged 18-28). Pupil diameter was measured throughout, as an index of cognitive effort. We compared activity to RVIP task hits to hits on a control task (with similar visual parameters and response requirements but no working memory load): this contrast showed activity in medial frontal, inferior and superior parietal, temporal and visual cortices, consistent with previous work, demonstrating that meaningful neural data can be extracted from the RVIP task over an extended interval and using an event-related design. Behavioural performance was not affected by genotype; however, a genotype by condition (experimental task/control task) interaction on pupil diameter suggested that ε4 carriers deployed more effort to the experimental compared to the control task. fMRI results showed a condition by genotype interaction in the right hippocampal formation: only ε4 carriers showed downregulation of this region to experimental task hits versus control task hits. Experimental task beta values were correlated against hit rate: parietal correlations were seen in ε4 carriers only, frontal correlations in non-carriers only. The data indicate that, in the absence of behavioural differences, young adult ε4 carriers already show a different linkage between functional brain activity and behaviour, as well as aberrant hippocampal recruitment patterns. This may have relevance for genotype differences in cognitive ageing trajectories.

Pain empathy in schizophrenia: an fMRI study

PubMed Central

Jimenez, Amy M.; Lee, Junghee; Wynn, Jonathan K.; Eisenberger, Naomi I.; Green, Michael F.

2016-01-01

Abstract Although it has been proposed that schizophrenia is characterized by impaired empathy, several recent studies found intact neural responses on tasks measuring the affective subdomain of empathy. This study further examined affective empathy in 21 schizophrenia outpatients and 21 healthy controls using a validated pain empathy paradigm with two components: (i) observing videos of people described as medical patients who were receiving a painful sound stimulation treatment; (ii) listening to the painful sounds (to create regions of interest). The observing videos component incorporated experimental manipulations of perspective taking (instructions to imagine ‘Self’ vs ‘Other’ experiencing pain) and cognitive appraisal (information about whether treatment was ‘Effective’ vs ‘Not Effective’). When considering activation across experimental conditions, both groups showed similar dorsal anterior cingulate cortex (dACC) and anterior insula (AI) activation while merely observing others in pain. However, there were group differences associated with perspective taking: controls showed relatively greater dACC and AI activation for the Self vs Other contrast whereas patients showed relatively greater activation in these and additional regions for the Other vs Self contrast. Although patients demonstrated grossly intact neural activity while observing others in pain, they showed more subtle abnormalities when required to toggle between imagining themselves vs others experiencing pain. PMID:26746181

Pain empathy in schizophrenia: an fMRI study.

PubMed

Horan, William P; Jimenez, Amy M; Lee, Junghee; Wynn, Jonathan K; Eisenberger, Naomi I; Green, Michael F

2016-05-01

Although it has been proposed that schizophrenia is characterized by impaired empathy, several recent studies found intact neural responses on tasks measuring the affective subdomain of empathy. This study further examined affective empathy in 21 schizophrenia outpatients and 21 healthy controls using a validated pain empathy paradigm with two components: (i) observing videos of people described as medical patients who were receiving a painful sound stimulation treatment; (ii) listening to the painful sounds (to create regions of interest). The observing videos component incorporated experimental manipulations of perspective taking (instructions to imagine 'Self' vs 'Other' experiencing pain) and cognitive appraisal (information about whether treatment was 'Effective' vs 'Not Effective'). When considering activation across experimental conditions, both groups showed similar dorsal anterior cingulate cortex (dACC) and anterior insula (AI) activation while merely observing others in pain. However, there were group differences associated with perspective taking: controls showed relatively greater dACC and AI activation for the Self vs Other contrast whereas patients showed relatively greater activation in these and additional regions for the Other vs Self contrast. Although patients demonstrated grossly intact neural activity while observing others in pain, they showed more subtle abnormalities when required to toggle between imagining themselves vs others experiencing pain. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Network topological analysis reveals the functional cohesiveness for the newly discovered links by Yeast 2 Hybrid approach

NASA Astrophysics Data System (ADS)

Ghiassian, Susan; Pevzner, Sam; Rolland, Thomas; Tassan, Murat; Barabasi, Albert Laszlo; Vidal, Mark; CCNR, Northeastern University Collaboration; Dana Farber Cancer Institute Collaboration

2014-03-01

Protein-protein interaction maps and interactomes are the blueprint of Network Medicine and systems biology and are being experimentally studied by different groups. Despite the wide usage of Literature Curated Interactome (LCI), these sources are biased towards different parameters such as highly studied proteins. Yeast two hybrid method is a high throughput experimental setup which screens proteins in an unbiased fashion. Current knowledge of protein interactions is far from complete. In fact the previous offered data from Y2H method (2005), is estimated to offer only 5% of all potential protein interactions. Currently this coverage has increased to 20% of what is known as reference HI In this work we study the topological properties of Y2H protein-protein interactions network with LCI and show although they both agree on some properties, LCI shows a clear unbiased nature of interaction selections. Most importantly, we assess the properties of PPI as it evolves with increasing the coverage. We show that, the newly discovered interactions tend to connect proteins that have been closer than average in the previous PPI release. reinforcing the modular structure of PPI. Furthermore, we show, some unseen effects on PPI (as opposed to LCI) can be explained by its incompleteness.

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.

Set-base dynamical parameter estimation and model invalidation for biochemical reaction networks.

PubMed

Rumschinski, Philipp; Borchers, Steffen; Bosio, Sandro; Weismantel, Robert; Findeisen, Rolf

2010-05-25

Mathematical modeling and analysis have become, for the study of biological and cellular processes, an important complement to experimental research. However, the structural and quantitative knowledge available for such processes is frequently limited, and measurements are often subject to inherent and possibly large uncertainties. This results in competing model hypotheses, whose kinetic parameters may not be experimentally determinable. Discriminating among these alternatives and estimating their kinetic parameters is crucial to improve the understanding of the considered process, and to benefit from the analytical tools at hand. In this work we present a set-based framework that allows to discriminate between competing model hypotheses and to provide guaranteed outer estimates on the model parameters that are consistent with the (possibly sparse and uncertain) experimental measurements. This is obtained by means of exact proofs of model invalidity that exploit the polynomial/rational structure of biochemical reaction networks, and by making use of an efficient strategy to balance solution accuracy and computational effort. The practicability of our approach is illustrated with two case studies. The first study shows that our approach allows to conclusively rule out wrong model hypotheses. The second study focuses on parameter estimation, and shows that the proposed method allows to evaluate the global influence of measurement sparsity, uncertainty, and prior knowledge on the parameter estimates. This can help in designing further experiments leading to improved parameter estimates.

Set-base dynamical parameter estimation and model invalidation for biochemical reaction networks

PubMed Central

2010-01-01

Background Mathematical modeling and analysis have become, for the study of biological and cellular processes, an important complement to experimental research. However, the structural and quantitative knowledge available for such processes is frequently limited, and measurements are often subject to inherent and possibly large uncertainties. This results in competing model hypotheses, whose kinetic parameters may not be experimentally determinable. Discriminating among these alternatives and estimating their kinetic parameters is crucial to improve the understanding of the considered process, and to benefit from the analytical tools at hand. Results In this work we present a set-based framework that allows to discriminate between competing model hypotheses and to provide guaranteed outer estimates on the model parameters that are consistent with the (possibly sparse and uncertain) experimental measurements. This is obtained by means of exact proofs of model invalidity that exploit the polynomial/rational structure of biochemical reaction networks, and by making use of an efficient strategy to balance solution accuracy and computational effort. Conclusions The practicability of our approach is illustrated with two case studies. The first study shows that our approach allows to conclusively rule out wrong model hypotheses. The second study focuses on parameter estimation, and shows that the proposed method allows to evaluate the global influence of measurement sparsity, uncertainty, and prior knowledge on the parameter estimates. This can help in designing further experiments leading to improved parameter estimates. PMID:20500862

Effects of flow changes on radiotracer binding: Simultaneous measurement of neuroreceptor binding and cerebral blood flow modulation.

PubMed

Sander, Christin Y; Mandeville, Joseph B; Wey, Hsiao-Ying; Catana, Ciprian; Hooker, Jacob M; Rosen, Bruce R

2017-01-01

The potential effects of changes in blood flow on the delivery and washout of radiotracers has been an ongoing question in PET bolus injection studies. This study provides practical insight into this topic by experimentally measuring cerebral blood flow (CBF) and neuroreceptor binding using simultaneous PET/MRI. Hypercapnic challenges (7% CO 2 ) were administered to non-human primates in order to induce controlled increases in CBF, measured with pseudo-continuous arterial spin labeling. Simultaneously, dopamine D 2 /D 3 receptor binding of [ 11 C]raclopride or [ 18 F]fallypride was monitored with dynamic PET. Experiments showed that neither time activity curves nor quantification of binding through binding potentials ( BP ND ) were measurably affected by CBF increases, which were larger than two-fold. Simulations of experimental procedures showed that even large changes in CBF should have little effect on the time activity curves of radiotracers, given a set of realistic assumptions. The proposed method can be applied to experimentally assess the flow sensitivity of other radiotracers. Results demonstrate that CBF changes, which often occur due to behavioral tasks or pharmacological challenges, do not affect PET [ 11 C]raclopride or [ 18 F]fallypride binding studies and their quantification. The results from this study suggest flow effects may have limited impact on many PET neuroreceptor tracers with similar properties.

Experimental and analytical parametric study of single-crystal unimorph beams for vibration energy harvesting.

PubMed

Karami, M Amin; Bilgen, Onur; Inman, Daniel J; Friswell, Michael I

2011-07-01

This research presents an experimental and theoretical energy harvesting characterization of beam-like, uniform cross-section, unimorph structures employing single-crystal piezoelectrics. Different piezoelectric materials, substrates, and configurations are examined to identify the best design configuration for lightweight energy harvesting devices for low-power applications. Three types of piezoelectrics (singlecrystal PMN-PZT, polycrystalline PZT-5A, and PZT-5H-type monolithic ceramics) are evaluated in a unimorph cantilevered beam configuration. The devices have been excited by harmonic base acceleration. All of the experimental characteristics have been used to validate an exact electromechanical model of the harvester. The study shows the optimum choice of substrate material for single-crystal piezoelectric energy harvesting. Comparison of energy scavengers with stainless steel substrates reveals that single-crystal harvesters produce superior power compared with polycrystalline devices. To further optimize the power harvesting, we study the relation between the thickness of the substrate and the power output for different substrate materials. The relation between power and substrate thickness profoundly varies among different substrate materials. The variation is understood by examining the change of mechanical transmissibility and the variations of the coupling figure of merit of the harvesters with thickness ratio. The investigation identifies the optimal thickness of the substrate for different substrate materials. The study also shows that the densities of the substrates and their mechanical damping coefficients have significant effects on the power output.

Self diffusion of alkaline-Earth in Ca-Mg-aluminosilicate melts: Experimental improvements on the determination of the self-diffusion coefficients

NASA Technical Reports Server (NTRS)

Paillat, O.; Wasserburg, G. J.

1993-01-01

Experimental studies of self-diffusion isotopes in silicate melts often have quite large uncertainties when comparing one study to another. We designed an experiment in order to improve the precision of the results by simultaneously studying several elements (Mg, Ca, Sr, Ba) during the same experiment thereby greatly reducing the relative experimental uncertainties. Results show that the uncertainties on the diffusion coefficients can be reduced to 10 percent, allowing a more reliable comparison of differences of self-diffusion coefficients of the elements. This type of experiment permits us to study precisely and simultaneously several elements with no restriction on any element. We also designed an experiment to investigate the possible effects of multicomponent diffusion during Mg self-diffusion experiments by comparing cases where the concentrations of the elements and the isotopic compositions are different. The results suggest that there are differences between the effective means of transport. This approach should allow us to investigate the importance of multicomponent diffusion in silicate melts.

Experimental Studies of the Brownian Diffusion of Boomerang Colloidal Particle in a Confined Geometry

NASA Astrophysics Data System (ADS)

Chakrabarty, Ayan; Wang, Feng; Joshi, Bhuwan; Wei, Qi-Huo

2011-03-01

Recent studies shows that the boomerang shaped molecules can form various kinds of liquid crystalline phases. One debated topic related to boomerang molecules is the existence of biaxial nematic liquid crystalline phase. Developing and optical microscopic studies of colloidal systems of boomerang particles would allow us to gain better understanding of orientation ordering and dynamics at ``single molecule'' level. Here we report the fabrication and experimental studies of the Brownian motion of individual boomerang colloidal particles confined between two glass plates. We used dark-field optical microscopy to directly visualize the Brownian motion of the single colloidal particles in a quasi two dimensional geometry. An EMCCD was used to capture the motion in real time. An indigenously developed imaging processing algorithm based on MatLab program was used to precisely track the position and orientation of the particles with sub-pixel accuracy. The experimental finding of the Brownian diffusion of a single boomerang colloidal particle will be discussed.

Modification of silicon nitride surfaces with GOPES and APTES for antibody immobilization: computational and experimental studies

NASA Astrophysics Data System (ADS)

Dien To, Thien; Nguyen, Anh Tuan; Nhat Thanh Phan, Khoa; Thu Thi Truong, An; Doan, Tin Chanh Duc; Mau Dang, Chien

2015-12-01

Chemical modification of silicon nitride (SiN) surfaces by silanization has been widely studied especially with 3-(aminopropyl)triethoxysilane (APTES) and 3-(glycidyloxypropyl) dimethylethoxysilane (GOPES). However few reports performed the experimental and computational studies together. In this study, surface modification of SiN surfaces with GOPES and APTES covalently bound with glutaraldehyde (GTA) was investigated for antibody immobilization. The monoclonal anti-cytokeratin-FITC (MACF) antibody was immobilized on the modified SiN surfaces. The modified surfaces were characterized by water contact angle measurements, atomic force microscopy and fluorescence microscopy. The FITC-fluorescent label indicated the existence of MACF antibody on the SiN surfaces and the efficiency of the silanization reaction. Absorption of APTES and GOPES on the oxidized SiN surfaces was computationally modeled and calculated by Materials Studio software. The computational and experimental results showed that modification of the SiN surfaces with APTES and GTA was more effective than the modification with GOPES.

Study on blade surface flow around wind turbine by using LDV measurements

NASA Astrophysics Data System (ADS)

Phengpom, Tinnapob; Kamada, Yasunari; Maeda, Takao; Murata, Junsuke; Nishimura, Shogo; Matsuno, Tasuku

2015-04-01

This paper has attempted to study a mechanism of three-dimensional flow around a horizontal axis wind turbine (HAWT) rotor blade. An experimental study of the flow phenomenon in the vicinity of the wind turbine blade is a challenging endeavor. In this research, the HAWT model with 2.4 m diameter was tested in the large wind tunnel. The flow around the rotating blade surface was measured simultaneously for three velocity components, and two probes were used for the synchronized measurement of three-dimensional flow components. The local velocity was detected for the single seeding particle measured in the point where three pairs of laser beams intersected. Blade sections of interest in this study are composed of radial positions r/R = 0.3, 0.5 and 0.7. Optimum and low tip speed ratio flow characteristics were also compared. The velocity flow vector, skin friction coefficient and bound circulation were calculated from LDV measurements, and the experimental research showed reasonably and clearly the experimental results.

Effect of family presence on pain and anxiety during invasive nursing procedures in an emergency department: A randomized controlled experimental study.

PubMed

İşlekdemir, Burcu; Kaya, Nurten

2016-01-01

Patients generally prefer to have their family present during medical or nursing interventions. Family presence is assumed to reduce anxiety, especially during painful interventions. This study employed a randomized controlled experimental design to determine the effects of family presence on pain and anxiety during invasive nursing procedures. The study population consisted of patients hospitalized in the observation unit of the internal medicine section in the emergency department of a university hospital. The sample comprised 138 patients assigned into the experimental and control groups by drawing lots. The invasive nursing procedure was carried out in the presence of family members, for members of the experimental group, and without family members, for members of the control group. Thus, the effects of family presence on pain and anxiety during the administration of an invasive nursing procedure to patients were analyzed. The results showed that members of the experimental and control groups did not differ with respect to the pain and state anxiety scores during the intervention. Family presence does not influence the participants' pain and anxiety during an invasive nursing procedure. Thus, the decision regarding family presence during such procedures should be based on patient preference. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Reducing stress levels and anxiety in primary-care physicians through training and practice of a mindfulness meditation technique].

PubMed

Franco Justo, Clemente

2010-11-01

To check the effectiveness of a mindfulness development meditation technique on stress and anxiety in a group of primary-care physicians. Quasi-experimental with pretest/posttest/follow-up measurements in a control group and an experimental group. SITE: University of Almeria. 38 primary-care physicians enrolled in a Teaching Aptitude Course (CAP). An experimental group and a control group were formed with 19 participants in each. The experimental group took a psycho-educational meditation program for training and practice in mindfulness. The Perceived Stress Scale (PSS), the Strain Questionnaire and the State-Trait Anxiety Questionnaire were used to measure stress and anxiety levels. A comparative statistical analysis was performed using the Mann-Whitney non-parametric U test, finding a significant reduction in all the primary-care physician stress and anxiety variables in the experimental group compared to the control group in pretest-posttest and follow-up tests. The results of this study support the effectiveness of mindfulness development meditation techniques in decreasing stress and anxiety in primary-care physicians. Nevertheless, the study shows various limitations that would have to be corrected in successive studies to bring more validity to the results. Copyright © 2009 Elsevier España, S.L. All rights reserved.

The Effects of General System Justification on Corruption Perception and Intent

PubMed Central

Tan, Xuyun; Liu, Li; Huang, Zhenwei; Zheng, Wenwen; Liang, Yuan

2016-01-01

Previous research stresses that system justifying belief can weaken corruption perception, by this possibly fostering unjust behaviors. However, general results of the effect of general system justification on corruption are ambiguous, indicating also a lessening impact. We conducted a line of studies trying to elucidate these circumstances by testing the effect of general system justification on corruption perception and intention. In addition, we explored institutional trust as a possible mediator in this process. For this purpose, we conducted three studies. The first two studies examined the association between general system justification and corruption. In Study 1, a correlational design was run using questionnaires to assess the relation between general system justification and corruption perception as well as corruption intention. In Study 2, an experimental design was conducted manipulating general system justification via exposure to high or low system threat condition, then measuring its effect on corruption perception and corrupt intention. In Study 3, two sub-studies using correlational and experimental designs were run to explore the mediating role of institutional trust, respectively. Results replicated former studies showing that general system justification is negatively associated with corruption perception. However, they also showed a negative correlation with corrupt intention. Furthermore, they showed that institutional trust mediated the relation between general system justification and corruption. We suggest to consider these findings to further elucidate the psychological basis underlying different effects of general system justification on human behaviors. PMID:27507954

The Effects of General System Justification on Corruption Perception and Intent.

PubMed

Tan, Xuyun; Liu, Li; Huang, Zhenwei; Zheng, Wenwen; Liang, Yuan

2016-01-01

Previous research stresses that system justifying belief can weaken corruption perception, by this possibly fostering unjust behaviors. However, general results of the effect of general system justification on corruption are ambiguous, indicating also a lessening impact. We conducted a line of studies trying to elucidate these circumstances by testing the effect of general system justification on corruption perception and intention. In addition, we explored institutional trust as a possible mediator in this process. For this purpose, we conducted three studies. The first two studies examined the association between general system justification and corruption. In Study 1, a correlational design was run using questionnaires to assess the relation between general system justification and corruption perception as well as corruption intention. In Study 2, an experimental design was conducted manipulating general system justification via exposure to high or low system threat condition, then measuring its effect on corruption perception and corrupt intention. In Study 3, two sub-studies using correlational and experimental designs were run to explore the mediating role of institutional trust, respectively. Results replicated former studies showing that general system justification is negatively associated with corruption perception. However, they also showed a negative correlation with corrupt intention. Furthermore, they showed that institutional trust mediated the relation between general system justification and corruption. We suggest to consider these findings to further elucidate the psychological basis underlying different effects of general system justification on human behaviors.