Identifying Structural Flow Defects in Disordered Solids Using Machine-Learning Methods

Science.gov (United States)

Cubuk, E. D.; Schoenholz, S. S.; Rieser, J. M.; Malone, B. D.; Rottler, J.; Durian, D. J.; Kaxiras, E.; Liu, A. J.

2015-03-01

We use machine-learning methods on local structure to identify flow defects—or particles susceptible to rearrangement—in jammed and glassy systems. We apply this method successfully to two very different systems: a two-dimensional experimental realization of a granular pillar under compression and a Lennard-Jones glass in both two and three dimensions above and below its glass transition temperature. We also identify characteristics of flow defects that differentiate them from the rest of the sample. Our results show it is possible to discern subtle structural features responsible for heterogeneous dynamics observed across a broad range of disordered materials.

The role of surface defects in HOPG on the electrochemical and physical deposition of Ag

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R. PETROVIC

1999-08-01

Full Text Available The role of defects on a substrate surface during the initial stages of nucleation and growth of Ag deposited electrochemically and physically on highly oriented pyrolytic graphite (HOPG has been observed ex situ by scanning tunneling microscopy (STM. The silver was electrodeposited under current controlled electrochemical conditions at 26 µA/cm2, which corresponded to a deposition rate of 0.1 monolayers (ML per second. For comparison, physical deposition of Ag on HOPG was performed by DC Ar+ ion sputtering, at the same deposition rate and for the same deposition times. In both cases, Ag grows in an island growth mode, but the distribution of the islands appears to be quite different. In physical deposition, the Ag islands are almost homogeneously distributed over the substrate surface and a slight accumulation of islands on steps does not contribute significantly to the overall morphology. This indicates the crucial role of point defects on the substrate in the initial stages of nucleation. In electrochemical deposition, more lined defects are observed after a flow of current, and their role in the beginning of the nucleation is more pronounced. Lined defects are responsible for the string-like shaped domains of deposited atoms. Also, the existence of string-like shaped nucleation exclusion zones is indicated. The problem of the formation of nucleation exclusion zones, which appear only in electrochemical deposition, has been reconsidered and a new explanaton of their formation is given. A mathematical model for the calculation of the radius of the nucleation exclusion zone has been developed.

The role of learning technologists in supporting e-research

Directory of Open Access Journals (Sweden)

Susi Peacock

2009-12-01

Full Text Available This article explores how the role of learning technologists, a professional group that has emerged during the last 15 to 20 years, may be diversifying to include supporting e-research. It contributes to the current debate about the emerging profession and the roles it should play in contemporary higher education. Previous studies have shown that, typically, the profession's role has focussed almost exclusively on curriculum development; traditionally, learning technologists work with students and tutors to enhance the learning environment with technology. This article presents two case studies of PhD research that used a standard e-learning tool, the virtual learning environment (VLE, to conduct focus groups online. The case studies demonstrate the expert role of the learning technologist in supporting researchers to make informed decisions about whether and how to use e-learning tools to conduct qualitative e-research. The learning technologist advised on the potential advantages and limitations of using the VLE for research and fostered collaborative, working relationships with the researchers, acquiring extensive background knowledge about their projects. This required the learning technologist to draw upon her own experience with research into e-learning and on her professional experience gained from supporting curriculum developments. It is suggested that many learning technologists could extend their roles, transferring their knowledge to include supporting e-research. A more inclusive model of the learning technologist's role in academia could help address the potential polarisation of the profession into researchers and practitioners.

The role of Frenkel defect diffusion in dynamic annealing in ion-irradiated Si

Energy Technology Data Exchange (ETDEWEB)

Wallace, J. B.; Aji, L. B. Bayu; Martin, A. A.; Shin, S. J.; Shao, L.; Kucheyev, S. O.

2017-01-06

The formation of stable radiation damage in crystalline solids often proceeds via complex dynamic annealing processes, involving migration and interaction of ballistically-generated point defects. The dominant dynamic annealing processes, however, remain unknown even for crystalline Si. Here, we use a pulsed ion beam method to study defect dynamics in Si bombarded in the temperature range from -20 to 140 °C with 500 keV Ar ions. Results reveal a defect relaxation time constant of ~10–0.2 ms, which decreases monotonically with increasing temperature. The dynamic annealing rate shows an Arrhenius dependence with two well-defined activation energies of 73 ± 5 meV and 420 ± 10 meV, below and above 60 °C, respectively. Rate theory modeling, bench-marked against this data, suggests a crucial role of both vacancy and interstitial diffusion, with the dynamic annealing rate limited by the migration and interaction of vacancies.

Learning in the workplace: the role of Nurse Managers.

Science.gov (United States)

Yen, Margaret; Trede, Franziska; Patterson, Carmel

2016-06-01

Objective This research explores Nurse Managers' (NMs') influence on workplace learning. The facilitation of staff learning has implications for the role of NMs, who are responsible for the quality and safety of patient care. However, this aspect of their work is implicit and there is limited research in the area. Methods This paper discusses the findings from one hospital as part of a broader philosophical hermeneutic study conducted in two public hospitals over a 20-month timeframe. NMs participated in interviews, a period of observation, follow-up interviews and a focus group. Transcribed data was thematically analysed. Eraut's 'Two triangle theory of workplace learning' was used to interpret participants' accounts of how they facilitated workplace learning. Findings The analysis found that NMs worked to positively influence staff performance through learning in three domains: orientating new staff, assessing staff performance and managing underperformance. Conclusions This study purports that NMs influence workplace learning in ways that are seldom recognised. A more conscious understanding of the impact of their role can enable NMs to more purposefully influence workplace learning. Such understanding also has implications for the professional preparation of NMs for their role in the context of workplace learning, facilitating learning for change and enabling the advancement of quality and safety in healthcare. What is known about the topic? Studies exploring the influence of Nurse Managers in workplace learning have been limited to their role in the facilitation of formal learning. There is a paucity of research that examines their role in influencing informal learning. What does this paper add? The findings of this study draw on Eraut's 'Two triangle theory of workplace learning' to further define the interdependent relationship between management and educational practices. What are the implications for practitioners? NMs' awareness and deliberate use of

Breakdown, fractoemission, diffusion: role of defects in dielectrics

International Nuclear Information System (INIS)

Vigouroux, J.P.; Serruys, Y.

1987-01-01

During the surface analysis of dielectric materials, the impinging ionising particles induce point defects localised in the band gap and build an electrical charge. The electric field created by the charged defects modifies the physico-chemical properties of surface and bulk. We show that the fundamental study of defects allows a better understanding of technological phenomena such as dielectric breakdown, fracture and diffusion [fr

Role of Class III phosphoinositide 3-kinase in the brain development: possible involvement in specific learning disorders.

Science.gov (United States)

Inaguma, Yutaka; Matsumoto, Ayumi; Noda, Mariko; Tabata, Hidenori; Maeda, Akihiko; Goto, Masahide; Usui, Daisuke; Jimbo, Eriko F; Kikkawa, Kiyoshi; Ohtsuki, Mamitaro; Momoi, Mariko Y; Osaka, Hitoshi; Yamagata, Takanori; Nagata, Koh-Ichi

2016-10-01

Class III phosphoinositide 3-kinase (PIK3C3 or mammalian vacuolar protein sorting 34 homolog, Vps34) regulates vesicular trafficking, autophagy, and nutrient sensing. Recently, we reported that PIK3C3 is expressed in mouse cerebral cortex throughout the developmental process, especially at early embryonic stage. We thus examined the role of PIK3C3 in the development of the mouse cerebral cortex. Acute silencing of PIK3C3 with in utero electroporation method caused positional defects of excitatory neurons during corticogenesis. Time-lapse imaging revealed that the abnormal positioning was at least partially because of the reduced migration velocity. When PIK3C3 was silenced in cortical neurons in one hemisphere, axon extension to the contralateral hemisphere was also delayed. These aberrant phenotypes were rescued by RNAi-resistant PIK3C3. Notably, knockdown of PIK3C3 did not affect the cell cycle of neuronal progenitors and stem cells at the ventricular zone. Taken together, PIK3C3 was thought to play a crucial role in corticogenesis through the regulation of excitatory neuron migration and axon extension. Meanwhile, when we performed comparative genomic hybridization on a patient with specific learning disorders, a 107 Kb-deletion was identified on 18q12.3 (nt. 39554147-39661206) that encompasses exons 5-23 of PIK3C3. Notably, the above aberrant migration and axon growth phenotypes were not rescued by the disease-related truncation mutant (172 amino acids) lacking the C-terminal kinase domain. Thus, functional defects of PIK3C3 might impair corticogenesis and relate to the pathophysiology of specific learning disorders and other neurodevelopmental disorders. Acute knockdown of Class III phosphoinositide 3-kinase (PIK3C3) evokes migration defects of excitatory neurons during corticogenesis. PIK3C3-knockdown also disrupts axon outgrowth, but not progenitor proliferation in vivo. Involvement of PIK3C3 in neurodevelopmental disorders might be an interesting future

Exploring Effects of Different Roles on Using an E-learning Service

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Yang H.J.

2016-01-01

Full Text Available The purpose of this study was to explore effects of different roles on learning satisfaction. For better hosting a e-learning service, there is a need to understand user’s satisfaction of the learning service. Data was collected from an on-line learning system. Based upon course learning activities, each course was assign to a certain role for the learner. There are six types of learning role from all course. 1 Reporter, 2 Listener, 3 Researcher, 4 Reporting Listener, 5 Reporting Researcher, 6 Report Listen Researcher; One-way ANOVA procedure was applied to exploring whether the role difference affects users satisfaction. According to the significant level less than .05, it was concluded that learning satisfaction of different roles are significant different. On the other word, learning roles affect users’ learning satisfaction.

Forensic Learning Disability Nursing Role Analysis

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Mason, Tom; Phipps, Dianne; Melling, Kat

2011-01-01

This article reports on a study carried out on the role constructs of forensic and nonforensic Learning Disability Nursing in relation to six binary themes. The aims were to identify if there were differences in perceptions of forensic learning disability nurses and nonforensic learning disability nurses in relation to the six binary themes of the…

Deterministic Role of Collision Cascade Density in Radiation Defect Dynamics in Si

Science.gov (United States)

Wallace, J. B.; Aji, L. B. Bayu; Shao, L.; Kucheyev, S. O.

2018-05-01

The formation of stable radiation damage in solids often proceeds via complex dynamic annealing (DA) processes, involving point defect migration and interaction. The dependence of DA on irradiation conditions remains poorly understood even for Si. Here, we use a pulsed ion beam method to study defect interaction dynamics in Si bombarded in the temperature range from ˜-30 ° C to 210 °C with ions in a wide range of masses, from Ne to Xe, creating collision cascades with different densities. We demonstrate that the complexity of the influence of irradiation conditions on defect dynamics can be reduced to a deterministic effect of a single parameter, the average cascade density, calculated by taking into account the fractal nature of collision cascades. For each ion species, the DA rate exhibits two well-defined Arrhenius regions where different DA mechanisms dominate. These two regions intersect at a critical temperature, which depends linearly on the cascade density. The low-temperature DA regime is characterized by an activation energy of ˜0.1 eV , independent of the cascade density. The high-temperature regime, however, exhibits a change in the dominant DA process for cascade densities above ˜0.04 at.%, evidenced by an increase in the activation energy. These results clearly demonstrate a crucial role of the collision cascade density and can be used to predict radiation defect dynamics in Si.

The nursing educator's role in e-learning: a literature review.

Science.gov (United States)

Koch, Lee F

2014-11-01

e-Learning is becoming more commonplace in nursing and healthcare professional education. Research has shown that e-learning can be just as effective at helping students achieve cognitive learning objectives as traditional face-to-face courses, provided that certain quality criteria are met. However, the decentralized, asynchronous nature of e-learning precludes spontaneous, personal interaction between the instructor and the learner. In addition to this, learning objectives in nursing and other healthcare professions are not only within the cognitive, but also within the affective and psychomotor domains. This article seeks to answer the following question: How does e-learning transform the role of nurse educators? Narrative literature review. A comprehensive database search was conducted using the English and German key words "teacher," "educator," "role," "e-learning," and "nursing" to identify literature that examined the role of (nurse) educators in e-learning. The search strategy resulted in the inclusion of 40 sources. The majority of the literature is expert opinion and examines the educator's role in e-learning from a theoretical point of view (n=30). There is a paucity of empirical research pertaining directly to the educator's role (n=10). Only four sources deal specifically with the nurse educator's role. The literature agrees on the need for a new role definition in light of e-learning. This role is more complex than the educator's traditional role. The literature does not provide any indication of how the educator's role can be adapted to the specific needs of online nurse education. There is a need for more empirical research on this subject. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Role of Motivation in Language Learning

Institute of Scientific and Technical Information of China (English)

李玉红

2004-01-01

The role of motivation in language learning has been studied since the 1960s. It is indeed one of the most important areas of linguistics. This paper suggests strategies of motivating language learners and focuses on the role which motivation can play in language learning. The concept of motivation from different points of view is defined, a number of suggestions on how to motivate language learners are presented and the role of motivation based on various motivational theories are highlighted. With regard to the role of motivation in language learning, it is concluded that motivation plays an increasingly important role in many aspects, such as identifying with the target language society, achieving long-term and short-term goals, improving language learners' internal and external powers and exerting a group force. It also indicates that there should be more research areas to be examined and a long way is probably requlred to go in future theoretical and practical study.

The role of defects in laser damage of multilayer coatings

International Nuclear Information System (INIS)

Kozlowski, M.R.; Chow, R.

1993-01-01

Laser induced damage to optical coatings is generally a localized phenomenon associated with coating defects. The most common of the defect types are the well-known nodule defect. This paper reviews the use of experiments and modeling to understand the formation of these defects and their interaction with laser light. Of particular interest are efforts to identify which defects are most susceptible to laser damage. Also discussed are possible methods for stabilizing these defects (laser conditioning) or preventing their initiation (source stabilization, spatter particle trapping)

Defect characterization by an adaptive learning classifier in ultrasonic inspection of ferritic materials

International Nuclear Information System (INIS)

Grozellier, M.; Bieth, M.; Romy, D.

1985-01-01

The purpose of the work presented here is to determine the efficiency and reliability of the discrimination method ''Adapatative Learning Network''. This process is used to identify the nature of defects detected during Ultrasonic Testing (UT), by analysing some of the echo parameters calculated in temporal and frequency domains. The survey which dealt with several hundreds of echoes, revealed that the machined artificial reflectors, well defined geometrically, were identified with a probability exceeding 95 %. The fatigue cracks, producing less characteristic echoes, are identified with a slightly lower probability (90 % - 95 %)

ROLE OF DATA MINING CLASSIFICATION TECHNIQUE IN SOFTWARE DEFECT PREDICTION

OpenAIRE

Dr.A.R.Pon Periyasamy; Mrs A.Misbahulhuda

2017-01-01

Software defect prediction is the process of locating defective modules in software. Software quality may be a field of study and apply that describes the fascinating attributes of software package product. The performance should be excellent with none defects. Software quality metrics are a set of software package metrics that target the standard aspects of the product, process, and project. The software package defect prediction model helps in early detection of defects and contributes to t...

The Role of a Commander in Military Lessons Learned Systems

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Zenon Waliński

2015-06-01

Full Text Available The aim of the paper is to investigate the role of a commander in military Lessons Learned systems. In order to achieve the aim, the paper presents (1 the architecture of the Lessons Learned capabilities in the U.S. Army, NATO and the Polish Armed Forces, (2 the commander’s role in the Lessons Learned process (3 the commander’s role in fostering Lessons Learned organisation culture. The paper is based on multiple case study analysis including Lessons Learned systems in NATO, the U.S. Army and the Polish Armed Forces.

The role of point defect clusters in reactor pressure vessel embrittlement

International Nuclear Information System (INIS)

Stoller, R.E.

1993-01-01

Radiation-induced point defect clusters (PDC) are a plausible source of matrix hardening in reactor pressure vessel (RPV) steels in addition to copper-rich precipitates. These PDCs can be of either interstitial or vacancy type, and could exist in either 2 or 3-D shapes, e.g. small loops, voids, or stacking fault tetrahedra. Formation and evolution of PDCs are primarily determined by displacement damage rate and irradiation temperature. There is experimental evidence that size distributions of these clusters are also influenced by impurities such as copper. A theoretical model has been developed to investigate potential role of PDCs in RPV embrittlement. The model includes a detailed description of interstitial cluster population; vacancy clusters are treated in a more approximate fashion. The model has been used to examine a broad range of irradiation and material parameters. Results indicate that magnitude of hardening increment due to these clusters can be comparable to that attributed to copper precipitates. Both interstitial and vacancy type defects contribute to this hardening, with their relative importance determined by the specific irradiation conditions

What Role do Metaphors Play in Game-Based Learning Processes?

DEFF Research Database (Denmark)

Henriksen, Thomas Duus

2014-01-01

This chapter explores the role played by metaphors in learning games and game-based learning processes. The aim is to contribute better understanding of the mechanisms of how such games contribute to learning and learning transfer. On the basis of an analytical strategy that emphasises metaphors...... as storylines, actors, acts and movement, three learning games are analysed in order to understand how learning emerges in association to game-embedded metaphors. As shown in this chapter, metaphors seem to play a profound role in game-based learning, both by providing participants with a suitcase containing...

Online Surface Defect Identification of Cold Rolled Strips Based on Local Binary Pattern and Extreme Learning Machine

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Yang Liu

2018-03-01

Full Text Available In the production of cold-rolled strip, the strip surface may suffer from various defects which need to be detected and identified using an online inspection system. The system is equipped with high-speed and high-resolution cameras to acquire images from the moving strip surface. Features are then extracted from the images and are used as inputs of a pre-trained classifier to identify the type of defect. New types of defect often appear in production. At this point the pre-trained classifier needs to be quickly retrained and deployed in seconds to meet the requirement of the online identification of all defects in the environment of a continuous production line. Therefore, the method for extracting the image features and the training for the classification model should be automated and fast enough, normally within seconds. This paper presents our findings in investigating the computational and classification performance of various feature extraction methods and classification models for the strip surface defect identification. The methods include Scale Invariant Feature Transform (SIFT, Speeded Up Robust Features (SURF and Local Binary Patterns (LBP. The classifiers we have assessed include Back Propagation (BP neural network, Support Vector Machine (SVM and Extreme Learning Machine (ELM. By comparing various combinations of different feature extraction and classification methods, our experiments show that the hybrid method of LBP for feature extraction and ELM for defect classification results in less training and identification time with higher classification accuracy, which satisfied online real-time identification.

Defect production in ceramics

Energy Technology Data Exchange (ETDEWEB)

Zinkle, S.J. [Oak Ridge National Lab., TN (United States); Kinoshita, C. [Kyushu Univ. (Japan)

1997-08-01

A review is given of several important defect production and accumulation parameters for irradiated ceramics. Materials covered in this review include alumina, magnesia, spinel silicon carbide, silicon nitride, aluminum nitride and diamond. Whereas threshold displacement energies for many ceramics are known within a reasonable level of uncertainty (with notable exceptions being AIN and Si{sub 3}N{sub 4}), relatively little information exists on the equally important parameters of surviving defect fraction (defect production efficiency) and point defect migration energies for most ceramics. Very little fundamental displacement damage information is available for nitride ceramics. The role of subthreshold irradiation on defect migration and microstructural evolution is also briefly discussed.

Defects in dilute nitrides

International Nuclear Information System (INIS)

Chen, W.M.; Buyanova, I.A.; Tu, C.W.; Yonezu, H.

2005-01-01

We provide a brief review our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in dilute nitrides, i.e. Ga(In)NAs and Ga(Al,In)NP. Defect complexes involving intrinsic defects such as As Ga antisites and Ga i self interstitials were positively identified.Effects of growth conditions, chemical compositions and post-growth treatments on formation of the defects are closely examined. These grown-in defects are shown to play an important role in non-radiative carrier recombination and thus in degrading optical quality of the alloys, harmful to performance of potential optoelectronic and photonic devices based on these dilute nitrides. (author)

Case studies and role play: learning strategies in nursing.

Science.gov (United States)

Cogo, Ana Luísa Petersen; Pai, Daiane Dal; Aliti, Graziella Badin; Hoefel, Heloísa Karnas; Azzolin, Karina de Oliveira; Busin, Lurdes; Unicovsky, Margarita Ana Rubin; Kruse, Maria Henriqueta Luce

2016-01-01

to report professors' experience in a public university of Southern region of Brazil using case studies and role play as learning strategies for nursing care of hospitalized adults. learning experience report from the Nursing Care of Adults I class of nursing undergraduate course. the development of case studies and role play considered health care needs from epidemiological profile of chronic noncommunicable diseases morbidity and mortality, nursing as an assisting method, and social aspects of hospitalized individuals. Role play planning was made by creating a stage in laboratory of practices and dialogues comprising students and professors interaction. case studies and role play encouraged students to active search for learning and brought theory closer to real health care situations.

Role of point defects and additives in kinetics of hydrogen storage materials

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van de Walle, Chris

2010-03-01

First-principles computational studies of hydrogen interactions with storage materials can provide direct insight into the processes of H uptake and release, and may help in developing guidelines for designing storage media with improved storage capacity and kinetics. One important conclusion is that the defects involved in kinetics of semiconducting or insulating H-storage materials are charged, and hence their formation energy is Fermi-level dependent and can be affected by the presence of impurities that change the Fermi level [1,2]. This provides an explanation for the role played by transition-metal impurities in the kinetics of NaAlH4 and related materials. Desorption of H and decomposition of NaAlH4 requires not only mass transport of H but also of Al and/or Na. This process is mediated by native defects. We have investigated the structure, stability, and migration enthalpy of native defects based on density functional theory. The results allow us to estimate diffusion activation energies for the defects that may be involved in mass transport. Most of the relevant defects exist in charge states other than neutral, and consideration of these charge states is essential for a proper description of kinetics. We propose specific new mechanisms to explain the observed activation energies and their dependence on the presence of impurities. We have also expanded our studies to materials other than NaAlH4. In the case of LiBH4 and Li4BN3H10 we have found that the calculations have predictive power in terms of identifying which impurities will actually enhance kinetics. Other complex hydrides that we are currently investigating include Li2NH and LiNH2. [4pt] [1] A. Peles and C. G. Van de Walle, Phys. Rev. B 76, 214101 (2007). [0pt] [2] C. G. Van de Walle, A. Peles, A. Janotti, and G. B. Wilson-Short, Physica B 404, 793 (2009).

What Role do Metaphors Play in Game-based Learning Processes?

DEFF Research Database (Denmark)

Henriksen, Thomas Duus

2015-01-01

This chapter explores the role played by metaphors in learning games and game-based learning processes. The aim is to contribute better understanding of the mechanisms of how such games contribute to learning and learning transfer. On the basis of an analytical strategy that emphasises metaphors...... as storylines, actors, acts and movement, three learning games are analysed in order to understand how learningemerges in association to game-embedded metaphors.As shown in this chapter, metaphorsseem to play a profound role in game-based learning, both by providing participantswith a suitcase containing...

Enhancing the strategic management of practice learning through the introduction of the role of Learning Environment Manager.

Science.gov (United States)

Congdon, Graham; Baker, Tracey; Cheesman, Amanda

2013-03-01

This paper describes a process evaluation project designed to enhance the strategic management of practice learning within a large Hospital in the North of England. The aim of the project was to introduce the role of the Learning Environment Manager with dedicated responsibility for practice learning of undergraduate student nurses within the Hospital's 49 practice-settings. Whilst aspects of this role were already evident in several of these settings, the project sought to locate and standardise responsibilities related to the organisation and management of learning and teaching in practice explicitly within the existing staffing structure of each practice-setting. Focus group interviews were used to explore significant aspects of the project with key stakeholder groups comprising Learning Environment Managers, the Hospital Clinical Educator, Hospital Department Managers, Ward Managers, Mentors, University Link Lecturers and undergraduate Student Nurses. Interview data were analysed using thematic content analysis. The findings of the project suggest that the Learning Environment Manager role affords providers of practice learning with a robust approach to establish organisation-wide benchmarks that standardise the strategic management of practice learning in collaboration with partner Universities. The role incorporated many operational activities previously undertaken by the Hospital Clinical Educator, thus enabling the Hospital Clinical Educator to make a more strategic contribution to the on-going quality monitoring and enhancement of practice learning across the Hospital. The Learning Environment Manager role was found to provide mentors with high levels of support which in turn helped to promote consistent, positive and holistic practice learning experiences for undergraduate student nurses across the Hospital. Importantly, the role offers a potent catalyst for nurses in practice to regain responsibility for practice learning and re-establish the value of

Cooperative learning with role play in Chinese pharmacology education.

Science.gov (United States)

Wang, Jun; Hu, Xiamin; Xi, Jinglei

2012-03-01

Cooperative learning (CL) and role play are both efficient educational tools for enhancing Chinese student active learning and communication skills. This study was designed to obtain student feedback on the format of CL together with role play in the study of pharmacology in Chinese pharmaceutical undergraduates. CL was used in the self-study of new drugs used clinically but neglected in textbook and class teaching, so that groups of students were assigned to become "specialists" in one area of new drugs. Then, these "specialists" taught their new-found knowledge to other groups in role play approach involving an interaction between the pharmacist and a patient. Student perceptions of CL together with role play were examined using an eight-item survey instrument. Students were satisfied with CL together with role play. Majority of the students believed this teaching method enhanced their learning experience, made them gain more pharmacological expertise, increased the awareness of their career in future and self-educational abilities, and fostered their cooperation spirit and confidence. The materials on CL and role play were also believed pertinent. Only 63.4-76.5% and 63.1-37.3% of the students thought "CL and role-play were very funny" and "I felt very relaxed during CL together with role-play", respectively. CL together with role play is an efficient educational tool for enhancing student active-learning and communication skills. But Chinese students will take some time to adapt to this new teaching method.

Utilizing Peer Mentor Roles in Learning Communities

Science.gov (United States)

Rieske, Laura Jo; Benjamin, Mimi

2015-01-01

For a number of learning community programs, peer mentors provide an additional layer of staffing support. This chapter highlights peer mentor roles from a sample of programs and suggests important components for the construction of these roles.

Role of Defects and Adsorbed Water Film in Influencing the Electrical, Optical and Catalytic Properties of Transition Metal Oxides

Science.gov (United States)

Wang, Qi

Transition metal oxides (TMOs) constitute a large group of materials that exhibit a wide range of optical, electrical, electrochemical, dielectric and catalytic properties, and thus making them highly regarded as promising materials for a variety of applications in next generation electronic, optoelectronic, catalytic, photonic, energy storage and energy conversion devices. Some of the unique properties of TMOs are their strong electron-electron correlations that exists between the valence electrons of narrow d- or f-shells and their ability to exist in variety of oxidation states. This gives TMOs an enormous range of fascinating electronic and other physical properties. Many of these remarkable properties of TMOs arises from the complex surface charge transfer processes at the oxide surface/electrochemical redox species interface and non-stoichiometry due to the presence of lattice vacancies that may cause significant perturbation to the electronic structure of the material. Stoichiometry, oxidation state of the metal center and lattice vacancy defects all play important roles in affecting the physical properties, electronic structures, device behavior and other functional properties of TMOs. However, the underlying relationships between them is not clearly known. For instance, the exchange of electrons between adsorbates and defects can lead to the passivation of existing defect states or formation of new defects, both of which affect defect equilibria, and consequently, functional properties. In depth understanding of the role of lattice defects on the electrical, catalytic and optical properties of TMOs is central to further expansion of the technological applications of TMO based devices. The focus of this work is to elucidate the interactions of vacancy defects with various electrochemical adsorbates in TMOs. The ability to directly probe the interactions of vacancy defects with gas and liquid phase species under in-operando conditions is highly desirable to

If Your Child Has a Heart Defect (For Parents)

Science.gov (United States)

... Videos for Educators Search English Español If Your Child Has a Heart Defect KidsHealth / For Parents / If ... has any of these symptoms. Caring for Your Child Parenting kids with heart defects includes learning about ...

Smart Training, Smart Learning: The Role of Cooperative Learning in Training for Youth Services.

Science.gov (United States)

Doll, Carol A.

1997-01-01

Examines cooperative learning in youth services and adult education. Discusses characteristics of cooperative learning techniques; specific cooperative learning techniques (brainstorming, mini-lecture, roundtable technique, send-a-problem problem solving, talking chips technique, and three-step interview); and the role of the trainer. (AEF)

Learned Helplessness and Learning Goals: Role played in School Refusal. A Study on Italian Students.

Directory of Open Access Journals (Sweden)

Luana Sorrenti

2016-08-01

Full Text Available Literature on school refusal has shown a link between school refusal and poor school performance. However, there has been little investigation into the individual underlying factors, and specifically factors directly related to the learning process, such as the learning goals of students and their expectations of success and/or failure. The main purpose of the present study is to investigate the influence of Learned Helplessness (LH and learning goals on school refusal. We hypothesized that LH and learning goals exert a unique role in predicting school refusal above and beyond the roles of academic achievement, age, and gender. The sample consisted of 201 Italian students with an average age of 11.93, with both low (57.2 % of students and high (42.8 % academic achievement. School refusal, LH, and learning goals were measured by means of questionnaires. The results confirm the hypothesis of this study; in fact, we found that learning goals and, above all, LH play a more predictive role of school refusal than academic achievement. These results extend previous studies on school refusal and, for the first time, they provide additional knowledge about this problem, analyzing the relationship between school refusal, learning goals, and LH, still neglected in the literature. Implications on the psychological well-being of students are discussed.

The Role of Motivation in Language Learning

OpenAIRE

Rahman, Anwar

2011-01-01

The mastery of English learning is influenced by some variables, one of them is motivation. Motivation in learning second language is classified as integrative motivation and instrumental motivation. Some experts of language teaching also categorized motivation into two types namely intrinsic motivation and extrinsic motivation. This paper discusses about kinds of motivation and how it takes a role in influencing students mastery in learning language. It was literature study that focused to f...

THE ROLE AND PLACE OF DISTANCE LEARNING IN E-LEARNING

Directory of Open Access Journals (Sweden)

Vladyslav Velychko

2016-11-01

Full Text Available The article discusses the role and place of distance education in electronic learning. The implementation of such important components as e-learning and e-education in the education system is an important tool to achieve the objectives of global education and requires specific knowledge. Teaching staff of educational institutions must learn new teaching tools such as cloud, Virtual Reality, Augmented Reality, mobile technology, Internet technology, designing distance learning courses, etc., or increase the level of this category. We consider the relevance and benefits of the use of distance education in electronic learning, and the need of its implementation at all levels of the educational process and basic steps for it. Distance learning courses have several types that differ in the degree of farness, individualization and its efficiency: "educational institution → Internet" (includes full-time training using Internet resources, videlicet to find things on the Internet and communicate with other network users; "educational institution → Internet → educational institution" (used in the full-time study, but has occasional problem with the mandatory use of the Internet; "the one who learns → Internet → the one who teaches" (distance learning complements the full-time education, it has an episodic format as consultations in a case of need; "the one who learns → Internet → Center" (full-time complement of training and has additional opportunities to strengthen the disclosure of a special creativity; "the one who learns → Internet" (it can serve as an additional training to full-time education, but can also be transformed into an independent "institution" that takes into account individual needs and capabilities of the individual and a flexible adjustment under her needs and interests using the educational resources on the Internet . There has been proved the necessity of mastering of the teaching staff of educational institutions

Extreme Learning Machine and Moving Least Square Regression Based Solar Panel Vision Inspection

Directory of Open Access Journals (Sweden)

Heng Liu

2017-01-01

Full Text Available In recent years, learning based machine intelligence has aroused a lot of attention across science and engineering. Particularly in the field of automatic industry inspection, the machine learning based vision inspection plays a more and more important role in defect identification and feature extraction. Through learning from image samples, many features of industry objects, such as shapes, positions, and orientations angles, can be obtained and then can be well utilized to determine whether there is defect or not. However, the robustness and the quickness are not easily achieved in such inspection way. In this work, for solar panel vision inspection, we present an extreme learning machine (ELM and moving least square regression based approach to identify solder joint defect and detect the panel position. Firstly, histogram peaks distribution (HPD and fractional calculus are applied for image preprocessing. Then an ELM-based defective solder joints identification is discussed in detail. Finally, moving least square regression (MLSR algorithm is introduced for solar panel position determination. Experimental results and comparisons show that the proposed ELM and MLSR based inspection method is efficient not only in detection accuracy but also in processing speed.

Theory of Defects in Semiconductors

CERN Document Server

Drabold, David A

2007-01-01

Semiconductor science and technology is the art of defect engineering. The theoretical modeling of defects has improved dramatically over the past decade. These tools are now applied to a wide range of materials issues: quantum dots, buckyballs, spintronics, interfaces, amorphous systems, and many others. This volume presents a coherent and detailed description of the field, and brings together leaders in theoretical research. Today's state-of-the-art, as well as tomorrow’s tools, are discussed: the supercell-pseudopotential method, the GW formalism,Quantum Monte Carlo, learn-on-the-fly molecular dynamics, finite-temperature treatments, etc. A wealth of applications are included, from point defects to wafer bonding or the propagation of dislocation.

Serine biosynthesis and transport defects.

Science.gov (United States)

El-Hattab, Ayman W

2016-07-01

l-serine is a non-essential amino acid that is biosynthesized via the enzymes phosphoglycerate dehydrogenase (PGDH), phosphoserine aminotransferase (PSAT), and phosphoserine phosphatase (PSP). Besides its role in protein synthesis, l-serine is a potent neurotrophic factor and a precursor of a number of essential compounds including phosphatidylserine, sphingomyelin, glycine, and d-serine. Serine biosynthesis defects result from impairments of PGDH, PSAT, or PSP leading to systemic serine deficiency. Serine biosynthesis defects present in a broad phenotypic spectrum that includes, at the severe end, Neu-Laxova syndrome, a lethal multiple congenital anomaly disease, intermediately, infantile serine biosynthesis defects with severe neurological manifestations and growth deficiency, and at the mild end, the childhood disease with intellectual disability. A serine transport defect resulting from deficiency of the ASCT1, the main transporter for serine in the central nervous system, has been recently described in children with neurological manifestations that overlap with those observed in serine biosynthesis defects. l-serine therapy may be beneficial in preventing or ameliorating symptoms in serine biosynthesis and transport defects, if started before neurological damage occurs. Herein, we review serine metabolism and transport, the clinical, biochemical, and molecular aspects of serine biosynthesis and transport defects, the mechanisms of these diseases, and the potential role of serine therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

The Role of Emotion in Word Learning

Science.gov (United States)

Doan, S. N.

2010-01-01

The way in which emotion interacts with cognition has been of great interest to researchers for hundreds of years. Emotion has been shown to play an important role in attention, learning and memory. However, the way in which emotion influences the basic process of word learning in infancy has largely been ignored. In the current paper, the…

A proposed defect tracking model for classifying the inserted defect reports to enhance software quality control.

Science.gov (United States)

Sultan, Torky; Khedr, Ayman E; Sayed, Mostafa

2013-01-01

NONE DECLARED Defect tracking systems play an important role in the software development organizations as they can store historical information about defects. There are many research in defect tracking models and systems to enhance their capabilities to be more specifically tracking, and were adopted with new technology. Furthermore, there are different studies in classifying bugs in a step by step method to have clear perception and applicable method in detecting such bugs. This paper shows a new proposed defect tracking model for the purpose of classifying the inserted defects reports in a step by step method for more enhancement of the software quality.

Supervisor's role in training programs as a manager of learning program

Directory of Open Access Journals (Sweden)

2011-06-01

Full Text Available According to the training literature, a supervisor's role in training programs has two major elements: supervisor support and supervisor communication. The ability of supervisors to play effective roles in training programs may increase employees' motivation to learn. The nature of this relationship is interesting, but the role of supervisor's role as a predicting variable is less emphasized in a training program models. Therefore, this study was conducted to examine the effect of supervisor's role in training programs on motivation to learn using 152 usable questionnaires gathered from non-academic employees who have worked in a technological based public university, Malaysia. The outcomes of stepwise regression analysis showed that the supervisor support and supervisor communication significantly associated with motivation to learn. Statistically, this result demonstrates that supervisor's role in training programs does act as an important predictor of motivation to learn in the organizational sample. In addition, discussion, implication and conclusion are elaborated.

The Role of e-Portfolios in Supporting Productive Learning

Science.gov (United States)

Yang, Min; Tai, Mui; Lim, Cher Ping

2016-01-01

e-Portfolios are a form of authentic assessment with formative functions that include showcasing and sharing learning artifacts, documenting reflective learning processes, connecting learning across various stages and enabling frequent feedback for improvements. This paper examines how e-portfolios take up these formative roles to support…

DEEP LEARNING AND IMAGE PROCESSING FOR AUTOMATED CRACK DETECTION AND DEFECT MEASUREMENT IN UNDERGROUND STRUCTURES

Directory of Open Access Journals (Sweden)

F. Panella

2018-05-01

Full Text Available This work presents the combination of Deep-Learning (DL and image processing to produce an automated cracks recognition and defect measurement tool for civil structures. The authors focus on tunnel civil structures and survey and have developed an end to end tool for asset management of underground structures. In order to maintain the serviceability of tunnels, regular inspection is needed to assess their structural status. The traditional method of carrying out the survey is the visual inspection: simple, but slow and relatively expensive and the quality of the output depends on the ability and experience of the engineer as well as on the total workload (stress and tiredness may influence the ability to observe and record information. As a result of these issues, in the last decade there is the desire to automate the monitoring using new methods of inspection. The present paper has the goal of combining DL with traditional image processing to create a tool able to detect, locate and measure the structural defect.

Semi-supervised rail defect detection from imbalanced image data

NARCIS (Netherlands)

Hajizadeh, S.; Nunez Vicencio, Alfredo; Tax, D.M.J.; Acarman, Tankut

2016-01-01

Rail defect detection by video cameras has recently gained much attention in both
academia and industry. Rail image data has two properties. It is highly imbalanced towards the non-defective class and it has a large number of unlabeled data samples available for semisupervised learning

Roles of Teachers in Orchestrating Learning in Elementary Science Classrooms

Science.gov (United States)

Zhai, Junqing; Tan, Aik-Ling

2015-01-01

This study delves into the different roles that elementary science teachers play in the classroom to orchestrate science learning opportunities for students. Examining the classroom practices of three elementary science teachers in Singapore, we found that teachers shuttle between four key roles in enabling student learning in science. Teachers…

The role of point defects and defect complexes in silicon device processing. Summary report and papers

Energy Technology Data Exchange (ETDEWEB)

Sopori, B.; Tan, T.Y.

1994-08-01

This report is a summary of a workshop hold on August 24--26, 1992. Session 1 of the conference discussed characteristics of various commercial photovoltaic silicon substrates, the nature of impurities and defects in them, and how they are related to the material growth. Session 2 on point defects reviewed the capabilities of theoretical approaches to determine equilibrium structure of defects in the silicon lattice arising from transitional metal impurities and hydrogen. Session 3 was devoted to a discussion of the surface photovoltaic method for characterizing bulk wafer lifetimes, and to detailed studies on the effectiveness of various gettering operations on reducing the deleterious effects of transition metals. Papers presented at the conference are also included in this summary report.

Disturbance of endogenous hydrogen sulfide generation and endoplasmic reticulum stress in hippocampus are involved in homocysteine-induced defect in learning and memory of rats.

Science.gov (United States)

Li, Man-Hong; Tang, Ji-Ping; Zhang, Ping; Li, Xiang; Wang, Chun-Yan; Wei, Hai-Jun; Yang, Xue-Feng; Zou, Wei; Tang, Xiao-Qing

2014-04-01

Homocysteine (Hcy) is a risk factor for Alzheimer's disease (AD). Hydrogen sulfide (H2S) acts as an endogenous neuromodulator and neuroprotectant. It has been shown that endoplasmic reticulum (ER) stress is involved in the pathological mechanisms of the learning and memory dysfunctions and that H2S exerts its neuroprotective role via suppressing ER stress. In the present work, we explored the effects of intracerebroventricular injection of Hcy on the formation of learning and memory, the generation of endogenous H2S, and the expression of ER stress in the hippocampus of rats. We found that intracerebroventricular injection of Hcy in rats leads to learning and memory dysfunctions in the Morris water maze and novel of object recognition test and decreases in the expression of cystathionine-β-synthase, the major enzyme responsible for endogenous H2S generation, and the generation of endogenous H2S in the hippocampus of rats. We also showed that exposure of Hcy could up-regulate the expressions of glucose-regulated protein 78 (GRP78), CHOP, and cleaved caspase-12, which are the major mark proteins of ER stress, in the hippocampus of rats. Taken together, these results suggest that the disturbance of hippocampal endogenous H2S generation and the increase in ER stress in the hippocampus are related to Hcy-induced defect in learning and memory. Copyright © 2014 Elsevier B.V. All rights reserved.

TOOLS FOR COLABORATIVE LEARNING: A ROLE-PLAYING PRACTICE

Directory of Open Access Journals (Sweden)

Marta Ortiz-de-Urbina Criado

2010-11-01

Full Text Available Role-playing is an active participation tool that facilitates cooperative learning. It has also proved to be more effective in developing competencies than traditional methods. This technique is essential to make theory and practice compatible as is required in order to adapt subjects to the new education system based on the Bolonia’s agreement, especially in Social Sciences disciplines. Consequently, the objective of this paper is to show the effect and use of role-playing applied to management area. Therefore, we analyze and design the role-playing, putting it in practice in the classroom in Human Resource Management subject of different academic degrees. To conclude, this paper has shown the importance of role-playing as a learning tool and development of skills like work cooperation, problem and conflict solving, decision making, and managing complex systems.

Selected topics in high temperature chemistry defect chemistry of solids

CERN Document Server

Johannesen, Ø

2013-01-01

The properties of materials at high temperature play a vital role in their processing and practical use. The real properties of materials at elevated temperatures are very often governed by defects in their structure. Lattice defects may consist of point defects like vacancies, interstitial atoms or substituted atoms. These classes are discussed in general and specifically for oxides, nitrides, carbides and sulfides. Defect aggregates, shear structures and adaptive structures are also described. Special attention is paid to hydrogen defects which seem to play an important role in several mater

Efficacy of Role Play in Concert with Lecture to Enhance Student Learning of Immunology

Directory of Open Access Journals (Sweden)

Samantha L. Elliott

2010-11-01

Full Text Available Despite numerous reports that active learning increases student understanding, many barriers still exist that prevent faculty from shedding the traditional passive lecture and adopting active learning strategies in the classroom. This study looks at the use of role play as an active learning technique to convey new material, or as reinforcement to traditional lecture. A pre- and post-test survey was utilized to determine student learning gains, along with an anonymous survey to determine student attitudes about role play. Student learning gains are similar regardless of class size, role-playing participation or learning style, and reflect an increase in lower order cognition. Attitudes and learning gains indicate role play is preferable as a reinforcement technique, although the order does not matter if both lecture and role play are utilized to convey information. These data provide insight into the best practices of role-playing implementation in concert with traditional lecture format.

Unpacking the Roles of the Facilitator in Higher Education Professional Learning Communities

Science.gov (United States)

Margalef, Leonor; Pareja Roblin, Natalie

2016-01-01

Facilitators are central for the success of professional learning communities (PLCs). Yet, their specific roles in supporting teacher learning remain still largely underexplored. To address this gap, the current multiple case study examines the roles of 4 university PLC facilitators, the strategies they used to support teacher learning, and the…

The Teacher's Role in Implementing Cooperative Learning in the Classroom.

NARCIS (Netherlands)

Gillies, R.; Ashman, A.; Terwel, J.

2008-01-01

The teacher’s role in implementing cooperative learning in the classroom provides a comprehensive overview of the theories, research outcomes, challenges and issues in guided cooperative learning. In many chapters there are clear guidelines and discussion about how cooperative learning practices can

The role of learning-related dopamine signals in addiction vulnerability.

Science.gov (United States)

Huys, Quentin J M; Tobler, Philippe N; Hasler, Gregor; Flagel, Shelly B

2014-01-01

Dopaminergic signals play a mathematically precise role in reward-related learning, and variations in dopaminergic signaling have been implicated in vulnerability to addiction. Here, we provide a detailed overview of the relationship between theoretical, mathematical, and experimental accounts of phasic dopamine signaling, with implications for the role of learning-related dopamine signaling in addiction and related disorders. We describe the theoretical and behavioral characteristics of model-free learning based on errors in the prediction of reward, including step-by-step explanations of the underlying equations. We then use recent insights from an animal model that highlights individual variation in learning during a Pavlovian conditioning paradigm to describe overlapping aspects of incentive salience attribution and model-free learning. We argue that this provides a computationally coherent account of some features of addiction. © 2014 Elsevier B.V. All rights reserved.

Polydispersity-driven topological defects as order-restoring excitations.

Science.gov (United States)

Yao, Zhenwei; Olvera de la Cruz, Monica

2014-04-08

The engineering of defects in crystalline matter has been extensively exploited to modify the mechanical and electrical properties of many materials. Recent experiments on manipulating extended defects in graphene, for example, show that defects direct the flow of electric charges. The fascinating possibilities offered by defects in two dimensions, known as topological defects, to control material properties provide great motivation to perform fundamental investigations to uncover their role in various systems. Previous studies mostly focus on topological defects in 2D crystals on curved surfaces. On flat geometries, topological defects can be introduced via density inhomogeneities. We investigate here topological defects due to size polydispersity on flat surfaces. Size polydispersity is usually an inevitable feature of a large variety of systems. In this work, simulations show well-organized induced topological defects around an impurity particle of a wrong size. These patterns are not found in systems of identical particles. Our work demonstrates that in polydispersed systems topological defects play the role of restoring order. The simulations show a perfect hexagonal lattice beyond a small defective region around the impurity particle. Elasticity theory has demonstrated an analogy between the elementary topological defects named disclinations to electric charges by associating a charge to a disclination, whose sign depends on the number of its nearest neighbors. Size polydispersity is shown numerically here to be an essential ingredient to understand short-range attractions between like-charge disclinations. Our study suggests that size polydispersity has a promising potential to engineer defects in various systems including nanoparticles and colloidal crystals.

Roles for Drosophila Mushroom Body Neurons in Olfactory Learning and Memory

Science.gov (United States)

Zong, Lin; Tanaka, Nobuaki K.; Ito, Kei; Davis, Ronald L.; Akalal, David-Benjamin G.; Wilson, Curtis F.

2006-01-01

Olfactory learning assays in Drosophila have revealed that distinct brain structures known as mushroom bodies (MBs) are critical for the associative learning and memory of olfactory stimuli. However, the precise roles of the different neurons comprising the MBs are still under debate. The confusion surrounding the roles of the different neurons…

On the influence of extrinsic point defects on irradiation-induced point-defect distributions in silicon

International Nuclear Information System (INIS)

Vanhellemont, J.; Romano-Rodriguez, A.

1994-01-01

A semi-quantitative model describing the influence of interfaces and stress fields on {113}-defect generation in silicon during 1-MeV electron irradiation, is further developed to take into account also the role of extrinsic point defects. It is shown that the observed distribution of {113}-defects in high-flux electron-irradiated silicon and its dependence on irradiation temperature and dopant concentration can be understood by taking into account not only the influence of the surfaces and interfaces as sinks for intrinsic point defects but also the thermal stability of the bulk sinks for intrinsic point defects. In heavily doped silicon the bulk sinks are related with pairing reactions of the dopant atoms with the generated intrinsic point defects or related with enhanced recombination of vacancies and self-interstitials at extrinsic point defects. The obtained theoretical results are correlated with published experimental data on boron-and phosphorus-doped silicon and are illustrated with observations obtained by irradiating cross-section transmission electron microscopy samples of wafer with highly doped surface layers. (orig.)

Unravelling salutogenic mechanisms in the workplace: the role of learning.

Science.gov (United States)

Pijpker, Roald; Vaandrager, Lenneke; Bakker, Evert Jan; Koelen, Maria

To explore the moderating and mediating role(s) of learning within the relationship between sense of coherence (SOC) and generalized resistance resources. Cross-sectional study (N=481), using a self-administered questionnaire, of employees working in the healthcare sector in the Netherlands in 2017. Four residential healthcare settings and one healthcare-related Facebook group were involved. Multiple linear regression models were used to test for moderating and mediating effects of learning. Social relations, task significance, and job control significantly explained variance in SOC. Conceptual, social, and instrumental learning, combined, moderated the relationship between SOC and task significance. Instrumental learning moderated the relationship between job control and SOC. Social learning also mediated this relationship. Conceptual learning did not show any moderating or mediating effect. The relationship between SOC and the three GRRs seems to be strengthened or explained-to a certain extent-by instrumental and social learning. Healthcare organizations are recommended to promote learning through formal activities as well as through cooperation, feedback, sharing experiences, and job challenges. This requires employee participation and a multilevel interdisciplinary approach. Copyright © 2018 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Observer roles that optimise learning in healthcare simulation education: a systematic review.

Science.gov (United States)

O'Regan, Stephanie; Molloy, Elizabeth; Watterson, Leonie; Nestel, Debra

2016-01-01

Simulation is widely used in health professional education. The convention that learners are actively involved may limit access to this educational method. The aim of this paper is to review the evidence for learning methods that employ directed observation as an alternative to hands-on participation in scenario-based simulation training. We sought studies that included either direct comparison of the learning outcomes of observers with those of active participants or identified factors important for the engagement of observers in simulation. We systematically searched health and education databases and reviewed journals and bibliographies for studies investigating or referring to observer roles in simulation using mannequins, simulated patients or role play simulations. A quality framework was used to rate the studies. We sought studies that included either direct comparison of the learning outcomes of observers with those of active participants or identified factors important for the engagement of observers in simulation. We systematically searched health and education databases and reviewed journals and bibliographies for studies investigating or referring to observer roles in simulation using mannequins, simulated patients or role play simulations. A quality framework was used to rate the studies. Nine studies met the inclusion criteria. Five studies suggest learning outcomes in observer roles are as good or better than hands-on roles in simulation. Four studies document learner satisfaction in observer roles. Five studies used a tool to guide observers. Eight studies involved observers in the debrief. Learning and satisfaction in observer roles is closely associated with observer tools, learner engagement, role clarity and contribution to the debrief. Learners that valued observer roles described them as affording an overarching view, examination of details from a distance, and meaningful feedback during the debrief. Learners who did not value observer roles

The Role of Small Enterprise in School Students' Workplace Learning.

Science.gov (United States)

Mulraney, James; Turner, Peter; Wyatt, Frank; Harris, Roger; Gibson, Terri

The role of small enterprise in Australian school students' workplace learning was examined. First, the literature on structured workplace learning in Australia, Europe, and North America was reviewed. Next, four structured learning programs in South Australia and four in New South Wales were studied. Interviews were conducted with a total of 41…

Elastic and failure response of imperfect three-dimensional metallic lattices: the role of geometric defects induced by Selective Laser Melting

Science.gov (United States)

Liu, Lu; Kamm, Paul; García-Moreno, Francisco; Banhart, John; Pasini, Damiano

2017-10-01

This paper examines three-dimensional metallic lattices with regular octet and rhombicuboctahedron units fabricated with geometric imperfections via Selective Laser Sintering. We use X-ray computed tomography to capture morphology, location, and distribution of process-induced defects with the aim of studying their role in the elastic response, damage initiation, and failure evolution under quasi-static compression. Testing results from in-situ compression tomography show that each lattice exhibits a distinct failure mechanism that is governed not only by cell topology but also by geometric defects induced by additive manufacturing. Extracted from X-ray tomography images, the statistical distributions of three sets of defects, namely strut waviness, strut thickness variation, and strut oversizing, are used to develop numerical models of statistically representative lattices with imperfect geometry. Elastic and failure responses are predicted within 10% agreement from the experimental data. In addition, a computational study is presented to shed light into the relationship between the amplitude of selected defects and the reduction of elastic properties compared to their nominal values. The evolution of failure mechanisms is also explained with respect to strut oversizing, a parameter that can critically cause failure mode transitions that are not visible in defect-free lattices.

Teaching psychosomatic medicine using problem-based learning and role-playing.

Science.gov (United States)

Heru, Alison M

2011-01-01

Problem-based learning (PBL) has been implemented in medical education world-wide. Despite its popularity, it has not been generally considered useful for residency programs. The author presents a model for the implementation of PBL in residency programs. The author presents a description of a PBL curriculum for teaching psychosomatic medicine to PGY 2 members in a psychiatry training program. The goals of PBL are to encourage self-directed learning; enhance curiosity, using case-based, contextualized learning; promote collaborative practice; and support patient-centered care. The addition of role-playing exercises helps PGY 2 residents to develop their skills from simply developing a differential diagnosis to being able to construct biopsychosocial formulations, and it provides these residents an opportunity to practice presenting case formulations to the patient and family. Residents and faculty enjoyed the PBL role-playing sessions. Residents wanted the learning objectives given to them rather than generating their own learning objectives, to move through the cases faster, and to receive more information and more cases. Teaching psychosomatic medicine, using PBL and role-playing, allows many of the proposed Academy of Psychosomatic Medicine residency core competencies to be met. However, further refinement of the PBL method needs to take place in order to adapt its use to residency programs.

SME Innovation and Learning: The Role of Networks and Crisis Events

Science.gov (United States)

Saunders, Mark N. K.; Gray, David E; Goregaokar, Harshita

2014-01-01

Purpose: The purpose of this paper is to contribute to the literature on innovation and entrepreneurial learning by exploring how SMEs learn and innovate, how they use both formal and informal learning and in particular the role of networks and crisis events within their learning experience. Design/methodology/approach: Mixed method study,…

Charged Semiconductor Defects Structure, Thermodynamics and Diffusion

CERN Document Server

Seebauer, Edmund G

2009-01-01

The technologically useful properties of a solid often depend upon the types and concentrations of the defects it contains. Not surprisingly, defects in semiconductors have been studied for many years, in many cases with a view towards controlling their behavior through various forms of "defect engineering." For example, in the bulk, charging significantly affects the total concentration of defects that are available to mediate phenomena such as solid-state diffusion. Surface defects play an important role in mediating surface mass transport during high temperature processing steps such as epitaxial film deposition, diffusional smoothing in reflow, and nanostructure formation in memory device fabrication. Charged Semiconductor Defects details the current state of knowledge regarding the properties of the ionized defects that can affect the behavior of advanced transistors, photo-active devices, catalysts, and sensors. Features: Group IV, III-V, and oxide semiconductors; Intrinsic and extrinsic defects; and, P...

Kinesthetic Role in Motorist Learning

OpenAIRE

Mukhlisin, Mukhlisin; Rahmawati, Lilis

2016-01-01

This article describes the role of kinesthetic in motor learning. It starts with a definition that kinesthetic is Generally regarded as "a feeling or awareness" of body position and body movement. But there are four factors are seemingly quite common in definitions of kinesthetic: positioning of body segments, precision of movement, balance, and spatial orientation. Any Appropriate reference explaining the reception and transmission of kinesthetic information during movement has not yet been ...

The Strategic Role of Digital Libraries: Issues in E-Learning Environments.

Science.gov (United States)

Wang, Mei-Yu

2003-01-01

Describes research aimed at providing educational organizations with practical strategies for implementing electronic learning (e-learning), based on focus group discussions at an elementary school in Taiwan. Considers the strategic role of digital libraries in electronic learning environments, library collections, digital technology, human…

40 CFR 1068.501 - How do I report emission-related defects?

Science.gov (United States)

2010-07-01

... shipped replacement parts for any individual component is high enough that good engineering judgment would... after you learn that the number of defects exceeds a threshold. Send us an updated defect report anytime... sampled data. Make adjusted calculations to take into account any bias that may remain. (h) Investigation...

Absorption and atom mobility in electric field: point defect role in glasses

International Nuclear Information System (INIS)

Serruys, Y.; Vigouroux, J.P.

1986-10-01

During the surface analysis of dielectric materials, the impinging ionising particles induce point defects localised in the band gap and build an electrical charge. The electric field created by the charged defects modifies the physico-chemical properties of surface and bulk. We show that the fundamental study of defects allows a better understanding of technological phenomena such as dielectric breakdown, fracture and diffusion [fr

The Role of Research on Science Teaching and Learning

Science.gov (United States)

National Science Teachers Association (NJ1), 2010

2010-01-01

Research on science teaching and learning plays an important role in improving science literacy, a goal called for in the National Science Education Standards (NRC 1996) and supported by the National Science Teachers Association (NSTA 2003). NSTA promotes a research agenda that is focused on the goal of enhancing student learning through effective…

The role of language in learning physics

Science.gov (United States)

Brookes, David T.

Many studies in PER suggest that language poses a serious difficulty for students learning physics. These difficulties are mostly attributed to misunderstanding of specialized terminology. This terminology often assigns new meanings to everyday terms used to describe physical models and phenomena. In this dissertation I present a novel approach to analyzing of the role of language in learning physics. This approach is based on the analysis of the historical development of physics ideas, the language of modern physicists, and students' difficulties in the areas of quantum mechanics, classical mechanics, and thermodynamics. These data are analyzed using linguistic tools borrowed from cognitive linguistics and systemic functional grammar. Specifically, I combine the idea of conceptual metaphor and grammar to build a theoretical framework that accounts for: (1) the role and function that language serves for physicists when they speak and reason about physical ideas and phenomena, (2) specific features of students' reasoning and difficulties that may be related to or derived from language that students read or hear. The theoretical framework is developed using the methodology of a grounded theoretical approach. The theoretical framework allows us to make predictions about the relationship between student discourse and their conceptual and problem solving difficulties. Tests of the theoretical framework are presented in the context of "heat" in thermodynamics and "force" in dynamics. In each case the language that students use to reason about the concepts of "heat" and "force" is analyzed using the theoretical framework. The results of this analysis show that language is very important in students' learning. In particular, students are (1) using features of physicists' conceptual metaphors to reason about physical phenomena, often overextending and misapplying these features, (2) drawing cues from the grammar of physicists' speech and writing to categorize physics

Driving down defect density in composite EUV patterning film stacks

Science.gov (United States)

Meli, Luciana; Petrillo, Karen; De Silva, Anuja; Arnold, John; Felix, Nelson; Johnson, Richard; Murray, Cody; Hubbard, Alex; Durrant, Danielle; Hontake, Koichi; Huli, Lior; Lemley, Corey; Hetzer, Dave; Kawakami, Shinichiro; Matsunaga, Koichi

2017-03-01

Extreme ultraviolet lithography (EUVL) technology is one of the leading candidates for enabling the next generation devices, for 7nm node and beyond. As the technology matures, further improvement is required in the area of blanket film defectivity, pattern defectivity, CD uniformity, and LWR/LER. As EUV pitch scaling approaches sub 20 nm, new techniques and methods must be developed to reduce the overall defectivity, mitigate pattern collapse and eliminate film related defect. IBM Corporation and Tokyo Electron Limited (TELTM) are continuously collaborating to develop manufacturing quality processes for EUVL. In this paper, we review key defectivity learning required to enable 7nm node and beyond technology. We will describe ongoing progress in addressing these challenges through track-based processes (coating, developer, baking), highlighting the limitations of common defect detection strategies and outlining methodologies necessary for accurate characterization and mitigation of blanket defectivity in EUV patterning stacks. We will further discuss defects related to pattern collapse and thinning of underlayer films.

Substitution and defect chemistry of La-Cu-O systems

International Nuclear Information System (INIS)

Gai, P.L.; McCarron, E.M.; Kunchur, M.

1991-01-01

In this paper substitutional effects of strontium in La-Cu-O system and defects accommodating stoichiometric deviations is investigated. The extended shear defects are analyzed using electron microscopy and the role in superconducting transport properties has been examined by magnetic measurements. The initial results suggest that the defects enhance flux pinning

"The Learning Sticks": Reflections on a Case Study of Role-Playing for Sustainability

Science.gov (United States)

Gordon, Sue; Thomas, Ian

2018-01-01

Use of role-plays to develop deep student-learning has many advocates. Role-play is a powerful approach for learning that develops relevant skills in a range of disciplines and situations. In Higher Education, sustainability programmes role-play pedagogy appears to have great relevance for developing the competencies that these graduates will…

Active Learning in Neuroscience: A Manipulative to Simulate Visual Field Defects

Science.gov (United States)

Li, Andrew Yue-Lin; Carvalho, Helena

2016-01-01

Prevalent in 20-57% of stroke patients, visual field defects have been shown to impact quality of life. Studies have shown increased risk of falling, ambulatory difficulties, impaired reading ability, and feelings of panic in crowded or unfamiliar places in patients with visual field defects. Rehabilitation, independence, and mental health may…

Examining the Roles of Blended Learning Approaches in Computer-Supported Collaborative Learning (CSCL) Environments: A Delphi Study

Science.gov (United States)

So, Hyo-Jeong; Bonk, Curtis J.

2010-01-01

In this study, a Delphi method was used to identify and predict the roles of blended learning approaches in computer-supported collaborative learning (CSCL) environments. The Delphi panel consisted of experts in online learning from different geographic regions of the world. This study discusses findings related to (a) pros and cons of blended…

The Role of L-type Calcium Channels in Olfactory Learning and Its Modulation by Norepinephrine

Directory of Open Access Journals (Sweden)

Abhinaba Ghosh

2017-12-01

Full Text Available L type calcium channels (LTCCs are prevalent in different systems and hold immense importance for maintaining/performing selective functions. In the nervous system, CaV1.2 and CaV1.3 are emerging as critical modulators of neuronal functions. Although the general role of these calcium channels in modulating synaptic plasticity and memory has been explored, their role in olfactory learning is not well understood. In this review article we first discuss the role of LTCCs in olfactory learning especially focusing on early odor preference learning in neonate rodents, presenting evidence that while NMDARs initiate stimulus-specific learning, LTCCs promote protein-synthesis dependent long-term memory (LTM. Norepinephrine (NE release from the locus coeruleus (LC is essential for early olfactory learning, thus noradrenergic modulation of LTCC function and its implication in olfactory learning is discussed here. We then address the differential roles of LTCCs in adult learning and learning in aged animals.

Learners' Perceptions of Blended Learning and the Roles and Interaction of f2f and Online Learning

Science.gov (United States)

Huang, Qiang

2016-01-01

The present study aims to probe into learners' perceptions of blended learning in relation to the respective roles of face-to-face learning (f2f learning) and online learning as well as their interaction in the blended EFL contexts. Questionnaires were used in the study to examine the attitudes of 296 university students towards a blended English…

The Role of Departmental Leadership for Professional Learning Communities

Science.gov (United States)

Vanblaere, Bénédicte; Devos, Geert

2018-01-01

Purpose: Department heads play a pivotal role in the functioning of departments in secondary schools. However, quantitative research about the role of departmental leadership for the development of professional learning communities (PLCs) in subject departments in secondary schools remains scarce. As PLCs are seen as promising contexts for…

THE BIGGS AND MOORE MODEL IN E-LEARNING: The Role of Motivation and Collaboration as Moderators

Directory of Open Access Journals (Sweden)

Matti J. HAVERILA

2012-04-01

Full Text Available The purpose of this paper is to report the findings of a research conducted to evaluate the effect of e-learning experience on students’ perceived learning outcomes, and more specifically the role of motivation and collaboration as moderators between the e-learning experience and the learning outcome. The perceived learning outcome was measured with whether the students perceived to learn more in e-learning vis-à-vis traditional learning context. The participants came from an undergraduate course at Tamk University of Applied Sciences in Tampere, Finland. The Biggs and Moore learning model indicates that the process variables (motivation and collaboration in this study have a mediating role. It was found out in this study, however, that these process variables have a moderating role rather than mediating role. Specific recommendations for the practitioners are provided, and implications for educators are discussed. Finally suggestions for further research on e-learning are provided.

Role of Defects in Swelling and Creep of Irradiated SiC

Energy Technology Data Exchange (ETDEWEB)

Szlufarska, Izabela [Univ. of Wisconsin, Madison, WI (United States); Voyles, Paul [Univ. of Wisconsin, Madison, WI (United States); Sridharan, Kumar [Univ. of Wisconsin, Madison, WI (United States); Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-01-16

Silicon carbide is a promising cladding material because of its high strength and relatively good corrosion resistance. However, SiC is brittle and therefore SiC-based components need to be carefully designed to avoid cracking and failure by fracture. In design of SiC-based composites for nuclear reactor applications it is essential to take into account how mechanical properties are affected by radiation and temperature, or in other words, what strains and stresses develop in this material due to environmental conditions. While thermal strains in SiC can be predicted using classical theories, radiation-induced strains are much less understood. In particular, it is critical to correctly account for radiation swelling and radiation creep, which contribute significantly to dimensional instability of SiC under radiation. Swelling typically increases logarithmically with radiation dose and saturates at relatively low doses (damage levels of a few dpa). Consequently, swelling-induced stresses are likely to develop within a few months of operation of a reactor. Radiation-induced volume swelling in SiC can be as high as 2%, which is significantly higher than the cracking strain of 0.1% in SiC. Swelling-induced strains will lead to enormous stresses and fracture, unless these stresses can be relaxed via some other mechanism. An effective way to achieve stress relaxation is via radiation creep. Although it has been hypothesized that both radiation swelling and radiation creep are driven by formation of defect clusters, existing models for swelling and creep in SiC are limited by the lack of understanding of specific defects that form due to radiation in the range of temperatures relevant to fuel cladding in light water reactors (LWRs) (<1000°C). For example, defects that can be detected with traditional transmission electron microscopy (TEM) techniques account only for 10-45% of the swelling measured in irradiated SiC. Here, we have undertaken an integrated experimental and

Role of Defects in Swelling and Creep of Irradiated SiC

International Nuclear Information System (INIS)

Szlufarska, Izabela; Voyles, Paul; Sridharan, Kumar; Katoh, Yutai

2016-01-01

Silicon carbide is a promising cladding material because of its high strength and relatively good corrosion resistance. However, SiC is brittle and therefore SiC-based components need to be carefully designed to avoid cracking and failure by fracture. In design of SiC-based composites for nuclear reactor applications it is essential to take into account how mechanical properties are affected by radiation and temperature, or in other words, what strains and stresses develop in this material due to environmental conditions. While thermal strains in SiC can be predicted using classical theories, radiation-induced strains are much less understood. In particular, it is critical to correctly account for radiation swelling and radiation creep, which contribute significantly to dimensional instability of SiC under radiation. Swelling typically increases logarithmically with radiation dose and saturates at relatively low doses (damage levels of a few dpa). Consequently, swelling-induced stresses are likely to develop within a few months of operation of a reactor. Radiation-induced volume swelling in SiC can be as high as 2%, which is significantly higher than the cracking strain of 0.1% in SiC. Swelling-induced strains will lead to enormous stresses and fracture, unless these stresses can be relaxed via some other mechanism. An effective way to achieve stress relaxation is via radiation creep. Although it has been hypothesized that both radiation swelling and radiation creep are driven by formation of defect clusters, existing models for swelling and creep in SiC are limited by the lack of understanding of specific defects that form due to radiation in the range of temperatures relevant to fuel cladding in light water reactors (LWRs) (<1000°C). For example, defects that can be detected with traditional transmission electron microscopy (TEM) techniques account only for 10-45% of the swelling measured in irradiated SiC. Here, we have undertaken an integrated experimental and

A central role for the small GTPase Rac1 in hippocampal plasticity and spatial learning and memory

DEFF Research Database (Denmark)

Haditsch, Ursula; Leone, Dino P; Farinelli, Mélissa

2009-01-01

in excitatory neurons in the forebrain in vivo not only affects spine structure, but also impairs synaptic plasticity in the hippocampus with consequent defects in hippocampus-dependent spatial learning. Furthermore, Rac1 mutants display deficits in working/episodic-like memory in the delayed matching...

Exploring atomic defects in molybdenum disulphide monolayers

KAUST Repository

Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

2015-01-01

Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 10 13 cm '2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices.

Exploring atomic defects in molybdenum disulphide monolayers

KAUST Repository

Hong, Jinhua

2015-02-19

Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 10 13 cm \\'2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices.

Endotracheal tube defects: Hidden causes of airway obstruction

Directory of Open Access Journals (Sweden)

Sofi Khalid

2010-01-01

Full Text Available Manufacturing defects of endotracheal tube (ETT are still encountered in anesthesia practice. Many such defects go unnoticed during routine inspection prior to their use. Such defects in ETT may lead to partial or complete airway obstruction in an intubated patient. We report a case of partial airway obstruction with a prepacked, single use, uncuffed ETT due to a manufacturing defect in the form of a plastic meniscus at the distal end of the tube. This case report highlights the significance of standard monitoring of ventilation and the role of a vigilant clinician in detecting such defects in avoiding critical events as can arise from the use of such defective ETTs. It also emphasizes the need for double checking ETTs prior to their use.

Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

International Nuclear Information System (INIS)

Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

2004-01-01

Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed

Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

Energy Technology Data Exchange (ETDEWEB)

Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

2004-08-01

Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed.

An Automated Defect Prediction Framework using Genetic Algorithms: A Validation of Empirical Studies

Directory of Open Access Journals (Sweden)

Juan Murillo-Morera

2016-05-01

Full Text Available Today, it is common for software projects to collect measurement data through development processes. With these data, defect prediction software can try to estimate the defect proneness of a software module, with the objective of assisting and guiding software practitioners. With timely and accurate defect predictions, practitioners can focus their limited testing resources on higher risk areas. This paper reports the results of three empirical studies that uses an automated genetic defect prediction framework. This framework generates and compares different learning schemes (preprocessing + attribute selection + learning algorithms and selects the best one using a genetic algorithm, with the objective to estimate the defect proneness of a software module. The first empirical study is a performance comparison of our framework with the most important framework of the literature. The second empirical study is a performance and runtime comparison between our framework and an exhaustive framework. The third empirical study is a sensitivity analysis. The last empirical study, is our main contribution in this paper. Performance of the software development defect prediction models (using AUC, Area Under the Curve was validated using NASA-MDP and PROMISE data sets. Seventeen data sets from NASA-MDP (13 and PROMISE (4 projects were analyzed running a NxM-fold cross-validation. A genetic algorithm was used to select the components of the learning schemes automatically, and to assess and report the results. Our results reported similar performance between frameworks. Our framework reported better runtime than exhaustive framework. Finally, we reported the best configuration according to sensitivity analysis.

Ion beam deposition system for depositing low defect density extreme ultraviolet mask blanks

Science.gov (United States)

Jindal, V.; Kearney, P.; Sohn, J.; Harris-Jones, J.; John, A.; Godwin, M.; Antohe, A.; Teki, R.; Ma, A.; Goodwin, F.; Weaver, A.; Teora, P.

2012-03-01

Extreme ultraviolet lithography (EUVL) is the leading next-generation lithography (NGL) technology to succeed optical lithography at the 22 nm node and beyond. EUVL requires a low defect density reflective mask blank, which is considered to be one of the top two critical technology gaps for commercialization of the technology. At the SEMATECH Mask Blank Development Center (MBDC), research on defect reduction in EUV mask blanks is being pursued using the Veeco Nexus deposition tool. The defect performance of this tool is one of the factors limiting the availability of defect-free EUVL mask blanks. SEMATECH identified the key components in the ion beam deposition system that is currently impeding the reduction of defect density and the yield of EUV mask blanks. SEMATECH's current research is focused on in-house tool components to reduce their contributions to mask blank defects. SEMATECH is also working closely with the supplier to incorporate this learning into a next-generation deposition tool. This paper will describe requirements for the next-generation tool that are essential to realize low defect density EUV mask blanks. The goal of our work is to enable model-based predictions of defect performance and defect improvement for targeted process improvement and component learning to feed into the new deposition tool design. This paper will also highlight the defect reduction resulting from process improvements and the restrictions inherent in the current tool geometry and components that are an impediment to meeting HVM quality EUV mask blanks will be outlined.

Self-Regulated Learning: The Role of Motivation, Emotion, and Use of Learning Strategies in Students' Learning Experiences in a Self-Paced Online Mathematics Course

Science.gov (United States)

Cho, Moon-Heum; Heron, Michele L.

2015-01-01

Enrollment in online remedial mathematics courses has increased in popularity in institutions of higher learning; however, students unskilled in self-regulated learning (SRL) find online remedial mathematics courses particularly challenging. We investigated the role of SRL, specifically motivation, emotion, and learning strategies, in students'…

Motor coordination defects in mice deficient for the Sam68 RNA-binding protein.

Science.gov (United States)

Lukong, Kiven E; Richard, Stéphane

2008-06-03

The role of RNA-binding proteins in the central nervous system and more specifically their role in motor coordination and learning are poorly understood. We previously reported that ablation of RNA-binding protein Sam68 in mice results in male sterility and delayed mammary gland development and protection against osteoporosis in females. Sam68 however is highly expressed in most regions of the brain especially the cerebellum and thus we investigated the cerebellar-related manifestations in Sam68-null mice. We analyzed the mice for motor function, sensory function, and learning and memory abilities. Herein, we report that Sam68-null mice have motor coordination defects as assessed by beam walking and rotorod performance. Forty-week-old Sam68-null mice (n=12) were compared to their wild-type littermates (n=12). The Sam68-null mice exhibited more hindpaw faults in beam walking tests and fell from the rotating drum at lower speeds and prematurely compared to the wild-type controls. The Sam68-null mice were, however, normal for forelimb strength, tail-hang reflex, balance test, grid walking, the Morris water task, recognition memory, visual discrimination, auditory stimulation and conditional taste aversion. Our findings support a role for Sam68 in the central nervous system in the regulation of motor coordination.

COMPETITIVE INTELLIGENCE: THE ENHANCING ROLE OF ORGANIZATIONAL LEARNING CAPABILITY

OpenAIRE

HAMAD, Zaina Mustafa Mahmoud; YOZGAT, Ugur

2017-01-01

Performinga strong intelligence grants an organization a guaranteeof long-term success. This paper investigates the enhancing effect of organizational learning capabilities on competitive intelligence atthe commercial banks in Jordan. A sample within top and middle managements was used.Measurement instrument validity and model fit were assessed before testinghypotheses. This study emphasizes the role learning capability plays inenhancing intelligence. Key findings support importance of organi...

The Role of Higher Education in Promoting Lifelong Learning. UIL Publication Series on Lifelong Learning Policies and Strategies: No. 3

Science.gov (United States)

Yang, Jin, Ed.; Schneller, Chripa, Ed.; Roche, Stephen, Ed.

2015-01-01

There is no doubt that universities have a vital role to play in promoting lifelong learning. This publication presents possible ways of expanding and transforming higher education to facilitate lifelong learning in different socio-economic contexts. Nine articles address the various dimensions of the role of higher education in promoting lifelong…

Using PLEs in Professional Learning Scenarios - The Festo Case for ROLE

OpenAIRE

Scheffel, Maren; Schmidt,, Manuel; Werkle, Michael; Wolpers, Martin

2013-01-01

The competitiveness of a company depends strongly on the skills and abilities of its employees. Teachers and learners within companies often lack media competence and the ability to use self-regulated learning (SRL). The evaluations conducted in the scope of the Responsive Open Learning Environment (ROLE) project showed that the vocational training and workplace learning providers appreciated the SRL approach and the idea of personalisation of the learning tools and content. Further, the impl...

The role of NPY in learning and memory

DEFF Research Database (Denmark)

Gøtzsche, C. R.; Woldbye, D. P. D.

2016-01-01

with Y1 receptor-mediated neurogenesis could constitute necessary steps in consolidation and long-term retention of spatial memory. Altogether, NPY-induced effects on learning and memory seem to be biphasic, anatomically and temporally differential, and in support of a modulatory role of NPY at keeping......High levels of NPY expression in brain regions important for learning and memory together with its neuromodulatory and neurotrophic effects suggest a regulatory role for NPY in memory processes. Therefore it is not surprising that an increasing number of studies have provided evidence for NPY...... acting as a modulator of neuroplasticity, neurotransmission, and memory. Here these results are presented in relation to the types of memory affected by NPY and its receptors. NPY can exert both inhibitory and stimulatory effects on memory, depending on memory type and phase, dose applied, brain region...

Principals' Collaborative Roles as Leaders for Learning

Science.gov (United States)

Kitchen, Margaret; Gray, Susan; Jeurissen, Maree

2016-01-01

This article draws on data from three multicultural New Zealand primary schools to reconceptualize principals' roles as leaders for learning. In doing so, the writers build on Sinnema and Robinson's (2012) article on goal setting in principal evaluation. Sinnema and Robinson found that even principals hand-picked for their experience fell short on…

Wiring Role Taking in Collaborative Learning Environments. SNA and Semantic Web can improve CSCL script?

Directory of Open Access Journals (Sweden)

Nicola Capuano

2014-04-01

Full Text Available Over the past years the concept of role in distance education has become a promising construct for analysing and facilitating collaborative processes and outcomes. Designing effective collaborative learning processes is a complex task that can be supported by existing good practices formulated as pedagogical patterns or scripts. Over the past years, the research on technology enhanced learning has shown that collaborative scripts for learning act as mediating artefacts not only designing educational scenarios but also structuring and prescribing roles and activities. Conversely, existing learning systems are not able to provide dynamic role management in the definition and execution of collaborative scripts. This work proposes the application of Social Network Analysis in order to evaluate the expertise level of a learner when he/she is acting, with an assigned role, within the execution of a collaborative script. Semantic extensions to both IMS Learning Design and Information Packaging specifications are also proposed to support roles management.

Effects of e-learning, lectures, and role playing on nursing students' knowledge acquisition, retention and satisfaction.

Science.gov (United States)

Pourghaznein, Tayebeh; Sabeghi, Hakimeh; Shariatinejad, Keyvan

2015-01-01

Nursing education can maintain its dynamic quality when it moves toward innovation and modern methods of teaching and learning. Therefore, teachers are required to employ up to date methods in their teaching plans. This study evaluated the effects of e-learning, lectures, and role playing on nursing students' learning, retention, and satisfaction. Sixty nursing students were selected as an experiment and control groups during two consecutive semesters. The educational content was presented as e-learning and role playing during one semester (experiment group) and as lectures in the next semester (control group). A questionnaire containing three parts was used to assess demographics, learning and satisfaction statuses. The questionnaire also included a final openended question to evaluate the students' ideas about the whole course. The mean scores of posttest were 16.13 ± 1.37 using role playing, 15.50 ± 1.44 using e-learning and 16.45 ± 1.23 using lectures. The differences between the mean scores of posttest and pretest were 12.84 ± 1.43, 12.56 ± 1.57, and 13.73 ± 1.53 in the mentioned methods, respectively. Lectures resulted in significantly better learning compared to role playing and e-learning. In contrast, retention rates were significantly lower using lectures than using role playing and e-learning. Students' satisfaction from e-learning was significantly lower than lecturing and role playing. Due to the lower rates of retention following lectures, the teachers are recommended to use student- centered approaches in their lectures. Since students' satisfaction with e-learning was lower than the other methods, further studies are suggested to explore the problems of e-learning in Iran.

The critical role of point defects in improving the specific capacitance of δ-MnO₂ nanosheets

Energy Technology Data Exchange (ETDEWEB)

Gao, Peng; Metz, Peter; Hey, Trevyn; Gong, Yuxuan; Liu, Dawei; Edwards, Doreen D.; Howe, Jane Y.; Huang, Rong; Misture, Scott T.

2017-02-23

3D porous nanostructures built from 2D δ-MnO₂ nanosheets are an environmentally friendly and industrially scalable class of supercapacitor electrode material. While both the electrochemistry and defects of this material have been studied, the role of defects in improving the energy storage density of these materials has not been addressed. In this work, δ-MnO₂ nanosheet assemblies with 150 m² g^-1 specific surface area are prepared by exfoliation of crystalline K_xMnO₂ and subsequent reassembly. Equilibration at different pH introduces intentional Mn vacancies into the nanosheets, increasing pseudocapacitance to over 300 F g^-1, reducing charge transfer resistance as low as 3 Ω, and providing a 50% improvement in cycling stability. X-ray absorption spectroscopy and high-energy X-ray scattering demonstrate a correlation between the defect content and the improved electrochemical performance. The results show that Mn vacancies provide ion intercalation sites which concurrently improve specific capacitance, charge transfer resistance and cycling stability.

Pipeline defect prediction using long range ultrasonic testing and intelligent processing

International Nuclear Information System (INIS)

Dino Isa; Rajprasad Rajkumar

2009-01-01

This paper deals with efforts to improve nondestructive testing (NDT) techniques by using artificial intelligence in detecting and predicting pipeline defects such as cracks and wall thinning. The main emphasis here will be on the prediction of corrosion type defects rather than just detection after the fact. Long range ultrasonic testing will be employed, where a ring of piezoelectric transducers are used to generate torsional guided waves. Various defects such as cracks as well as corrosion under insulation (CUI) will be simulated on a test pipe. The machine learning algorithm known as the Support Vector Machine (SVM) will be used to predict and classify transducer signals using regression and large margin classification. Regression results show that the SVM is able to accurately predict future defects based on trends of previous defect. The classification performance was also exceptional showing a facility to detect defects at different depths as well as for distinguishing closely spaced defects. (author)

Resident burnout: evaluating the role of the learning environment.

Science.gov (United States)

van Vendeloo, Stefan N; Godderis, Lode; Brand, Paul L P; Verheyen, Kees C P M; Rowell, Suria A; Hoekstra, Harm

2018-03-27

Although burnout is viewed as a syndrome rooted in the working environment and organizational culture, the role of the learning environment in the development of resident burnout remains unclear. We aimed to evaluate the association between burnout and the learning environment in a cohort of Belgian residents. We conducted a cross-sectional online survey among residents in a large university hospital in Belgium. We used the Dutch version of the Maslach Burnout Inventory (UBOS-C) to assess burnout and the Dutch Residency Educational Climate Test (D-RECT) to assess the learning environment. A total of 236 residents (29 specialties) completed the survey (response rate 34.6%), of which 98 (41.5%) met standard criteria for burnout. After multivariate regression analysis adjusting for hours worked per week, quality of life and satisfaction with work-life balance, we found an inverse association between D-RECT scores and the risk of burnout (adjusted odds ratio; 0.47 for each point increase in D-RECT score; 95% CI, 0.23 - 0.95; p = 0.01). Resident burnout is highly prevalent in our cohort of Belgian residents. Our results suggest that the learning environment plays an important role in reducing the risk of burnout among residents.

Learning Cultures in Small to Medium-Size Enterprises and Their Role in Supporting the Learning Region

Science.gov (United States)

Fitzpatrick, Maeve; O'Connell, Janice; Murphy, Eamonn

2010-01-01

The role of work-based learning is a pivotal part of developing the learning region. With rates of employment at their highest for many years across Europe, the need for up-skilling the workforce in many areas will be essential to retain competitiveness and employability. This paper will focus on quality management up-skilling in small to…

The Role of Corticostriatal Systems in Speech Category Learning.

Science.gov (United States)

Yi, Han-Gyol; Maddox, W Todd; Mumford, Jeanette A; Chandrasekaran, Bharath

2016-04-01

One of the most difficult category learning problems for humans is learning nonnative speech categories. While feedback-based category training can enhance speech learning, the mechanisms underlying these benefits are unclear. In this functional magnetic resonance imaging study, we investigated neural and computational mechanisms underlying feedback-dependent speech category learning in adults. Positive feedback activated a large corticostriatal network including the dorsolateral prefrontal cortex, inferior parietal lobule, middle temporal gyrus, caudate, putamen, and the ventral striatum. Successful learning was contingent upon the activity of domain-general category learning systems: the fast-learning reflective system, involving the dorsolateral prefrontal cortex that develops and tests explicit rules based on the feedback content, and the slow-learning reflexive system, involving the putamen in which the stimuli are implicitly associated with category responses based on the reward value in feedback. Computational modeling of response strategies revealed significant use of reflective strategies early in training and greater use of reflexive strategies later in training. Reflexive strategy use was associated with increased activation in the putamen. Our results demonstrate a critical role for the reflexive corticostriatal learning system as a function of response strategy and proficiency during speech category learning. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Early Retinal Defects in Fmr1-/y Mice: Toward a Critical Role of Visual Dys-Sensitivity in the Fragile X Syndrome Phenotype?

Science.gov (United States)

Perche, Olivier; Felgerolle, Chloé; Ardourel, Maryvonne; Bazinet, Audrey; Pâris, Arnaud; Rossignol, Rafaëlle; Meyer-Dilhet, Géraldine; Mausset-Bonnefont, Anne-Laure; Hébert, Betty; Laurenceau, David; Montécot-Dubourg, Céline; Menuet, Arnaud; Bizot, Jean-Charles; Pichon, Jacques; Ranchon-Cole, Isabelle; Briault, Sylvain

2018-01-01

Fragile X Syndrome (FXS) is caused by a deficiency in Fragile X Mental Retardation Protein (FMRP) leading to global sensorial abnormalities, among which visual defects represent a critical part. These visual defects are associated with cerebral neuron immaturity especially in the primary visual cortex. However, we recently demonstrated that retinas of adult Fmr1 -/y mice, the FXS murine model, present molecular, cellular and functional alterations. However, no data are currently available on the evolution pattern of such defects. As retinal stimulation through Eye Opening (EO) is a crucial signal for the cerebral visual system maturation, we questioned the precocity of molecular and functional retinal phenotype. To answer this question, we studied the retinal molecular phenotype of Fmr1 -/y mice before EO until adult age and the consequences of the retinal loss of Fmrp on retinal function in young and adult mice. We showed that retinal molecular defects are present before EO and remain stable at adult age, leading to electrophysiological impairments without any underlying structural changes. We underlined that loss of Fmrp leads to a wide range of defects in the retina, settled even before EO. Our work demonstrates a critical role of the sensorial dysfunction in the Fmr1 -/y mice overall phenotype, and provides evidence that altered peripheral perception is a component of the sensory processing defect in FXS conditions.

The Role of Audiovisual Mass Media News in Language Learning

Science.gov (United States)

Bahrani, Taher; Sim, Tam Shu

2011-01-01

The present paper focuses on the role of audio/visual mass media news in language learning. In this regard, the two important issues regarding the selection and preparation of TV news for language learning are the content of the news and the linguistic difficulty. Content is described as whether the news is specialized or universal. Universal…

Reponsive and Open Learning Environments (ROLE: Requirements, Evaluation and Reflection

Directory of Open Access Journals (Sweden)

Effie Lai-Chong Law

2013-02-01

Full Text Available Coordinating requirements engineering (RE and evaluation studies across heterogeneous technology-enhanced learning (TEL environments is deemed challenging, because each of them is situated in a specific organizational, technical and socio-cultural context. We have dealt with such challenges in the project of ROLE (http://www.role-project.eu/ in which five test-beds are involved in deploying and evaluating Personal Learning Environments (PLEs. They include Higher Education Institutions (HEIs and global enterprises in and beyond Europe, representing a range of values and assumptions. While the diversity provides fertile grounds for validating our research ideas, it poses many challenges for conducting comparison studies. In the paper, we first provide an overview of the ROLE project, focusing on its missions and aims. Next we present a Web2.0-inspired RE approach called Social Requirements Engineering (SRE. Then we depict our initial attempts to evaluate the ROLE framework and report some preliminary findings. One major outcome is that the technology adoption process must work on the basis of existing LMS, extending them with the ROLE functionality rather than embracing LMS functionality in ROLE.

Progressive Structural Defects in Canine Centronuclear Myopathy Indicate a Role for HACD1 in Maintaining Skeletal Muscle Membrane Systems.

Science.gov (United States)

Walmsley, Gemma L; Blot, Stéphane; Venner, Kerrie; Sewry, Caroline; Laporte, Jocelyn; Blondelle, Jordan; Barthélémy, Inès; Maurer, Marie; Blanchard-Gutton, Nicolas; Pilot-Storck, Fanny; Tiret, Laurent; Piercy, Richard J

2017-02-01

Mutations in HACD1/PTPLA cause recessive congenital myopathies in humans and dogs. Hydroxyacyl-coA dehydratases are required for elongation of very long chain fatty acids, and HACD1 has a role in early myogenesis, but the functions of this striated muscle-specific enzyme in more differentiated skeletal muscle remain unknown. Canine HACD1 deficiency is histopathologically classified as a centronuclear myopathy (CNM). We investigated the hypothesis that muscle from HACD1-deficient dogs has membrane abnormalities in common with CNMs with different genetic causes. We found progressive changes in tubuloreticular and sarcolemmal membranes and mislocalized triads and mitochondria in skeletal muscle from animals deficient in HACD1. Furthermore, comparable membranous abnormalities in cultured HACD1-deficient myotubes provide additional evidence that these defects are a primary consequence of altered HACD1 expression. Our novel findings, including T-tubule dilatation and disorganization, associated with defects in this additional CNM-associated gene provide a definitive pathophysiologic link with these disorders, confirm that dogs deficient in HACD1 are relevant models, and strengthen the evidence for a unifying pathogenesis in CNMs via defective membrane trafficking and excitation-contraction coupling in muscle. These results build on previous work by determining further functional roles of HACD1 in muscle and provide new insight into the pathology and pathogenetic mechanisms of HACD1 CNM. Consequently, alterations in membrane properties associated with HACD1 mutations should be investigated in humans with related phenotypes. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

The Library's role and challenges in implementing an e-learning strategy: a case study from northern Australia.

Science.gov (United States)

Ritchie, Ann

2011-03-01

  The Northern Territory Department of Health and Families' (DHF) Library supports education programs for all staff. DHF is implementing an e-learning strategy, which may be viewed as a vehicle for coordinating the education function throughout the organisation.   The objective of this study is to explore the concept of e-learning in relation to the Library's role in implementing an organisation-wide e-learning strategy.   The main findings of a literature search about the effectiveness of e-learning in health professionals' education, and the responsibility and roles of health librarians in e-learning are described. A case study approach is used to outline the current role and future opportunities and challenges for the Library.   The case study presents the organisation's strategic planning context. Four areas of operational activity which build on the Library's current educational activities are suggested: the integration of library resources 'learning objects' within a Learning Management System; developing online health information literacy training programs; establishing a physical and virtual 'e-Learning Library/Centre'; developing collaborative partnerships, taking on new responsibilities in e-learning development, and creating a new e-learning librarian role.   The study shows that the Library's role is fundamental to developing the organisation's e-learning capacity and implementing an organisation-wide e-learning strategy. © 2010 The authors. Health Information and Libraries Journal © 2010 Health Libraries Group.

Role of masking oxide on silicon in processes of defect generation at formation of SIMOX structures

CERN Document Server

Askinazi, A Y; Miloglyadova, L V

2002-01-01

One investigated into Si-SiO sub 2 structures formed by implantation of oxygen ions into silicon (SIMOX-technology) by means of techniques based on measuring of high-frequency volt-farad characteristics and by means of electroluminescence. One determined existence of electrically active centres and of luminescence centres in the formed oxide layer near boundary with silicon. One clarified the role SiO sub 2 masking layer in silicon in defect generation under formation of the masked oxide layer. One established dependence of concentration of electrically active and luminescence centres on thickness of masking layer

The roles of lesson study in the development of mathematics learning instrument based on learning trajectory

Science.gov (United States)

Misnasanti; Dien, C. A.; Azizah, F.

2018-03-01

This study is aimed to describe Lesson Study (LS) activity and its roles in the development of mathematics learning instruments based on Learning Trajectory (LT). This study is a narrative study of teacher’s experiences in joining LS activity. Data collecting in this study will use three methods such as observation, documentations, and deep interview. The collected data will be analyzed with Milles and Huberman’s model that consists of reduction, display, and verification. The study result shows that through LS activity, teachers know more about how students think. Teachers also can revise their mathematics learning instrument in the form of lesson plan. It means that LS activity is important to make a better learning instruments and focus on how student learn not on how teacher teach.

The role of topological spin defects in magnetotransport of CrO2

International Nuclear Information System (INIS)

Yanagihara, H; Salamon, M B

2007-01-01

We investigated the temperature dependence of the resistivity for a wide temperature range for CrO 2 (100) epitaxial films. The temperature derivative dρ/dT definitely shows the same character as the magnetic heat capacity anomaly in the critical regime even in a finite magnetic field and the critical exponents (α) deduced are consistent with those of 3D Heisenberg ferromagnets. In addition, we found that the spin dependent resistivity over a wide temperature range can be simply proportional to the density of diluted topological spin defects (Skyrmion strings) suggesting that those nontrivial topological defects scatter conduction electrons just like impurities. The excitation energy of such topological defects is quite comparable to that obtained by anomalous Hall effect analysis of the Ye et al model based on the Berry phase. The overall results give a simple picture wherein the density of the topological defects can be a dominant mechanism of resistivity, like the anomalous Hall effect. The results concerning the critical exponent analysis and intuition concerning scattering centres of magnetic disorder suggest a specific picture of the Fisher-Langer model

Roles and Characteristics of Television and Some Implications for Distance Learning.

Science.gov (United States)

Bates, Tony W.

1982-01-01

Explores some recent theory and research developments on the role and character of television, and its impact on learning in distance education. The implications for learning of distributional and social, control, and symbolic (audiovisual) characteristics of television are discussed. Fifteen references and an outline of television applications…

Defects and defect processes in nonmetallic solids

CERN Document Server

Hayes, W

2004-01-01

This extensive survey covers defects in nonmetals, emphasizing point defects and point-defect processes. It encompasses electronic, vibrational, and optical properties of defective solids, plus dislocations and grain boundaries. 1985 edition.

The roles of the temperature on the structural and electronic properties of deep-level V{sub As}V{sub Ga} defects in gallium arsenide

Energy Technology Data Exchange (ETDEWEB)

Ma, Deming, E-mail: xautmdm@163.com; Chen, Xi; Qiao, Hongbo; Shi, Wei; Li, Enling

2015-07-15

Highlights: • The energy gap of the Ga{sub As}As{sub Ga}V{sub As}V{sub Ga} is 0.82 eV. • Proves that the Ga{sub As}As{sub Ga}V{sub As}V{sub Ga} belongs to EL2 deep-level defect in GaAs. • Proves that EL2 and EL6 deep-level defects can transform into each other. • Temperature has an important effect on the microstructure of deep-level defects. - Abstract: The roles of temperature on the structural and electronic properties of V{sub As}V{sub Ga} defects in gallium arsenide have been studied by using ab-initio molecular dynamic (MD) simulation. Our calculated results show that the relatively stable quaternary complex defect of Ga{sub As}As{sub Ga}V{sub As}V{sub Ga} can be converted from the V{sub As}V{sub Ga} complex clusters defect between 300 K and 1173 K; however, from 1173 K to 1373 K, the decomposition of the complex defect Ga{sub As}As{sub Ga}V{sub As}V{sub Ga} occurs, turning into a deep-level V{sub As}V{sub Ga} cluster defect and an isolated As{sub Ga} antisite defect, and relevant defect of Ga{sub As} is recovered. The properties of Ga{sub As}As{sub Ga}V{sub As}V{sub Ga} defect has been studied by first-principles calculations based on hybrid density functional theory. Our calculated results show that the Ga{sub As}As{sub Ga}V{sub As}V{sub Ga} belongs to EL2 deep-level defect in GaAs. Thus, we reveal that the temperature has an important effect on the microstructure of deep-level defects and defect energy level in gallium arsenide that EL2 and EL6 deep-level defects have a certain correlation, which means they could transform into each other. Controlling temperature in the growth process of GaAs could change the microstructure of deep-level defects and defect energy levels in gallium arsenide materials, whereby affects the electron transport properties of materials.

Creating a Role for Embedded Librarians Within an Active Learning Environment.

Science.gov (United States)

Hackman, Dawn E; Francis, Marcia J; Johnson, Erika; Nickum, Annie; Thormodson, Kelly

2017-01-01

In 2013, the librarians at a small academic health sciences library reevaluated their mission, vision, and strategic plan to expand their roles. The school was transitioning to a new pedagogical culture and a new building designed to emphasize interprofessional education and active learning methodologies. Subsequent efforts to implement the new strategic plan resulted in the librarians joining curriculum committees and other institutional initiatives, such as an Active Learning Task Force, and participating in faculty development workshops. This participation has increased visibility and led to new roles and opportunities for librarians.

Role of Mobile Technology in Promoting Campus-Wide Learning Environment

Science.gov (United States)

Hussain, Irshad; Adeeb, Muhammad Aslam

2009-01-01

The present study examines the role of mobile technology in promoting campus-wide learning environment. Its main objectives were to a) evaluate the role of mobile technology in higher education in terms of its i). appropriateness ii). flexibility iii). Interactivity, & iv). availability & usefulness and to b). identify the problems of…

Evidence for a developmental role for TLR4 in learning and memory.

Directory of Open Access Journals (Sweden)

Eitan Okun

Full Text Available Toll-like receptors (TLRs play essential roles in innate immunity and increasing evidence indicates that these receptors are expressed in neurons, astrocytes and microglia in the brain where they mediate responses to infection, stress and injury. Very little is known about the roles of TLRs in cognition. To test the hypothesis that TLR4 has a role in hippocampus-dependent spatial learning and memory, we used mice deficient for TLR4 and mice receiving chronic TLR4 antagonist infusion to the lateral ventricles in the brain. We found that developmental TLR4 deficiency enhances spatial reference memory acquisition and memory retention, impairs contextual fear-learning and enhances motor functions, traits that were correlated with CREB up-regulation in the hippocampus. TLR4 antagonist infusion into the cerebral ventricles of adult mice did not affect cognitive behavior, but instead affected anxiety responses. Our findings indicate a developmental role for TLR4 in shaping spatial reference memory, and fear learning and memory. Moreover, we show that central TLR4 inhibition using a TLR4 antagonist has no discernible physiological role in regulating spatial and contextual hippocampus-dependent cognitive behavior.

The role of professional objects in technology-enhanced learning environments in higher education

NARCIS (Netherlands)

Zitter, I.I.; Bruijn, E. de; Simons, P.R.J.; Cate, Th.J. ten

2010-01-01

We study project-based, technology-enhanced learning environments in higher education, which should produce, by means of specific mechanisms, learning outcomes in terms of transferable knowledge and learning-, thinking-, collaboration- and regulation-skills. Our focus is on the role of objects from

Role of oxygen defects on the magnetic properties of ultra-small Sn1-xFexO2 nanoparticles

Science.gov (United States)

Dodge, Kelsey; Chess, Jordan; Eixenberger, Josh; Alanko, Gordon; Hanna, Charles B.; Punnoose, Alex

2013-05-01

Although the role of oxygen defects in the magnetism of metal oxide semiconductors has been widely discussed, it is been difficult to directly measure the oxygen defect concentration of samples to verify this. This work demonstrates a direct correlation between the photocatalytic activity of Sn1-xFexO2 nanoparticles and their magnetic properties. For this, a series of ˜2.6 nm sized, well characterized, single-phase Sn1-xFexO2 crystallites with x = 0-0.20 were synthesized using tin acetate, urea, and appropriate amounts of iron acetate. X-ray photoelectron spectroscopy confirmed the concentration and 3+ oxidation state of the doped Fe ions. The maximum magnetic moment/Fe ion, μ, of 1.6 × 10-4 μB observed for the 0.1% Fe doped sample is smaller than the expected spin-only contribution from either high or low spin Fe3+ ions, and μ decreases with increasing Fe concentration. This behavior cannot be explained by the existing models of magnetic exchange. Photocatalytic studies of pure and Fe-doped SnO2 were used to understand the roles of doped Fe3+ ions and of the oxygen vacancies and defects. The photocatalytic rate constant k also showed an increase when SnO2 nanoparticles were doped with low concentrations of Fe3+, reaching a maximum at 0.1% Fe, followed by a rapid decrease of k for further increase in Fe%. Fe doping presumably increases the concentration of oxygen vacancies, and both Fe3+ ions and oxygen vacancies act as electron acceptors to reduce e--h+ recombination and promote transfer of electrons (and/or holes) to the nanoparticle surface, where they participate in redox reactions. This electron transfer from the Fe3+ ions to local defect density of states at the nanoparticle surface could develop a magnetic moment at the surface states and leads to spontaneous ferromagnetic ordering of the surface shell under favorable conditions. However, at higher doping levels, the same Fe3+ ions might act as recombination centers causing a decrease of both k and

Using process monitor wafers to understand directed self-assembly defects

Science.gov (United States)

Cao, Yi; Her, YoungJun; Delgadillo, Paulina R.; Vandenbroeck, Nadia; Gronheid, Roel; Chan, Boon Teik; Hashimoto, Yukio; Romo, Ainhoa; Somervell, Mark; Nafus, Kathleen; Nealey, Paul F.

2013-03-01

As directed self-assembly (DSA) has gained momentum over the past few years, questions about its application to high volume manufacturing have arisen. One of the major concerns is about the fundamental limits of defectivity that can be attained with the technology. If DSA applications demonstrate defectivity that rivals of traditional lithographic technologies, the pathway to the cost benefits of the technology creates a very compelling case for its large scale implementation. To address this critical question, our team at IMEC has established a process monitor flow to track the defectivity behaviors of an exemplary chemo-epitaxy application for printing line/space patterns. Through establishing this baseline, we have been able to understand both traditional lithographic defect sources in new materials as well as new classes of assembly defects associated with DSA technology. Moreover, we have explored new materials and processing to lower the level of the defectivity baseline. The robustness of the material sets and process is investigated as well. In this paper, we will report the understandings learned from the IMEC DSA process monitor flow.

The learning curve, interobserver, and intraobserver agreement of endoscopic confocal laser endomicroscopy in the assessment of mucosal barrier defects.

Science.gov (United States)

Chang, Jeff; Ip, Matthew; Yang, Michael; Wong, Brendon; Power, Theresa; Lin, Lisa; Xuan, Wei; Phan, Tri Giang; Leong, Rupert W

2016-04-01

Confocal laser endomicroscopy can dynamically assess intestinal mucosal barrier defects and increased intestinal permeability (IP). These are functional features that do not have corresponding appearance on histopathology. As such, previous pathology training may not be beneficial in learning these dynamic features. This study aims to evaluate the diagnostic accuracy, learning curve, inter- and intraobserver agreement for identifying features of increased IP in experienced and inexperienced analysts and pathologists. A total of 180 endoscopic confocal laser endomicroscopy (Pentax EC-3870FK; Pentax, Tokyo, Japan) images of the terminal ileum, subdivided into 6 sets of 30 were evaluated by 6 experienced analysts, 13 inexperienced analysts, and 2 pathologists, after a 30-minute teaching session. Cell-junction enhancement, fluorescein leak, and cell dropout were used to represent increased IP and were either present or absent in each image. For each image, the diagnostic accuracy, confidence, and quality were assessed. Diagnostic accuracy was significantly higher for experienced analysts compared with inexperienced analysts from the first set (96.7% vs 83.1%, P 0.86 for experienced observers. Features representative of increased IP can be rapidly learned with high inter- and intraobserver agreement. Confidence and image quality were significant predictors of accurate interpretation. Previous pathology training did not have an effect on learning. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

The Role of Interactive E-Learning in Problem-Solving Skill and Independent Learning of Medical Students in Psychology Courses

OpenAIRE

Sahar Mohamadi; Sayedeh Maryam Hosseiny; Sayedeh Sana Hosseiny

2016-01-01

Introduction: Today, due to the speed and amount of science production in the world, knowledge processing and learning is changing. In this regard, independent learning using new instructional methods interactively with a specific goal in order to dominate the content and assignments with self-regulation strategies is of great importance. This study is aimed to evaluate interactive e-learning role on medical students’ learning in psychology courses. Methods: This study is a experimental r...

An investigation of the role of background music in IVWs for learning

OpenAIRE

Richards, Debbie; Fassbender, Eric; Bilgin, Ayse; Thompson, William Forde

2008-01-01

Empirical evidence is needed to corroborate the intuitions of gamers and game developers in understanding the benefits of Immersive Virtual Worlds (IVWs) as a learning environment and the role that music plays within these environments. We report an investigation to determine if background music of the genre typically found in computer-based role-playing games has an effect on learning in a computer-animated history lesson about the Macquarie Lighthouse within an IVW. In Experiment 1, music s...

The theoretical base of e-learning and its role in surgical education.

Science.gov (United States)

Evgeniou, Evgenios; Loizou, Peter

2012-01-01

The advances in Internet and computer technology offer many solutions that can enhance surgical education and increase the effectiveness of surgical teaching. E-learning plays an important role in surgical education today, with many e-learning projects already available on the Internet. E-learning is based on a mixture of educational theories that derive from behaviorist, cognitivist, and constructivist educational theoretical frameworks. CAN EDUCATIONAL THEORY IMPROVE E-LEARNING?: Conventional educational theory can be applied to improve the quality and effectiveness of e-learning. The theory of "threshold concepts" and educational theories on reflection, motivation, and communities of practice can be applied when designing e-learning material. E-LEARNING IN SURGICAL EDUCATION: E-learning has many advantages but also has weaknesses. Studies have shown that e-learning is an effective teaching method that offers high levels of learner satisfaction. Instead of trying to compare e-learning with traditional methods of teaching, it is better to integrate in e-learning elements of traditional teaching that have been proven to be effective. E-learning can play an important role in surgical education as a blended approach, combined with more traditional methods of teaching, which offer better face-to-interaction with patients and colleagues in different circumstances and hands on practice of practical skills. National provision of e-learning can make evaluation easier. The correct utilization of Internet and computer resources combined with the application of valid conventional educational theory to design e-learning relevant to the various levels of surgical training can be effective in the training of future surgeons. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Exploring the Roles of Parents and Students in EFL Literacy Learning: A Colombian Case

Science.gov (United States)

Hurtado Torres, Sergio Aldemar; Castañeda-Peña, Harold Andrés

2016-01-01

There is little scholarly information about parent involvement in their children's English as a Foreign Language (EFL henceforth) literacy learning in the Colombian context. This exploratory-qualitative study looks into the possible roles of parents and children in EFL literacy learning at home, with special emphasis on parental roles and…

Early Retinal Defects in Fmr1−/y Mice: Toward a Critical Role of Visual Dys-Sensitivity in the Fragile X Syndrome Phenotype?

Science.gov (United States)

Perche, Olivier; Felgerolle, Chloé; Ardourel, Maryvonne; Bazinet, Audrey; Pâris, Arnaud; Rossignol, Rafaëlle; Meyer-Dilhet, Géraldine; Mausset-Bonnefont, Anne-Laure; Hébert, Betty; Laurenceau, David; Montécot-Dubourg, Céline; Menuet, Arnaud; Bizot, Jean-Charles; Pichon, Jacques; Ranchon-Cole, Isabelle; Briault, Sylvain

2018-01-01

Fragile X Syndrome (FXS) is caused by a deficiency in Fragile X Mental Retardation Protein (FMRP) leading to global sensorial abnormalities, among which visual defects represent a critical part. These visual defects are associated with cerebral neuron immaturity especially in the primary visual cortex. However, we recently demonstrated that retinas of adult Fmr1−/y mice, the FXS murine model, present molecular, cellular and functional alterations. However, no data are currently available on the evolution pattern of such defects. As retinal stimulation through Eye Opening (EO) is a crucial signal for the cerebral visual system maturation, we questioned the precocity of molecular and functional retinal phenotype. To answer this question, we studied the retinal molecular phenotype of Fmr1−/y mice before EO until adult age and the consequences of the retinal loss of Fmrp on retinal function in young and adult mice. We showed that retinal molecular defects are present before EO and remain stable at adult age, leading to electrophysiological impairments without any underlying structural changes. We underlined that loss of Fmrp leads to a wide range of defects in the retina, settled even before EO. Our work demonstrates a critical role of the sensorial dysfunction in the Fmr1−/y mice overall phenotype, and provides evidence that altered peripheral perception is a component of the sensory processing defect in FXS conditions. PMID:29681800

Early Retinal Defects in Fmr1−/y Mice: Toward a Critical Role of Visual Dys-Sensitivity in the Fragile X Syndrome Phenotype?

Directory of Open Access Journals (Sweden)

Olivier Perche

2018-04-01

Full Text Available Fragile X Syndrome (FXS is caused by a deficiency in Fragile X Mental Retardation Protein (FMRP leading to global sensorial abnormalities, among which visual defects represent a critical part. These visual defects are associated with cerebral neuron immaturity especially in the primary visual cortex. However, we recently demonstrated that retinas of adult Fmr1−/y mice, the FXS murine model, present molecular, cellular and functional alterations. However, no data are currently available on the evolution pattern of such defects. As retinal stimulation through Eye Opening (EO is a crucial signal for the cerebral visual system maturation, we questioned the precocity of molecular and functional retinal phenotype. To answer this question, we studied the retinal molecular phenotype of Fmr1−/y mice before EO until adult age and the consequences of the retinal loss of Fmrp on retinal function in young and adult mice. We showed that retinal molecular defects are present before EO and remain stable at adult age, leading to electrophysiological impairments without any underlying structural changes. We underlined that loss of Fmrp leads to a wide range of defects in the retina, settled even before EO. Our work demonstrates a critical role of the sensorial dysfunction in the Fmr1−/y mice overall phenotype, and provides evidence that altered peripheral perception is a component of the sensory processing defect in FXS conditions.

Learning experiences on role-emerging placements: an exploration from the students' perspective.

Science.gov (United States)

Dancza, Karina; Warren, Alison; Copley, Jodie; Rodger, Sylvia; Moran, Monica; McKay, Elizabeth; Taylor, Ann

2013-12-01

Occupational therapy educators are challenged to provide students with practical experiences which prepare them for ever changing health-care contexts on graduation. Role-emerging placements have been widely used internationally to help meet this challenge, but research into the learning experiences of students during these innovative placements is limited. This research investigated the enablers and barriers to learning from the perspectives of students on such placements from two European universities. Two separate qualitative studies tracked 10 final year students. Interviews explored their learning experiences prior to, during and after an eight- or 10-week role-emerging placement in a range of settings. Four themes emerged, which were (1) adapting to less doing, more thinking and planning; (2) understanding the complexity of collaboration and making it work; (3) emotional extremes; and (4) realising and using the occupational therapy perspective. These placements presented a 'roller coaster' of authentic learning experiences which created the opportunity for students to use occupation in practice and develop skills for collaborative working in an interprofessional environment. Whereas students viewed their role-emerging placement experiences positively, challenges included the emotional responses of students and placement pace. Findings suggest the need for supportive student placement experiences in both established and role-emerging areas to prepare students for a range of opportunities in an uncertain future. © 2013 Occupational Therapy Australia.

The role of the basal ganglia in learning and memory: Insight from Parkinson's disease

Science.gov (United States)

2013-01-01

It has long been known that memory is not a single process. Rather, there are different kinds of memory that are supported by distinct neural systems. This idea stemmed from early findings of dissociable patterns of memory impairments in patients with selective damage to different brain regions. These studies highlighted the role of the basal ganglia in non-declarative memory, such as procedural or habit learning, contrasting it with the known role of the medial temporal lobes in declarative memory. In recent years, major advances across multiple areas of neuroscience have revealed an important role for the basal ganglia in motivation and decision making. These findings have led to new discoveries about the role of the basal ganglia in learning and highlighted the essential role of dopamine in specific forms of learning. Here we review these recent advances with an emphasis on novel discoveries from studies of learning in patients with Parkinson's disease. We discuss how these findings promote the development of current theories away from accounts that emphasize the verbalizability of the contents of memory and towards a focus on the specific computations carried out by distinct brain regions. Finally, we discuss new challenges that arise in the face of accumulating evidence for dynamic and interconnected memory systems that jointly contribute to learning. PMID:21945835

The role of the basal ganglia in learning and memory: insight from Parkinson's disease.

Science.gov (United States)

Foerde, Karin; Shohamy, Daphna

2011-11-01

It has long been known that memory is not a single process. Rather, there are different kinds of memory that are supported by distinct neural systems. This idea stemmed from early findings of dissociable patterns of memory impairments in patients with selective damage to different brain regions. These studies highlighted the role of the basal ganglia in non-declarative memory, such as procedural or habit learning, contrasting it with the known role of the medial temporal lobes in declarative memory. In recent years, major advances across multiple areas of neuroscience have revealed an important role for the basal ganglia in motivation and decision making. These findings have led to new discoveries about the role of the basal ganglia in learning and highlighted the essential role of dopamine in specific forms of learning. Here we review these recent advances with an emphasis on novel discoveries from studies of learning in patients with Parkinson's disease. We discuss how these findings promote the development of current theories away from accounts that emphasize the verbalizability of the contents of memory and towards a focus on the specific computations carried out by distinct brain regions. Finally, we discuss new challenges that arise in the face of accumulating evidence for dynamic and interconnected memory systems that jointly contribute to learning. Copyright © 2011 Elsevier Inc. All rights reserved.

Evaluating the Effectiveness Roles of Variables in the Novice Programmers Learning

Science.gov (United States)

Shi, Nianfeng; Cui, Wen; Zhang, Ping; Sun, Ximing

2018-01-01

This research applies the roles of variables to the novice programmers in the C language programming. The results are evaluated using the Structure of Observed Learning Outcomes (SOLO) taxonomy. The participants were divided into an experimental group and a control group. The students from the control group learned programming in the traditional…

The Physiology of Fear: Reconceptualizing the Role of the Central Amygdala in Fear Learning

Science.gov (United States)

Keifer, Orion P.; Hurt, Robert C.; Ressler, Kerry J.

2015-01-01

The historically understood role of the central amygdala (CeA) in fear learning is to serve as a passive output station for processing and plasticity that occurs elsewhere in the brain. However, recent research has suggested that the CeA may play a more dynamic role in fear learning. In particular, there is growing evidence that the CeA is a site of plasticity and memory formation, and that its activity is subject to tight regulation. The following review examines the evidence for these three main roles of the CeA as they relate to fear learning. The classical role of the CeA as a routing station to fear effector brain structures like the periaqueductal gray, the lateral hypothalamus, and paraventricular nucleus of the hypothalamus will be briefly reviewed, but specific emphasis is placed on recent literature suggesting that the CeA 1) has an important role in the plasticity underlying fear learning, 2) is involved in regulation of other amygdala subnuclei, and 3) is itself regulated by intra- and extra-amygdalar input. Finally, we discuss the parallels of human and mouse CeA involvement in fear disorders and fear conditioning, respectively. PMID:26328883

The role of training structure in perceptual learning of accented speech.

Science.gov (United States)

Tzeng, Christina Y; Alexander, Jessica E D; Sidaras, Sabrina K; Nygaard, Lynne C

2016-11-01

Foreign-accented speech contains multiple sources of variation that listeners learn to accommodate. Extending previous findings showing that exposure to high-variation training facilitates perceptual learning of accented speech, the current study examines to what extent the structure of training materials affects learning. During training, native adult speakers of American English transcribed sentences spoken in English by native Spanish-speaking adults. In Experiment 1, training stimuli were blocked by speaker, sentence, or randomized with respect to speaker and sentence (Variable training). At test, listeners transcribed novel English sentences produced by unfamiliar Spanish-accented speakers. Listeners' transcription accuracy was highest in the Variable condition, suggesting that varying both speaker identity and sentence across training trials enabled listeners to generalize their learning to novel speakers and linguistic content. Experiment 2 assessed the extent to which ordering of training tokens by a single factor, speaker intelligibility, would facilitate speaker-independent accent learning, finding that listeners' test performance did not reliably differ from that in the no-training control condition. Overall, these results suggest that the structure of training exposure, specifically trial-to-trial variation on both speaker's voice and linguistic content, facilitates learning of the systematic properties of accented speech. The current findings suggest a crucial role of training structure in optimizing perceptual learning. Beyond characterizing the types of variation listeners encode in their representations of spoken utterances, theories of spoken language processing should incorporate the role of training structure in learning lawful variation in speech. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

On the Role of Cognitive Abilities in Second Language Vowel Learning.

Science.gov (United States)

Ghaffarvand Mokari, Payam; Werner, Stefan

2018-03-01

This study investigated the role of different cognitive abilities-inhibitory control, attention control, phonological short-term memory (PSTM), and acoustic short-term memory (AM)-in second language (L2) vowel learning. The participants were 40 Azerbaijani learners of Standard Southern British English. Their perception of L2 vowels was tested through a perceptual discrimination task before and after five sessions of high-variability phonetic training. Inhibitory control was significantly correlated with gains from training in the discrimination of L2 vowel pairs. However, there were no significant correlations between attention control, AM, PSTM, and gains from training. These findings suggest the potential role of inhibitory control in L2 phonological learning. We suggest that inhibitory control facilitates the processing of L2 sounds by allowing learners to ignore the interfering information from L1 during training, leading to better L2 segmental learning.

Thermo-enhanced field emission from ZnO nanowires: Role of defects and application in a diode flat panel X-ray source

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhipeng; Chen, Daokun; Chen, Wenqing; Chen, Yicong; Song, Xiaomeng; Zhan, Runze; Deng, Shaozhi; Xu, Ningsheng; Chen, Jun, E-mail: stscjun@mail.sysu.edu.cn

2017-03-31

Highlights: • A thermo-enhanced field emission phenomenon was observed from dendritic ZnO nanowires under the temperature of 323–723 K. • Defect-assisted field emission mechanism was proposed and quantitative calculation fits well with the experiment results. • The mechanism was verified by the field emission from ZnO nanowires with different defect concentrations. • A diode X-ray source making use of thermo-enhanced field emission phenomenon was proposed for separate tuning of dose and energy. - Abstract: A thermo-enhanced field emission phenomenon was observed from ZnO nanowires. The field emission current increased by almost two orders of magnitude under a constant applied electric field, and the turn-on field decreased from 6.04 MV/m to 5.0 MV/m when the temperature increased from 323 to 723 K. The Poole–Frenkel electron excitation from the defect-induced trapping centers to the conduction band under high electric fields is believed to be the primary cause of the observed phenomenon. The experimental results fit well with the proposed physical model. The field emission from ZnO nanowires with different defect concentrations further confirmed the role of defects. Using the thermo-enhanced field emission phenomenon, a diode flat panel X-ray source was demonstrated, for which the energy and dose can be separately tuned. The thermo-enhanced field emission phenomenon observed from ZnO nanowires could be an effective way to realize a large area flat panel multi-energy X-ray source.

The Impact of Role Modeling on Proteges' Personal Learning and Work-to-Family Enrichment

Science.gov (United States)

Kwan, Ho Kwong; Mao, Yina; Zhang, Haina

2010-01-01

The present study investigates the impact of role modeling as perceived by proteges on their personal learning (i.e., relational job learning and personal skill development) and work-to-family enrichment (WFE). Results from a two-wave field survey of 173 proteges in the People's Republic of China indicate that role modeling positively affects…

Role of the hippocampus on learning and memory functioning and pain modulation

Institute of Scientific and Technical Information of China (English)

Haimei Wang

2008-01-01

The hippocampus, an important part of the limbic system, is considered to be an important region of the brain for learning and memory functioning. Recent studies have demonstrated that synaptic plasticity is thought to be the basis of learning and memory functioning. A series of studies report that similar synaptic plasticity also exists in the spinal cord in the conduction pathway of pain sensation, which may contribute to hyperalgesia, abnormal pain, and analgesia. The synaptic plasticity of learning and memory functioning and that of the pain conduction pathway have similar mechanisms, which are related to the N-methyl-D-aspartic acid receptor. The hippocampus also has a role in pain modulation. As pain signals can reach the hippocampus, the precise correlation between synaptic plasticity of the pain pathway and that of learning and memory functioning deserves further investigation. The role of the hippocampus in processing pain information requires to be identified.

The Role of Subjective Task Value in Service-Learning Engagement among Chinese College Students.

Science.gov (United States)

Li, Yulan; Guo, Fangfang; Yao, Meilin; Wang, Cong; Yan, Wenfan

2016-01-01

Most service-learning studies in higher education focused on its effects on students' development. The dynamic processes and mechanisms of students' development during service-learning, however, have not been explored thoroughly. Student engagement in service-learning may affect service-learning outcomes and be affected by subjective task value at the same time. The present study aimed to explore the effect of subjective task value on Chinese college student engagement during service-learning. Fifty-four Chinese college students participated in a 9-weeks service-learning program of interacting with children with special needs. Students' engagement and subjective task value were assessed via self-report questionnaires and 433 weekly reflective journals. The results indicated that the cognitive, emotional and behavioral engagement of Chinese college students demonstrated different developmental trends during service-learning process. Subjective task value played an essential role in student engagement in service-learning activities. However, the role of subjective task value varied with different stages. Finally, the implications for implementing service-learning in Chinese education were discussed.

The Role of Subjective Task Value in Service-Learning Engagement among Chinese College Students

Science.gov (United States)

Li, Yulan; Guo, Fangfang; Yao, Meilin; Wang, Cong; Yan, Wenfan

2016-01-01

Most service-learning studies in higher education focused on its effects on students’ development. The dynamic processes and mechanisms of students’ development during service-learning, however, have not been explored thoroughly. Student engagement in service-learning may affect service-learning outcomes and be affected by subjective task value at the same time. The present study aimed to explore the effect of subjective task value on Chinese college student engagement during service-learning. Fifty-four Chinese college students participated in a 9-weeks service-learning program of interacting with children with special needs. Students’ engagement and subjective task value were assessed via self-report questionnaires and 433 weekly reflective journals. The results indicated that the cognitive, emotional and behavioral engagement of Chinese college students demonstrated different developmental trends during service-learning process. Subjective task value played an essential role in student engagement in service-learning activities. However, the role of subjective task value varied with different stages. Finally, the implications for implementing service-learning in Chinese education were discussed. PMID:27445919

Facilitating pragmatic skills through role-play in learners with language learning disability.

Science.gov (United States)

Abdoola, Fareeaa; Flack, Penelope S; Karrim, Saira B

2017-07-26

Role-based learning involves the process whereby learners acquire skills, knowledge and understanding through the assumption of roles within real-life settings. Role-play holds potential as an effective learning strategy for children; however, there is limited research on the use of role-play as a therapy method within the field of speech-language pathology. Children with language learning disability (LLD) typically present with difficulties in social communication, which can negatively affect their social and academic achievement. The aim of this study was to determine the effectiveness of role-play as a therapy approach targeting the pragmatic skills of stylistic variation and requesting for clarification in learners with LLD. The use of combined positivist and interpretivist paradigms allowed for the implementation of an embedded mixed methods design. An experimental pretest-posttest design was implemented. Eight participants, who were learners with a diagnosis of LLD, were purposefully selected. Data collection was conducted over five phases, utilising the Clinical Evaluation of Language Fundamentals (4th Ed.) Pragmatics Profile, discourse completion tasks, session plans and session records. Quantitative data were analysed using descriptive statistics and were supplemented by qualitative data from session records. Results revealed improvements in stylistic variation and requesting for clarification post role-play intervention, with minimal changes in the control group. Limitations of the study have been reported for consideration when interpreting results. Role-play as a therapy approach targeting two pragmatic skills, stylistic variation and requesting for clarification, was found to be beneficial for learners with LLD. Recommendations for the implementation of role-play as a therapy approach were made.

Customer's potential value: The role of learning

OpenAIRE

Komulainen, Hanna; Mainela, Tuija; Tähtinen, Jaana

2013-01-01

Current views on value creation emphasize the role of the customer, mutual investments, and value co-creation. Nevertheless, at present the customer-focused research concentrates on value expectations and value experiences as outcomes but disregards the analysis of potential value that is dependent on the customer's activity and learning in the process. The present study explores customer perceived value as a multidimensional phenomenon incorporating expected, realized, and potential dimensio...

The Role of Motivation in Self-regulated Learning and Language Learning Strategy: In the Case of Chinese EFL Learners

Directory of Open Access Journals (Sweden)

Maryam Banisaeid

2015-09-01

Full Text Available Although self-regulation, derived from educational psychology, is a new topic in the second language learning field, language learning strategy was the main focus of many studies in the last two decades. Also, among the L2 individual differences, motivation plays an important role in achieving the educational goals. In this research, motivation is investigated from self-determination theory by which five types of motivation are presented. No study was found to investigate the role of motivation in both self-regulation and language learning strategy. For such a purpose, 49 Chinese EFL learners respond to SILL, MSLQ and LLOS_IEA respectively proposed by Oxford (1990, Pintrich et al (1991 and Noel et al (2000. The results running Pearson correlation showed that there is a significant relationship between motivation, self-regulation and language learning strategies. It is also revealed that Chinese EFL learners use memory, social and affective strategy more than the other ones. The most common motivational orientation is identified regulation. Among self-regulated learning strategies, effort regulation is highly used by them. At the end some implication is considered.

Learning Behaviour and Learning Outcomes: The Roles for Social Influence and Field of Study

Science.gov (United States)

Smyth, Lillian; Mavor, Kenneth I.; Platow, Michael J.

2017-01-01

Research has demonstrated a significant role of discipline social identification in predicting learning approaches, even controlling for individual differences. Smyth et al. ("Educ Psychol" 35(1):53-72, 2015. doi:10.1080/01443410.2013.822962) suggest that learners share discipline-based social identifications, and that this…

Learning through role-playing games: an approach for active learning and teaching

Directory of Open Access Journals (Sweden)

Marco Antonio Ferreira Randi

Full Text Available This study evaluates the use of role-playing games (RPGs as a methodological approach for teaching cellular biology, assessing student satisfaction, learning outcomes, and retention of acquired knowledge. First-year undergraduate medical students at two Brazilian public universities attended either an RPG-based class (RPG group or a lecture (lecture-based group on topics related to cellular biology. Pre- and post-RPG-based class questionnaires were compared to scores in regular exams and in an unannounced test one year later to assess students' attitudes and learning. From the 230 students that attended the RPG classes, 78.4% responded that the RPG-based classes were an effective tool for learning; 55.4% thought that such classes were better than lectures but did not replace them; and 81% responded that they would use this method. The lecture-based group achieved a higher grade in 1 of 14 regular exam questions. In the medium-term evaluation (one year later, the RPG group scored higher in 2 of 12 questions. RPG classes are thus quantitatively as effective as formal lectures, are well accepted by students, and may serve as educational tools, giving students the chance to learn actively and potentially retain the acquired knowledge more efficiently.

Detection of paint polishing defects

Science.gov (United States)

Rebeggiani, S.; Wagner, M.; Mazal, J.; Rosén, B.-G.; Dahlén, M.

2018-06-01

Surface finish plays a major role on perceived product quality, and is the first thing a potential buyer sees. Today end-of-line repairs of the body of cars and trucks are inevitably to secure required surface quality. Defects that occur in the paint shop, like dust particles, are eliminated by manual sanding/polishing which lead to other types of defects when the last polishing step is not performed correctly or not fully completed. One of those defects is known as ‘polishing roses’ or holograms, which are incredibly hard to detect in artificial light but are clearly visible in sunlight. This paper will present the first tests with a measurement set-up newly developed to measure and analyse polishing roses. The results showed good correlations to human visual evaluations where repaired panels were estimated based on the defects’ intensity, severity and viewing angle.

The role of surface and deep-level defects on the emission of tin oxide quantum dots

International Nuclear Information System (INIS)

Kumar, Vinod; Kumar, Vijay; Som, S; Ntwaeaborwa, O M; Swart, H C; Neethling, J H; Lee, Mike

2014-01-01

This paper reports on the role of surface and deep-level defects on the blue emission of tin oxide quantum dots (SnO 2 QDs) synthesized by the solution-combustion method at different combustion temperatures. X-ray diffraction studies showed the formation of a single rutile SnO 2 phase with a tetragonal lattice structure. High resolution transmission electron microscopy studies revealed an increase in the average dot size from 2.2 to 3.6 nm with an increase of the combustion temperature from 350 to 550 °C. A decrease in the band gap value from 3.37 to 2.76 eV was observed with the increase in dot size due to the quantum confinement effect. The photoluminescence emission was measured for excitation at 325 nm and it showed a broad blue emission band for all the combustion temperatures studied. This was due to the creation of various oxygen and tin vacancies/defects as confirmed by x-ray photoelectron spectroscopy data. The origin of the blue emission in the SnO 2 QDs is discussed with the help of an energy band diagram. (paper)

Light-emitting diode assessment of dentinal defects: the role of presumed extraction forces

Directory of Open Access Journals (Sweden)

Marcelo Santos Coelho

2017-07-01

Full Text Available Objectives The evaluation of iatrogenic dentinal defects in extracted teeth may be influenced by extraction forces and prolonged dry times. The purpose of this study was to compare the presence of dentinal defects in freshly extracted, periodontally compromised teeth with those in a group of teeth with uncontrolled extraction forces and storage time. Materials and Methods The experimental group consisted of eighteen roots obtained from teeth extracted due to periodontal reasons with class II or III mobility. They were kept in saline and sectioned within 1 hour following extraction. The control group consisted of matched root types obtained from an anonymous tooth collection, consistent with previous dentinal defect studies. The slices were obtained at 3, 6, and 9 mm from the apex. The imaging process exposed all specimens to no more than 60 seconds of dry time. The × 12.8 magnification was used for the 9 mm slices and × 19.2 magnification for the 3 mm and 6 mm slices under light-emitting diode (LED transillumination. The root canal spaces and periodontal tissues were masked to minimize extraneous factors that might influence the evaluators. Chi-square test was used for statistical analysis. Results Dentinal defects were detected in 17% of the experimental group teeth, compared to 61% of control teeth (p = 0.015. Conclusions LED transillumination assessment of freshly extracted roots with class II or III mobility showed smaller number of dentinal defects than roots with uncontrolled storage time and extraction forces. The use of freshly extracted roots with mobility should be considered for future dental defect assessment studies.

Anosognosia for obvious visual field defects in stroke patients.

Science.gov (United States)

Baier, Bernhard; Geber, Christian; Müller-Forell, Wiebke; Müller, Notger; Dieterich, Marianne; Karnath, Hans-Otto

2015-01-01

Patients with anosognosia for visual field defect (AVFD) fail to recognize consciously their visual field defect. There is still unclarity whether specific neural correlates are associated with AVFD. We studied AVFD in 54 patients with acute stroke and a visual field defect. Nineteen percent of this unselected sample showed AVFD. By using modern voxelwise lesion-behaviour mapping techniques we found an association between AVFD and parts of the lingual gyrus, the cuneus as well as the posterior cingulate and corpus callosum. Damage to these regions appears to induce unawareness of visual field defects and thus may play a significant role for conscious visual perception.

An Exploration of Community Learning Disability Nurses' Therapeutic Role

Science.gov (United States)

Marsham, Marian

2012-01-01

This literature review and primary qualitative research explores therapeutic role from the perspective of Community Learning Disability Nurses. Semi-structured interviews, based on Critical Incident Technique ("Psychol Bull", 51, 1954, 327), and descriptive phenomenological methodology were adopted to elicit data amenable to systematic…

Gauge theory and defects in solids

CERN Document Server

Edelen, DGB

2012-01-01

This new series Mechanics and Physics of Discrete Systems aims to provide a coherent picture of the modern development of discrete physical systems. Each volume will offer an orderly perspective of disciplines such as molecular dynamics, crystal mechanics and/or physics, dislocation, etc. Emphasized in particular are the fundamentals of mechanics and physics that play an essential role in engineering applications.Volume 1, Gauge Theory and Defects in Solids, presents a detailed development of a rational theory of the dynamics of defects and damage in solids. Solutions to field e

Fatigue crack initiation – The role of point defects

Czech Academy of Sciences Publication Activity Database

Polák, Jaroslav; Man, Jiří

2014-01-01

Roč. 65, AUG (2014), s. 18-27 ISSN 0142-1123 R&D Projects: GA ČR(CZ) GAP108/10/2371; GA ČR(CZ) GA13-23652S Institutional support: RVO:68081723 Keywords : Fatigue crack initiation * Point defects * Persistent slip band * Intrusion * Extrusion Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.275, year: 2014

The role of leadership in facilitating Organisational Learning and collective capacity building

OpenAIRE

Piranfar, Hosein

2007-01-01

The paper examines the role of leadership in facilitating collective learning and capacity building by utilising ideas from the fields of evolutionary learning, operations strategy, quality, project and risk management. Two contrasting cases are chosen to show how success and failure can depend upon collective capacity building through participative leadership and Organisational Learning (OL). The bulk of the literature surveyed concerns evolutionary OL in particular those that involve leader...

Aggregation of Frenkel defects under irradiation: a mesoscopic approach

International Nuclear Information System (INIS)

Soppe, W.; Kotomin, E.

1993-08-01

The radiation-induced aggregation of Frenkel defects in solids is studied in terms of a mesoscopic approach. The asymmetry in elastic interactions between mobile interstitials (I-I) and between interstitials and vacancies (I-V) plays a decisive role in the aggregation of similar defects. The conditions for defect aggregation are studied in detail for NaCl crystals. The critical dose rate for aggregation has been calculated as a function of the temperature as well as the aggregation rate as a function of temperature and dose rate. Furthermore, the role of deep traps (like impurities and di-vacancies), reducing the mobility of interstitials, and the role of dislocations serving as sinks for interstitials, are studied. The aggregation appears to reach a maximum at a distinct temperature which is in agreement both with experiment and the Jain-Lidiard theory. The model also predicts a shift of this maximum towards lower temperatures if the dose rate is decreased. The consequences of the model for the disposal of nuclear waste in rock salt formations, are briefly discussed. (orig.)

Senior veterinary students' perceptions of using role play to learn communication skills.

Science.gov (United States)

Brandt, Jennifer C; Bateman, Shane W

2006-01-01

Recent studies of veterinary practice have suggested a correlation between well-developed communication skills and job satisfaction, career retention, customer satisfaction, decreased lawsuits, and financial remuneration for veterinarians. Veterinary educators are under growing pressure to teach functional communication skills to veterinary students; however, the methods employed have not been well evaluated. In this study we have evaluated veterinary student's attitudes to learning communication skills by participating in role play. The study indicates that experiential learning modalities such as role play are perceived as effective by students, despite reluctance to participate and some discomfort surrounding participation.

Application of artificial neural networks to evaluate weld defects of nuclear components

International Nuclear Information System (INIS)

Amin, E.S.

2007-01-01

Artificial neural networks (ANNs) are computational representations based on the biological neural architecture of the brain. ANNs have been successfully applied to a wide range of engineering and scientific applications, such as signal, image processing and data analysis. Although Radiographic testing is widely used for welding defects, it is unsuccessful in identifying some welding defects because of the nature of image formation and quality. Neoteric algorithms have been used for the purpose of weld defects identifications in radiographic images to replace the expert knowledge. The application of artificial neural networks in noise detection of radiographic films is used. Radial Basis (RB) and learning vector quantization (LVQ) were applied. The method shows good performance in weld defects recognition and classification problems.

Facilitating pragmatic skills through role-play in learners with language learning disability

Directory of Open Access Journals (Sweden)

Fareeaa Abdoola

2017-07-01

Full Text Available Background: Role-based learning involves the process whereby learners acquire skills, knowledge and understanding through the assumption of roles within real-life settings. Role-play holds potential as an effective learning strategy for children; however, there is limited research on the use of role-play as a therapy method within the field of speech-language pathology. Children with language learning disability (LLD typically present with difficulties in social communication, which can negatively affect their social and academic achievement. Aim: The aim of this study was to determine the effectiveness of role-play as a therapy approach targeting the pragmatic skills of stylistic variation and requesting for clarification in learners with LLD. Method: The use of combined positivist and interpretivist paradigms allowed for the implementation of an embedded mixed methods design. An experimental pretest-posttest design was implemented. Eight participants, who were learners with a diagnosis of LLD, were purposefully selected. Data collection was conducted over five phases, utilising the Clinical Evaluation of Language Fundamentals (4th Ed. Pragmatics Profile, discourse completion tasks, session plans and session records. Quantitative data were analysed using descriptive statistics and were supplemented by qualitative data from session records. Results: Results revealed improvements in stylistic variation and requesting for clarification post role-play intervention, with minimal changes in the control group. Limitations of the study have been reported for consideration when interpreting results. Conclusion: Role-play as a therapy approach targeting two pragmatic skills, stylistic variation and requesting for clarification, was found to be beneficial for learners with LLD. Recommendations for the implementation of role-play as a therapy approach were made.

The roles of electronic books in the transformation of learning and instruction

NARCIS (Netherlands)

Huang, Ronghuai; Chen, Nian-Shing; Kang, Myunghee; McKenney, Susan; Churchill, Daniel

2014-01-01

Huang, R., Chen, N., Kang, M. McKenney, S. & Churchill, D. (2013). The roles of electronic books in the transformation of learning and instruction. In N. Chen, R. Huang, Kinshuk, Y. Li, D. G. Sampson (Eds.) Proceedings of the IEEE 13th International Conference on Advanced Learning Technologies

The Role of Leadership in Facilitating Organisational Learning and Collective Capacity Building

Science.gov (United States)

Piranfar, Hosein

2007-01-01

The paper examines the role of leadership in facilitating collective learning and capacity building by utilising ideas from the fields of evolutionary learning, operations strategy, quality, project and risk management. Two contrasting cases are chosen to show how success and failure can depend upon collective capacity building through…

Multi-Role Project (MRP): A New Project-Based Learning Method for STEM

Science.gov (United States)

Warin, Bruno; Talbi, Omar; Kolski, Christophe; Hoogstoel, Frédéric

2016-01-01

This paper presents the "Multi-Role Project" method (MRP), a broadly applicable project-based learning method, and describes its implementation and evaluation in the context of a Science, Technology, Engineering, and Mathematics (STEM) course. The MRP method is designed around a meta-principle that considers the project learning activity…

Charge mobility modification of semiconducting carbon nanotubes by intrinsic defects

International Nuclear Information System (INIS)

Bai, Hongcun; Ma, Yujia; Ma, Jinsuo; Mei, Jingnan; Tong, Yan; Ji, Yongqiang

2017-01-01

Charge carrier mobility is a central transport property in nanoscale electronics. Carbon nanotubes (CNTs) are supposed to have high carrier mobility. The preparation methods of CNTs have been greatly improved, but the defects always exist. This work presented first-principle investigations on the charge carrier mobility of carbon nanotubes containing several intrinsic defects. The charge carrier mobilities of zigzag (10, 0) tubes with Stone–Wales, mono vacant and 5/8/5 defects were studied as an example to explore the role of defects. Most carrier mobilities were decreased, but several values of mobility are unexpectedly increased upon the appearance of the defects. This interesting result is discussed based on the changes of the stretching modulus, the effective mass of the carrier and deformation potential constant induced by the defects. (paper)

Two datasets of defect reports labeled by a crowd of annotators of unknown reliability

Directory of Open Access Journals (Sweden)

Jerónimo Hernández-González

2018-06-01

Full Text Available Classifying software defects according to any defined taxonomy is not straightforward. In order to be used for automatizing the classification of software defects, two sets of defect reports were collected from public issue tracking systems from two different real domains. Due to the lack of a domain expert, the collected defects were categorized by a set of annotators of unknown reliability according to their impact from IBM's orthogonal defect classification taxonomy. Both datasets are prepared to solve the defect classification problem by means of techniques of the learning from crowds paradigm (Hernández-González et al. [1].Two versions of both datasets are publicly shared. In the first version, the raw data is given: the text description of defects together with the category assigned by each annotator. In the second version, the text of each defect has been transformed to a descriptive vector using text-mining techniques.

Renewed roles for librarians in problem-based learning in the medical curriculum.

Science.gov (United States)

Mi, Misa

2011-01-01

Problem-based learning (PBL) is a teaching-learning process or method of instruction that is widely used in medical education curricula. Librarians play important roles as facilitators for PBL as well as guides for information resources. Involvement in PBL activities presents unique opportunities to incorporate library resources and instruction into the medical curriculum. This article reviews the problem-based learning method within the conceptual framework of the learning theory of constructivism. It describes how a medical librarian at a U.S. medical school used emerging technologies to facilitate PBL small group case discussions, guide students to quality information resources, and enhance the learning environment for the PBL process.

Mobility of a 5|7 defect in carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Lee, Youngmin; Han, Jihoon; Im, Seyoung [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Science Town, Daejeon, 305-701 (Korea, Republic of); Lee, In-Ho, E-mail: sim@kaist.ac.kr [Korea Research Institute of Standards and Science (KRISS), Daejeon, 305-600 (Korea, Republic of)

2011-03-11

The movement of a 5|7 defect in the plastic deformations of a carbon nanotube (CNT) plays the role of dislocation glide in the plastic deformations of metals. This work is concerned with the atomic shift mechanism of the 5|7 defect and the energy barrier when the CNT is subjected to tensile loading. Action-derived molecular dynamics (ADMD) is applied to find the minimum energy path and the energy barrier. It is found that the tensile loads make it easy for the 5|7 defect to glide, and lower the energy barrier. The minimum load level that makes a 5|7 defect glide freely with no energy barrier in the presence of an adatom is obtained.

Mobility of a 5|7 defect in carbon nanotubes

International Nuclear Information System (INIS)

Lee, Youngmin; Han, Jihoon; Im, Seyoung; Lee, In-Ho

2011-01-01

The movement of a 5|7 defect in the plastic deformations of a carbon nanotube (CNT) plays the role of dislocation glide in the plastic deformations of metals. This work is concerned with the atomic shift mechanism of the 5|7 defect and the energy barrier when the CNT is subjected to tensile loading. Action-derived molecular dynamics (ADMD) is applied to find the minimum energy path and the energy barrier. It is found that the tensile loads make it easy for the 5|7 defect to glide, and lower the energy barrier. The minimum load level that makes a 5|7 defect glide freely with no energy barrier in the presence of an adatom is obtained.

Preliminary Study on the Role of Social Presence in Blended Learning Environment in Higher Education

Science.gov (United States)

Jusoff, Kamaruzaman; Khodabandelou, Rouhollah

2009-01-01

This paper contributes to the growing body of knowledge which identifies benefits for Blended Learning in the understanding of social processes role. It reports on an exploratory study into the role of social presence in blended learning environment. Employing a qualitative methodology, the study sought to understand social presence of learners in…

A Study on the Role of Drama in Learning Mathematics

Directory of Open Access Journals (Sweden)

Elahe Masoum

2013-08-01

Full Text Available Present educational systems needs modern strategies for teaching and learning. Mathematics education has to change for students in elementary schools. One of the modern strategies, it is drama activities. The drama is as empirical aspect of learning. The student may learn from what they are doing in drama. They are so active instead having a passive shape in drama, in fact, students are learning, finding experiences and new paths from drama as well. The students could find its capabilities, recommendations and strength-weakness points through the different drama. This study is looking to investigate the role of drama so that have a better understanding of mathematical concepts in Zahedan's girly elementary students (2011-12. This research is used on 36 three grade students through quasi-experiment method. The emerging results clearly showed that using drama in mathematics education has been better results against the traditional teaching. Then it seems that cited method is suitable for elementary students to learn mathematical concepts.

Dopants and defects in semiconductors

CERN Document Server

McCluskey, Matthew D

2012-01-01

"The book goes beyond the usual textbook in that it provides more specific examples of real-world defect physics … The book will be most useful for beginning graduate students in materials science. … an easy reading, broad introductory overview of the field …"-Materials Today, July-August 2012"… well written, with clear, lucid explanations …"-Chemistry World"The scientific development towards the method of controllable doping transformed the erratic and not reproducible family of semiconductor materials into the truly wonderful basis of modern microelectronics. This book tells the remarkable success story and I recommend it!"-Hans J. Queisser, Max-Planck-Institute, Stuttgart, Germany"McCluskey and Haller have written an outstanding modern guide to this field that will be useful to newcomers, and also to active researchers who want to broaden their horizons, as a means to learn the capabilities and limitations of the many techniques that are used in semiconductor-defect science."-Professor Michael J....

What can we learn from Raman Spectroscopy on irradiation-induced defects in UO2?

International Nuclear Information System (INIS)

Desgranges, L.; Martin, Ph.; Simon, P.; Guimbretiere, G.; Baldinozzi, G.

2014-01-01

Recent results on irradiated UO 2 by Raman spectroscopy evidenced Raman lines that are characteristic of irradiation-induced defects. Three main mechanisms are identified to explain their origin: resonant Raman, formation of new molecular entities, or breakdown in symmetry. Arguments are given to consider breakdown in symmetry as the predominant mechanism. A tentative description of the defects at the origin of this symmetry breakdown is proposed in terms of coordination polyhedrons of uranium. This discussion led us to consider that the Raman defect modes could be related to area with different stoichiometry. (authors)

Perceptions of Challenge: The Role of Catastrophe Theory in Piano Learning

Science.gov (United States)

Bugos, Jennifer; Lee, William

2015-01-01

The purpose of this study is to evaluate the perceptions of private piano instructors on the role of challenge in teaching and learning the piano and to examine the potential application of catastrophe theory in understanding the role and outcomes of such challenges. A 23-item electronic questionnaire was administered to collect quantitative and…

The Role of Mathematics Learning Centres in Engineering Education.

Science.gov (United States)

Fuller, Milton

2002-01-01

Points out the diminishing demand for mathematics undergraduate programs and the strong trend in engineering education to make greater use of computer coursework such as Mathcad, Matlab, and other software systems for the mathematical and statistical components of engineering programs. Describes the changing role of mathematics learning centers…

The Role of Emotion in Informal Science Learning: Testing an Exploratory Model

Science.gov (United States)

Staus, Nancy L.; Falk, John H.

2017-01-01

Although there is substantial research on the effect of emotions on educational outcomes in the classroom, relatively little is known about how emotion affects learning in informal science contexts. We examined the role of emotion in the context of an informal science learning experience by utilizing a path model to investigate the relationships…

Excess Oxygen Defects in Layered Cuprates

Science.gov (United States)

Lightfoot, P.; Pei, S. Y.; Jorgensen, J. D.; Manthiram, A.; Tang, X. X.; Goodenough, J. B.

1990-09-01

Neutron powder diffraction has been used to study the oxygen defect chemistry of two non-superconducting layered cuprates, La{sub 1. 25}Dy{sub 0.75}Cu{sub 3.75}F{sub 0.5}, having a T{sup {asterisk}}- related structure, and La{sub 1.85}Sr{sub 1.15}Cu{sub 2}O{sub 6.25}, having a structure related to that of the newly discovered double-layer superconductor La{sub 2-x}Sr{sub x}CaCu{sub 2}O{sub 6}. The role played by oxygen defects in determining the superconducting properties of layered cuprates is discussed.

Vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association with Mayer-Rokitansky-Küster-Hauser syndrome in co-occurrence

DEFF Research Database (Denmark)

Bjørsum-Meyer, Thomas; Herlin, Morten; Qvist, Niels

2016-01-01

Background: The vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome are rare conditions. We aimed to present two cases with the vertebral defect, anal atresia, cardiac...... defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser co-occurrence from our local surgical center and through a systematic literature search detect published cases. Furthermore, we aimed to collect existing knowledge...... in the embryopathogenesis and genetics in order to discuss a possible link between the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome. Case presentation: Our first case was a white girl...

The Role of Humor in Learning Physics: A Study of Undergraduate Students

Science.gov (United States)

Berge, Maria

2017-01-01

We all know that they do it, but what do students laugh "about" when learning science together? Although research has shown that students do use humor when they learn science, the role of humor in science education has received little attention. In this study, undergraduate students' laughter during collaborative work in physics has been…

The role of NPY in learning and memory.

Science.gov (United States)

Gøtzsche, C R; Woldbye, D P D

2016-02-01

High levels of NPY expression in brain regions important for learning and memory together with its neuromodulatory and neurotrophic effects suggest a regulatory role for NPY in memory processes. Therefore it is not surprising that an increasing number of studies have provided evidence for NPY acting as a modulator of neuroplasticity, neurotransmission, and memory. Here these results are presented in relation to the types of memory affected by NPY and its receptors. NPY can exert both inhibitory and stimulatory effects on memory, depending on memory type and phase, dose applied, brain region, and NPY receptor subtypes. Thus NPY act as a resilience factor by impairing associative implicit memory after stressful and aversive events, as evident in models of fear conditioning, presumably via Y1 receptors in the amygdala and prefrontal cortex. In addition, NPY impairs acquisition but enhances consolidation and retention in models depending on spatial and discriminative types of associative explicit memory, presumably involving Y2 receptor-mediated regulations of hippocampal excitatory transmission. Moreover, spatial memory training leads to increased hippocampal NPY gene expression that together with Y1 receptor-mediated neurogenesis could constitute necessary steps in consolidation and long-term retention of spatial memory. Altogether, NPY-induced effects on learning and memory seem to be biphasic, anatomically and temporally differential, and in support of a modulatory role of NPY at keeping the system in balance. Obtaining further insight into memory-related effects of NPY could inspire the engineering of new therapeutics targeting diseases where impaired learning and memory are central elements. Copyright © 2015 Elsevier Ltd. All rights reserved.

Topological defect clustering and plastic deformation mechanisms in functionalized graphene

Science.gov (United States)

Nunes, Ricardo; Araujo, Joice; Chacham, Helio

2011-03-01

We present ab initio results suggesting that strain plays a central role in the clustering of topological defects in strained and functionalized graphene models. We apply strain onto the topological-defect graphene networks from our previous work, and obtain topological-defect clustering patterns which are in excellent agreement with recent observations in samples of reduced graphene oxide. In our models, the graphene layer, containing an initial concentration of isolated topological defects, is covered by hydrogen or hydroxyl groups. Our results also suggest a rich variety of plastic deformation mechanism in functionalized graphene systems. We acknowledge support from the Brazilian agencies: CNPq, Fapemig, and INCT-Materiais de Carbono.

No significant role for beta tubulin mutations and mismatch repair defects in ovarian cancer resistance to paclitaxel/cisplatin

International Nuclear Information System (INIS)

Mesquita, Bárbara; Veiga, Isabel; Pereira, Deolinda; Tavares, Ana; Pinto, Isabel M; Pinto, Carla; Teixeira, Manuel R; Castedo, Sérgio

2005-01-01

The mechanisms of chemoresistance in ovarian cancer patients remain largely to be elucidated. Paclitaxel/cisplatin combination is the standard chemotherapeutic treatment for this disease, although some patients do not respond to therapy. Our goals were to investigate whether TUBB mutations and mismatch repair defects underlie paclitaxel and cisplatin resistance. Thirty-four patients with primary ovarian carcinomas (26 serous and eight clear cell carcinomas) treated with paclitaxel/cisplatin were analysed. TUBB exon 4 was analysed by nested PCR after a first round PCR using intronic primers. Microsatellite analysis was performed with the quasimonomorphic markers BAT 26 and BAT 34. Twenty-two of the 34 ovarian cancers (64.7%) presented residual tumour after surgery, seven of which (7/22; 31.8%) were shown to be chemoresistant (five serous and two clear cell tumours). Sequence analysis did not find any mutation in TUBB exon 4. Microsatellite instability was not detected in any of the ovarian carcinomas. We conclude that TUBB exon 4 mutations and mismatch repair defects do not play a significant role in paclitaxel/cisplatin resistance

A Description Grid to Support the Design of Learning Role-Play Games

Science.gov (United States)

Mariais, Christelle; Michau, Florence; Pernin, Jean-Philippe

2012-01-01

To strengthen the motivation of learners, the professional training sector is focusing more and more on game-based learning. In this context, the authors have become interested in the design of Learning Role-Play Game (LRPG) scenarios. The aim of this article is to improve the designers' confidence in the validity of the game-based learning…

Birth Defects

Science.gov (United States)

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of ... in the United States is born with a birth defect. A birth defect may affect how the ...

Defect dynamics in Li substituted nanocrystalline ZnO: A spectroscopic analysis

Science.gov (United States)

Ghosh, S.; Nambissan, P. M. G.; Thapa, S.; Mandal, K.

2014-12-01

Very recently, vacancy-type defects have been found to play a major role in stabilizing d0 ferromagnetism in various low dimensional ZnO systems. In this context, the evolution of vacancy-type defects within the ZnO nanocrystals due to the doping of ZnO by alkali metal lithium (Li) is investigated using X-ray photoelectron (XPS), photoluminescence (PL) and positron annihilation spectroscopy (PAS). Li-doping is found to have significant effects in modifying the vacancy-type defects, especially the Zn vacancy (VZn) defects within the ZnO lattice. XPS measurement indicated that initially the Li1+ ions substitute at Zn2+ sites, but when Li concentration exceeds 7 at%, excess Li starts to move through the interstitial sites. The increase in positron lifetime components and the lineshape S-parameter obtained from coincident Doppler broadening spectra with Li-doping indicated an enhancement of VZn defect concentration within the doped ZnO lattice. The vacancy type defects, initially of the predominant configuration VZn+O+Zn got reduced to neutral ZnO divacancies due to the partial recombination by the doped Li1+ ions but, when the doping concentration exceeded 7 at% and Li1+ ions started migrating to the interstitials, positron diffusion is partly impeded and this results in reduced probability of annihilation. PL spectra have shown intense green and yellow-orange emission due to the stabilization of a large number of VZn defects and Li substitutional (LiZn) defects respectively. Hence Li can be a very useful dopant in stabilizing and modifying significant amount of Zn vacancy-defects which can play a useful role in determining the material behavior.

Defect dynamics in Li substituted nanocrystalline ZnO: A spectroscopic analysis

International Nuclear Information System (INIS)

Ghosh, S.; Nambissan, P.M.G.; Thapa, S.; Mandal, K.

2014-01-01

Very recently, vacancy-type defects have been found to play a major role in stabilizing d 0 ferromagnetism in various low dimensional ZnO systems. In this context, the evolution of vacancy-type defects within the ZnO nanocrystals due to the doping of ZnO by alkali metal lithium (Li) is investigated using X-ray photoelectron (XPS), photoluminescence (PL) and positron annihilation spectroscopy (PAS). Li-doping is found to have significant effects in modifying the vacancy-type defects, especially the Zn vacancy (V Zn ) defects within the ZnO lattice. XPS measurement indicated that initially the Li 1+ ions substitute at Zn 2+ sites, but when Li concentration exceeds 7 at%, excess Li starts to move through the interstitial sites. The increase in positron lifetime components and the lineshape S-parameter obtained from coincident Doppler broadening spectra with Li-doping indicated an enhancement of V Zn defect concentration within the doped ZnO lattice. The vacancy type defects, initially of the predominant configuration V Zn+O+Zn got reduced to neutral ZnO divacancies due to the partial recombination by the doped Li 1+ ions but, when the doping concentration exceeded 7 at% and Li 1+ ions started migrating to the interstitials, positron diffusion is partly impeded and this results in reduced probability of annihilation. PL spectra have shown intense green and yellow-orange emission due to the stabilization of a large number of V Zn defects and Li substitutional (Li Zn ) defects respectively. Hence Li can be a very useful dopant in stabilizing and modifying significant amount of Zn vacancy-defects which can play a useful role in determining the material behavior

A specific implicit sequence learning deficit as an underlying cause of dyslexia? Investigating the role of attention in implicit learning tasks.

Science.gov (United States)

Staels, Eva; Van den Broeck, Wim

2017-05-01

Recently, a general implicit sequence learning deficit was proposed as an underlying cause of dyslexia. This new hypothesis was investigated in the present study by including a number of methodological improvements, for example, the inclusion of appropriate control conditions. The second goal of the study was to explore the role of attentional functioning in implicit and explicit learning tasks. In a 2 × 2 within-subjects design 4 tasks were administered in 30 dyslexic and 38 control children: an implicit and explicit serial reaction time (RT) task and an implicit and explicit contextual cueing task. Attentional functioning was also administered. The entire learning curves of all tasks were analyzed using latent growth curve modeling in order to compare performances between groups and to examine the role of attentional functioning on the learning curves. The amount of implicit learning was similar for both groups. However, the dyslexic group showed slower RTs throughout the entire task. This group difference reduced and became nonsignificant after controlling for attentional functioning. Both implicit learning tasks, but none of the explicit learning tasks, were significantly affected by attentional functioning. Dyslexic children do not suffer from a specific implicit sequence learning deficit. The slower RTs of the dyslexic children throughout the entire implicit sequence learning process are caused by their comorbid attention problems and overall slowness. A key finding of the present study is that, in contrast to what was assumed for a long time, implicit learning relies on attentional resources, perhaps even more than explicit learning does. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Role of Structure in Learning Non-Euclidean Geometry

Science.gov (United States)

Asmuth, Jennifer A.

2009-01-01

How do people learn novel mathematical information that contradicts prior knowledge? The focus of this thesis is the role of structure in the acquisition of knowledge about hyperbolic geometry, a non-Euclidean geometry. In a series of three experiments, I contrast a more holistic structure--training based on closed figures--with a mathematically…

Revisit of Nasolabial flap in the reconstruction of defects involving ...

African Journals Online (AJOL)

Conclusion: Data from this study suggest that NL flap is a reliable option for reconstruction of the oral floor, in form as well as function, without esthetic compromise and has a major role even in this era of free flaps. Keywords: Floor of mouth defects, local flaps, nasolabail flap, oral cavity defects, reconstruction, regional flaps ...

The Biggs and Moore Model in E-Learning: The Role of Motivation and Collaboration as Moderators

Science.gov (United States)

Haverila, Matti J.

2012-01-01

The purpose of this paper is to report the findings of a research conducted to evaluate the effect of e-learning experience on students' perceived learning outcomes, and more specifically the role of motivation and collaboration as moderators between the e-learning experience and the learning outcome. The perceived learning outcome was measured…

Surface Casting Defects Inspection Using Vision System and Neural Network Techniques

Directory of Open Access Journals (Sweden)

Świłło S.J.

2013-12-01

Full Text Available The paper presents a vision based approach and neural network techniques in surface defects inspection and categorization. Depending on part design and processing techniques, castings may develop surface discontinuities such as cracks and pores that greatly influence the material’s properties Since the human visual inspection for the surface is slow and expensive, a computer vision system is an alternative solution for the online inspection. The authors present the developed vision system uses an advanced image processing algorithm based on modified Laplacian of Gaussian edge detection method and advanced lighting system. The defect inspection algorithm consists of several parameters that allow the user to specify the sensitivity level at which he can accept the defects in the casting. In addition to the developed image processing algorithm and vision system apparatus, an advanced learning process has been developed, based on neural network techniques. Finally, as an example three groups of defects were investigated demonstrates automatic selection and categorization of the measured defects, such as blowholes, shrinkage porosity and shrinkage cavity.

Yarn-dyed fabric defect classification based on convolutional neural network

Science.gov (United States)

Jing, Junfeng; Dong, Amei; Li, Pengfei; Zhang, Kaibing

2017-09-01

Considering that manual inspection of the yarn-dyed fabric can be time consuming and inefficient, we propose a yarn-dyed fabric defect classification method by using a convolutional neural network (CNN) based on a modified AlexNet. CNN shows powerful ability in performing feature extraction and fusion by simulating the learning mechanism of human brain. The local response normalization layers in AlexNet are replaced by the batch normalization layers, which can enhance both the computational efficiency and classification accuracy. In the training process of the network, the characteristics of the defect are extracted step by step and the essential features of the image can be obtained from the fusion of the edge details with several convolution operations. Then the max-pooling layers, the dropout layers, and the fully connected layers are employed in the classification model to reduce the computation cost and extract more precise features of the defective fabric. Finally, the results of the defect classification are predicted by the softmax function. The experimental results show promising performance with an acceptable average classification rate and strong robustness on yarn-dyed fabric defect classification.

E-learning Constructive Role Plays for EFL Learners in China's Tertiary Education

Science.gov (United States)

Shen, Lin; Suwanthep, Jitpanat

2011-01-01

Recently, speaking has played an increasingly important role in second/foreign language settings. However, in many Chinese universities, EFL students rarely communicate in English with other people effectively. The existing behavioristic role plays on New Horizon College English (NHCE) e-learning do not function successfully in supplementing EFL…

Simulation modelling: educational development roles for learning technologists

Directory of Open Access Journals (Sweden)

David Riley

2002-12-01

Full Text Available Simulation modelling was in the mainstream of CAL development in the 1980s when the late David Squires introduced this author to the Dynamic Modelling System. Since those early days, it seems that simulation modelling has drifted into a learning technology backwater to become a member of Laurillard's underutilized, 'adaptive and productive' media. Referring to her Conversational Framework, Laurillard constructs a pedagogic case for modelling as a productive student activity but provides few references to current practice and available resources. This paper seeks to complement her account by highlighting the pioneering initiatives of the Computers in the Curriculum Project and more recent developments in systems modelling within geographic and business education. The latter include improvements to system dynamics modelling programs such as STELLA®, the publication of introductory textbooks, and the emergence of online resources. The paper indicates several ways in which modelling activities may be approached and identifies some educational development roles for learning technologists. The paper concludes by advocating simulation modelling as an exemplary use of learning technologies - one that realizes their creative-transformative potential.

Analysis of probability of defects in the disposal canisters

International Nuclear Information System (INIS)

Holmberg, J.-E.; Kuusela, P.

2011-06-01

This report presents a probability model for the reliability of the spent nuclear waste final disposal canister. Reliability means here that the welding of the canister lid has no critical defects from the long-term safety point of view. From the reliability point of view, both the reliability of the welding process (that no critical defects will be born) and the non-destructive testing (NDT) process (all critical defects will be detected) are equally important. In the probability model, critical defects in a weld were simplified into a few types. Also the possibility of human errors in the NDT process was taken into account in a simple manner. At this moment there is very little representative data to determine the reliability of welding and also the data on NDT is not well suited for the needs of this study. Therefore calculations presented here are based on expert judgements and on several assumptions that have not been verified yet. The Bayesian probability model shows the importance of the uncertainty in the estimation of the reliability parameters. The effect of uncertainty is that the probability distribution of the number of defective canisters becomes flat for larger numbers of canisters compared to the binomial probability distribution in case of known parameter values. In order to reduce the uncertainty, more information is needed from both the reliability of the welding and NDT processes. It would also be important to analyse the role of human factors in these processes since their role is not reflected in typical test data which is used to estimate 'normal process variation'.The reported model should be seen as a tool to quantify the roles of different methods and procedures in the weld inspection process. (orig.)

Strategic organisational transformation: The role of learning,leadership and culture

Directory of Open Access Journals (Sweden)

K. Viljoen

2001-12-01

Full Text Available Today's organisation need to continuously adapts itself to challenges, brought about by modern business environment. This paper argues that leadership, learning and culture play a major role in securing an organisation's ability to face and adapt to these new challenges.

Effect of consanguinity on birth defects in Saudi women; results from a nested case-control study

DEFF Research Database (Denmark)

Majeed-Saidan, Muhammad Ali; Ammari, Amer N; AlHashem, Amal M

2015-01-01

BACKGROUND: The role of consanguinity in the etiology of structural birth defects outside of chromosomal and inherited disorders has always been debated. We studied the independent role of consanguinity on birth defects in Saudi women with a high prevalence of consanguineous marriages. METHODS: T...

The Impact of Taiwanese College Students' Learning Motivation from Self-Determination Perspective on Learning Outcomes: Moderating Roles of Multi-Traits

Science.gov (United States)

Ho, Sophia Shi-Huei

2017-01-01

The purpose of this study is to explore the associations among learning motivation, engagement and outcomes, and the moderating role of various traits in the relationship between deep approaches to learning and outcomes. Based on data from 2,340 students in multiple universities in Taiwan, this study proposes two alternative models, tested by…

Distinct roles of the RasGAP family proteins in C. elegans associative learning and memory.

Science.gov (United States)

Gyurkó, M Dávid; Csermely, Péter; Sőti, Csaba; Steták, Attila

2015-10-15

The Ras GTPase activating proteins (RasGAPs) are regulators of the conserved Ras/MAPK pathway. Various roles of some of the RasGAPs in learning and memory have been reported in different model systems, yet, there is no comprehensive study to characterize all gap genes in any organism. Here, using reverse genetics and neurobehavioural tests, we studied the role of all known genes of the rasgap family in C. elegans in associative learning and memory. We demonstrated that their proteins are implicated in different parts of the learning and memory processes. We show that gap-1 contribute redundantly with gap-3 to the chemosensation of volatile compounds, gap-1 plays a major role in associative learning, while gap-2 and gap-3 are predominantly required for short- and long-term associative memory. Our results also suggest that the C. elegans Ras orthologue let-60 is involved in multiple processes during learning and memory. Thus, we show that the different classes of RasGAP proteins are all involved in cognitive function and their complex interplay ensures the proper formation and storage of novel information in C. elegans.

Optical properties of GaSb(001)-c(2 x 6): The role of surface antisite defects

Energy Technology Data Exchange (ETDEWEB)

Hogan, Conor; Del Sole, Rodolfo [Department of Physics, CNR-INFM-SMC, Roma (Italy); European Theoretical Spectroscopy Facility (ETSF), University of Rome ' ' Tor Vergata' ' , Roma (Italy); Magri, Rita [Centro S3-CNR-Istituto di Nanoscienze, Modena (Italy); Department of Physics, University of Modena and Reggio Emilia, Modena (Italy)

2010-08-15

We consider the formation of surface antisite defects on a previously proposed model for the GaSb(001)-c(2 x 6) surface. Based on ab initio total energy calculations, we show how these defects stabilize the otherwise metallic surface and how their formation is driven by the excess charge associated with the Sb-rich surface conditions. The surface-sensitive optical technique of reflectance anisotropy spectroscopy is shown to be crucial for detecting the defects, and computation of spectra yields a good agreement with experiment when defects are included in the surface reconstruction. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

The Role of Involvement in Learning Management System Success

Science.gov (United States)

Klobas, Jane E.; McGill, Tanya J.

2010-01-01

Learning management systems (LMS) have been adopted by the majority of higher education institutions and research that explores the factors that influence the success of LMS is needed. This paper investigates the roles of student and instructor involvement in LMS success, using the DeLone and McLean (2003) model of information systems success as a…

THE BIGGS AND MOORE MODEL IN E-LEARNING: The Role of Motivation and Collaboration as Moderators

OpenAIRE

Matti J. HAVERILA

2012-01-01

The purpose of this paper is to report the findings of a research conducted to evaluate the effect of e-learning experience on students’ perceived learning outcomes, and more specifically the role of motivation and collaboration as moderators between the e-learning experience and the learning outcome. The perceived learning outcome was measured with whether the students perceived to learn more in e-learning vis-à-vis traditional learning context. The participants came from an undergraduat...

Dark matter from cosmic defects on galactic scales?

International Nuclear Information System (INIS)

Guerreiro, N.; Carvalho, J. P. M. de; Avelino, P. P.; Martins, C. J. A. P.

2008-01-01

We discuss the possible dynamical role of extended cosmic defects on galactic scales, specifically focusing on the possibility that they may provide the dark matter suggested by the classical problem of galactic rotation curves. We emphasize that the more standard defects (such as Goto-Nambu strings) are unsuitable for this task but show that more general models (such as transonic wiggly strings) could in principle have a better chance. In any case, we show that observational data severely restricts any such scenarios.

Defect dynamics in Li substituted nanocrystalline ZnO: A spectroscopic analysis

Energy Technology Data Exchange (ETDEWEB)

Ghosh, S., E-mail: sghoshphysics@gmail.com [Department of Material Science, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India); Nambissan, P.M.G.; Thapa, S. [Applied Nuclear Physics Division, Saha Institute of Nuclear Physics, Sector 1, Block AF, Bidhannagar, Kolkata 700064 (India); Mandal, K. [Department of Condensed Matter Physics and Material Sciences, S.N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098 (India)

2014-12-01

Very recently, vacancy-type defects have been found to play a major role in stabilizing d{sup 0} ferromagnetism in various low dimensional ZnO systems. In this context, the evolution of vacancy-type defects within the ZnO nanocrystals due to the doping of ZnO by alkali metal lithium (Li) is investigated using X-ray photoelectron (XPS), photoluminescence (PL) and positron annihilation spectroscopy (PAS). Li-doping is found to have significant effects in modifying the vacancy-type defects, especially the Zn vacancy (V{sub Zn}) defects within the ZnO lattice. XPS measurement indicated that initially the Li{sup 1+} ions substitute at Zn{sup 2+} sites, but when Li concentration exceeds 7 at%, excess Li starts to move through the interstitial sites. The increase in positron lifetime components and the lineshape S-parameter obtained from coincident Doppler broadening spectra with Li-doping indicated an enhancement of V{sub Zn} defect concentration within the doped ZnO lattice. The vacancy type defects, initially of the predominant configuration V{sub Zn+O+Zn} got reduced to neutral ZnO divacancies due to the partial recombination by the doped Li{sup 1+} ions but, when the doping concentration exceeded 7 at% and Li{sup 1+} ions started migrating to the interstitials, positron diffusion is partly impeded and this results in reduced probability of annihilation. PL spectra have shown intense green and yellow-orange emission due to the stabilization of a large number of V{sub Zn} defects and Li substitutional (Li{sub Zn}) defects respectively. Hence Li can be a very useful dopant in stabilizing and modifying significant amount of Zn vacancy-defects which can play a useful role in determining the material behavior.

Thermal buckling behavior of defective CNTs under pre-load: A molecular dynamics study.

Science.gov (United States)

Mehralian, Fahimeh; Tadi Beni, Yaghoub; Kiani, Yaser

2017-05-01

Current study is concentrated on the extraordinary properties of defective carbon nanotubes (CNTs). The role of vacancy defects in thermal buckling response of precompressed CNTs is explored via molecular dynamics (MD) simulations. Defective CNTs are initially compressed at a certain ratio of their critical buckling strain and then undergo a uniform temperature rise. Comprehensive study is implemented on both armchair and zigzag CNTs with different vacancy defects including monovacancy, symmetric bivacancy and asymmetric bivacancy. The results reveal that defects have a pronounced impact on the buckling behavior of CNTs; interestingly, defective CNTs under compressive pre-load show higher resistance to thermal buckling than pristine ones. In the following, the buckling response of defective CNTs is shown to be dependent on the vacancy defects, location of defects and chirality. Copyright © 2017 Elsevier Inc. All rights reserved.

Loss of C. elegans BBS-7 and BBS-8 protein function results in cilia defects and compromised intraflagellar transport

Science.gov (United States)

Blacque, Oliver E.; Reardon, Michael J.; Li, Chunmei; McCarthy, Jonathan; Mahjoub, Moe R.; Ansley, Stephen J.; Badano, Jose L.; Mah, Allan K.; Beales, Philip L.; Davidson, William S.; Johnsen, Robert C.; Audeh, Mark; Plasterk, Ronald H.A.; Baillie, David L.; Katsanis, Nicholas; Quarmby, Lynne M.; Wicks, Stephen R.; Leroux, Michel R.

2004-01-01

Bardet-Biedl syndrome (BBS) is a genetically heterogeneous developmental disorder whose molecular basis is largely unknown. Here, we show that mutations in the Caenorhabditis elegans bbs-7 and bbs-8 genes cause structural and functional defects in cilia. C. elegans BBS proteins localize predominantly at the base of cilia, and like proteins involved in intraflagellar transport (IFT), a process necessary for cilia biogenesis and maintenance, move bidirectionally along the ciliary axoneme. Importantly, we demonstrate that BBS-7 and BBS-8 are required for the normal localization/motility of the IFT proteins OSM-5/Polaris and CHE-11, and to a notably lesser extent, CHE-2. We propose that BBS proteins play important, selective roles in the assembly and/or function of IFT particle components. Our findings also suggest that some of the cardinal and secondary symptoms of BBS, such as obesity, diabetes, cardiomyopathy, and learning defects may result from cilia dysfunction. PMID:15231740

Defect creation in solids by a decay of electronic excitations

International Nuclear Information System (INIS)

Klinger, M.I.; Lushchik, Ch.B.; Mashovets, T.V.; Kholodar', G.A.; Shejnkman, M.K.; Ehlango, M.A.; Kievskij Gosudarstvennyj Univ.; AN Ukrainskoj SSR, Kiev. Inst. Poluprovodnikov)

1985-01-01

A new type of radiationless transitions in nonmetallic solids accompanied by neither the extraction of a heat nor the luminescence, but by a large (in comparison with the interatomic distance) displacements of a small number of atoms is discussed. A classification is given of the instabilities (electrostatic, electron-vibrational, structural) leading to a creation of the defects in crystalline and glassy solids. The processes of the defect creation, due to both the decay of self-trapped excitions in ionic crystals and the multiple ionization of atoms near the pre-existing charged centres in semiconductor are described. The mechanisms of the complex defects reconstruction in semiconductors by nonequilibrium charge carriers and by an electron-hole recombination are discussed. The role of charge carriers in a thermal defect generation is considered. A mechanism of the peculiar defect creation in glassy semiconductors is discussed

Defects and Disorder in the Drosophila Eye

Science.gov (United States)

Kim, Sangwoo; Carthew, Richard; Hilgenfeldt, Sascha

Cell division and differentiation tightly control the regular pattern in the normal eye of the Drosophila fruit fly while certain genetic mutations introduce disorder in the form of topological defects. Analyzing data from pupal retinas, we develop a model based on Voronoi construction that explains the defect statistics as a consequence of area variation of individual facets (ommatidia). The analysis reveals a previously unknown systematic long-range area variation that spans the entire eye, with distinct effects on topological disorder compared to local fluctuations. The internal structure of the ommatidia and the stiffness of their interior cells also plays a crucial role in the defect generation. Accurate predictions of the correlation between the area variation and the defect density in both normal and mutant animals are obtained without free parameters. This approach can potentially be applied to cellular systems in many other contexts to identify size-topology correlations near the onset of symmetry breaking. This work has been supported by the NIH (GM098077) and the NSF (Grant No. 1504301).

Electronic Human Resource Management: Organizational Responses to Role Conflicts Created by e-Learning

Science.gov (United States)

Oiry, Ewan

2009-01-01

Could enthusiasm for e-learning be dampened because it is detrimental to the relationships between those undergoing e-training and their direct managers or colleagues? Interviews conducted in four French banks provide material to explore this question. We see that e-learning has increasingly been adopted because it goes beyond the role limitations…

Congenital Heart Defects and Receipt of Special Education Services.

Science.gov (United States)

Riehle-Colarusso, Tiffany; Autry, Andrew; Razzaghi, Hilda; Boyle, Coleen A; Mahle, William T; Van Naarden Braun, Kim; Correa, Adolfo

2015-09-01

We investigated the prevalence of receipt of special education services among children with congenital heart defects (CHDs) compared with children without birth defects. Children born from 1982 to 2004 in metropolitan Atlanta with CHDs (n = 3744) were identified from a population-based birth defect surveillance program; children without birth defects (n = 860 715) were identified from birth certificates. Cohorts were linked to special education files for the 1992-2012 school years to identify special education services. Children with noncardiac defects or genetic syndromes were excluded; children with CHDs were classified by presence or absence of critical CHDs (ie, CHDs requiring intervention by age one year). We evaluated the prevalence of receipt of special education services and prevalence rate ratios using children without birth defects as a reference. Compared with children without birth defects, children with CHDs were 50% more likely to receive special education services overall (adjusted prevalence rate ratio [aPRR] = 1.5; 95% confidence interval [CI]: 1.4-1.7). Specifically, they had higher prevalence of several special education categories including: intellectual disability (aPRR = 3.8; 95% CI: 2.8-5.1), sensory impairment (aPRR = 3.0; 95% CI: 1.8-5.0), other health impairment (aPRR = 2.8; 95% CI: 2.2-3.5), significant developmental delay (aPRR = 1.9; 95% CI: 1.3-2.8), and specific learning disability (aPRR = 1.4; 95% CI: 1.1-1.7). For most special education services, the excess prevalence did not vary by presence of critical CHDs. Children with CHDs received special education services more often than children without birth defects. These findings highlight the need for special education services and the importance of developmental screening for all children with CHDs. Copyright © 2015 by the American Academy of Pediatrics.

The Role of Metacognitive Strategies in Learning Music: A Multiple Case Study

Science.gov (United States)

Colombo, Barbara; Antonietti, Alessandro

2017-01-01

The positive role of metacognition in music learning and practice is well assessed, but the role of musicians' metacognitive skills in such a context is not yet clear. Teachers often state that they apply a metacognitive approach during their lessons, but students fail to acknowledge it and report that they become metacognitive learners thanks to…

Curvature-Controlled Topological Defects

Directory of Open Access Journals (Sweden)

Luka Mesarec

2017-05-01

Full Text Available Effectively, two-dimensional (2D closed films exhibiting in-plane orientational ordering (ordered shells might be instrumental for the realization of scaled crystals. In them, ordered shells are expected to play the role of atoms. Furthermore, topological defects (TDs within them would determine their valence. Namely, bonding among shells within an isotropic liquid matrix could be established via appropriate nano-binders (i.e., linkers which tend to be attached to the cores of TDs exploiting the defect core replacement mechanism. Consequently, by varying configurations of TDs one could nucleate growth of scaled crystals displaying different symmetries. For this purpose, it is of interest to develop a simple and robust mechanism via which one could control the position and number of TDs in such atoms. In this paper, we use a minimal mesoscopic model, where variational parameters are the 2D curvature tensor and the 2D orientational tensor order parameter. We demonstrate numerically the efficiency of the effective topological defect cancellation mechanism to predict positional assembling of TDs in ordered films characterized by spatially nonhomogeneous Gaussian curvature. Furthermore, we show how one could efficiently switch among qualitatively different structures by using a relative volume v of ordered shells, which represents a relatively simple naturally accessible control parameter.

Carbon nanotube as NEMS sensor - effect of chirality and stone-wales defect intend

International Nuclear Information System (INIS)

Gayathri, V; Geetha, R

2006-01-01

Having nanosize and unique electrical properties, carbon nanotubes (CNTs) attract lot of interest among scientific community all over the world. One of the recent observations is its role as nanosensors. Obviously the nanosize and high strength of CNT are most preferred parameter for technical and electromechanical field in the industrial point of view. The defects in CNT structure have a vital role in determining their electrical and mechanical properties. Our earlier study indicates an effective role played by the topological defects like pentagon and octagon on the electromechanical properties of these nanostructures. Here our aim is to look in to the effect of Stone-wales defect and chirality on this property of nanotubes deformed under applied pressure. Among the three kinds of tubes considered for this study, we observed that armchair (5, 5) tube is more suitable for sensor applications

[Are Visual Field Defects Reversible? - Visual Rehabilitation with Brains].

Science.gov (United States)

Sabel, B A

2017-02-01

Visual field defects are considered irreversible because the retina and optic nerve do not regenerate. Nevertheless, there is some potential for recovery of the visual fields. This can be accomplished by the brain, which analyses and interprets visual information and is able to amplify residual signals through neuroplasticity. Neuroplasticity refers to the ability of the brain to change its own functional architecture by modulating synaptic efficacy. This is actually the neurobiological basis of normal learning. Plasticity is maintained throughout life and can be induced by repetitively stimulating (training) brain circuits. The question now arises as to how plasticity can be utilised to activate residual vision for the treatment of visual field loss. Just as in neurorehabilitation, visual field defects can be modulated by post-lesion plasticity to improve vision in glaucoma, diabetic retinopathy or optic neuropathy. Because almost all patients have some residual vision, the goal is to strengthen residual capacities by enhancing synaptic efficacy. New treatment paradigms have been tested in clinical studies, including vision restoration training and non-invasive alternating current stimulation. While vision training is a behavioural task to selectively stimulate "relative defects" with daily vision exercises for the duration of 6 months, treatment with alternating current stimulation (30 min. daily for 10 days) activates and synchronises the entire retina and brain. Though full restoration of vision is not possible, such treatments improve vision, both subjectively and objectively. This includes visual field enlargements, improved acuity and reaction time, improved orientation and vision related quality of life. About 70 % of the patients respond to the therapies and there are no serious adverse events. Physiological studies of the effect of alternating current stimulation using EEG and fMRI reveal massive local and global changes in the brain. These include

Strong Coupling between Nanofluidic Transport and Interfacial Chemistry: How Defect Reactivity Controls Liquid-Solid Friction through Hydrogen Bonding.

Science.gov (United States)

Joly, Laurent; Tocci, Gabriele; Merabia, Samy; Michaelides, Angelos

2016-04-07

Defects are inevitably present in nanofluidic systems, yet the role they play in nanofluidic transport remains poorly understood. Here, we report ab initio molecular dynamics (AIMD) simulations of the friction of liquid water on defective graphene and boron nitride sheets. We show that water dissociates at certain defects and that these "reactive" defects lead to much larger friction than the "nonreactive" defects at which water molecules remain intact. Furthermore, we find that friction is extremely sensitive to the chemical structure of reactive defects and to the number of hydrogen bonds they can partake in with the liquid. Finally, we discuss how the insight obtained from AIMD can be used to quantify the influence of defects on friction in nanofluidic devices for water treatment and sustainable energy harvesting. Overall, we provide new insight into the role of interfacial chemistry on nanofluidic transport in real, defective systems.

BDA: A novel method for identifying defects in body-centered cubic crystals.

Science.gov (United States)

Möller, Johannes J; Bitzek, Erik

2016-01-01

The accurate and fast identification of crystallographic defects plays a key role for the analysis of atomistic simulation output data. For face-centered cubic (fcc) metals, most existing structure analysis tools allow for the direct distinction of common defects, such as stacking faults or certain low-index surfaces. For body-centered cubic (bcc) metals, on the other hand, a robust way to identify such defects is currently not easily available. We therefore introduce a new method for analyzing atomistic configurations of bcc metals, the BCC Defect Analysis (BDA). It uses existing structure analysis algorithms and combines their results to uniquely distinguish between typical defects in bcc metals. In essence, the BDA method offers the following features:•Identification of typical defect structures in bcc metals.•Reduction of erroneously identified defects by iterative comparison to the defects in the atom's neighborhood.•Availability as ready-to-use Python script for the widespread visualization tool OVITO [http://ovito.org].

Eddy Current Signature Classification of Steam Generator Tube Defects Using A Learning Vector Quantization Neural Network

International Nuclear Information System (INIS)

Garcia, Gabe V.

2005-01-01

A major cause of failure in nuclear steam generators is degradation of their tubes. Although seven primary defect categories exist, one of the principal causes of tube failure is intergranular attack/stress corrosion cracking (IGA/SCC). This type of defect usually begins on the secondary side surface of the tubes and propagates both inwards and laterally. In many cases this defect is found at or near the tube support plates

Potential Role of Honey in Learning and Memory

Directory of Open Access Journals (Sweden)

Zahiruddin Othman

2015-04-01

Full Text Available The composition and physicochemical properties of honey are variable depending on its floral source and often named according to the geographical location. The potential medicinal benefits of Tualang honey, a multifloral jungle honey found in Malaysia, have recently been attracting attention because of its reported beneficial effects in various diseases. This paper reviews the effects of honey, particularly Tualang honey, on learning and memory. Information regarding the effects of Tualang honey on learning and memory in human as well as animal models is gleaned to hypothesize its underlying mechanisms. These studies show that Tualang honey improves morphology of memory-related brain areas, reduces brain oxidative stress, increases brain-derived neurotrophic factor (BDNF and acetylcholine (ACh concentrations, and reduces acetylcholinesterase (AChE in the brain homogenates. Its anti-inflammatory roles in reducing inflammatory trigger and microglial activation have yet to be investigated. It is hypothesized that the improvement in learning and memory following Tualang honey supplementation is due to the significant improvement in brain morphology and enhancement of brain cholinergic system secondary to reduction in brain oxidative damage and/or upregulation of BDNF concentration. Further studies are imperative to elucidate the molecular mechanism of actions.

Midgap states and band gap modification in defective graphene/h-BN heterostructures

NARCIS (Netherlands)

Sachs, B.; Wehling, T.O.; Katsnelson, M.I.; Lichtenstein, A.I.

2016-01-01

The role of defects in van der Waals heterostructures made of graphene and hexagonal boron nitride (h-BN) is studied using a combination of ab initio and model calculations. Despite the weak van der Waals interaction between layers, defects residing in h-BN, such as carbon impurities and antisite

The role of culture in perceptual learning styles

OpenAIRE

حسینی فاطمی ، پیشقدم حسینی فاطمی ، پیشقدم

2009-01-01

The major aim of this article is to determine the role of culture in perceptual learning style (PLS) preferences of Iranian English learners, in order to minimize teacher-student style conflict in the classroom. To do this, 400 university students from different fields of study were selected from Allameh Tabatabaee University in Tehran, Ferdowsi University of Mashhad and Mashhad University of Medical Sciences. The subjects were asked to answer Reid’s questionnaire (1987) which was designed to...

Observation of zone folding induced acoustic topological insulators and the role of spin-mixing defects

Science.gov (United States)

Deng, Yuanchen; Ge, Hao; Tian, Yuan; Lu, Minghui; Jing, Yun

2017-11-01

This article reports on the experimental realization of a flow-free, pseudospin-based acoustic topological insulator designed using the strategy of zone folding. Robust sound one-way propagation is demonstrated with the presence of non-spin-mixing defects. On the other hand, it is shown that spin-mixing defects, which break the geometric symmetry and therefore the pseudo-time-reversal symmetry, can open up nontrivial band gaps within the edge state frequency band, and their width can be tailored by the extent of the defect. This provides a possible route for realizing tunable acoustic topological insulators.

The role of defects in the design of space elevator cable: From nanotube to megatube

Energy Technology Data Exchange (ETDEWEB)

Pugno, Nicola M. [Department of Structural Engineering and Geotechnics, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy)], E-mail: nicola.pugno@polito.it

2007-09-15

Researchers are claiming that the feasibility of space elevator cable is now realistic, thanks to carbon nanotube technology, proposing its realization within a decade. However, the current view of basing the design of the megacable on the theoretical strength of a single carbon nanotube is naive, as has recently been emphasized. In this paper the role of thermodynamically unavoidable atomistic defects with different size and shape is quantified on brittle fracture, fatigue and elasticity, for nanotubes and nanotube bundles. Nonasymptotic regimes, elastic plasticity, rough cracks, finite domains and size effects are also discussed. The results are compared with atomistic simulations and nanotensile tests of carbon nanotubes. Key simple formulas for the design of a flaw-tolerant space elevator megacable are reported, suggesting that it would need a taper ratio (for uniform stress) of about two orders of magnitude larger than currently proposed.

Separating genetic and hemodynamic defects in neuropilin 1 knockout embryos.

Science.gov (United States)

Jones, Elizabeth A V; Yuan, Li; Breant, Christine; Watts, Ryan J; Eichmann, Anne

2008-08-01

Targeted inactivation of genes involved in murine cardiovascular development frequently leads to abnormalities in blood flow. As blood fluid dynamics play a crucial role in shaping vessel morphology, the presence of flow defects generally prohibits the precise assignment of the role of the mutated gene product in the vasculature. In this study, we show how to distinguish between genetic defects caused by targeted inactivation of the neuropilin 1 (Nrp1) receptor and hemodynamic defects occurring in homozygous knockout embryos. Our analysis of a Nrp1 null allele bred onto a C57BL/6 background shows that vessel remodeling defects occur concomitantly with the onset of blood flow and cause death of homozygous mutants at E10.5. Using mouse embryo culture, we establish that hemodynamic defects are already present at E8.5 and continuous circulation is never established in homozygous mutants. The geometry of yolk sac blood vessels is altered and remodeling into yolk sac arteries and veins does not occur. To separate flow-induced deficiencies from those caused by the Nrp1 mutation, we arrested blood flow in cultured wild-type and mutant embryos and followed their vascular development. We find that loss of Nrp1 function rather than flow induces the altered geometry of the capillary plexus. Endothelial cell migration, but not replication, is altered in Nrp1 mutants. Gene expression analysis of endothelial cells isolated from freshly dissected wild-type and mutants and after culture in no-flow conditions showed down-regulation of the arterial marker genes connexin 40 and ephrin B2 related to the loss of Nrp1 function. This method allows genetic defects caused by loss-of-function of a gene important for cardiovascular development to be isolated even in the presence of hemodynamic defects.

Using Massively Multiplayer Online Role-Playing Games for Online Learning

Science.gov (United States)

Childress, Marcus D.; Braswell, Ray

2006-01-01

This article addresses the use of a massively multiplayer online role-playing game (MMORPG) to foster communication and interaction and to facilitate cooperative learning in an online course. The authors delineate the definition and history of massively multiplayer online games (MMOGs), and describe current uses of MMORPGs in education, including…

Personal Learning Environments and University Teacher Roles Explored Using Delphi

Science.gov (United States)

Shaikh, Zaffar Ahmed; Khoja, Shakeel Ahmed

2014-01-01

This paper presents the results of research using an online Delphi method, which aimed to explore university teacher roles and readiness for learner-centred pedagogy, driven by personal learning environments (PLEs). Using a modified Policy Delphi technique, a group of researchers worked with 34 international experts who are university teachers by…

Interactive Role of Organizational Learning and Informal Norms in Accountability and Job Performance in 2014

Directory of Open Access Journals (Sweden)

Abolfazl Ghasemzadeh

2015-09-01

Full Text Available Introduction: Although the contribution of organizational learning to employee organizational performance is well documented, the mechanisms that explain such relationship remain unclear. Accordingly, the purpose of this paper is to investigate the interactional role of organizational learning and informal norms in accountability and job performance of the staff in a medical department. Methods: The research method of the study is descriptive-correlational type. The statistical population of this study included all staff (N=315 of the Medical Department in Oshnavieh Hospital in 2014. For data gathering in this study, a sample comprising of 180 staff was selected using stratified random sampling. The data were collected through standard questionnaires of Neefe for organizational learning, informal norms of Hall, job performance of Paterson, and the questionnaire of individual accountability of Hochwarter. Pearson and moderated multiple regression analysis were used to test hypotheses. Results: Results showed that organizational learning has a positive and significant correlation with job performance and individual accountability. The results, also, showed a positive and significant correlation between informal norms, personal accountability, and job performance. Regression results showed the interactive role of learning structure dimensions, strategy, and shared vision with informal norms, predicting individual accountability of the staff. Also, interactive role of organizational learning and informal norms was confirmed in predicting job performance of the medical staff. Conclusion: The result of this study hold out that organizational learning directly and with interaction of informal norms improves staffs' performance and accountability. As a result of improved informal norms in a medical setting, we will have staff’s strong accountability and performance.

Immobile defects in ferroelastic walls: Wall nucleation at defect sites

Science.gov (United States)

He, X.; Salje, E. K. H.; Ding, X.; Sun, J.

2018-02-01

Randomly distributed, static defects are enriched in ferroelastic domain walls. The relative concentration of defects in walls, Nd, follows a power law distribution as a function of the total defect concentration C: N d ˜ C α with α = 0.4 . The enrichment Nd/C ranges from ˜50 times when C = 10 ppm to ˜3 times when C = 1000 ppm. The resulting enrichment is due to nucleation at defect sites as observed in large scale MD simulations. The dynamics of domain nucleation and switching is dependent on the defect concentration. Their energy distribution follows the power law with exponents during yield between ɛ ˜ 1.82 and 2.0 when the defect concentration increases. The power law exponent is ɛ ≈ 2.7 in the plastic regime, independent of the defect concentration.

Improving health care quality and safety: the role of collective learning.

Science.gov (United States)

Singer, Sara J; Benzer, Justin K; Hamdan, Sami U

2015-01-01

Despite decades of effort to improve quality and safety in health care, this goal feels increasingly elusive. Successful examples of improvement are infrequently replicated. This scoping review synthesizes 76 empirical or conceptual studies (out of 1208 originally screened) addressing learning in quality or safety improvement, that were published in selected health care and management journals between January 2000 and December 2014 to deepen understanding of the role that collective learning plays in quality and safety improvement. We categorize learning activities using a theoretical model that shows how leadership and environmental factors support collective learning processes and practices, and in turn team and organizational improvement outcomes. By focusing on quality and safety improvement, our review elaborates the premise of learning theory that leadership, environment, and processes combine to create conditions that promote learning. Specifically, we found that learning for quality and safety improvement includes experimentation (including deliberate experimentation, improvisation, learning from failures, exploration, and exploitation), internal and external knowledge acquisition, performance monitoring and comparison, and training. Supportive learning environments are characterized by team characteristics like psychological safety, appreciation of differences, openness to new ideas social motivation, and team autonomy; team contextual factors including learning resources like time for reflection, access to knowledge, organizational capabilities; incentives; and organizational culture, strategy, and structure; and external environmental factors including institutional pressures, environmental dynamism and competitiveness and learning collaboratives. Lastly learning in the context of quality and safety improvement requires leadership that reinforces learning through actions and behaviors that affect people, such as coaching and trust building, and through

The role of visual representation in physics learning: dynamic versus static visualization

Science.gov (United States)

Suyatna, Agus; Anggraini, Dian; Agustina, Dina; Widyastuti, Dini

2017-11-01

This study aims to examine the role of visual representation in physics learning and to compare the learning outcomes of using dynamic and static visualization media. The study was conducted using quasi-experiment with Pretest-Posttest Control Group Design. The samples of this research are students of six classes at State Senior High School in Lampung Province. The experimental class received a learning using dynamic visualization and control class using static visualization media. Both classes are given pre-test and post-test with the same instruments. Data were tested with N-gain analysis, normality test, homogeneity test and mean difference test. The results showed that there was a significant increase of mean (N-Gain) learning outcomes (p physical phenomena and requires long-term observation.

Prospects of closed-circuit television in detecting surface defects

International Nuclear Information System (INIS)

Kaisler, L. et al.

The use is discussed of closed-circuit television for optical in-service testing of surface defects of nuclear reactors. Experience gained by UJV Rez with in-service testing of the WWR-S reactor is briefly reported. Main attention is devoted to recognizability of defects and to determining the fundamental conditions of the applicability and limitations of the closed-circuit television method. In experiments, resolution of the method was tested and the role of the human factor was assessed in evaluating the results. The need was stressed of thorough training of operators. Based on the experiments conducted, considerations are presented regarding modifications of the individual elements of the tv chain aimed at improved quality of information and a limited role of the observer. (B.S.)

Role-Play in Literature Lectures: The Students' Assessment of Their Learning

Science.gov (United States)

Riain, Isobel Ní; Dawson, Ciarán; McCarthy, Marian

2018-01-01

The following article is based on a piece of qualitative research on the use of role-play in a literature module in the Modern Irish Dept. of University College Cork, Ireland, in 2015. There were 18 students involved in the research. The aim of the research was to investigate if students associate learning with the use of role-play in literature…

Adult sibling experience, roles, relationships and future concerns - a review of the literature in learning disabilities.

Science.gov (United States)

Davys, Deborah; Mitchell, Duncan; Haigh, Carol

2011-10-01

This paper provides a review of the literature related to adult siblings of learning-disabled people. Siblings of learning-disabled people are often looked upon as next of kin when older parents die; however, there is little research regarding sibling views and wishes. A literature review of published peer-reviewed empirical research was undertaken. Electronic databases and citation tracking were used to collate data using key terms such as adult siblings and learning disability. Relevant articles were analysed, compared and contrasted. Six key themes emerged suggesting a varied impact of learning disability upon sibling lives in areas that include life choices, relationships, identity and future plans. Some siblings report a positive impact upon life, others state their lives are comparable with other adults who do not have a learning-disabled sibling and others still report a negative impact. Sibling roles and relationships are varied. Evidence suggests that sibling roles, relationships and experience are affected by life stage. Parents often have a primary care role for the disabled person, whilst siblings perform a more distant role; however, sibling involvement often rises when parents are no longer able to provide previous levels of support. Many factors appear to affect the sibling experience and uptake of roles including gender, life stage and circumstances, level of disability, health status and relationships between family members. Siblings are concerned about the future, particularly when parents are no longer able to provide support, and many appear to have expectations of future responsibilities regarding their disabled sibling. As siblings of people who have a learning disability are often expected by society to provide support, it is important that health and social care practitioners are aware of issues that may impact on this relationship. © 2011 Blackwell Publishing Ltd.

Phononic thermal conductivity in silicene: the role of vacancy defects and boundary scattering

Science.gov (United States)

Barati, M.; Vazifehshenas, T.; Salavati-fard, T.; Farmanbar, M.

2018-04-01

We calculate the thermal conductivity of free-standing silicene using the phonon Boltzmann transport equation within the relaxation time approximation. In this calculation, we investigate the effects of sample size and different scattering mechanisms such as phonon–phonon, phonon-boundary, phonon-isotope and phonon-vacancy defect. We obtain some similar results to earlier works using a different model and provide a more detailed analysis of the phonon conduction behavior and various mode contributions. We show that the dominant contribution to the thermal conductivity of silicene, which originates from the in-plane acoustic branches, is about 70% at room temperature and this contribution becomes larger by considering vacancy defects. Our results indicate that while the thermal conductivity of silicene is significantly suppressed by the vacancy defects, the effect of isotopes on the phononic transport is small. Our calculations demonstrate that by removing only one of every 400 silicon atoms, a substantial reduction of about 58% in thermal conductivity is achieved. Furthermore, we find that the phonon-boundary scattering is important in defectless and small-size silicene samples, especially at low temperatures.

Amygdala's involvement in facilitating associative learning-induced plasticity: a promiscuous role for the amygdala in memory acquisition.

Science.gov (United States)

Chau, Lily S; Galvez, Roberto

2012-01-01

It is widely accepted that the amygdala plays a critical role in acquisition and consolidation of fear-related memories. Some of the more widely employed behavioral paradigms that have assisted in solidifying the amygdala's role in fear-related memories are associative learning paradigms. With most associative learning tasks, a neutral conditioned stimulus (CS) is paired with a salient unconditioned stimulus (US) that elicits an unconditioned response (UR). After multiple CS-US pairings, the subject learns that the CS predicts the onset or delivery of the US, and thus elicits a learned conditioned response (CR). Most fear-related associative paradigms have suggested that an aspect of the fear association is stored in the amygdala; however, some fear-motivated associative paradigms suggest that the amygdala is not a site of storage, but rather facilitates consolidation in other brain regions. Based upon various learning theories, one of the most likely sites for storage of long-term memories is the neocortex. In support of these theories, findings from our laboratory, and others, have demonstrated that trace-conditioning, an associative paradigm where there is a separation in time between the CS and US, induces learning-specific neocortical plasticity. The following review will discuss the amygdala's involvement, either as a site of storage or facilitating storage in other brain regions such as the neocortex, in fear- and non-fear-motivated associative paradigms. In this review, we will discuss recent findings suggesting a broader role for the amygdala in increasing the saliency of behaviorally relevant information, thus facilitating acquisition for all forms of memory, both fear- and non-fear-related. This proposed promiscuous role of the amygdala in facilitating acquisition for all memories further suggests a potential role of the amygdala in general learning disabilities.

Using a Corporate Partnership to Enhance Learning in a Sourcing Negotiation Role-play

Science.gov (United States)

Hartley, Janet L.; Eboch, Karen; Gilberg, Jonathan

2017-01-01

Although role-plays can be effective teaching tools for buyer-supplier negotiation, learning can be somewhat limited because typically novices are negotiating with each other. We describe how we collaborated with a corporate partner, CACI International, to develop and implement a repeatable sourcing and negotiation role-play that helps to address…

Achieving DFT accuracy with a machine-learning interatomic potential: Thermomechanics and defects in bcc ferromagnetic iron

Science.gov (United States)

Dragoni, Daniele; Daff, Thomas D.; Csányi, Gábor; Marzari, Nicola

2018-01-01

We show that the Gaussian Approximation Potential (GAP) machine-learning framework can describe complex magnetic potential energy surfaces, taking ferromagnetic iron as a paradigmatic challenging case. The training database includes total energies, forces, and stresses obtained from density-functional theory in the generalized-gradient approximation, and comprises approximately 150,000 local atomic environments, ranging from pristine and defected bulk configurations to surfaces and generalized stacking faults with different crystallographic orientations. We find the structural, vibrational, and thermodynamic properties of the GAP model to be in excellent agreement with those obtained directly from first-principles electronic-structure calculations. There is good transferability to quantities, such as Peierls energy barriers, which are determined to a large extent by atomic configurations that were not part of the training set. We observe the benefit and the need of using highly converged electronic-structure calculations to sample a target potential energy surface. The end result is a systematically improvable potential that can achieve the same accuracy of density-functional theory calculations, but at a fraction of the computational cost.

Computer simulation of defect behavior under fusion irradiation environments

International Nuclear Information System (INIS)

Muroga, T.; Ishino, S.

1983-01-01

To simulate defect behavior under irradiation, three kinds of cascade-annealing calculations have been carried out in alpha-iron using the codes MARLOWE, DAIQUIRI and their modifications. They are (1) cascade-annealing calculation with different masses of projectile, (2) defect drifting near dislocations after cascade production and (3) cascade-overlap calculation. The defect survival ratio is found to increase as decreasing mass of the projectile both after athermal close-pair recombination and after thermal annealing. It is shown that at moderate temperatures vacancy clustering is enhanced near dislocations. Cascade-overlap is found to decrease the defect survivability. In addition, the role of helium in vacancy clustering has been calculated in aluminium lattices and its effect is found to depend strongly on temperature, interstitials and the mobility of small clusters. These results correspond well to the experimental data and will be helpful for correlating between fusion and simulation irradiations. (orig.)

An investigation of the role of defect levels on the radiation response of synthetic diamond crystals when used as sensors for the detection of mammography X-rays.

Science.gov (United States)

Ade, Nicholas

2017-09-01

This study evaluates the role of defects on the performances of synthetic diamond sensors on exposure to mammography X-rays. Through systematic investigations, the main cause of instability of response of examined sensors necessitating pre-irradiation was isolated and ascribed to the presence of ambient light which has the effect of emptying shallow trapping levels. The changes in response between measurements in light and dark conditions varied from 2.8 ± 1.2% to 63.0 ± 0.3%. Sensitivities between 0.4 and 6.7nCGy -1 mm -3 determined for the sensors varied with defect levels. The study indicates that differences in crystal quality due to the presence and influence of defects would cause a discrepancy in the dosimetric performances of various diamond detectors. Once a sensor plate is selected (based on the influence of defect levels) and coupled to the probe housing with the response of the diamond sensor stabilised and appropriately shielded from ambient light, daily priming is not needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

GESTURE'S ROLE IN CREATING AND LEARNING LANGUAGE.

Science.gov (United States)

Goldin-Meadow, Susan

2010-09-22

Imagine a child who has never seen or heard language. Would such a child be able to invent a language? Despite what one might guess, the answer is "yes". This chapter describes children who are congenitally deaf and cannot learn the spoken language that surrounds them. In addition, the children have not been exposed to sign language, either by their hearing parents or their oral schools. Nevertheless, the children use their hands to communicate--they gesture--and those gestures take on many of the forms and functions of language (Goldin-Meadow 2003a). The properties of language that we find in these gestures are just those properties that do not need to be handed down from generation to generation, but can be reinvented by a child de novo. They are the resilient properties of language, properties that all children, deaf or hearing, come to language-learning ready to develop. In contrast to these deaf children who are inventing language with their hands, hearing children are learning language from a linguistic model. But they too produce gestures, as do all hearing speakers (Feyereisen and de Lannoy 1991; Goldin-Meadow 2003b; Kendon 1980; McNeill 1992). Indeed, young hearing children often use gesture to communicate before they use words. Interestingly, changes in a child's gestures not only predate but also predict changes in the child's early language, suggesting that gesture may be playing a role in the language-learning process. This chapter begins with a description of the gestures the deaf child produces without speech. These gestures assume the full burden of communication and take on a language-like form--they are language. This phenomenon stands in contrast to the gestures hearing speakers produce with speech. These gestures share the burden of communication with speech and do not take on a language-like form--they are part of language.

[Progress on metaplasticity and its role in learning and memory].

Science.gov (United States)

Wang, Shao-Li; Lu, Wei

2016-08-25

Long-term potentiation (LTP) and long-term depression (LTD) are two major forms of synaptic plasticity that are widely considered as important cellular models of learning and memory. Metaplasticity is defined as the plasticity of synaptic plasticity and thus is an advanced form of plasticity. The history of synaptic activity can affect the subsequent synaptic plasticity induction. Therefore, it is important to study metaplasticity to explore new mechanisms underlying various brain functions including learning and memory. Since the concept of metaplasticity was proposed, it has aroused widespread concerns and attracted numerous researchers to dig more details on this topic. These new-found experimental phenomena and cellular mechanisms have established the basis of theoretical studies on metaplasticity. In recent years, researchers have found that metaplasticity can not only affect the synaptic plasticity, but also regulate the neural network to encode specific content and enhance the learning and memory. These findings have greatly enriched our knowledge on plasticity and opened a new route to study the mechanism of learning and memory. In this review, we discuss the recent progress on metaplasticity on following three aspects: (1) the molecular mechanisms of metaplasticity; (2) the role of metaplasticity in learning and memory; and (3) the outlook of future study on metaplasticity.

Studies of defects and defect agglomerates by positron annihilation spectroscopy

DEFF Research Database (Denmark)

Eldrup, Morten Mostgaard; Singh, B.N.

1997-01-01

A brief introduction to positron annihilation spectroscopy (PAS), and in particular lo its use for defect studies in metals is given. Positrons injected into a metal may become trapped in defects such as vacancies, vacancy clusters, voids, bubbles and dislocations and subsequently annihilate from...... the trapped state iri the defect. The annihilation characteristics (e.g., the lifetime of the positron) can be measured and provide information about the nature of the defect (e.g., size, density, morphology). The technique is sensitive to both defect size (in the range from monovacancies up to cavities...

What Drives Students' Loyalty-Formation in Social Media Learning within a Personal Learning Environment Approach? The Moderating Role of Need for Cognition

Science.gov (United States)

Arquero, José L.; del Barrio-García, Salvador; Romero-Frías, Esteban

2017-01-01

Our study analyzes an educational experience based on the integrated use of social media within a higher education course under a personal learning environment approach and investigates the factors that determine students' loyalty to social media learning. We examined the moderating role of need for cognition (NFC) in students' formation of…

Point defects in dilute nitride III-N-As and III-N-P

International Nuclear Information System (INIS)

Chen, W.M.; Buyanova, I.A.; Tu, C.W.; Yonezu, H.

2006-01-01

We provide a brief review of our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in two most important dilute nitride systems-Ga(In)NAs grown on GaAs substrates and Ga(Al,In)NP grown on Si and GaP substrates. These results have led to the identification of defect complexes in the alloys, involving intrinsic defects such as As Ga antisites and Ga i self-interstitials. They have also shed light on formation mechanisms of the defects and on their role in non-radiative carrier recombination that is harmful to the performance of potential optoelectronic and photonic devices based on these dilute nitrides

Work Engagement: Antecedents, the Mediating Role of Learning Goal Orientation and Job Performance

Science.gov (United States)

Chughtai, Aamir Ali; Buckley, Finian

2011-01-01

Purpose: The present paper aims to explore the effects of state (trust in supervisor) and trait (trust propensity) trust on employees' work engagement. Furthermore, it seeks to investigate the mediating role of learning goal orientation in the relationship between work engagement and two forms of performance: in-role job performance and innovative…

The role of alpha-rhythm states in perceptual learning: insights from experiments and computational models

Science.gov (United States)

Sigala, Rodrigo; Haufe, Sebastian; Roy, Dipanjan; Dinse, Hubert R.; Ritter, Petra

2014-01-01

During the past two decades growing evidence indicates that brain oscillations in the alpha band (~10 Hz) not only reflect an “idle” state of cortical activity, but also take a more active role in the generation of complex cognitive functions. A recent study shows that more than 60% of the observed inter-subject variability in perceptual learning can be ascribed to ongoing alpha activity. This evidence indicates a significant role of alpha oscillations for perceptual learning and hence motivates to explore the potential underlying mechanisms. Hence, it is the purpose of this review to highlight existent evidence that ascribes intrinsic alpha oscillations a role in shaping our ability to learn. In the review, we disentangle the alpha rhythm into different neural signatures that control information processing within individual functional building blocks of perceptual learning. We further highlight computational studies that shed light on potential mechanisms regarding how alpha oscillations may modulate information transfer and connectivity changes relevant for learning. To enable testing of those model based hypotheses, we emphasize the need for multidisciplinary approaches combining assessment of behavior and multi-scale neuronal activity, active modulation of ongoing brain states and computational modeling to reveal the mathematical principles of the complex neuronal interactions. In particular we highlight the relevance of multi-scale modeling frameworks such as the one currently being developed by “The Virtual Brain” project. PMID:24772077

The role of alpha-rhythm states in perceptual learning: insights from experiments and computational models

Directory of Open Access Journals (Sweden)

Rodrigo eSigala

2014-04-01

Full Text Available During the past two decades growing evidence indicates that brain oscillations in the alpha band (~10 Hz not only reflect an ‘idle’ state of cortical activity, but also take a more active role in the generation of complex cognitive functions. A recent study shows that more than 60% of the observed inter-subject variability in perceptual learning can be ascribed to ongoing alpha activity. This evidence indicates a significant role of alpha oscillations for perceptual learning and hence motivates to explore the potential underlying mechanisms. Hence, it is the purpose of this review to highlight existent evidence that ascribes intrinsic alpha oscillations a role in shaping our ability to learn. In the review, we disentangle the alpha rhythm into different neural signatures that control information processing within individual functional building blocks of perceptual learning. We further highlight computational studies that shed light on potential mechanisms regarding how alpha oscillations may modulate information transfer and connectivity changes relevant for learning. To enable testing of those model based hypotheses, we emphasize the need for multidisciplinary approaches combining assessment of behavior and multi-scale neuronal activity, active modulation of ongoing brain states and computational modeling to reveal the mathematical principles of the complex neuronal interactions. In particular we highlight the relevance of multi-scale modeling frameworks such as the one currently being developed by The Virtual Brain project.

Defect modelling

International Nuclear Information System (INIS)

Norgett, M.J.

1980-01-01

Calculations, drawing principally on developments at AERE Harwell, of the relaxation about lattice defects are reviewed with emphasis on the techniques required for such calculations. The principles of defect modelling are outlined and various programs developed for defect simulations are discussed. Particular calculations for metals, ionic crystals and oxides, are considered. (UK)

The role of reference in cross-situational word learning.

Science.gov (United States)

Wang, Felix Hao; Mintz, Toben H

2018-01-01

Word learning involves massive ambiguity, since in a particular encounter with a novel word, there are an unlimited number of potential referents. One proposal for how learners surmount the problem of ambiguity is that learners use cross-situational statistics to constrain the ambiguity: When a word and its referent co-occur across multiple situations, learners will associate the word with the correct referent. Yu and Smith (2007) propose that these co-occurrence statistics are sufficient for word-to-referent mapping. Alternative accounts hold that co-occurrence statistics alone are insufficient to support learning, and that learners are further guided by knowledge that words are referential (e.g., Waxman & Gelman, 2009). However, no behavioral word learning studies we are aware of explicitly manipulate subjects' prior assumptions about the role of the words in the experiments in order to test the influence of these assumptions. In this study, we directly test whether, when faced with referential ambiguity, co-occurrence statistics are sufficient for word-to-referent mappings in adult word-learners. Across a series of cross-situational learning experiments, we varied the degree to which there was support for the notion that the words were referential. At the same time, the statistical information about the words' meanings was held constant. When we overrode support for the notion that words were referential, subjects failed to learn the word-to-referent mappings, but otherwise they succeeded. Thus, cross-situational statistics were useful only when learners had the goal of discovering mappings between words and referents. We discuss the implications of these results for theories of word learning in children's language acquisition. Copyright © 2017 Elsevier B.V. All rights reserved.

The role of learning environment on high school chemistry students' motivation and self-regulatory processes

Science.gov (United States)

Judd, Jeffrey S.

Changes to the global workforce and technological advancements require graduating high school students to be more autonomous, self-directed, and critical in their thinking. To reflect societal changes, current educational reform has focused on developing more problem-based, collaborative, and student-centered classrooms to promote effective self-regulatory learning strategies, with the goal of helping students adapt to future learning situations and become life-long learners. This study identifies key features that may characterize these "powerful learning environments", which I term "high self-regulating learning environments" for ease of discussion, and examine the environment's role on students' motivation and self-regulatory processes. Using direct observation, surveys, and formal and informal interviews, I identified perceptions, motivations, and self-regulatory strategies of 67 students in my high school chemistry classes as they completed academic tasks in both high and low self-regulating learning environments. With social cognitive theory as a theoretical framework, I then examined how students' beliefs and processes changed after they moved from low to a high self-regulating learning environment. Analyses revealed that key features such as task meaning, utility, complexity, and control appeared to play a role in promoting positive changes in students' motivation and self-regulation. As embedded cases, I also included four students identified as high self-regulating, and four students identified as low self-regulating to examine whether the key features of high and low self-regulating learning environments played a similar role in both groups. Analysis of findings indicates that key features did play a significant role in promoting positive changes in both groups, with high self-regulating students' motivation and self-regulatory strategies generally remaining higher than the low self-regulating students; this was the case in both environments. Findings

The Role of Elicited Verbal Imitation in Toddlers' Word Learning

Science.gov (United States)

Hodges, Rosemary; Munro, Natalie; Baker, Elise; McGregor, Karla; Docking, Kimberley; Arciuli, Joanne

2016-01-01

This study is about the role of elicited verbal imitation in toddler word learning. Forty-eight toddlers were taught eight nonwords linked to referents. During training, they were asked to imitate the nonwords. Naming of the referents was tested at three intervals (one minute later [uncued], five minutes, and 1-7 days later [cued]) and recognition…

The roles of games in teaching and learning of mathematics in junior ...

African Journals Online (AJOL)

The roles of games in teaching and learning of mathematics in junior secondary schools. ... The research seeks to enhance the status of games in teaching mathematics in junior secondary schools curriculum ... AJOL African Journals Online.

Linking supervisor’s role in training programs to motivation to learn as an antecedent of job performance

Directory of Open Access Journals (Sweden)

Azman Bin Ismail

2010-02-01

Full Text Available According to the literature pertaining to human resource development (HRD, a supervisor’s role in training programs has two major characteristics: support and communication. The ability of supervisors to play effective roles in training programs may increase employees’ job performance. More importantly, extant research in this field reveals that the effect of the supervisor’s role in training programs on job performance is indirectly affected by the motivation to learn. The nature of this relationship is less emphasized in training management literature. Therefore, this study was conducted to measure the effect of the supervisor’s role in training programs and the motivation to learn on job performance using 91 usable questionnaires gathered from employees who have worked in a state library in East Malaysia, Malaysia. The outcomes of stepwise regression analysis displayed that the inclusion of motivation to learn in the analysis had increased the effects of the two supervisor’s role elements of support and communication on job performance. This result demonstrates that the motivation to learn acts as a mediating variable in the training model of the organizational sample. The implications of this study to the theory and practice of training programs, methodological and conceptual limitations as well as future directions are elaborated.

Understanding the Role of Negative Emotions in Adult Learning and Achievement: A Social Functional Perspective

Science.gov (United States)

Fitness, Julie

2018-01-01

The role of emotions in adult learning and achievement has received increasing attention in recent years. However, much of the emphasis has been on test anxiety, rather than the wider spectrum of negative emotions such as sadness, grief, boredom and anger. This paper reports findings of a qualitative study exploring the experience and functionality of negative emotions at university. Thirty-six academic staff and students from an Australian university were interviewed about emotional responses to a range of learning events. Data analysis was informed by a prototype approach to emotion research. Four categories of discrete negative emotions (anger, sadness, fear, boredom) were considered by teachers and students to be especially salient in learning, with self-conscious emotions (guilt, embarrassment, shame) mentioned by more students than staff. While negative emotions were frequently viewed as detrimental to motivation, performance and learning, they were also construed under some circumstances as beneficial. The findings are discussed in relation to the value of social functional approaches for a better understanding of the diverse roles of negative emotions in learning and achievement. PMID:29461487

Understanding the Role of Negative Emotions in Adult Learning and Achievement: A Social Functional Perspective.

Science.gov (United States)

Rowe, Anna D; Fitness, Julie

2018-02-20

The role of emotions in adult learning and achievement has received increasing attention in recent years. However, much of the emphasis has been on test anxiety, rather than the wider spectrum of negative emotions such as sadness, grief, boredom and anger. This paper reports findings of a qualitative study exploring the experience and functionality of negative emotions at university. Thirty-six academic staff and students from an Australian university were interviewed about emotional responses to a range of learning events. Data analysis was informed by a prototype approach to emotion research. Four categories of discrete negative emotions (anger, sadness, fear, boredom) were considered by teachers and students to be especially salient in learning, with self-conscious emotions (guilt, embarrassment, shame) mentioned by more students than staff. While negative emotions were frequently viewed as detrimental to motivation, performance and learning, they were also construed under some circumstances as beneficial. The findings are discussed in relation to the value of social functional approaches for a better understanding of the diverse roles of negative emotions in learning and achievement.

Understanding the Role of Negative Emotions in Adult Learning and Achievement: A Social Functional Perspective

Directory of Open Access Journals (Sweden)

Anna D. Rowe

2018-02-01

Full Text Available The role of emotions in adult learning and achievement has received increasing attention in recent years. However, much of the emphasis has been on test anxiety, rather than the wider spectrum of negative emotions such as sadness, grief, boredom and anger. This paper reports findings of a qualitative study exploring the experience and functionality of negative emotions at university. Thirty-six academic staff and students from an Australian university were interviewed about emotional responses to a range of learning events. Data analysis was informed by a prototype approach to emotion research. Four categories of discrete negative emotions (anger, sadness, fear, boredom were considered by teachers and students to be especially salient in learning, with self-conscious emotions (guilt, embarrassment, shame mentioned by more students than staff. While negative emotions were frequently viewed as detrimental to motivation, performance and learning, they were also construed under some circumstances as beneficial. The findings are discussed in relation to the value of social functional approaches for a better understanding of the diverse roles of negative emotions in learning and achievement.

ASPECTS REGARDING THE ROLE OF FACILITATORS IN CREATIVE LEARNING AND INNOVATIVE TEACHING

Directory of Open Access Journals (Sweden)

TODORUȚ AMALIA VENERA

2017-12-01

Full Text Available In this paper I have analysed a series of facilitators that determine creativity and innovation in teaching learning processes, emphasising the role of assessment, organizational culture and information technologies as relevant and essential elements within this challenging approach to create the conditions for an intelligent development of the educational processes. Also I approached issues related to creative learning and innovative teaching in a society in which knowledge takes more and more intense forms and, they require changes and deep transformations in all educational environments. The fundamental objective was to underline the need to learn creatively and to teach innovatively, given the conditions of the development of information technologies and a deeper and deeper immersion in this information environment, with effects on involving more effectively the students in their own learning approach. Based on scientific researches, observation and comparative analyzes, I identified the facilitators which, along with the technologies, support the creative learning and innovative teaching.

2012 Gordon Research Conference on Defects in Semiconductors - Formal Schedule and Speaker/Poster Program

Energy Technology Data Exchange (ETDEWEB)

Glaser, Evan [Naval Research Lab. (NRL), Washington, DC (United States)

2012-08-17

The meeting shall strive to develop and further the fundamental understanding of defects and their roles in the structural, electronic, optical, and magnetic properties of bulk, thin film, and nanoscale semiconductors and device structures. Point and extended defects will be addressed in a broad range of electronic materials of particular current interest, including wide bandgap semiconductors, metal-oxides, carbon-based semiconductors (e.g., diamond, graphene, etc.), organic semiconductors, photovoltaic/solar cell materials, and others of similar interest. This interest includes novel defect detection/imaging techniques and advanced defect computational methods.

Shp2 knockdown and Noonan/LEOPARD mutant Shp2-induced gastrulation defects.

Directory of Open Access Journals (Sweden)

Chris Jopling

2007-12-01

Full Text Available Shp2 is a cytoplasmic protein-tyrosine phosphatase that is essential for normal development. Activating and inactivating mutations have been identified in humans to cause the related Noonan and LEOPARD syndromes, respectively. The cell biological cause of these syndromes remains to be determined. We have used the zebrafish to assess the role of Shp2 in early development. Here, we report that morpholino-mediated knockdown of Shp2 in zebrafish resulted in defects during gastrulation. Cell tracing experiments demonstrated that Shp2 knockdown induced defects in convergence and extension cell movements. In situ hybridization using a panel of markers indicated that cell fate was not affected by Shp2 knock down. The Shp2 knockdown-induced defects were rescued by active Fyn and Yes and by active RhoA. We generated mutants of Shp2 with mutations that were identified in human patients with Noonan or LEOPARD Syndrome and established that Noonan Shp2 was activated and LEOPARD Shp2 lacked catalytic protein-tyrosine phosphatase activity. Expression of Noonan or LEOPARD mutant Shp2 in zebrafish embryos induced convergence and extension cell movement defects without affecting cell fate. Moreover, these embryos displayed craniofacial and cardiac defects, reminiscent of human symptoms. Noonan and LEOPARD mutant Shp2s were not additive nor synergistic, consistent with the mutant Shp2s having activating and inactivating roles in the same signaling pathway. Our results demonstrate that Shp2 is required for normal convergence and extension cell movements during gastrulation and that Src family kinases and RhoA were downstream of Shp2. Expression of Noonan or LEOPARD Shp2 phenocopied the craniofacial and cardiac defects of human patients. The finding that defective Shp2 signaling induced cell movement defects as early as gastrulation may have implications for the monitoring and diagnosis of Noonan and LEOPARD syndrome.

Effects of in-cascade defect clustering on near-term defect evolution

Energy Technology Data Exchange (ETDEWEB)

Heinisch, H.L. [Pacific Northwest National Lab., Richland, WA (United States)

1997-08-01

The effects of in-cascade defect clustering on the nature of the subsequent defect population are being studied using stochastic annealing simulations applied to cascades generated in molecular dynamics (MD) simulations. The results of the simulations illustrates the strong influence of the defect configuration existing in the primary damage state on subsequent defect evolution. The large differences in mobility and stability of vacancy and interstitial defects and the rapid one-dimensional diffusion of small, glissile interstitial loops produced directly in cascades have been shown to be significant factors affecting the evolution of the defect distribution. In recent work, the effects of initial cluster sizes appear to be extremely important.

Contrasting role of octopamine in appetitive and aversive learning in the crab Chasmagnathus.

Directory of Open Access Journals (Sweden)

Laura Kaczer

Full Text Available BACKGROUND: Biogenic amines are implicated in reinforcing associative learning. Octopamine (OA is considered the invertebrate counterpart of noradrenaline and several studies in insects converge on the idea that OA mediates the reward in appetitive conditioning. However, it is possible to assume that OA could have a different role in an aversive conditioning. METHODOLOGY/PRINCIPAL FINDINGS: Here we pharmacologically studied the participation of OA in two learning processes in the crab Chasmagnathus granulatus, one appetitive and one aversive. It is shown that the aversive memory is impaired by an OA injection applied immediately or 30 minutes after the last training trial. By contrast, the appetitive memory is blocked by OA antagonists epinastine and mianserine, but enhanced by OA when injected together with the supply of a minimum amount of reinforcement. Finally, double-learning experiments in which crabs are given the aversive and the appetitive learning either successively or simultaneously allow us to study the interaction between both types of learning and analyze the presumed action of OA. We found that the appetitive training offered immediately, but not one hour, after an aversive training has an amnesic effect on the aversive memory, mimicking the effect and the kinetic of an OA injection. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that the role of OA is divergent in two memory processes of opposite signs: on the one hand it would mediate the reinforcement in appetitive learning, and on the other hand it has a deleterious effect over aversive memory consolidation.

Exploring the roles of interaction and flow in explaining nurses' e-learning acceptance.

Science.gov (United States)

Cheng, Yung-Ming

2013-01-01

To provide safe and competent patient care, it is very important that medical institutions should provide nurses with continuing education by using appropriate learning methods. As compared to traditional learning, electronic learning (e-learning) is a more flexible method for nurses' in-service learning. Hence, e-learning is expected to play a pivotal role in providing continuing education for nurses. This study's purpose was to explore the role and relevance of interaction factors, intrinsic motivator (i.e., flow), and extrinsic motivators (i.e., perceived usefulness (PU) and perceived ease of use (PEOU)) in explaining nurses' intention to use the e-learning system. Based on the technology acceptance model (TAM) with the flow theory, this study's research model presents three types of interaction factors, learner-system interaction, instructor-learner interaction, and learner-learner interaction to construct an extended TAM to explore nurses' intention to use the e-learning system. Sample data were gathered from nurses at two regional hospitals in Taiwan. A total of 320 questionnaires were distributed, 254 (79.375%) questionnaires were returned. Consequently, 218 usable questionnaires were analyzed in this study, with a usable response rate of 68.125%. First, confirmatory factor analysis was used to develop the measurement model. Second, to explore the causal relationships among all constructs, the structural model for the research model was tested by using structural equation modeling. First, learner-system interaction, instructor-learner interaction, and learner-learner interaction respectively had significant effects on PU, PEOU, and flow. Next, flow had significant effects on PU and PEOU, and PEOU had a significant effect on PU. Finally, the effects of flow, PU, and PEOU on intention to use were significant. Synthetically speaking, learner-system interaction, instructor-learner interaction, and learner-learner interaction can indirectly make significant

Defect generation/passivation by low energy hydrogen implant for silicon solar cells

International Nuclear Information System (INIS)

Sopori, B.L.; Zhou, T.Q.; Rozgonyi, G.A.

1990-01-01

Low energy ion implant is shown to produce defects in silicon. These defects include surface damage, hydrogen agglomeration, formation of platelets with (111) habit plane and decoration of dislocations. Hydrogen also produces an inversion type of surface on boron doped silicon. These effects indicate that a preferred approach for passivation is to incorporate hydrogen from the back side of the cell. A backside H + implant technique is described. The results show that degree of passivation differs for various devices. A comparison of the defect structures of hydrogenated devices indicates that the structure and the distribution of defects in the bulk of the material plays a significant role in determining the degree of passivation

The role of picture books in young children’s mathematics learning

NARCIS (Netherlands)

van den Heuvel-Panhuizen, M.H.A.M; Elia, I.

2013-01-01

In this chapter we address the role of picture books in kindergartners’ learning of mathematics. The chapter is based on various studies we carried out on this topic from different perspectives. All studies sought to provide insight into the power of picture books to contribute to the development of

Dirichlet topological defects

International Nuclear Information System (INIS)

Carroll, S.M.; Trodden, M.

1998-01-01

We propose a class of field theories featuring solitonic solutions in which topological defects can end when they intersect other defects of equal or higher dimensionality. Such configurations may be termed open-quotes Dirichlet topological defects,close quotes in analogy with the D-branes of string theory. Our discussion focuses on defects in scalar field theories with either gauge or global symmetries, in 3+1 dimensions; the types of defects considered include walls ending on walls, strings on walls, and strings on strings. copyright 1998 The American Physical Society

Highly Efficient Defect Emission from ZnO:Zn and ZnO:S Powders

Science.gov (United States)

Everitt, Henry

2013-03-01

Bulk Zinc Oxide (ZnO) is a wide band gap semiconductor with an ultraviolet direct band gap energy of 3.4 eV and a broad, defect-related visible wavelength emission band centered near 2 eV. We have shown that the external quantum efficiency can exceed 50% for this nearly white emission band that closely matches the human dark-adapted visual response. To explore the potential of ZnO as a rare earth-free white light phosphor, we investigated the mechanism of efficient defect emission in three types of ZnO powders: unannealed, annealed, and sulfur-doped. Annealing and sulfur-doping of ZnO greatly increase the strength of defect emission while suppressing the UV band edge emission. Continuous wave and ultrafast one- and two-photon excitation spectroscopy are used to examine the defect emission mechanism. Low temperature photoluminescence (PL) and PL excitation (PLE) spectra were measured for all three compounds, and it was found that bound excitons mediate the defect emission. Temperature-dependent PLE spectra for the defect and band edge emission were measured to estimate trapping and activation energies of the bound excitons and clarify the role they play in the defect emission. Time-resolved techniques were used to ascertain the role of exciton diffusion, the effects of reabsorption, and the spatial distributions of radiative and non-radiative traps. In unannealed ZnO we find that defect emission is suppressed and UV band edge emission is inefficient (reduced, and a high density of defects responsible for the broad visible emission are created near the surface. Interestingly, nearly identical PLE spectra are found for both the band edge and the defect emission, one of many indications that the defect emission is deeply connected to bound excitons. Quantum efficiency, also measured as a function of excitation wavelength, closely mirrors the PLE spectra for both emission bands. Sulfur-doped ZnO exhibits additional PLE and X-ray features indicative of a ZnS-rich surface

Possible mechanism for d0 ferromagnetism mediated by intrinsic defects

KAUST Repository

Zhang, Zhenkui

2014-01-01

We examine the effects of several intrinsic defects on the magnetic behavior of ZnS nanostructures using hybrid density functional theory to gain insights into d0 ferromagnetism. Previous studies have predicted that the magnetism is due to a coupling between partially filled defect states. By taking into account the electronic correlations, we find an additional splitting of the defect states in Zn vacancies and thus the possibility of gaining energy by preferential filling of hole states, establishing ferromagnetism between spin polarized S 3p holes. We demonstrate a crucial role of neutral S vacancies in promoting ferromagnetism between positively charged S vacancies. S dangling bonds on the nanoparticle surface also induce ferromagnetism. This journal is

Stringy models of modified gravity: space-time defects and structure formation

International Nuclear Information System (INIS)

Mavromatos, Nick E.; Sakellariadou, Mairi; Yusaf, Muhammad Furqaan

2013-01-01

Starting from microscopic models of space-time foam, based on brane universes propagating in bulk space-times populated by D0-brane defects (''D-particles''), we arrive at effective actions used by a low-energy observer on the brane world to describe his/her observations of the Universe. These actions include, apart from the metric tensor field, also scalar (dilaton) and vector fields, the latter describing the interactions of low-energy matter on the brane world with the recoiling point-like space-time defect (D-particle). The vector field is proportional to the recoil velocity of the D-particle and as such it satisfies a certain constraint. The vector breaks locally Lorentz invariance, which however is assumed to be conserved on average in a space-time foam situation, involving the interaction of matter with populations of D-particle defects. In this paper we clarify the role of fluctuations of the vector field on structure formation and galactic growth. In particular we demonstrate that, already at the end of the radiation era, the (constrained) vector field associated with the recoil of the defects provides the seeds for a growing mode in the evolution of the Universe. Such a growing mode survives during the matter dominated era, provided the variance of the D-particle recoil velocities on the brane is larger than a critical value. We note that in this model, as a result of specific properties of D-brane dynamics in the bulk, there is no issue of overclosing the brane Universe for large defect densities. Thus, in these models, the presence of defects may be associated with large-structure formation. Although our string inspired models do have (conventional, from a particle physics point of view) dark matter components, nevertheless it is interesting that the role of ''extra'' dark matter is also provided by the population of massive defects. This is consistent with the weakly interacting character of the D-particle defects, which predominantly interact only

Amygdala’s involvement in facilitating associative learning-induced plasticity: a promiscuous role for the amygdala in memory acquisition

Directory of Open Access Journals (Sweden)

Lily S Chau

2012-10-01

Full Text Available It is widely accepted that the amygdala plays a critical role in acquisition and consolidation of fear-related memories. Some of the more widely employed behavioral paradigms that have assisted in solidifying the amygdala’s role in fear-related memories are associative learning paradigms. With most associative learning tasks, a neutral conditioned stimulus (CS is paired with a salient unconditioned stimulus (US that elicits an unconditioned response (UR. After multiple CS-US pairings, the subject learns that the CS predicts the onset or delivery of the US, and thus elicits a learned conditioned response (CR. Most fear-related associative paradigms have suggested that an aspect of the fear association is stored in the amygdala; however, some fear-motivated associative paradigms suggest that the amygdala is not a site of storage, but rather facilitates consolidation in other brain regions. Based upon various learning theories, one of the most likely sites for storage of long-term memories is the neocortex. In support of these theories, findings from our laboratory, and others, have demonstrated that trace-conditioning, an associative paradigm where there is a separation in time between the CS and US, induces learning-specific neocortical plasticity. The following review will discuss the amygdala’s involvement, either as a site of storage or facilitating storage in other brain regions such as the neocortex, in fear- and non-fear-motivated associative paradigms. In this review, we will discuss recent findings suggesting a broader role for the amygdala in increasing the saliency of behaviorally relevant information, thus facilitating acquisition for all forms of memory, both fear- and non-fear-related. This proposed promiscuous role of the amygdala in facilitating acquisition for all memories further suggests a potential role of the amygdala in general learning disabilities.

Learning to Learn.

Science.gov (United States)

Weiss, Helen; Weiss, Martin

1988-01-01

The article reviews theories of learning (e.g., stimulus-response, trial and error, operant conditioning, cognitive), considers the role of motivation, and summarizes nine research-supported rules of effective learning. Suggestions are applied to teaching learning strategies to learning-disabled students. (DB)

Future Ready Learning: Reimagining the Role of Technology in Education. 2016 National Education Technology Plan

Science.gov (United States)

Thomas, Susan

2016-01-01

The National Education Technology Plan is the flagship educational technology policy document for the United States. The 2016 Plan, "Future Ready Learning: Reimagining the Role of Technology in Education," articulates a vision of equity, active use, and collaborative leadership to make everywhere, all-the-time learning possible. While…

Designing a mobile learning game to investigate the impact of role-playing on helping behavior

NARCIS (Netherlands)

Schmitz, Birgit; Ternier, Stefaan; Klemke, Roland; Kalz, Marco; Specht, Marcus

2013-01-01

Schmitz, B., Ternier, S., Klemke, R., Kalz, M., & Specht, M. (2013). Designing a mobile learning game to investigate the impact of role-playing on helping behavior. In D. Hernández-Leo et al. (Eds.), Scaling up Learning for Sustained Impact. Proceedings of European Conference on Technology Enhanced

Monte Carlo simulations of core/shell nanoparticles containing interfacial defects: Role of disordered ferromagnetic spins

International Nuclear Information System (INIS)

Ho, Le Bin; Lan, Tran Nguyen; Hai, Tran Hoang

2013-01-01

In this work, we have used the Monte Carlo simulation to investigate the magnetic properties of an isolated composite magnetic nanoparticle with ferromagnetic (FM) core and antiferromagnetic (AFM) shell morphology. The defects were assumed to be randomly located at the AFM interface. The Néel anisotropy was used for the FM interface spins at where there are the lacks of crystal symmetry due to the vacancies at AFM interface. With a moderate defect concentration, the coercive field non-monotonously depends on the Néel anisotropy. We have examined the dependence of coercivity, exchange bias field, and vertical shift on defect concentration. We found that in addition to AFM shell, the disordered FM interface is another pining-source for exchange bias phenomenon. We discuss our simulated results in the relation to recent experimental findings

Aquaglyceroporin-null trypanosomes display glycerol transport defects and respiratory-inhibitor sensitivity.

Directory of Open Access Journals (Sweden)

Laura Jeacock

2017-03-01

Full Text Available Aquaglyceroporins (AQPs transport water and glycerol and play important roles in drug-uptake in pathogenic trypanosomatids. For example, AQP2 in the human-infectious African trypanosome, Trypanosoma brucei gambiense, is responsible for melarsoprol and pentamidine-uptake, and melarsoprol treatment-failure has been found to be due to AQP2-defects in these parasites. To further probe the roles of these transporters, we assembled a T. b. brucei strain lacking all three AQP-genes. Triple-null aqp1-2-3 T. b. brucei displayed only a very moderate growth defect in vitro, established infections in mice and recovered effectively from hypotonic-shock. The aqp1-2-3 trypanosomes did, however, display glycerol uptake and efflux defects. They failed to accumulate glycerol or to utilise glycerol as a carbon-source and displayed increased sensitivity to salicylhydroxamic acid (SHAM, octyl gallate or propyl gallate; these inhibitors of trypanosome alternative oxidase (TAO can increase intracellular glycerol to toxic levels. Notably, disruption of AQP2 alone generated cells with glycerol transport defects. Consistent with these findings, AQP2-defective, melarsoprol-resistant clinical isolates were sensitive to the TAO inhibitors, SHAM, propyl gallate and ascofuranone, relative to melarsoprol-sensitive reference strains. We conclude that African trypanosome AQPs are dispensable for viability and osmoregulation but they make important contributions to drug-uptake, glycerol-transport and respiratory-inhibitor sensitivity. We also discuss how the AQP-dependent inverse sensitivity to melarsoprol and respiratory inhibitors described here might be exploited.

A hypothesis on a role of oxytocin in the social mechanisms of speech and vocal learning.

Science.gov (United States)

Theofanopoulou, Constantina; Boeckx, Cedric; Jarvis, Erich D

2017-08-30

Language acquisition in humans and song learning in songbirds naturally happen as a social learning experience, providing an excellent opportunity to reveal social motivation and reward mechanisms that boost sensorimotor learning. Our knowledge about the molecules and circuits that control these social mechanisms for vocal learning and language is limited. Here we propose a hypothesis of a role for oxytocin (OT) in the social motivation and evolution of vocal learning and language. Building upon existing evidence, we suggest specific neural pathways and mechanisms through which OT might modulate vocal learning circuits in specific developmental stages. © 2017 The Authors.

Defect forces, defect couples and path integrals in fracture mechanics

International Nuclear Information System (INIS)

Roche, R.L.

1979-07-01

In this work, it is shown that the path integrals can be introduced without any reference to the material behavior. The method is based on the definition in a continuous medium of a set of vectors and couples having the dimension of a force or a moment. More precisely, definitions are given of volume defect forces, surface defect forces, volume defect couples, and surface defect couples. This is done with the help of the stress working variation of a particule moving through the solid. The most important result is: the resultant of all the defect forces included in a volume V is the J integral on the surface surrounding V and the moment resultant is the L integral. So these integrals are defined without any assumption on the material constitutive equation. Another result is the material form of the virtual work principle - defect forces are acting like conventional forces in the conventional principles of virtual work. This lead to the introduction of the energy momentum tensor and of the associated couple stress. Application of this method is made to fracture mechanics in studying the defect forces distribution around a crack [fr

Neural Tube Defects

Science.gov (United States)

Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

The Role of Age and Executive Function in Auditory Category Learning

Science.gov (United States)

Reetzke, Rachel; Maddox, W. Todd; Chandrasekaran, Bharath

2015-01-01

Auditory categorization is a natural and adaptive process that allows for the organization of high-dimensional, continuous acoustic information into discrete representations. Studies in the visual domain have identified a rule-based learning system that learns and reasons via a hypothesis-testing process that requires working memory and executive attention. The rule-based learning system in vision shows a protracted development, reflecting the influence of maturing prefrontal function on visual categorization. The aim of the current study is two-fold: (a) to examine the developmental trajectory of rule-based auditory category learning from childhood through adolescence, into early adulthood; and (b) to examine the extent to which individual differences in rule-based category learning relate to individual differences in executive function. Sixty participants with normal hearing, 20 children (age range, 7–12), 21 adolescents (age range, 13–19), and 19 young adults (age range, 20–23), learned to categorize novel dynamic ripple sounds using trial-by-trial feedback. The spectrotemporally modulated ripple sounds are considered the auditory equivalent of the well-studied Gabor patches in the visual domain. Results revealed that auditory categorization accuracy improved with age, with young adults outperforming children and adolescents. Computational modeling analyses indicated that the use of the task-optimal strategy (i.e. a conjunctive rule-based learning strategy) improved with age. Notably, individual differences in executive flexibility significantly predicted auditory category learning success. The current findings demonstrate a protracted development of rule-based auditory categorization. The results further suggest that executive flexibility coupled with perceptual processes play important roles in successful rule-based auditory category learning. PMID:26491987

Graphene defect formation by extreme ultraviolet generated photoelectrons

NARCIS (Netherlands)

Gao, An; Lee, Christopher James; Bijkerk, Frederik

2014-01-01

We have studied the effect of photoelectrons on defect formation in graphene during extreme ultraviolet (EUV) irradiation. Assuming the major role of these low energy electrons, we have mimicked the process by using low energy primary electrons. Graphene is irradiated by an electron beam with energy

Role of state-dependent learning in the cognitive effects of caffeine in mice

OpenAIRE

Sanday, Leandro [UNIFESP; Zanin, Karina Agustini [UNIFESP; Patti, Camilla de Lima [UNIFESP; Fernandes-Santos, Luciano [UNIFESP; Oliveira, Larissa C. [UNIFESP; Longo, Beatriz Monteiro [UNIFESP; Andersen, Monica Levy [UNIFESP; Tufik, Sergio [UNIFESP; Frussa-Filho, Roberto [UNIFESP

2013-01-01

Caffeine is the most widely used psychoactive substance in the world and it is generally believed that it promotes beneficial effects on cognitive performance. However, there is also evidence suggesting that caffeine has inhibitory effects on learning and memory. Considering that caffeine may have anxiogenic effects, thus changing the emotional state of the subjects, state-dependent learning may play a role in caffeine-induced cognitive alterations. Mice were administered 20 mg/kg caffeine be...

Modeling learning technology systems as business systems

NARCIS (Netherlands)

Avgeriou, Paris; Retalis, Symeon; Papaspyrou, Nikolaos

2003-01-01

The design of Learning Technology Systems, and the Software Systems that support them, is largely conducted on an intuitive, ad hoc basis, thus resulting in inefficient systems that defectively support the learning process. There is now justifiable, increasing effort in formalizing the engineering

Learning Strategies and Learner Attitudes in the Massively Multiplayer Online Role-Playing Game Cube World

Science.gov (United States)

Goh, Shu Li

2016-01-01

The rapid progress of technology has revolutionized learning and in the field of computer assisted language learning, the use of digital games has expanded significantly. One type of game that has been attracting interest is massively multiplayer online role-playing games (henceforth MMORPGs). Recent research has drawn attention to the potential…

Defect-impurity interactions in irradiated germanium

International Nuclear Information System (INIS)

Cleland, J.W.; James, F.J.; Westbrook, R.D.

1975-07-01

Results of experiments are used to formulate a better model for the structures of lattice defects and defect-impurity complexes in irradiated n-type Ge. Single crystals were grown by the Czochralski process from P, As, or Sb-doped melts, and less than or equal to 10 15 to greater than or equal to 10 17 oxygen cm -3 was added to the furnace chamber after approximately 1 / 3 of the crystal had been solidified. Hall coefficient and resistivity measurements (at 77 0 K) were used to determine the initial donor concentration due to the dopant and clustered oxygen, and infrared absorption measurements (at 11.7 μ) were used to determine the dissociated oxygen concentration. Certain impurity and defect-impurity interactions were then investigated that occurred as a consequence of selected annealing, quenching, Li diffusion, and irradiation experiments at approximately 300 0 K with 60 Co photons, 1.5 to 2.0 MeV electrons, or thermal energy neutrons. Particular attention was given to determining the electrical role of the irradiation produced interstitial and vacancy, and to look for any evidence from electrical and optical measurements of vacancy--oxygen, lithium--oxygen, and lithium--vacancy interactions. (U.S.)

Defective TiO2 with oxygen vacancies: synthesis, properties and photocatalytic applications

Science.gov (United States)

Pan, Xiaoyang; Yang, Min-Quan; Fu, Xianzhi; Zhang, Nan; Xu, Yi-Jun

2013-04-01

Titanium dioxide (TiO2), as an important semiconductor metal oxide, has been widely investigated in the field of photocatalysis. The properties of TiO2, including its light absorption, charge transport and surface adsorption, are closely related to its defect disorder, which in turn plays a significant role in the photocatalytic performance of TiO2. Among all the defects identified in TiO2, oxygen vacancy is one of the most important and is supposed to be the prevalent defect in many metal oxides, which has been widely investigated both by theoretical calculations and experimental characterizations. Here, we give a short review on the existing strategies for the synthesis of defective TiO2 with oxygen vacancies, and the defect related properties of TiO2 including structural, electronic, optical, dissociative adsorption and reductive properties, which are intimately related to the photocatalytic performance of TiO2. In particular, photocatalytic applications with regard to defective TiO2 are outlined. In addition, we offer some perspectives on the challenge and new direction for future research in this field. We hope that this tutorial minireview would provide some useful contribution to the future design and fabrication of defective semiconductor-based nanomaterials for diverse photocatalytic applications.Titanium dioxide (TiO2), as an important semiconductor metal oxide, has been widely investigated in the field of photocatalysis. The properties of TiO2, including its light absorption, charge transport and surface adsorption, are closely related to its defect disorder, which in turn plays a significant role in the photocatalytic performance of TiO2. Among all the defects identified in TiO2, oxygen vacancy is one of the most important and is supposed to be the prevalent defect in many metal oxides, which has been widely investigated both by theoretical calculations and experimental characterizations. Here, we give a short review on the existing strategies for the

The Role of Guided Induction in Paper-Based Data-Driven Learning

Science.gov (United States)

Smart, Jonathan

2014-01-01

This study examines the role of guided induction as an instructional approach in paper-based data-driven learning (DDL) in the context of an ESL grammar course during an intensive English program at an American public university. Specifically, it examines whether corpus-informed grammar instruction is more effective through inductive, data-driven…

The Roles of Working Memory and Cognitive Load in Geoscience Learning

Science.gov (United States)

Jaeger, Allison J.; Shipley, Thomas F.; Reynolds, Stephen J.

2017-01-01

Working memory is a cognitive system that allows for the simultaneous storage and processing of active information. While working memory has been implicated as an important element for success in many science, technology, engineering, and mathematics (STEM) fields, its specific role in geoscience learning is not fully understood. The major goal of…

Epigenetic control of learning and memory in Drosophila by Tip60 HAT action.

Science.gov (United States)

Xu, Songjun; Wilf, Rona; Menon, Trisha; Panikker, Priyalakshmi; Sarthi, Jessica; Elefant, Felice

2014-12-01

Disruption of epigenetic gene control mechanisms in the brain causes significant cognitive impairment that is a debilitating hallmark of most neurodegenerative disorders, including Alzheimer's disease (AD). Histone acetylation is one of the best characterized of these epigenetic mechanisms that is critical for regulating learning- and memory- associated gene expression profiles, yet the specific histone acetyltransferases (HATs) that mediate these effects have yet to be fully characterized. Here, we investigate an epigenetic role for the HAT Tip60 in learning and memory formation using the Drosophila CNS mushroom body (MB) as a well-characterized cognition model. We show that Tip60 is endogenously expressed in the Kenyon cells, the intrinsic neurons of the MB, and in the MB axonal lobes. Targeted loss of Tip60 HAT activity in the MB causes thinner and shorter axonal lobes while increasing Tip60 HAT levels cause no morphological defects. Functional consequences of both loss and gain of Tip60 HAT levels in the MB are evidenced by defects in immediate-recall memory. Our ChIP-Seq analysis reveals that Tip60 target genes are enriched for functions in cognitive processes, and, accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, we find that both learning and immediate-recall memory deficits that occur under AD-associated, amyloid precursor protein (APP)-induced neurodegenerative conditions can be effectively rescued by increasing Tip60 HAT levels specifically in the MB. Together, our findings uncover an epigenetic transcriptional regulatory role for Tip60 in cognitive function and highlight the potential of HAT activators as a therapeutic option for neurodegenerative disorders. Copyright © 2014 by the Genetics Society of America.

Electronic structure of point defects in semiconductors

International Nuclear Information System (INIS)

Bruneval, Fabien

2014-01-01

This 'Habilitation a diriger des Recherches' memoir presents most of my scientific activities during the past 7 years, in the field of electronic structure calculations of defects in solids. Point defects (vacancies, interstitials, impurities) in functional materials are a key parameter to determine if these materials will actually fill the role they have been assigned or not. Indeed, the presence of defects cannot be avoided when the temperature is increased or when the material is subjected to external stresses, such as irradiation in the nuclear reactors and in artificial satellites with solar radiations. However, in many cases, defects are introduced in the materials on purpose to tune the electronic transport, optical or even magnetic properties. This procedure is called the doping of semiconductors, which is the foundation technique for transistors, diodes, or photovoltaic cells. However, doping is not always straightforward and unexpected features may occur, such as doping asymmetry or Fermi level pinning, which can only be explained by complex phenomena involving different types of defects or complexes of defects. In this context, the calculations of electronic structure ab initio is an ideal tool to complement the experimental observations, to gain the understanding of phenomena at the atomic level, and even to predict the properties of defects. The power of the ab initio calculations comes from their ability to describe any system of electrons and nuclei without any specific adjustment. But although there is a strong need for numerical simulations in this field, the ab initio calculations for defects are still under development as of today. The work presented in this memoir summarizes my contributions to methodological developments on this subject. These developments have followed two main tracks. The first topic is the better understanding of the unavoidable finite size effects. Indeed, defects in semiconductors or insulators are generally present in

How do we learn to "kill" in volleyball?: The role of working memory capacity and expertise in volleyball motor learning.

Science.gov (United States)

Bisagno, Elisa; Morra, Sergio

2018-03-01

This study examines young volleyball players' learning of increasingly complex attack gestures. The main purpose of the study was to examine the predictive role of a cognitive variable, working memory capacity (or "M capacity"), in the acquisition and development of motor skills in a structured sport. Pascual-Leone's theory of constructive operators (TCO) was used as a framework; it defines working memory capacity as the maximum number of schemes that can be simultaneously activated by attentional resources. The role of expertise in motor learning was also considered. The expertise of each athlete was assessed in terms of years of practice and number of training sessions per week. The participants were 120 volleyball players, aged between 6 and 26 years, who performed both working memory tests and practical tests of volleyball involving the execution of the "third touch" by means of technical gestures of varying difficulty. We proposed a task analysis of these different gestures framed within the TCO. The results pointed to a very clear dissociation. On the one hand, M capacity was the best predictor of correct motor performance, and a specific capacity threshold was found for learning each attack gesture. On the other hand, experience was the key for the precision of the athletic gestures. This evidence could underline the existence of two different cognitive mechanisms in motor learning. The first one, relying on attentional resources, is required to learn a gesture. The second one, based on repeated experience, leads to its automatization. Copyright © 2017 Elsevier Inc. All rights reserved.

The Role of the Basal Ganglia in Implicit Contextual Learning: A Study of Parkinson's Disease

Science.gov (United States)

van Asselen, Marieke; Almeida, Ines; Andre, Rui; Januario, Cristina; Goncalves, Antonio Freire; Castelo-Branco, Miguel

2009-01-01

Implicit contextual learning refers to the ability to memorize contextual information from our environment. This contextual information can then be used to guide our attention to a specific location. Although the medial temporal lobe is important for this type of learning, the basal ganglia might also be involved considering its role in many…

Point defects in lines in single crystalline phosphorene: directional migration and tunable band gaps.

Science.gov (United States)

Li, Xiuling; Ma, Liang; Wang, Dayong; Zeng, Xiao Cheng; Wu, Xiaojun; Yang, Jinlong

2016-10-20

Extended line defects in two-dimensional (2D) materials can play an important role in modulating their electronic properties. During the experimental synthesis of 2D materials, line defects are commonly generated at grain boundaries between domains of different orientations. In this work, twelve types of line-defect structures in single crystalline phosphorene are examined by using first-principles calculations. These line defects are typically formed via migration and aggregation of intrinsic point defects, including the Stone-Wales (SW), single or double vacancy (SV or DV) defects. Our calculated results demonstrate that the migration of point defects in phosphorene is anisotropic, for instance, the lowest migration energy barriers are 1.39 (or 0.40) and 2.58 (or 0.49) eV for SW (or SV) defects in zigzag and armchair directions, respectively. The aggregation of point defects into lines is energetically favorable compared with the separated point defects in phosphorene. In particular, the axis of line defects in phosphorene is direction-selective, depending on the composed point defects. The presence of line defects effectively modulates the electronic properties of phosphorene, rendering the defect-containing phosphorene either metallic or semiconducting with a tunable band gap. Of particular interest is the fact that the SV-based line defect can behave as a metallic wire, suggesting a possibility to fabricate a circuit with subnanometer widths in the semiconducting phosphorene for nanoscale electronic application.

Muon spin rotation studies of defect states in solids: the story of anomalous muonium

International Nuclear Information System (INIS)

Estle, T.L.

1983-01-01

Muon spin rotation (μSR) is a powerful technique to study magnetic phenomena, light interstitial diffusion, and hydrogenic chemistry. However it has been applied in several other areas of science where its applicability was not immediately apparent. One of these is the study of an unusual muonic defect, anomalous muonium, produced when μ + stops in semiconducting crystals. The study of anomalous muonium and the process of inferring its structure are described. For this defect, μSR has learned far more than have efforts to study the analogous hydrogenic center

TEACHER ROLE IN FORMATION POLITENESS OF STUDENT LEARNING PROCESS

Directory of Open Access Journals (Sweden)

Wahyuni Oktavia

2016-09-01

Full Text Available Language as a communication tool has an important role in human interaction. Language can be used to convey ideas, ideas, feelings, desires, and so forth to others. To be able to communicate well certainly should be able to adjust the language used. One of the main functions of communication is to maintain the continuity of the relationship between the narrator and hearer. Language is an important pillar in the formation of character, in addition to religious education and moral education. In education, teachers must have pedagogical, professional, personal, and social. Teachers who have a good competence speech acts certainly have a good and well mannered to students. In the learning process, teachers and students communicate in give and receive course materials. The learning process is certainly not only provides knowledge alone, but give the values of character to students. In this case, the teacher must have a principle that must be controlled properly, correctly and precisely. Thus, teachers are expected to master the communication and understanding the principles of politeness in speaking well and correctly. The goal is a description of a form of politeness in the learning process. This research is a descriptive study which seeks to describe a form of politeness in the learning process. Data collection method used is the method refer to the data collection techniques are 1 recording technique using a tape recorder, and 2 technical note on the data card. Furthermore, methods of data analysis using pragmatic frontier.

ESL students learning biology: The role of language and social interactions

Science.gov (United States)

Jaipal, Kamini

This study explored three aspects related to ESL students in a mainstream grade 11 biology classroom: (1) the nature of students' participation in classroom activities, (2) the factors that enhanced or constrained ESL students' engagement in social interactions, and (3) the role of language in the learning of science. Ten ESL students were observed over an eight-month period in this biology classroom. Data were collected using qualitative research methods such as participant observation, audio-recordings of lessons, field notes, semi-structured interviews, short lesson recall interviews and students' written work. The study was framed within sociocultural perspectives, particularly the social constructivist perspectives of Vygotsky (1962, 1978) and Wertsch (1991). Data were analysed with respect to the three research aspects. Firstly, the findings showed that ESL students' preferred and exhibited a variety of participation practices that ranged from personal-individual to socio-interactive in nature. Both personal-individual and socio-interactive practices appeared to support science and language learning. Secondly, the findings indicated that ESL students' engagement in classroom social interactions was most likely influenced by the complex interactions between a number of competing factors at the individual, interpersonal and community/cultural levels (Rogoff, Radziszewska, & Masiello, 1995). In this study, six factors that appeared to enhance or constrain ESL students' engagement in classroom social interactions were identified. These factors were socio-cultural factors, prior classroom practice, teaching practices, affective factors, English language proficiency, and participation in the research project. Thirdly, the findings indicated that language played a significant mediational role in ESL students' learning of science. The data revealed that the learning of science terms and concepts can be explained by a functional model of language that includes: (1

A Hybrid Instance Selection Using Nearest-Neighbor for Cross-Project Defect Prediction

Institute of Scientific and Technical Information of China (English)

Duksan Ryu; Jong-In Jang; Jongmoon Baik; Member; ACM; IEEE

2015-01-01

Software defect prediction (SDP) is an active research field in software engineering to identify defect-prone modules. Thanks to SDP, limited testing resources can be effectively allocated to defect-prone modules. Although SDP requires suffcient local data within a company, there are cases where local data are not available, e.g., pilot projects. Companies without local data can employ cross-project defect prediction (CPDP) using external data to build classifiers. The major challenge of CPDP is different distributions between training and test data. To tackle this, instances of source data similar to target data are selected to build classifiers. Software datasets have a class imbalance problem meaning the ratio of defective class to clean class is far low. It usually lowers the performance of classifiers. We propose a Hybrid Instance Selection Using Nearest-Neighbor (HISNN) method that performs a hybrid classification selectively learning local knowledge (via k-nearest neighbor) and global knowledge (via na¨ıve Bayes). Instances having strong local knowledge are identified via nearest-neighbors with the same class label. Previous studies showed low PD (probability of detection) or high PF (probability of false alarm) which is impractical to use. The experimental results show that HISNN produces high overall performance as well as high PD and low PF.

A fundamental role for context in instrumental learning and extinction.

Science.gov (United States)

Bouton, Mark E; Todd, Travis P

2014-05-01

The purpose of this article is to review recent research that has investigated the effects of context change on instrumental (operant) learning. The first part of the article discusses instrumental extinction, in which the strength of a reinforced instrumental behavior declines when reinforcers are withdrawn. The results suggest that extinction of either simple or discriminated operant behavior is relatively specific to the context in which it is learned: As in prior studies of Pavlovian extinction, ABA, ABC, and AAB renewal effects can all be observed. Further analysis supports the idea that the organism learns to refrain from making a specific response in a specific context, or in more formal terms, an inhibitory context-response association. The second part of the article then discusses research suggesting that the context also controls instrumental behavior before it is extinguished. Several experiments demonstrate that a context switch after either simple or discriminated operant training causes a decrement in the strength of the response. Over a range of conditions, the animal appears to learn a direct association between the context and the response. Under some conditions, it can also learn a hierarchical representation of context and the response-reinforcer relation. Extinction is still more context-specific than conditioning, as indicated by ABC and AAB renewal. Overall, the results establish that the context can play a significant role in both the acquisition and extinction of operant behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

Exploring the Moderating Role of Perceived Flexibility Advantages in Mobile Learning Continuance Intention (MLCI

Directory of Open Access Journals (Sweden)

Rui-Ting Huang

2014-07-01

Full Text Available The primary purpose of this study was to explore the key factors that could affect mobile learning continuance intention (MLCI, and examine the moderating effect of perceived flexibility advantages (PFA on the relationship between key mobile learning elements and continuance intention. Five hundred undergraduate students who had previously adopted mobile devices to learn English took part in this study. Partial least squares (PLS analysis was utilized to test the hypotheses in this study. It has been found that the perceived usefulness of mobile technology, subjective norm, and self-management of learning could be closely linked to mobile learning continuance intention. With particular respect to the moderating role of perceived flexibility advantages, it has been demonstrated that PFA could moderate the relationship between perceived usefulness of mobile technology and mobile learning continuance intention, as well as the association between subjective norm and mobile learning continuance intention, whereas PFA did not moderate the link between self-management of learning and mobile learning continuance intention.This report has further added to the body of knowledge in the field of mobile learning through empirical examination.

Examining the Role of Emotional Intelligence between Organizational Learning and Adaptive Performance in Indian Manufacturing Industries

Science.gov (United States)

Pradhan, Rabindra Kumar; Jena, Lalatendu Kesari; Singh, Sanjay Kumar

2017-01-01

Purpose: The purpose of this study is to examine the relationship between organisational learning and adaptive performance. Furthermore, the study investigates the moderating role of emotional intelligence in the perspective of organisational learning for addressing adaptive performance of executives employed in manufacturing organisations.…

APPLICATION METHODS TO INCREASE OF ROLE PLAYING ON LEARNING MATERIALS PRESERVING NKRI (PENERAPAN METODE ROLE PLAY UNTUK MENINGKATKAN HASIL BELAJAR PADA MATERI MENJAGA KEUTUHAN NKRI

Directory of Open Access Journals (Sweden)

Mahfudin -

2016-10-01

Full Text Available Abstract. Uncertainty in the nation's economy, the impact of globalization as well as various crises and disasters are problems that may lead to national disintegration which make few groups want to secede from NKRI. All these problems unilaterally are evidences of the unreliability of civic education learning as a subject that mandates to maintain the integrity of NKRI, not in the macro scope but in giving civic education as early as possible from the elementary school. The learning outcomes of civic education learning do not only include the acquisition of knowledge, but more to the acquisition of feeling and behavior. Consequently, in the pre-cycle, the researcher found difficulties to integrate the two domains, which made the learning outcomes below the mini-mum mastery criteria, students’ behavior lacking the feeling of love to their homeland and stu-dents’ motivation in learning low. To solve the problems, the researcher used role play method and as a result, after two cycles, students’ learning outcomes increased. The percentage of stu-dents’ minimum mastery criteria increased from 52% (score 75 to 69% in cycle I and 96% in cycle II. In addition, the students’ were more motivated in learning, followed ceremony in an or-derly manner, and behaved in ways that reflect the love of homeland. It can be concluded that ap-plying role play method in the lesson of preserving the integrity of NKRI at Grade V SDN Cilengkrang North Sumedang Regencey, students’ learning outcomes could be improved. Keywords: Role Play Method, Civic Education Learning, Integrity of The Unitary State of The Republic of Indonesia Abstrak. Ketidakpastian kondisi perekonomian bangsa, pengaruh globalisasi serta berbagai krisis dan bencana merupakan permasalahan yang merujuk ke arah disintegrasi bangsa. Sehingga segelintir kelompok ingin memisahkan diri dari NKRI. Semua permasalahan diatas secara sepihak merupakan suatu bukti ketidak mempanan pembelajaran PKn

On the dependence of static flat seal efficiency to surface defects

International Nuclear Information System (INIS)

Ledoux, Y.; Lasseux, D.; Favreliere, H.; Samper, S.; Grandjean, J.

2011-01-01

We report on the role of the modal content of surface defects on static flat seal efficiency. The configuration under consideration is an annular contact between two surfaces, one holding all the defects, the other being assumed flat and infinitely rigid. The analysis is carried out on synthetic 'turned-like' surfaces generated by combinations of the first 50 vibrational eigen modes determined from modal discrete decomposition. The transmissivity of the contact, that fully characterizes the seal efficiency, is computed on the basis of a Reynolds model for incompressible flow. The dependence of the transmissivity upon the modal content of the surface defects is analyzed on a contact pressure range of common use employing a simplified deformation algorithm. Impact of the defects modal content is investigated statistically through a pair of experimental designs. It is shown that, i) the uncertainty on transmissivity, while considering a series of parts, can be drastically reduced if defect modes are well selected; ii) the transmissivity itself can be very significantly decreased when the defects modal content is conveniently controlled. While clearly indicating that the common surface roughness specification is generally not a relevant one to ensure a required seal performance, this work opens wide perspectives on the seal improvement by surface defects optimization only. - Highlights: → Computation of contact transmissivity qualifying static seal efficiency. → Statistical analysis of surface defects modal content on static flat seal. → Improvement of static flat seal efficiency. → Significant transmissivity reduction by convenient control of surface defects modes. → Drastic reduction of transmissivity uncertainty by surface defects modes selection.

Phononic crystals with one-dimensional defect as sensor materials

Science.gov (United States)

Aly, Arafa H.; Mehaney, Ahmed

2017-09-01

Recently, sensor technology has attracted great attention in many fields due to its importance in many engineering applications. In the present work, we introduce a study using the innovative properties of phononic crystals in enhancing a new type of sensors based on the intensity of transmitted frequencies inside the phononic band gaps. Based on the transfer matrix method and Bloch theory, the expressions of the reflection coefficient and dispersion relation are presented. Firstly, the influences of filling fraction ratio and the angle of incidence on the band gap width are discussed. Secondly, the localization of waves inside band gaps is discussed by enhancing the properties of the defected phononic crystal. Compared to the periodic structure, localization modes involved within the band structure of phononic crystals with one and two defect layers are presented and compared. Trapped localized modes can be detected easily and provide more information about defected structures. Such method could increase the knowledge of manufacturing defects by measuring the intensity of propagated waves in the resonant cavities and waveguides. Moreover, several factors enhance the role of the defect layer on the transmission properties of defected phononic crystals are presented. The acoustic band gap can be used to detect or sense the type of liquids filling the defect layer. The liquids make specific resonant modes through the phononic band gaps that related to the properties of each liquid. The frequency where the maximum resonant modes occur is correlated to material properties and allows to determine several parameters such as the type of an unknown material.

Chemotherapeutic-Induced Cardiovascular Dysfunction: Physiological Effects, Early Detection—The Role of Telomerase to Counteract Mitochondrial Defects and Oxidative Stress

Science.gov (United States)

Quryshi, Nabeel; Norwood Toro, Laura E.; Ait-Aissa, Karima; Kong, Amanda; Beyer, Andreas M.

2018-01-01

Although chemotherapeutics can be highly effective at targeting malignancies, their ability to trigger cardiovascular morbidity is clinically significant. Chemotherapy can adversely affect cardiovascular physiology, resulting in the development of cardiomyopathy, heart failure and microvascular defects. Specifically, anthracyclines are known to cause an excessive buildup of free radical species and mitochondrial DNA damage (mtDNA) that can lead to oxidative stress-induced cardiovascular apoptosis. Therefore, oncologists and cardiologists maintain a network of communication when dealing with patients during treatment in order to treat and prevent chemotherapy-induced cardiovascular damage; however, there is a need to discover more accurate biomarkers and therapeutics to combat and predict the onset of cardiovascular side effects. Telomerase, originally discovered to promote cellular proliferation, has recently emerged as a potential mechanism to counteract mitochondrial defects and restore healthy mitochondrial vascular phenotypes. This review details mechanisms currently used to assess cardiovascular damage, such as C-reactive protein (CRP) and troponin levels, while also unearthing recently researched biomarkers, including circulating mtDNA, telomere length and telomerase activity. Further, we explore a potential role of telomerase in the mitigation of mitochondrial reactive oxygen species and maintenance of mtDNA integrity. Telomerase activity presents a promising indicator for the early detection and treatment of chemotherapy-derived cardiac damage. PMID:29534446

Reciprocal Benefits, Legacy and Risk: Applying Ellinger and Bostrom's Model of Line Manager Role Identity as Facilitators of Learning

Science.gov (United States)

Campbell, Paul; Evans, Peter

2016-01-01

Purpose: The purpose of this paper is to explore the beliefs held by managers about their roles as facilitators of learning with their employees in a public utilities organisation. Design/methodology/approach: The research was based on Ellinger and Bostrom's (2002) study on managers' beliefs on their role as facilitators of learning in…

"SAFEGUARDING THE INTERESTS OF THE STATE" FROM DEFECTIVE DELINQUENT GIRLS.

Science.gov (United States)

Sohasky, Kate E

2016-01-01

The 1911 mental classification, "defective delinquent," was created as a temporary legal-medical category in order to identify a peculiar class of delinquent girls in a specific institutional setting. The defective delinquent's alleged slight mental defect, combined with her appearance of normalcy, rendered her a "dangerous" and "incurable" citizen. At the intersection of institutional history and the history of ideas, this article explores the largely overlooked role of borderline mental classifications of near-normalcy in the medicalization of intelligence and criminality during the first third of the twentieth-century United States. Borderline classifications served as mechanisms of control over women's bodies through the criminalization of their minds, and the advent of psychometric tests legitimated and facilitated the spread of this classification beyond its original and intended context. The borderline case of the defective delinquent girl demonstrates the significance of marginal mental classifications to the policing of bodies through the medicalization of intellect. © 2015 Wiley Periodicals, Inc.

An interactive machine-learning approach for defect detection in computed tomogaraphy (CT) images of hardwood logs

Science.gov (United States)

Erol Sarigul; A. Lynn Abbott; Daniel L. Schmoldt; Philip A. Araman

2005-01-01

This paper describes recent progress in the analysis of computed tomography (CT) images of hardwood logs. The long-term goal of the work is to develop a system that is capable of autonomous (or semiautonomous) detection of internal defects, so that log breakdown decisions can be optimized based on defect locations. The problem is difficult because wood exhibits large...

Blood flow patterns underlie developmental heart defects.

Science.gov (United States)

Midgett, Madeline; Thornburg, Kent; Rugonyi, Sandra

2017-03-01

Although cardiac malformations at birth are typically associated with genetic anomalies, blood flow dynamics also play a crucial role in heart formation. However, the relationship between blood flow patterns in the early embryo and later cardiovascular malformation has not been determined. We used the chicken embryo model to quantify the extent to which anomalous blood flow patterns predict cardiac defects that resemble those in humans and found that restricting either the inflow to the heart or the outflow led to reproducible abnormalities with a dose-response type relationship between blood flow stimuli and the expression of cardiac phenotypes. Constricting the outflow tract by 10-35% led predominantly to ventricular septal defects, whereas constricting by 35-60% most often led to double outlet right ventricle. Ligation of the vitelline vein caused mostly pharyngeal arch artery malformations. We show that both cardiac inflow reduction and graded outflow constriction strongly influence the development of specific and persistent abnormal cardiac structure and function. Moreover, the hemodynamic-associated cardiac defects recapitulate those caused by genetic disorders. Thus our data demonstrate the importance of investigating embryonic blood flow conditions to understand the root causes of congenital heart disease as a prerequisite to future prevention and treatment. NEW & NOTEWORTHY Congenital heart defects result from genetic anomalies, teratogen exposure, and altered blood flow during embryonic development. We show here a novel "dose-response" type relationship between the level of blood flow alteration and manifestation of specific cardiac phenotypes. We speculate that abnormal blood flow may frequently underlie congenital heart defects. Copyright © 2017 the American Physiological Society.

On holographic defect entropy

International Nuclear Information System (INIS)

Estes, John; Jensen, Kristan; O’Bannon, Andy; Tsatis, Efstratios; Wrase, Timm

2014-01-01

We study a number of (3+1)- and (2+1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3+1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1+1)-dimensional field theories generalizes to higher dimensions

Vacancy-related defect distributions in 11B-, 14N-, and 27Al-implanted 4H-SiC: Role of channeling

International Nuclear Information System (INIS)

Janson, M.S.; Slotte, J.; Kuznetsov, A.Yu.; Saarinen, K.; Hallen, A.

2004-01-01

The defect distributions in 11 B-, 14 N-, and 27 Al-implanted epitaxial 4H-SiC are studied using monoenergetic positron beams. At least three types of defects are needed to account for the Doppler broadening annihilation spectra and two of the defects are tentatively identified as V Si , and V Si V C . By comparing the defect profiles extracted from the annihilation spectra to the chemical profiles determined by secondary ion mass spectrometry, and to the primary defect profiles obtained from binary collision approximation simulations, it is concluded that the defects found at depths considerably deeper than the projected range of the implanted ions mainly originate from deeply channeled ions

An investigation of the role of background music in IVWs for learning

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Debbie Richards

2008-12-01

Full Text Available Empirical evidence is needed to corroborate the intuitions of gamers and game developers in understanding the benefits of Immersive Virtual Worlds (IVWs as a learning environment and the role that music plays within these environments. We report an investigation to determine if background music of the genre typically found in computer-based role-playing games has an effect on learning in a computer-animated history lesson about the Macquarie Lighthouse within an IVW. In Experiment 1, music stimuli were created from four different computer game soundtracks. Seventy-two undergraduate students watched the presentation and completed a survey including biographical details, questions on the historical material presented and questions relating to their perceived level of immersion. While the tempo and pitch of the music was unrelated to learning, music conditions resulted in a higher number of accurately remembered facts than the no music condition. One soundtrack showed a statistically significant improvement in memorisation of facts over other music conditions. Also an interaction between the levels of perceived immersion and ability to accurately remember facts was observed. Experiment 2, involving 48 undergraduate students, further investigated the effect of music, sense of immersion and how different display systems affect memory for facts.

Teamwork orientation and personal learning: The role of individual cultural values and value congruence

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Ghulam Mustafa

2017-11-01

Full Text Available Orientation: There is a growing body of research that indicates that personal factors such as collectivist value orientation play an important role in individuals’ preference for teamwork, and an individual’s propensity to work in a team is seen as a contributing factor in one’s personal learning. Research purpose: The purpose of this article is twofold. Firstly, the article aims to explore whether individual-level cultural values of power distance, uncertainty avoidance and masculinity–femininity interact with individual collectivist values to influence teamwork orientation. Secondly, the study aims to examine the influence of teamwork orientation on personal learning further exploring the role of perceived value congruence in this relationship. Motivation for the study: While an extensive amount of research has been conducted on teamwork orientation, the question of how individual cultural values influence formation of teamwork orientation is still largely unanswered. This lack is especially evident with regard to how the influence of collectivism on the development of positive attitudes towards teamwork is promoted or inhibited by other values such as power distance, uncertainty avoidance and masculinity–femininity. Moreover, the current evidence about the influence of teamwork orientation on personal learning and the role of personal and contextual factors in such a relationship is still scarce. Research design, approach and method: The study used a cross-sectional survey, with data collected from 120 business students engaged in project teams at a Norwegian university. All the hypothesised relationships were assessed using partial least square structural equation modelling technique. Main findings: The findings indicate that the link between collectivism–teamwork orientation is stronger for team members who scored high on uncertainty avoidance values and the relationship was weaker for team members who endorsed high

A Constructive Reframing of Student Roles and Systems Learning in Medical Education Using a Communities of Practice Lens.

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Gonzalo, Jed D; Thompson, Britta M; Haidet, Paul; Mann, Karen; Wolpaw, Daniel R

2017-12-01

Health systems are in the midst of a transformation that is being driven by a variety of forces. This has important implications for medical educators because clinical practice environments play a key role in learning and professional development, and evolving health systems are beginning to demand that providers have "systems-ready" knowledge, attitudes, and skills. Such implications provide a clear mandate for medical schools to modify their goals and prepare physicians to practice flexibly within teams and effectively contribute to the improvement of health care delivery. In this context, the concepts of value-added medical education, authentic student roles, and health systems science are emerging as increasingly important. In this Article, the authors use a lens informed by communities of practice theory to explore these three concepts, examining the implications that the communities of practice theory has in the constructive reframing of educational practices-particularly common student roles and experiences-and charting future directions for medical education that better align with the needs of the health care system. The authors apply several key features of the communities of practice theory to current experiential roles for students, then propose a new approach to students' clinical experiences-value-added clinical systems learning roles-that provides students with opportunities to make meaningful contributions to patient care while learning health systems science at the patient and population level. Finally, the authors discuss implications for professional role formation and anticipated challenges to the design and implementation of value-added clinical systems learning roles.

A role for calcium-permeable AMPA receptors in synaptic plasticity and learning.

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Brian J Wiltgen

2010-09-01

Full Text Available A central concept in the field of learning and memory is that NMDARs are essential for synaptic plasticity and memory formation. Surprisingly then, multiple studies have found that behavioral experience can reduce or eliminate the contribution of these receptors to learning. The cellular mechanisms that mediate learning in the absence of NMDAR activation are currently unknown. To address this issue, we examined the contribution of Ca(2+-permeable AMPARs to learning and plasticity in the hippocampus. Mutant mice were engineered with a conditional genetic deletion of GluR2 in the CA1 region of the hippocampus (GluR2-cKO mice. Electrophysiology experiments in these animals revealed a novel form of long-term potentiation (LTP that was independent of NMDARs and mediated by GluR2-lacking Ca(2+-permeable AMPARs. Behavioral analyses found that GluR2-cKO mice were impaired on multiple hippocampus-dependent learning tasks that required NMDAR activation. This suggests that AMPAR-mediated LTP interferes with NMDAR-dependent plasticity. In contrast, NMDAR-independent learning was normal in knockout mice and required the activation of Ca(2+-permeable AMPARs. These results suggest that GluR2-lacking AMPARs play a functional and previously unidentified role in learning; they appear to mediate changes in synaptic strength that occur after plasticity has been established by NMDARs.

Management of Anterior Skull Base Defect Depending on Its Size and Location

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Bernal-Sprekelsen, Manuel; Rioja, Elena; Enseñat, Joaquim; Enriquez, Karla; Viscovich, Liza; Agredo-Lemos, Freddy Enrique; Alobid, Isam

2014-01-01

Introduction. We present our experience in the reconstruction of these leaks depending on their size and location. Material and Methods. Fifty-four patients who underwent advanced skull base surgery (large defects, >20 mm) and 62 patients with CSF leaks of different origin (small, 2–10 mm, and midsize, 11–20 mm, defects) were included in the retrospective study. Large defects were reconstructed with a nasoseptal pedicled flap positioned on fat and fascia lata. In small and midsized leaks. Fascia lata in an underlay position was used for its reconstruction covered with mucoperiosteum of either the middle or the inferior turbinate. Results. The most frequent etiology for small and midsized defects was spontaneous (48.4%), followed by trauma (24.2%), iatrogenic (5%). The success rate after the first surgical reconstruction was 91% and 98% in large skull base defects and small/midsized, respectively. Rescue surgery achieved 100%. Conclusions. Endoscopic surgery for any type of skull base defect is the gold standard. The size of the defects does not seem to play a significant role in the success rate. Fascia lata and mucoperiosteum of the turbinate allow a two-layer reconstruction of small and midsized defects. For larger skull base defects, a combination of fat, fascia lata, and nasoseptal pedicled flaps provides a successful reconstruction. PMID:24895567

Defects in semiconductors

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Romano, Lucia; Jagadish, Chennupati

2015-01-01

This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

Exploring the Role of the Learning Strategist at a Canadian College and University: The Tale of Two Professionals

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Woloshyn, Vera E.; Munn, Caitlin

2014-01-01

In this article, we synthesize literature related to the experiences of students with learning disabilities in postsecondary settings, including support service initiatives. We also synthesize the role of the learning strategists in context of working with these students. We then explore the daily experiences of two senior learning strategists…

The role of functionally defective rare germline variants of sialic acid acetylesterase in autoimmune Addison's disease

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Gan, Earn H; MacArthur, Katie; Mitchell, Anna L; Pearce, Simon H S

2012-01-01

Background Autoimmune Addison's disease (AAD) is a rare condition with a complex genetic basis. A panel of rare and functionally defective genetic variants in the sialic acid acetylesterase (SIAE) gene has recently been implicated in several common autoimmune conditions. We performed a case–control study to determine whether these rare variants are associated with a rarer condition, AAD. Method We analysed nine SIAE gene variants (W48X, M89V, C196F, C226G, R230W, T312M, Y349C, F404S and R479C) in a United Kingdom cohort of 378 AAD subjects and 387 healthy controls. All samples were genotyped using Sequenom iPlex chemistry to characterise primer extension products. Results A heterozygous rare allele at codon 312 (312*M) was found in one AAD patient (0.13%) but was not detected in the healthy controls. The commoner, functionally recessive variant at codon 89 (89*V) was found to be homozygous in two AAD patients but was only found in the heterozygous state in controls. Taking into account all nine alleles examined, 4/378 (1.06%) AAD patients and 1/387 (0.25%) healthy controls carried the defective SIAE alleles, with a calculated odds ratio of 4.13 (95% CI 0.44–97.45, two-tailed P value 0.212, NS). Conclusion We demonstrated the presence of 89*V homozygotes and the 312*M rare allele in the AAD cohort, but overall, our analysis does not support a role for rare variants in SIAE in the pathogenesis of AAD. However, the relatively small collection of AAD patients limits the power to exclude a small effect. PMID:23011869

The role of service-learning in college students' environmental literacy: Content knowledge, attitudes, and behaviors

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Singletary, Joanna Lynn Bush

This study evaluated the relationship of environmental service-learning on environmental literacy in undergraduates. The subjects were 36 undergraduates at a small liberal arts university enrolled in an environmental biology course. To determine the role of environmental service-learning on college students' environmental knowledge, attitudes, behaviors, and environmental literacy, this study utilized concurrent mixed methods approach for qualitative and quantitative analysis. A quasi-experimental repeated measures approach was the design of the quantitative component of the study. Data were collected on attitude, behavior, and content knowledge aspects of environmental literacy as measured by the Environmental Literacy Survey (Kibert, 2000). Hypotheses were tested by independent samples ttests and repeated measures ANOVA. Repeated measures ANOVA conducted on participants' three subscales scores for the Environmental Literacy Survey (attitude, behavior, and knowledge) indicated that students who participated in environmental service-learning scored statistically significantly higher than those that did not initially participate in service-learning. Qualitative data collected in the form of journal reflections and portfolios were evaluated for themes of environmental attitudes or affective statements, environmentally positive behaviors and skills, and ecological content. Quantitative and qualitative data support the positive role of environmental service-learning in the development of environmental literacy in undergraduate students.

How doctors learn: the role of clinical problems across the medical school-to-practice continuum.

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Slotnick, H B

1996-01-01

The author proposes a theory of how physicians learn that uses clinical problem solving as its central feature. His theory, which integrates insights from Maslow, Schön, Norman, and others, claims that physicians-in-training and practicing physicians learn largely by deriving insights from clinical experience. These insights allow the learner to solve future problems and thereby address the learner's basic human needs for security, affiliation, and self-esteem. Ensuring that students gain such insights means that the proper roles of the teacher are (1) to select problems for students to solve and offer guidance on how to solve them, and (2) to serve as a role model of how to reflect on the problem, its solution, and the solution's effectiveness. Three principles guide instruction within its framework for learning: (1) learners, whether physicians-in-training or practicing physicians, seek to solve problems they recognize they have; (2) learners want to be involved in their own learning; and (3) instruction must both be time-efficient and also demonstrate the range of ways in which students can apply what they learn. The author concludes by applying the theory to an aspect of undergraduate education and to the general process of continuing medical education.

Developmental changes in children's normative reasoning across learning contexts and collaborative roles.

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Riggs, Anne E; Young, Andrew G

2016-08-01

What influences children's normative judgments of conventional rules at different points in development? The current study explored the effects of two contextual factors on children's normative reasoning: the way in which the rules were learned and whether the rules apply to the self or others. Peer dyads practiced a novel collaborative board game comprising two complementary roles. Dyads were either taught both the prescriptive (i.e., what to do) and proscriptive (i.e., what not to do) forms of the rules, taught only the prescriptive form of the rules, or created the rules themselves. Children then judged whether third parties were violating or conforming to the rules governing their own roles and their partner's roles. Early school-aged children's (6- to 7-year-olds; N = 60) normative judgments were strongest when they had been taught the rules (with or without the proscriptive form), but were more flexible for rules they created themselves. Preschool-aged children's (4- to 5-year-olds; N = 60) normative judgments, however, were strongest when they were taught both the prescriptive and proscriptive forms of the rules. Additionally, preschoolers exhibited stronger normative judgments when the rules governed their own roles rather than their partner's roles, whereas school-aged children treated all rules as equally normative. These results demonstrate that children's normative reasoning is contingent on contextual factors of the learning environment and, moreover, highlight 2 specific areas in which children's inferences about the normativity of conventions strengthen over development. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Role of Consulting a Dictionary in Reading and Vocabulary Learning

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Carol A. Fraser

1999-12-01

Full Text Available Abstract This article reviews recent research on consulting a dictionary in L2 reading and vocabulary learning. From the perspective of cognitive learning theory, the author re-evaluates the limited role that has often been accorded to dictionary consulting. It is noted that, among the three available lexical processing strategies (inferencing, consulting and ignoring, learners tend to use consulting infrequently and selectively and also to differ among each other in their strategy use. Consulting in combination with inferencing is shown to have the greatest positive effect on performance in L2 reading and vocabulary learning, although consulting is found to slow down task completion. Excerpts from think-aloud protocols illustrate the potential contribution of strategic dictionary use to the cognitive processes required for vocabulary acquisition: attention to form-meaning connections, rehearsal of words for storage in long-term memory and elaboration of associations with other knowledge. Among the pedagogical implications of these findings is the need for training in lexical processing strategies in order to help learners use the dictionary effectively and accurately in L2 reading comprehension and vocabulary learning.

The Role of Resorbable Plate and Artificial Bone Substitute in Reconstruction of Large Orbital Floor Defect

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Ho Kwon

2016-01-01

Full Text Available It is essential to reduce and reconstruct bony defects adequately in large orbital floor fracture and defect. Among many reconstructive methods, alloplastic materials have attracted attention because of their safety and ease of use. We have used resorbable plates combined with artificial bone substitutes in large orbital floor defect reconstructions and have evaluated their long-term reliability compared with porous polyethylene plate. A total of 147 patients with traumatic orbital floor fracture were included in the study. Surgical results were evaluated by clinical evaluations, exophthalmometry, and computed tomography at least 12 months postoperatively. Both orbital floor height discrepancy and orbital volume change were calculated and compared with preoperative CT findings. The average volume discrepancy and vertical height discrepancies were not different between two groups. Also, exophthalmometric measurements were not significantly different between the two groups. No significant postoperative complication including permanent diplopia, proptosis, and enophthalmos was noted. Use of a resorbable plate with an artificial bone substitute to repair orbital floor defects larger than 2.5 cm2 in size yielded long-lasting, effective reconstruction without significant complications. We therefore propose our approach as an effective alternative method for large orbital floor reconstructions.

Influence of growth temperature on bulk and surface defects in hybrid lead halide perovskite films

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Peng, Weina; Anand, Benoy; Liu, Lihong; Sampat, Siddharth; Bearden, Brandon E.; Malko, Anton V.; Chabal, Yves J.

2016-01-01

The rapid development of perovskite solar cells has focused its attention on defects in perovskites, which are gradually realized to strongly control the device performance. A fundamental understanding is therefore needed for further improvement in this field. Recent efforts have mainly focused on minimizing the surface defects and grain boundaries in thin films. Using time-resolved photoluminescence spectroscopy, we show that bulk defects in perovskite samples prepared using vapor assisted solution process (VASP) play a key role in addition to surface and grain boundary defects. The defect state density of samples prepared at 150 °C (~1017 cm-3) increases by 5 fold at 175 °C even though the average grains size increases slightly, ruling out grain boundary defects as the main mechanism for the observed differences in PL properties upon annealing. Upon surface passivation using water molecules, the PL intensity and lifetime of samples prepared at 200 °C are only partially improved, remaining significantly lower than those prepared at 150 °C. Thus, the present study indicates that the majority of these defect states observed at elevated growth temperatures originates from bulk defects and underscores the importance to control the formation of bulk defects together with grain boundary and surface defects to further improve the optoelectronic properties of perovskites.The rapid development of perovskite solar cells has focused its attention on defects in perovskites, which are gradually realized to strongly control the device performance. A fundamental understanding is therefore needed for further improvement in this field. Recent efforts have mainly focused on minimizing the surface defects and grain boundaries in thin films. Using time-resolved photoluminescence spectroscopy, we show that bulk defects in perovskite samples prepared using vapor assisted solution process (VASP) play a key role in addition to surface and grain boundary defects. The defect state

The Role of Parenting for the Adjustment of Children with and without Learning Disabilities: A Person-Oriented Approach

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Barkauskiene, Rasa

2009-01-01

A person-oriented approach was used to examine the role of parenting in the associations between single learning disabilities and multiple learning disabilities and the adjustment difficulties in 8-11-year-olds. The results revealed that multiple, but not single, learning disabilities were associated with greater difficulties in emotional and…

Teaching-Learning Conceptions and Academic Achievement: The Mediating Role of Test Anxiety

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Bas, Gökhan

2016-01-01

The current research aimed at examining the mediating role of test anxiety in the relationship between teaching-learning conceptions and academic achievement. The correlation investigation model was adopted in this research. The participants of the research were volunteering teachers (n = 108) and students (n = 526) from five different high…

Exploring the Impact of Role-Playing on Peer Feedback in an Online Case-Based Learning Activity

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Ching, Yu-Hui

2014-01-01

This study explored the impact of role-playing on the quality of peer feedback and learners' perception of this strategy in a case-based learning activity with VoiceThread in an online course. The findings revealed potential positive impact of role-playing on learners' generation of constructive feedback as role-playing was associated with higher…

Imaging atomic-level random walk of a point defect in graphene

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Kotakoski, Jani; Mangler, Clemens; Meyer, Jannik C.

2014-05-01

Deviations from the perfect atomic arrangements in crystals play an important role in affecting their properties. Similarly, diffusion of such deviations is behind many microstructural changes in solids. However, observation of point defect diffusion is hindered both by the difficulties related to direct imaging of non-periodic structures and by the timescales involved in the diffusion process. Here, instead of imaging thermal diffusion, we stimulate and follow the migration of a divacancy through graphene lattice using a scanning transmission electron microscope operated at 60 kV. The beam-activated process happens on a timescale that allows us to capture a significant part of the structural transformations and trajectory of the defect. The low voltage combined with ultra-high vacuum conditions ensure that the defect remains stable over long image sequences, which allows us for the first time to directly follow the diffusion of a point defect in a crystalline material.

Advanced defect detection algorithm using clustering in ultrasonic NDE

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Gongzhang, Rui; Gachagan, Anthony

2016-02-01

A range of materials used in industry exhibit scattering properties which limits ultrasonic NDE. Many algorithms have been proposed to enhance defect detection ability, such as the well-known Split Spectrum Processing (SSP) technique. Scattering noise usually cannot be fully removed and the remaining noise can be easily confused with real feature signals, hence becoming artefacts during the image interpretation stage. This paper presents an advanced algorithm to further reduce the influence of artefacts remaining in A-scan data after processing using a conventional defect detection algorithm. The raw A-scan data can be acquired from either traditional single transducer or phased array configurations. The proposed algorithm uses the concept of unsupervised machine learning to cluster segmental defect signals from pre-processed A-scans into different classes. The distinction and similarity between each class and the ensemble of randomly selected noise segments can be observed by applying a classification algorithm. Each class will then be labelled as `legitimate reflector' or `artefacts' based on this observation and the expected probability of defection (PoD) and probability of false alarm (PFA) determined. To facilitate data collection and validate the proposed algorithm, a 5MHz linear array transducer is used to collect A-scans from both austenitic steel and Inconel samples. Each pulse-echo A-scan is pre-processed using SSP and the subsequent application of the proposed clustering algorithm has provided an additional reduction to PFA while maintaining PoD for both samples compared with SSP results alone.

Fibrous metaphyseal defects

International Nuclear Information System (INIS)

Ritschl, P.; Hajek, P.C.; Pechmann, U.

1989-01-01

Sixteen patients with fibrous metaphyseal defects were examined with both plain radiography and magnetic resonance (MR) imaging. Depending on the age of the fibrous metaphyseal defects, characteristic radiomorphologic changes were found which correlated well with MR images. Following intravenous Gadolinium-DTPA injection, fibrous metaphyseal defects invariably exhibited a hyperintense border and signal enhancement. (orig./GDG)

Disruption of the folate pathway in zebrafish causes developmental defects

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Lee Marina S

2012-04-01

Full Text Available Abstract Background Folic acid supplementation reduces the risk of neural tube defects and congenital heart defects. The biological mechanisms through which folate prevents birth defects are not well understood. We explore the use of zebrafish as a model system to investigate the role of folate metabolism during development. Results We first identified zebrafish orthologs of 12 human folate metabolic genes. RT-PCR and in situ analysis indicated maternal transcripts supply the embryo with mRNA so that the embryo has an intact folate pathway. To perturb folate metabolism we exposed zebrafish embryos to methotrexate (MTX, a potent inhibitor of dihydrofolate reductase (Dhfr an essential enzyme in the folate metabolic pathway. Embryos exposed to high doses of MTX exhibited developmental arrest prior to early segmentation. Lower doses of MTX resulted in embryos with a shortened anterior-posterior axis and cardiac defects: linear heart tubes or incomplete cardiac looping. Inhibition of dhfr mRNA with antisense morpholino oligonucleotides resulted in embryonic lethality. One function of the folate pathway is to provide essential one-carbon units for dTMP synthesis, a rate-limiting step of DNA synthesis. After 24 hours of exposure to high levels of MTX, mutant embryos continue to incorporate the thymidine analog BrdU. However, additional experiments indicate that these embryos have fewer mitotic cells, as assayed with phospho-histone H3 antibodies, and that treated embryos have perturbed cell cycles. Conclusions Our studies demonstrate that human and zebrafish utilize similar one-carbon pathways. Our data indicate that folate metabolism is essential for early zebrafish development. Zebrafish studies of the folate pathway and its deficiencies could provide insight into the underlying etiology of human birth defects and the natural role of folate in development.

The Role of Work-Integrated Learning in Student Preferences of Instructional Methods in an Accounting Curriculum

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Abeysekera, Indra

2015-01-01

The role of work-integrated learning in student preferences of instructional methods is largely unexplored across the accounting curriculum. This study conducted six experiments to explore student preferences of instructional methods for learning, in six courses of the accounting curriculum that differed in algorithmic rigor, in the context of a…

Vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association with Mayer-Rokitansky-Küster-Hauser syndrome in co-occurrence: two case reports and a review of the literature.

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Bjørsum-Meyer, Thomas; Herlin, Morten; Qvist, Niels; Petersen, Michael B

2016-12-21

The vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome are rare conditions. We aimed to present two cases with the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser co-occurrence from our local surgical center and through a systematic literature search detect published cases. Furthermore, we aimed to collect existing knowledge in the embryopathogenesis and genetics in order to discuss a possible link between the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome. Our first case was a white girl delivered by caesarean section at 37 weeks of gestation; our second case was a white girl born at a gestational age of 40 weeks. A co-occurrence of vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal defect, and limb defect association and Mayer-Rokitansky-Küster-Hauser syndrome was diagnosed in both cases. We performed a systematic literature search in PubMed ((VACTERL) OR (VATER)) AND ((MRKH) OR (Mayer-Rokitansky-Küster-Hauser) OR (mullerian agenesis) OR (mullerian aplasia) OR (MURCS)) without limitations. A similar search was performed in Embase and the Cochrane library. We added two cases from our local center. All cases (n = 9) presented with anal atresia and renal defect. Vertebral defects were present in eight patients. Rectovestibular fistula was confirmed in seven patients. Along with the uterovaginal agenesis, fallopian tube aplasia appeared in five of nine cases and in two cases ovarian involvement also existed. The co-occurrence of the vertebral defect, anal atresia, cardiac defect, tracheoesophageal fistula/esophageal atresia, renal

Evolutionary fuzzy ARTMAP neural networks for classification of semiconductor defects.

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Tan, Shing Chiang; Watada, Junzo; Ibrahim, Zuwairie; Khalid, Marzuki

2015-05-01

Wafer defect detection using an intelligent system is an approach of quality improvement in semiconductor manufacturing that aims to enhance its process stability, increase production capacity, and improve yields. Occasionally, only few records that indicate defective units are available and they are classified as a minority group in a large database. Such a situation leads to an imbalanced data set problem, wherein it engenders a great challenge to deal with by applying machine-learning techniques for obtaining effective solution. In addition, the database may comprise overlapping samples of different classes. This paper introduces two models of evolutionary fuzzy ARTMAP (FAM) neural networks to deal with the imbalanced data set problems in a semiconductor manufacturing operations. In particular, both the FAM models and hybrid genetic algorithms are integrated in the proposed evolutionary artificial neural networks (EANNs) to classify an imbalanced data set. In addition, one of the proposed EANNs incorporates a facility to learn overlapping samples of different classes from the imbalanced data environment. The classification results of the proposed evolutionary FAM neural networks are presented, compared, and analyzed using several classification metrics. The outcomes positively indicate the effectiveness of the proposed networks in handling classification problems with imbalanced data sets.

Role of Personality Traits, Learning Styles and Metacognition in Predicting Critical Thinking of Undergraduate Students

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Soliemanifar O

2015-04-01

The aim of this study was to investigate the role of personality traits, learning styles and metacognition in predicting critical thinking. Instrument & Methods: In this descriptive correlative study, 240 students (130 girls and 110 boys of Ahvaz Shahid Chamran University were selected by multi-stage random sampling method. The instruments for collecting data were NEO Five-Factor Inventory, learning style inventory of Kolb (LSI, metacognitive assessment inventory (MAI of Schraw & Dennison (1994 and California Critical Thinking Skills Test (CCTST. The data were analyzed using Pearson correlation coefficient, stepwise regression analysis and Canonical correlation analysis.  Findings: Openness to experiment (b=0.41, conscientiousness (b=0.28, abstract conceptualization (b=0.39, active experimentation (b=0.22, reflective observation (b=0.12, knowledge of cognition (b=0.47 and regulation of cognition (b=0.29 were effective in predicting critical thinking. Openness to experiment and conscientiousness (r2=0.25, active experimentation, abstract conceptualization and reflective observation learning styles (r2=0.21 and knowledge and regulation of cognition metacognitions (r2=0.3 had an important role in explaining critical thinking. The linear combination of critical thinking skills (evaluation, analysis, inference was predictable by a linear combination of dispositional-cognitive factors (openness, conscientiousness, abstract conceptualization, active experimentation, knowledge of cognition and regulation of cognition. Conclusion: Personality traits, learning styles and metacognition, as dispositional-cognitive factors, play a significant role in students' critical thinking.

From learning to memory: what flies can tell us about intellectual disability treatment.

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Alaura eAndroschuk

2015-06-01

Full Text Available Intellectual disability (ID, previously known as mental retardation, affects 3 % of the population and remains without pharmacological treatment. ID is characterized by impaired general mental abilities with associated defects in adaptive function in which onset occurs before 18 years old. In severe ID, genetic causes are increasingly recognized in large part due to genome-wide techniques such as microarrays and exome sequencing. Unfortunately drug discovery for treatment of ID has not followed the same pace as gene discovery, leaving clinicians, patients and families without the ability to ameliorate symptoms. Despite this, several model organisms have proven valuable in developing and screening candidate drugs. One such model organism is the fruit fly Drosophila. First, we review the current understanding of memory in human and its model in Drosophila. Second, we describe key signaling pathways involved in ID and memory such as the cAMP-CREB pathway, the regulation of protein synthesis, the role of receptors and anchoring proteins, the role of neuronal proliferation, and finally the role of neurotransmitters. Third, we characterize the types of memory defects found in patients with ID. Finally, we discuss how important insights gained from Drosophila learning and memory could be translated in clinical research to lead to better treatment development.

Can we meet the sustainability challenges? The role of education and lifelong learning

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Wals, Arjen E.J.; Benavot, Aaron

2017-01-01

Education and lifelong learning are increasingly being mobilised to address the global environmental crisis and accompanying sustainability challenges. This article discusses the many roles of education about and for sustainable development, drawing on evidence and arguments put forward in the

ILT based defect simulation of inspection images accurately predicts mask defect printability on wafer

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Deep, Prakash; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

2016-05-01

At advanced technology nodes mask complexity has been increased because of large-scale use of resolution enhancement technologies (RET) which includes Optical Proximity Correction (OPC), Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO). The number of defects detected during inspection of such mask increased drastically and differentiation of critical and non-critical defects are more challenging, complex and time consuming. Because of significant defectivity of EUVL masks and non-availability of actinic inspection, it is important and also challenging to predict the criticality of defects for printability on wafer. This is one of the significant barriers for the adoption of EUVL for semiconductor manufacturing. Techniques to decide criticality of defects from images captured using non actinic inspection images is desired till actinic inspection is not available. High resolution inspection of photomask images detects many defects which are used for process and mask qualification. Repairing all defects is not practical and probably not required, however it's imperative to know which defects are severe enough to impact wafer before repair. Additionally, wafer printability check is always desired after repairing a defect. AIMSTM review is the industry standard for this, however doing AIMSTM review for all defects is expensive and very time consuming. Fast, accurate and an economical mechanism is desired which can predict defect printability on wafer accurately and quickly from images captured using high resolution inspection machine. Predicting defect printability from such images is challenging due to the fact that the high resolution images do not correlate with actual mask contours. The challenge is increased due to use of different optical condition during inspection other than actual scanner condition, and defects found in such images do not have correlation with actual impact on wafer. Our automated defect simulation tool predicts

Defect detection based on extreme edge of defective region histogram

Directory of Open Access Journals (Sweden)

Zouhir Wakaf

2018-01-01

Full Text Available Automatic thresholding has been used by many applications in image processing and pattern recognition systems. Specific attention was given during inspection for quality control purposes in various industries like steel processing and textile manufacturing. Automatic thresholding problem has been addressed well by the commonly used Otsu method, which provides suitable results for thresholding images based on a histogram of bimodal distribution. However, the Otsu method fails when the histogram is unimodal or close to unimodal. Defects have different shapes and sizes, ranging from very small to large. The gray-level distributions of the image histogram can vary between unimodal and multimodal. Furthermore, Otsu-revised methods, like the valley-emphasis method and the background histogram mode extents, which overcome the drawbacks of the Otsu method, require preprocessing steps and fail to use the general threshold for multimodal defects. This study proposes a new automatic thresholding algorithm based on the acquisition of the defective region histogram and the selection of its extreme edge as the threshold value to segment all defective objects in the foreground from the image background. To evaluate the proposed defect-detection method, common standard images for experimentation were used. Experimental results of the proposed method show that the proposed method outperforms the current methods in terms of defect detection.

Improving health care quality and safety: the role of collective learning

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Singer SJ

2015-11-01

Full Text Available Sara J Singer,1–4 Justin K Benzer,4–6 Sami U Hamdan4,6 1Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, Boston, MA, USA; 2Department of Medicine, Harvard Medical School, Boston, MA, USA; 3Mongan Institute for Health Policy, Massachusetts General Hospital, Boston, MA, USA; 4Center for Healthcare Organization and Implementation Research, VA Boston Healthcare System, Boston, MA, USA; 5VISN 17 Center of Excellence for Research on Returning War Veterans, Waco, TX, USA; 6Department of Health Policy and Management, Boston University School of Public Health, Boston, MA, USA Abstract: Despite decades of effort to improve quality and safety in health care, this goal feels increasingly elusive. Successful examples of improvement are infrequently replicated. This scoping review synthesizes 76 empirical or conceptual studies (out of 1208 originally screened addressing learning in quality or safety improvement, that were published in selected health care and management journals between January 2000 and December 2014 to deepen understanding of the role that collective learning plays in quality and safety improvement. We categorize learning activities using a theoretical model that shows how leadership and environmental factors support collective learning processes and practices, and in turn team and organizational improvement outcomes. By focusing on quality and safety improvement, our review elaborates the premise of learning theory that leadership, environment, and processes combine to create conditions that promote learning. Specifically, we found that learning for quality and safety improvement includes experimentation (including deliberate experimentation, improvisation, learning from failures, exploration, and exploitation, internal and external knowledge acquisition, performance monitoring and comparison, and training. Supportive learning environments are characterized by team characteristics like psychological

Nonlinear X-ray production of defect spins in vitreous SiO2: the roles of creation and activation

International Nuclear Information System (INIS)

Galeener, F.L.; Kerwin, D.B.; Miller, A.J.

1992-01-01

The dependence of spin concentration on X-ray dose is shown to be nonlinear in distinctive ways for the three most common defect structures in vitreous SiO 2 . We fit the data with a model invoking two concurrent simple processes: creation of new defects and activation of preexisting ones. The resultant fit parameters show dependencies on hydroxyl concentration and fictive temperature that shed new light on the processes, the defects, their origins and the radiation hardness of v-SiO 2 . (author)

The role of socio-cognitive variables in predicting learning satisfaction in smart schools

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Mohammad Reza Firoozi

2017-03-01

Full Text Available The present study aimed to investigate the role of Socio-Cognitive variables in predicting learning satisfaction in Smart Schools. The population was all the primary school students studying in smart schools in the city of Shiraz in the school year 2014-2015. The sample, randomly chosen through multi-stage cluster sampling, was 383 primary school students studying in smart schools in Shiraz. The instruments were the Computer Self-Efficiency Questionnaire developed by Torkzadeh (2003, Performance Expectation Questionnaire developed by Compeau and Higgins (1995, System Functionality and Content Feature Questionnaire developed by Pituch and Lee (2006, Interaction Questionnaire developed by Johnston, Killion and Oomen (2005, Learning Climate Questionnaire developed by Chou` and Liu (2005 and Learning Satisfaction Questionnaire developed by Chou and Liu (2005. In order to determine the possible relationship between variables and to predict the changes in the degree of satisfaction, we made use of correlational procedures and step-wise regression analysis. The results indicated that all the socio-cognitive variables have a positive and significant correlation with learning satisfaction. Out of the socio-cognitive variables in question, Computer Self-Efficiency, Performance Expectation and Learning Climate significantly explained 53% of the variance of learning satisfaction.

The Role of Socio-Cognitive Variables in Predicting Learning Satisfaction in Smart Schools

Directory of Open Access Journals (Sweden)

Mohammad Reza FIROOZI

2017-03-01

Full Text Available The present study aimed to investigate the role of Socio-Cognitive variables in predicting learning satisfaction in Smart Schools. The population was all the primary school students studying in smart schools in the city of Shiraz in the school year 2014-2015. The sample, randomly chosen through multi-stage cluster sampling, was 383 primary school students studying in smart schools in Shiraz. The instruments were the Computer Self-Efficiency Questionnaire developed by Torkzadeh (2003, Performance Expectation Questionnaire developed by Compeau and Higgins (1995, System Functionality and Content Feature Questionnaire developed by Pituch and Lee (2006, Interaction Questionnaire developed by Johnston, Killion and Oomen (2005, Learning Climate Questionnaire developed by Chou` and Liu (2005 and Learning Satisfaction Questionnaire developed by Chou and Liu (2005. In order to determine the possible relationship between variables and to predict the changes in the degree of satisfaction, we made use of correlational procedures and step-wise regression analysis. The results indicated that all the socio-cognitive variables have a positive and significant correlation with learning satisfaction. Out of the socio-cognitive variables in question, Computer Self-Efficiency, Performance Expectation and Learning Climate significantly explained 53% of the variance of learning satisfaction.

Role Models and Teachers: medical students perception of teaching-learning methods in clinical settings, a qualitative study from Sri Lanka.

Science.gov (United States)

Jayasuriya-Illesinghe, Vathsala; Nazeer, Ishra; Athauda, Lathika; Perera, Jennifer

2016-02-09

Medical education research in general, and those focusing on clinical settings in particular, have been a low priority in South Asia. This explorative study from 3 medical schools in Sri Lanka, a South Asian country, describes undergraduate medical students' experiences during their final year clinical training with the aim of understanding the teaching-learning experiences. Using qualitative methods we conducted an exploratory study. Twenty eight graduates from 3 medical schools participated in individual interviews. Interview recordings were transcribed verbatim and analyzed using qualitative content analysis method. Emergent themes reveled 2 types of teaching-learning experiences, role modeling, and purposive teaching. In role modelling, students were expected to observe teachers while they conduct their clinical work, however, this method failed to create positive learning experiences. The clinical teachers who predominantly used this method appeared to be 'figurative' role models and were not perceived as modelling professional behaviors. In contrast, purposeful teaching allowed dedicated time for teacher-student interactions and teachers who created these learning experiences were more likely to be seen as 'true' role models. Students' responses and reciprocations to these interactions were influenced by their perception of teachers' behaviors, attitudes, and the type of teaching-learning situations created for them. Making a distinction between role modeling and purposeful teaching is important for students in clinical training settings. Clinical teachers' awareness of their own manifest professional characterizes, attitudes, and behaviors, could help create better teaching-learning experiences. Moreover, broader systemic reforms are needed to address the prevailing culture of teaching by humiliation and subordination.

The making of a nurse manager: the role of experiential learning in leadership development.

Science.gov (United States)

Cathcart, Eloise Balasco; Greenspan, Miriam; Quin, Matthew

2010-05-01

To articulate the experientially acquired knowledge, skill and ethics embedded in nurse manager practice and describe the ways in which they were developed. The role of the nurse manager is usually described in lists of competencies, talents and traits which fail to capture the experience-based judgment and practical knowledge in this pivotal organizational role. Using Benner's methodology of practice articulation, 32 nurse managers wrote and interpreted first person narratives of their practice. The experience level of the group ranged from new nurse managers to those with more than 10 years' role tenure. The seminars were facilitated by a seasoned nurse executive and nurse manager with expertise in narrative interpretation. Interpretation of the paradigm case of one nurse manager suggests that complex leadership challenges can be a source of significant experiential learning for the individual and for the group. CONCLUSIONS; Articulating and reflecting on experiential learning elucidates the skilled knowledge and judgment embedded in nurse manager practice which cannot be accessed in any other way. Articulating the practical knowledge which is necessary for effective nurse manager practice can hasten the development of role incumbents.

The Role of Space in Learning: Spatio-Educational Experiences of Female Students within Emirati Higher Education

OpenAIRE

Zaidan, Gergana

2015-01-01

This interdisciplinary research examines the intersectional relationship between\\ud the domains of space, gender and education. It aims, first, to understand the\\ud spatio-educational experience of Emirati female learners; and second, to make\\ud it possible to enhance their learning experience by exploring the role of space in\\ud learning in a single gender context. This thesis addresses the lack of literature\\ud on women’s spatiality and space in learning, specifically in relation to Arab\\ud...

Defects in silicon effect on device performance and relationship to crystal growth conditions

Science.gov (United States)

Jastrzebski, L.

1985-01-01

A relationship between material defects in silicon and the performance of electronic devices will be described. A role which oxygen and carbon in silicon play during the defects generation process will be discussed. The electronic properties of silicon are a strong function of the oxygen state in the silicon. This state controls mechanical properties of silicon efficiency for internal gettering and formation of defects in the device's active area. In addition, to temperature, time, ambience, and the cooling/heating rates of high temperature treatments, the oxygen state is a function of the crystal growth process. The incorporation of carbon and oxygen into silicon crystal is controlled by geometry and rotation rates applied to crystal and crucible during crystal growths. Also, formation of nucleation centers for oxygen precipitation is influenced by the growth process, although there is still a controversy which parameters play a major role. All these factors will be reviewed with special emphasis on areas which are still ambiguous and controversial.

Application of pulsed flash thermography method for specific defect estimation in aluminum

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Tomić Ljubiša D.

2015-01-01

Full Text Available Nondestructive thermal examination can uncover the presence of defects via temperature distribution profile anomalies that are created on the surface as a result of a defect. There are many factors that affect the temperature distribution map of the surface being tested by Infrared Thermography. Internal defect properties such as thermal conductivity, heat capacity and defect depth, play an important role in the temperature behavior of the pixels or regions being analyzed. Also, it is well known that other external factors such as the convection heat transfer, variations on the surface emissivity and ambient radiation reflectivity can affect the thermographic signal received by the infrared camera. In this paper we considered a simple structure in the form of flat plate covered with several defects, whose surface we heated with a uniform heat flux impulse. We conducted a theoretical analysis and experimental test of the method for case of defects on an aluminum surface. First, experiments were conducted on surfaces with intentionally created defects in order to determine conditions and boundaries for application of the method. Experimental testing of the pulsed flash thermography (PFT method was performed on simulated defects on an aluminum test plate filled with air and organic compound n-hexadecane, hydrocarbon that belongs to the Phase Change Materials (PCMs. Study results indicate that it is possible, using the PFT method, to detect the type of material inside defect holes, whose presence disturbs the homogeneous structure of aluminum.

Synthetic Defects for Vibrothermography

Science.gov (United States)

Renshaw, Jeremy; Holland, Stephen D.; Thompson, R. Bruce; Eisenmann, David J.

2010-02-01

Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane.

Role of Demyelination Efficiency within Acellular Nerve Scaffolds during Nerve Regeneration across Peripheral Defects

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Meiqin Cai

2017-01-01

Full Text Available Hudson’s optimized chemical processing method is the most commonly used chemical method to prepare acellular nerve scaffolds for the reconstruction of large peripheral nerve defects. However, residual myelin attached to the basal laminar tube has been observed in acellular nerve scaffolds prepared using Hudson’s method. Here, we describe a novel method of producing acellular nerve scaffolds that eliminates residual myelin more effectively than Hudson’s method through the use of various detergent combinations of sulfobetaine-10, sulfobetaine-16, Triton X-200, sodium deoxycholate, and peracetic acid. In addition, the efficacy of this new scaffold in repairing a 1.5 cm defect in the sciatic nerve of rats was examined. The modified method produced a higher degree of demyelination than Hudson’s method, resulting in a minor host immune response in vivo and providing an improved environment for nerve regeneration and, consequently, better functional recovery. A morphological study showed that the number of regenerated axons in the modified group and Hudson group did not differ. However, the autograft and modified groups were more similar in myelin sheath regeneration than the autograft and Hudson groups. These results suggest that the modified method for producing a demyelinated acellular scaffold may aid functional recovery in general after nerve defects.

E-learning on antibiotic prescribing-the role of autonomous motivation in participation: a prospective cohort study.

Science.gov (United States)

Caris, Martine G; Sikkens, Jonne J; Kusurkar, Rashmi A; van Agtmael, Michiel A

2018-05-10

E-learning is increasingly used in education on antimicrobial stewardship, but participation rates are often low. Insight into factors that affect participation is therefore needed. Autonomous motivation is associated with higher achievements in medical education and could also play a role in e-learning participation. We therefore aimed to investigate the role of residents' autonomous motivation in their participation in e-learning on antibiotic prescribing. We performed a multicentre cohort study in two academic and two teaching hospitals. Residents who filled out questionnaires on antibiotic knowledge, the perceived importance of antibiotics and motivation [Self-Regulation Questionnaire - Academic (SRQ-a)] received e-learning access. We used the SRQ-a to calculate relative autonomous motivation (RAM), an index that estimates the amount of autonomous motivation compared with the amount of controlled motivation. We then analysed associations between RAM and participation in e-learning with logistic regression. Eighty-six residents participated (74% female, mean age 30 years). Overall e-learning participation was 58% (n = 50). Participation was 41% in residents with negative RAM (i.e. more controlled motivation) and 62% in residents with positive RAM (i.e. more autonomous motivation). RAM was positively associated with participation, adjusted for residency in an academic hospital (adjusted OR 2.6, 95% CI 1.5-4.6). Participation in non-obligatory e-learning on antibiotic prescribing is higher in residents with more autonomous motivation. Interventions to increase autonomous motivation could improve participation. Preceding e-learning on antibiotic prescribing with face-to-face education, to explain the importance of the subject, could enhance autonomous motivation and thus optimize e-learning efficiency.

Role of Adult Learning Theories in the Development of Corporate Training in the USA

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Iryna Lytovchenko

2016-07-01

Full Text Available The article presents the analysis of the role of adult learning theories in the development of corporate training in the USA. Considering that corporate education is part of the adult education system in this country, the author examines theories of organizational learning in the context of adult learning. The results of the study have revealed that adult education in the US is based on dif erent learning theories which should be viewed from the perspective of several main orientations: behaviorism, cognitivism, humanism, developmental theories, social learning, constructivism, which have dif erent philosophical background and, accordingly, different understanding of the nature and methodology of adult learning. Based on the results of the study it has been concluded that theories of organizational learning which explain motivation of students, their needs and goals, cognitive processes and other aspects of the learning in organizations and have had the main influence on the development of corporate education in the United States should be viewed in the context of the above-mentioned basic orientations to learning, too. From the methodological perspective, the research was based on interdisciplinary and systemic approaches. Thus, we used a set of interrelated research methods: comparative, structural, systemic-functional analyses, comparison and synthesis.

Networking for Learning The role of Networking in a Lifelong Learner's Professional Development

NARCIS (Netherlands)

Rajagopal, Kamakshi

2016-01-01

This dissertation discusses the role the social activity of networking plays in lifelong learners’ professional and personal continuous development. The main hypothesis of this thesis is that networking is a learning strategy for lifelong learners, in which conversations are key activities through

Children's Learning in Scientific Thinking: Instructional Approaches and Roles of Variable Identification and Executive Function

Science.gov (United States)

Blums, Angela

The present study examines instructional approaches and cognitive factors involved in elementary school children's thinking and learning the Control of Variables Strategy (CVS), a critical aspect of scientific reasoning. Previous research has identified several features related to effective instruction of CVS, including using a guided learning approach, the use of self-reflective questions, and learning in individual and group contexts. The current study examined the roles of procedural and conceptual instruction in learning CVS and investigated the role of executive function in the learning process. Additionally, this study examined how learning to identify variables is a part of the CVS process. In two studies (individual and classroom experiments), 139 third, fourth, and fifth grade students participated in hands-on and paper and pencil CVS learning activities and, in each study, were assigned to either a procedural instruction, conceptual instruction, or control (no instruction) group. Participants also completed a series of executive function tasks. The study was carried out with two parts--Study 1 used an individual context and Study 2 was carried out in a group setting. Results indicated that procedural and conceptual instruction were more effective than no instruction, and the ability to identify variables was identified as a key piece to the CVS process. Executive function predicted ability to identify variables and predicted success on CVS tasks. Developmental differences were present, in that older children outperformed younger children on CVS tasks, and that conceptual instruction was slightly more effective for older children. Some differences between individual and group instruction were found, with those in the individual context showing some advantage over the those in the group setting in learning CVS concepts. Conceptual implications about scientific thinking and practical implications in science education are discussed.

THE MEDIATING ROLE OF SCIENCE MUSEUM IN STRUCTURING AND SYNTHESIS OF LEARNING

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Fanny Angulo Delgado

2016-10-01

Full Text Available Understanding the mediating role of science museum in learning scientific content in school, it involves reflecting on the contributions of research to the question of what and how people learn in non-conventional educational settings. It has been shown that most people spend less than 3% of their lives learning in school, which emphasizes the importance of conceptualizing what they are and how much of their learning take place. While that question is resolved, it speaks at this bioassay on the complementary relationship between the museum and the school, as both institutions share the same educational purpose, but differ in the ways of achieving it. The science museum joins the class as a mediator that facilitates student learning as part of an education that promotes understanding of the phenomena of the world through models, which means that school learning goes in stages, one of which is that students have opportunity to structure new knowledge and synthesize on its own model. For this it is necessary that students speak, read, listen and write in science class, while the thought is expressed in language to attest to the facts. These communication skills arise in science class as indicators of mediation exercised by the museum and allow us to understand that it takes place in at least two dimensions: museographic and didactics.

An Investigation of the Role of Background Music in IVWs for Learning

Science.gov (United States)

Richards, Debbie; Fassbender, Eric; Bilgin, Ayse; Thompson, William Forde

2008-01-01

Empirical evidence is needed to corroborate the intuitions of gamers and game developers in understanding the benefits of Immersive Virtual Worlds (IVWs) as a learning environment and the role that music plays within these environments. We report an investigation to determine if background music of the genre typically found in computer-based…

Locus of Control and Individual Learning: The Moderating Role of Interactional Justice

Science.gov (United States)

Cappetta, Rossella; Magni, Massimo

2015-01-01

Organizations are increasingly investing in training programs for building managerial skills, with a special focus on employees considered "talents" who must be prepared to cover strategic roles within the organization. One of the main goals of such programs is to develop participants' learning in order to tap their potential in a short…

Safety learning among young newly employed in three trades – the role of the profession?

DEFF Research Database (Denmark)

Grytnes, Regine; Dyreborg, Johnny; Jørgensen, Astrid

2017-01-01

Background Young workers aged 18-24 years have an increased risk of injuries at work compared to older workers. This is a problem not only for young workers themselves but also for the society and it lends relevance to the question of how young people learn safe working practices. Safety learning...... to be 'something everyone can do'. Learning safe working practices are shown to be part of canonical and non- canonical professional norms and safety learning is thus an integral part of local and professional induction practices....... is not achieved through information and campaigns alone; it also involves practical training and mentorship at the specific work place. In this paper an analysis of how induction practices relates to safety learning in three different trades is pursued focusing especially on the role of the professions...

Implantation processing of Si: A unified approach to understanding ion-induced defects and their impact

International Nuclear Information System (INIS)

Holland, O.W.; Roth, E.G.

1997-05-01

A model is presented to account for the effects of ion-induced defects during implantation processing of Si. It will be shown that processing is quite generally affected by the presence of defect excesses rather than the total number of defects. a defect is considered excess if it represents a surplus locally of one defect type over its compliment. Processing spanning a wide range of implantation conditions will be presented to demonstrate that the majority of the total defects played little or no role in the process. This is a direct result of the ease with which the spatially correlated Frenkel pairs recombine either dynamically or during a post-implantation annealing. Based upon this model, a method will be demonstrated for manipulating or engineering the excess defects to modify their effects. In particular high-energy, self-ions are shown to inject vacancies into a boron implanted region resulting in suppression of transient enhanced diffusion of the dopant

Automatic Defect Detection for TFT-LCD Array Process Using Quasiconformal Kernel Support Vector Data Description

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Yi-Hung Liu

2011-09-01

Full Text Available Defect detection has been considered an efficient way to increase the yield rate of panels in thin film transistor liquid crystal display (TFT-LCD manufacturing. In this study we focus on the array process since it is the first and key process in TFT-LCD manufacturing. Various defects occur in the array process, and some of them could cause great damage to the LCD panels. Thus, how to design a method that can robustly detect defects from the images captured from the surface of LCD panels has become crucial. Previously, support vector data description (SVDD has been successfully applied to LCD defect detection. However, its generalization performance is limited. In this paper, we propose a novel one-class machine learning method, called quasiconformal kernel SVDD (QK-SVDD to address this issue. The QK-SVDD can significantly improve generalization performance of the traditional SVDD by introducing the quasiconformal transformation into a predefined kernel. Experimental results, carried out on real LCD images provided by an LCD manufacturer in Taiwan, indicate that the proposed QK-SVDD not only obtains a high defect detection rate of 96%, but also greatly improves generalization performance of SVDD. The improvement has shown to be over 30%. In addition, results also show that the QK-SVDD defect detector is able to accomplish the task of defect detection on an LCD image within 60 ms.

Correlations of memory and learning with vision in aged patients before and after a cataract operation.

Science.gov (United States)

Fagerström, R

1992-12-01

The connection between memory and learning with vision was investigated by studying 100 cataract operation patients, aged 71 to 76 years, 25 of them being men and 75 women. The cataract operation restored sufficient acuity of vision for reading (minimum E-test value 0.40) to 79% of the subjects. Short-term memory was studied with series of numbers, homogenic and heterogenic inhibition, and long sentences. Learning was tested with paired-associate learning and word learning. Psychological symptoms were measured on the Brief Psychiatric Rating Scale and personality on the Mini-Mult MMPI. Memory and learning improved significantly when vision was normalized after the cataract operation. Poor memory and learning scores correlated with monocular vision before the operation and with defects in the field of vision, due to glaucoma and exceeding 20%, postsurgery. Monocular vision and defects in the visual field caused a continuous sense of abnormalness, which impaired old people's ability to concentrate on tasks of memory and learning. Cerebrovascular disturbances, beginning dementia, and moderate psychological symptoms obstructed memory and learning on both test rounds. Depression was the most important psychological symptom contributing to poor memory and learning scores after the cataract operation. The memory and learning defects mainly reflected disturbances in memorizing.

Bone Marrow Aspirate Concentrate-Enhanced Marrow Stimulation of Chondral Defects

Science.gov (United States)

Eichler, Hermann; Orth, Patrick

2017-01-01

Mesenchymal stem cells (MSCs) from bone marrow play a critical role in osteochondral repair. A bone marrow clot forms within the cartilage defect either as a result of marrow stimulation or during the course of the spontaneous repair of osteochondral defects. Mobilized pluripotent MSCs from the subchondral bone migrate into the defect filled with the clot, differentiate into chondrocytes and osteoblasts, and form a repair tissue over time. The additional application of a bone marrow aspirate (BMA) to the procedure of marrow stimulation is thought to enhance cartilage repair as it may provide both an additional cell population capable of chondrogenesis and a source of growth factors stimulating cartilage repair. Moreover, the BMA clot provides a three-dimensional environment, possibly further supporting chondrogenesis and protecting the subchondral bone from structural alterations. The purpose of this review is to bridge the gap in our understanding between the basic science knowledge on MSCs and BMA and the clinical and technical aspects of marrow stimulation-based cartilage repair by examining available data on the role and mechanisms of MSCs and BMA in osteochondral repair. Implications of findings from both translational and clinical studies using BMA concentrate-enhanced marrow stimulation are discussed. PMID:28607559

Electronic structure of defects in semiconductor heterojunctions

International Nuclear Information System (INIS)

Haussy, Bernard; Ganghoffer, Jean Francois

2002-01-01

Full text.heterojunctions and semiconductors and superlattices are well known and well used by people interested in optoelectronics communications. Components based on the use of heterojunctions are interesting for confinement of light and increase of quantum efficiency. An heterojunction is the contact zone between two different semiconductors, for example GaAs and Ga 1-x Al x As. Superlattices are a succession of heterojunctions (up to 10 or 20). These systems have been the subjects of many experiments ao analyse the contact between semiconductors. They also have been theoretically studied by different types of approach. The main result of those studies is the prediciton of band discontinuities. Defects in heterojunctions are real traps for charge carriers; they can affect the efficiency of the component decreasing the currents and the fluxes in it. the knowledge of their electronic structure is important, a great density of defects deeply modifies the electronic structure of the whole material creating real new bands of energy in the band structure of the component. in the first part of this work, we will describe the heterostructure and the defect in terms of quantum wells and discrete levels. This approach allows us to show the role of the width of the quantum well describing the structure but induces specific behaviours due to the one dimensional modelling. Then a perturbative treatment is proposed using the Green's functions formalism. We build atomic chains with different types of atoms featuring the heterostructure and the defect. Densities of states of a structure with a defect and levels associated to the defect are obtained. Results are comparable with the free electrons work, but the modelling do not induce problems due to a one dimensional approach. To extend our modelling, a three dimensions approach, based on a cavity model, is investigated. The influence of the defect, - of hydrogenoid type - introduced in the structure, is described by a cavity

Point defects in nickel

International Nuclear Information System (INIS)

Peretto, P.

1969-01-01

The defects in electron irradiated nickel (20 deg. K) or neutron irradiated nickel (28 deg. K) are studied by simultaneous analysis using the magnetic after-effect, electron microscopy and electrical resistivity recovery. We use zone refined nickel (99.999 per cent) which, for some experiments, is alloyed with a small amount of iron (for example 0.1 per cent Fe). The temperature dependant electrical recovery may be divided in four stages. The sub-stages I B (31 deg. K), I C (42 deg. K), I D (from to 57 deg. K) and I E (62 deg. K) of stage I are due to the disappearance of single interstitials into vacancies. The interstitial defect has a split configuration with a migration energy of about 0.15 eV. In the close pair which disappears in stage I B the interstitial is found to be in a 3. neighbour position whilst in stage I D it is near the direction from the vacancy. In stage I E there is no longer any interaction between the interstitial and the vacancy. The stage II is due to more complicated interstitial defects: di-interstitials for stage II B (84 deg. K) and larger and larger interstitial loops for the following sub-stages. The loops may be seen by electron microscopy. Impurities can play the role of nucleation centers for the loops. Stages III A (370 deg. K) and III B (376 deg. K) are due to two types of di-vacancies. During stage IV (410 deg. K) the single vacancies migrate. Vacancy type loops and interstitial type loops grow concurrently and disappear at about 800 deg. K as observed by electron microscopy. (author) [fr

Predicting congenital heart defects: A comparison of three data mining methods.

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Yanhong Luo

Full Text Available Congenital heart defects (CHD is one of the most common birth defects in China. Many studies have examined risk factors for CHD, but their predictive abilities have not been evaluated. In particular, few studies have attempted to predict risks of CHD from, necessarily unbalanced, population-based cross-sectional data. Therefore, we developed and validated machine learning models for predicting, before and during pregnancy, women's risks of bearing children with CHD. We compared the results of these models in a large-scale, comprehensive population-based retrospective cross-sectional epidemiological survey of birth defects in six counties in Shanxi Province, China, covering 2006 to 2008. This contained 78 cases of CHD among 33831 live births. We constructed nine synthetic variables to use in the models: maternal age, annual per capita income, family history, maternal history of illness, nutrition and folic acid deficiency, maternal illness in pregnancy, medication use in pregnancy, environmental risk factors in pregnancy, and unhealthy maternal lifestyle in pregnancy. The machine learning algorithms Weighted Support Vector Machine (WSVM and Weighted Random Forest (WRF were trained on, and a logistic regression (Logit was fitted to, two-thirds of the data. Their predictive abilities were then tested in the remaining data. True positive rate (TPR, true negative rate (TNR, accuracy (ACC, area under the curves (AUC, G-means, and Weighted accuracy (WTacc were used to compare the classification performance of the models. Median values, from repeating the data partitioning 1000 times, were used in all comparisons. The TPR and TNR of the three classifiers were above 0.65 and 0.93, respectively, better than any reported in the literature. TPR, wtACC, AUC and G were highest for WSVM, showing that it performed best. All three models are precise enough to identify groups at high risk of CHD. They should all be considered for future investigations of other

Rendering photoreactivity to ceria. The role of defects

Energy Technology Data Exchange (ETDEWEB)

Yang, Chengwu; Yu, Xiaojuan; Heissler, Stefan; Weidler, Peter G.; Nefedov, Alexei; Wang, Yuemin; Woell, Christof [Institute of Functional Interfaces, IFG, Karlsruhe Institute of Technology - KIT, Eggenstein-Leopoldshafen (Germany); Plessow, Philipp N.; Studt, Felix [Institute of Catalysis Research and Technology, IKFT, Karlsruhe Institute of Technology - KIT, Eggenstein-Leopoldshafen (Germany)

2017-11-06

The photoreactivity of ceria, a photochemically inert oxide with a large band gap, can be increased to competitive values by introducing defects. This previously unexplained phenomenon has been investigated by monitoring the UV-induced decomposition of N{sub 2}O on well-defined single crystals of ceria by using infrared reflection-absorption spectroscopy (IRRAS). The IRRAS data, in conjunction with theory, provide direct evidence that reducing the ceria(110) surface yields high photoreactivity. No such effects are seen on the (111) surface. The low-temperature photodecomposition of N{sub 2}O occurs at surface O vacancies on the (110) surface, where the electron-rich cerium cations with a significantly lowered coordination number cause a local lowering of the huge band gap (ca. 6 eV). The quantum efficiency of strongly reduced ceria(110) surfaces in the photodecomposition of N{sub 2}O amounts to 0.03 %, and is thus comparable to that reported for the photooxidation of CO on rutile TiO{sub 2}(110). (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

An Evaluation of the Pattern between Students' Motivation, Learning Strategies and Their Epistemological Beliefs: The Mediator Role of Motivation

Science.gov (United States)

Sen, S.; Yilmaz, A.; Yurdagül, H.

2014-01-01

This study aims at analysing the relations between students' achievement motivation, learning strategies and their epistemological beliefs in learning through structural equation modelling, and at exploring the mediation role of motivation in the relations between learning strategies and epistemological beliefs. The study group was composed of 446…

Plain defects and their vortex configuration in dilute Mo-B alloys in dissipative structure

International Nuclear Information System (INIS)

Sofronova, R.M.

1992-01-01

Electron microscopic study of single crystal of Mo-0.003 mas.% B alloy after zone melting and annealing at 2373 K was conducted to reveal the nature of planar defects and the role of boron in their formation. It was shown that planar defects should be considered as preprecipitations of MoB nonequilibrous phase out of molybdenum base solid solution. A planar defect was found to constitute a monolayer of boron atoms which consisted of B-B zigzag-like chains. Inturn the chains were surrounded by Mo atoms which formed hexagonal prism. The coherency of planar defects with matrix was due to close lattice parameters of Mo, β-MoB and δ-MoB. The planar defects in molybdenum base alloy were considered as elements of dissipative structure. They determined formation of supercellular dislocation structure under deformation

Massively Multiplayer Online Role-Playing Games as Arenas for Second Language Learning

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Peterson, Mark

2010-01-01

This article investigates contemporary research on the use of massively multiplayer online role-playing games (MMORPGs) in language education. The development and key features of these games are explored. This is followed by an examination of the theories proposed as a basis for game-based learning, and the claims made regarding the value of…

The Effectiveness of Role Theory Based Group Counseling on Family Function of Families With Slow-Learning Children

Directory of Open Access Journals (Sweden)

فرناز حوله کیان

2015-12-01

Full Text Available The purpose of this study was to examine the effectiveness of group counseling based on the role theory on function of families with slow-learningchildren. The present study is a Quasi - experimental research with pre-test and post - test, and with experimental and control groups. Statistical population in cludes all mothers of slow - learning children in thecity of Hamadan. A sample of 30 subjects selected through available sampling method from high schools with equal numbers of both genders. Based on cloning features were allocated in experimental and control groups. The experimental group received 10 group counseling and control group was placed in the waiting list. Data collection instrument is family function questionnaire. Descriptive statistics, covariance analysis and t-test were applied to analyze data. It was found that there is a significant difference between post-test of experimental and control group (p<0/001. t-test showed significant difference in effectiveness of role theory group counseling for mothers with slow-learning girl and boy (p<0/001. So we can conclude that group counseling based on the role theory is effective on improving the function of families with slow-learning children. In addition, this effectivenessis different for families of slow-learning children based on the gender of child.

Facts about Birth Defects

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... label> Information For… Media Policy Makers Facts about Birth Defects Language: English (US) Español (Spanish) Recommend on ... having a baby born without a birth defect. Birth Defects Are Common Every 4 ½ minutes, a ...

The Mediating Role of Organizational Learning in?the Relationship of Organizational Intelligence and Organizational Agility

OpenAIRE

Bahrami, Mohammad Amin; Kiani, Mohammad Mehdi; Montazeralfaraj, Raziye; Zadeh, Hossein Fallah; Zadeh, Morteza Mohammad

2016-01-01

Objectives Organizational learning is defined as creating, absorbing, retaining, transferring, and application of knowledge within an organization. This article aims to examine the mediating role of organizational learning in the relationship of organizational intelligence and organizational agility. Methods This analytical and cross-sectional study was conducted in 2015 at four teaching hospitals of Yazd city, Iran. A total of 370 administrative and medical staff contributed to the study. We...

Tendon tissue engineering and its role on healing of the experimentally induced large tendon defect model in rabbits: a comprehensive in vivo study.

Science.gov (United States)

Meimandi-Parizi, Abdolhamid; Oryan, Ahmad; Moshiri, Ali

2013-01-01

Healing of large tendon defects is challenging. We studied the role of collagen implant with or without polydioxanone (PDS) sheath on the healing of a large Achilles tendon defect model, in rabbits. Sixty rabbits were divided into three groups. A 2 cm gap was created in the left Achilles tendon of all rabbits. In the control lesions, no implant was used. The other two groups were reconstructed by collagen and collagen-PDS implants respectively. The animals were clinically examined at weekly intervals and their lesions were observed by ultrasonography. Blood samples were obtained from the animals and were assessed for hematological analysis and determination of serum PDGF level, at 60 days post injury (DPI). The animals were then euthanized and their lesions were assessed for gross and histopathology, scanning electron microscopy, biomechanical testing, dry matter and hydroxyproline content. Another 65 pilot animals were also studied grossly and histopathologically to define the host implant interaction and graft incorporation at serial time points. The treated animals gained significantly better clinical scoring compared to the controls. Treatment with collagen and collagen-PDS implants significantly increased the biomechanical properties of the lesions compared to the control tendons at 60DPI (Ptendon. Implantation of the bioimplants had a significant role in initiating tendon healing and the implants were biocompatible, biodegradable and safe for application in tendon reconstructive surgery. The results of the present study may be valuable in clinical practice.

X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia disease: a combined immune deficiency with magnesium defect.

Science.gov (United States)

Ravell, Juan; Chaigne-Delalande, Benjamin; Lenardo, Michael

2014-12-01

To describe the role of the magnesium transporter 1 (MAGT1) in the pathogenesis of 'X-linked immunodeficiency with magnesium defect, Epstein-Barr virus (EBV) infection, and neoplasia' (XMEN) disease and its clinical implications. The magnesium transporter protein MAGT1 participates in the intracellular magnesium ion (Mg) homeostasis and facilitates a transient Mg influx induced by the activation of the T-cell receptor. Loss-of-function mutations in MAGT1 cause an immunodeficiency named 'XMEN syndrome', characterized by CD4 lymphopenia, chronic EBV infection, and EBV-related lymphoproliferative disorders. Patients with XMEN disease have impaired T-cell activation and decreased cytolytic function of natural killer (NK) and CD8 T cells because of decreased expression of the NK stimulatory receptor 'natural-killer group 2, member D' (NKG2D). Patients may have defective specific antibody responses secondary to T cell dysfunction, but B cells have not been shown to be directly affected by mutations in MAGT1. XMEN disease has revealed a novel role for free intracellular magnesium in the immune system. Further understanding of the MAGT1 signaling pathway may lead to new diagnostic and therapeutic approaches.

The roles of testicular nuclear receptor 4 (TR4 in male fertility-priapism and sexual behavior defects in TR4 knockout mice

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Bao Bo-Ying

2011-10-01

Full Text Available Abstract Background Successful reproductive efforts require the establishment of a situation favorable for reproduction that requires integration of both behavior and internal physiological events. TR4 nuclear receptor is known to be involved in male fertility via controlling spermatogenesis, yet its roles in regulating other biological events related to reproduction have not been completely revealed. Methods Male TR4 knockout (TR4-/- and wild type mice were used for the sexual behavior and penile dysfunction studies. Mice were sacrificed for histological examination and corresponding genes profiles were analyzed by quantitative RT-PCR. Reporter gene assays were performed. Results We describe an unexpected finding of priapism in TR4-/- mice. As a transcriptional factor, we demonstrated that TR4 transcriptionally modulates a key enzyme regulating penis erection and neuronal nitric oxide synthese NOS (nNOS. Thereby, elimination of TR4 results in nNOS reduction in both mRNA and protein levels, consequently may lead to erectile dysfunction. In addition, male TR4-/- mice display defects in sexual and social behavior, with increased fear or anxiety, as well as reduced mounting, intromission, and ejaculation. Reduction of ER alpha, ER beta, and oxytocin in the hypothalamus may contribute to defects in sexual behavior and stress response. Conclusions Together, these results provide in vivo evidence of important TR4 roles in penile physiology, as well as in male sexual behavior. In conjunction with previous finding, TR4 represents a key factor that controls male fertility via regulating behavior and internal physiological events.

Can We Meet the Sustainability Challenges? The Role of Education and Lifelong Learning

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Wals, Arjen E. J.; Benavot, Aaron

2017-01-01

Education and lifelong learning are increasingly being mobilised to address the global environmental crisis and accompanying sustainability challenges. This article discusses the many roles of education about and for sustainable development, drawing on evidence and arguments put forward in the 2016 Global Education Monitoring Report,…

Designing After-School Learning Using the Massively Multiplayer Online Role-Playing Game

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King, Elizabeth M.

2015-01-01

Digital games have become popular for engaging students in a range of learning goals, both in the classroom and the after-school space. In this article, I discuss a specific genre of video game, the massively multiplayer online role-playing game (MMO), which has been identified as a dynamic environment for encountering 21st-century workplace…

Genital and Urinary Tract Defects

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... conditions > Genital and urinary tract defects Genital and urinary tract defects E-mail to a friend Please fill ... and extra fluids. What problems can genital and urinary tract defects cause? Genital and urinary tract defects affect ...

Relationship between Individual and Organizational Learning: Mediating Role of Team Learning

Directory of Open Access Journals (Sweden)

Monika Stelmaszczyk

2016-12-01

Full Text Available The aim of this paper is to recognize the relationships between individual and organizational learning while considering team learning as a mediator of these relationships. The research object is a large Polish enterprise specializing in the production of cast-iron items. In order to test assumed research hypotheses, statistical analyses were conducted using the IBM SPSS Statistics Suite, version 20. The suite helped conduct correlation analyses concatenation, line regression analyses and mediation analyses using the PROCESS macro by Hayes and Preacher. The research results show a statistically significant relationship between individual learning and each of the five dimensions of organizational learning [clarity of purpose and mission; leadership commitment and empowerment; knowledge transfer; experimentation and rewards; and teamwork and group problem solving]. What is more, they prove that team learning is a mediator of a relationship between individual and organizational learning. Interestingly, only one full mediation has been observed while researching the mediative effect of team learning in relation to each out of the five dimensions of organizational learning. It occurred in relation to experimentation and rewards. In the remaining cases these were partial mediations.

Defect detection on videos using neural network

Directory of Open Access Journals (Sweden)

Sizyakin Roman

2017-01-01

Full Text Available In this paper, we consider a method for defects detection in a video sequence, which consists of three main steps; frame compensation, preprocessing by a detector, which is base on the ranking of pixel values, and the classification of all pixels having anomalous values using convolutional neural networks. The effectiveness of the proposed method shown in comparison with the known techniques on several frames of the video sequence with damaged in natural conditions. The analysis of the obtained results indicates the high efficiency of the proposed method. The additional use of machine learning as postprocessing significantly reduce the likelihood of false alarm.

The Roles of Phasic and Tonic Dopamine in Tic Learning and Expression.

Science.gov (United States)

Maia, Tiago V; Conceição, Vasco A

2017-09-15

Tourette syndrome (TS) prominently involves dopaminergic disturbances, but the precise nature of those disturbances has remained elusive. A substantial body of empirical work and recent computational models have characterized the specific roles of phasic and tonic dopamine (DA) in action learning and selection, respectively. Using insights from this work and models, we suggest that TS involves increases in both phasic and tonic DA, which produce increased propensities for tic learning and expression, respectively. We review the evidence from reinforcement-learning and habit-learning studies in TS, which supports the idea that TS involves increased phasic DA responses; we also review the evidence that tics engage the habit-learning circuitry. On the basis of these findings, we suggest that tics are exaggerated, maladaptive, and persistent motor habits reinforced by aberrant, increased phasic DA responses. Increased tonic DA amplifies the tendency to execute learned tics and also provides a fertile ground of motor hyperactivity for tic learning. We review evidence suggesting that antipsychotics may counter both the increased propensity for tic expression, by increasing excitability in the indirect pathway, and the increased propensity for tic learning, by shifting plasticity in the indirect pathway toward long-term potentiation (and possibly also through more complex mechanisms). Finally, we review evidence suggesting that low doses of DA agonists that effectively treat TS decrease both phasic and tonic DA, thereby also reducing the propensity for both tic learning and tic expression, respectively. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Role of interfacial defect creation-annihilation processes at grain boundaries on the diffusional creep of polycrystalline alumina

International Nuclear Information System (INIS)

Ikuma, Y.; Gordon, R.S.

1981-01-01

It is generally assumed in the diffusional creep of a polycrystalline solid that grain boundaries act as perfect sources and sinks for lattice defects. However, if this assumption is not valid, then diffusional creep can become rate limited by interfacial defect reactions at grain boundaries. Steady state diffusional creep data will be presented at 1450 to 1500 0 C for polycrystalline alumina doped with Ti and a Mg-Ti co-dopant, which are consistent with interfacial controlled kinetics over an intermediate grain size range. A new type of creep deformation map will be presented which reveals the range of grain sizes and impurity concentrations over which interfacial defect creation and/or annihilation processes are important in the steady state creep of polycrystalline alumina

The defect structure of ceramic high Tc superconductors

International Nuclear Information System (INIS)

Van Tendeloo, G.; Amelinckx, S.; Zandbergen, H.W.; Verwerft, M.

1989-01-01

In this paper an overview is given of electron microscopy studies on the different ceramic superconductors: YBa 2 Cu 3 O 7 , Bi(Tl)-Sr(Ba)- Ca-Cu-O and Pb 2 Sr 2 Y 0.5 Ca 0.5 Cu 3 O x . Planar defects in these materials play an important role in the superconducting properties. Their structural characteristics are discussed

Ion channeling study of defects in compound crystals using Monte Carlo simulations

Science.gov (United States)

Turos, A.; Jozwik, P.; Nowicki, L.; Sathish, N.

2014-08-01

Ion channeling is a well-established technique for determination of structural properties of crystalline materials. Defect depth profiles have been usually determined basing on the two-beam model developed by Bøgh (1968) [1]. As long as the main research interest was focused on single element crystals it was considered as sufficiently accurate. New challenge emerged with growing technological importance of compound single crystals and epitaxial heterostructures. Overlap of partial spectra due to different sublattices and formation of complicated defect structures makes the two beam method hardly applicable. The solution is provided by Monte Carlo computer simulations. Our paper reviews principal aspects of this approach and the recent developments in the McChasy simulation code. The latter made it possible to distinguish between randomly displaced atoms (RDA) and extended defects (dislocations, loops, etc.). Hence, complex defect structures can be characterized by the relative content of these two components. The next refinement of the code consists of detailed parameterization of dislocations and dislocation loops. Defect profiles for variety of compound crystals (GaN, ZnO, SrTiO3) have been measured and evaluated using the McChasy code. Damage accumulation curves for RDA and extended defects revealed non monotonous defect buildup with some characteristic steps. Transition to each stage is governed by the different driving force. As shown by the complementary high resolution XRD measurements lattice strain plays here the crucial role and can be correlated with the concentration of extended defects.

The role of diffusion measurements in the study of crystal lattice defects

Energy Technology Data Exchange (ETDEWEB)

Kidson, G V

1965-07-15

Measurements of atomic mobility in solids are frequently of direct interest to those concerned with the design, development and utilization of materials in engineering. Increasing attention, however, is currently devoted to an under standing of such properties in terms of the occurrence and nature of point and line defects in the crystals. This paper reviews some recent diffusion studies conducted at C.R,N.L. that provide, in addition to data of interest in nuclear technology, a means of gaining some insight into the more fundamental nature of the lattice defects occurring in the materials. The systems discussed are (i) self diffusion in the high temperature phase of pure zirconium (ii) solute diffusion in lead and (iii) interdiffusion of aluminum and zirconium The unusual and at present incompletely understood results described in (i) are briefly reviewed. Evidence is given to suggest that diffusion occurs either through a dense dislocation network produced as a result of a martensitic phase transformation, or, alternatively, by excess vacancies introduced into the crystal by impurities. In (ii) the extraordinarily rapid diffusion of noble metal solutes in high purity lead single crystals will be discussed n terms of the state of solution of the solute atoms. It will be shown that their diffusion behaviour can be understood by assuming that a fraction f{sub i} of the dissolved solute atoms occupy interstitial sites, The measured diffusion coefficient D{sub m} is related to the interstitial diffusion coefficient by D{sub m} = f{sub i} D{sub i}. In (iii) the formation and rapid growth of single intermetallic compound ZrAl{sub 3} in the diffusion zone formed between pure zirconium and pure aluminum is described and the diffusion mechanism is interpreted in terms of the structure of the compound lattice. The results indicate that ZrAl{sub 3} forms a defect lattice, leading to the relatively rapid migration of aluminum atoms. (author)

Role of σ1 Receptors in Learning and Memory and Alzheimer's Disease-Type Dementia.

Science.gov (United States)

Maurice, Tangui; Goguadze, Nino

2017-01-01

The present chapter will review the role of σ 1 receptor in learning and memory and neuroprotection , against Alzheimer's type dementia. σ 1 Receptor agonists have been tested in a variety of pharmacological and pathological models of learning impairments in rodents these last past 20 years. Their anti-amnesic effects have been explained by the wide-range modulatory role of σ 1 receptors on Ca 2+ mobilizations, neurotransmitter responses, and particularly glutamate and acetylcholine systems, and neurotrophic factors. Recent observations from genetic and pharmacological studies have shown that σ 1 receptor can also be targeted in neurodegenerative diseases, and particularly Alzheimer's disease . Several compounds, acting partly through the σ 1 receptor, have showed effective neuroprotection in transgenic mouse models of Alzheimer's disease . We will review the data and discuss the possible mechanisms of action, particularly focusing on oxidative stress and mitochondrial integrity, trophic factors and a novel hypothesis suggesting a functional interaction between the σ 1 receptor and α 7 nicotinic acetylcholine receptor. Finally, we will discuss the pharmacological peculiarities of non-selective σ 1 receptor ligands, now developed as neuroprotectants in Alzheimer's disease , and positive modulators, recently described and that showed efficacy against learning and memory deficits.

Exploration of the feasibility for MOOC to be developed for EFL learn-ing in the Chinese Context

Institute of Scientific and Technical Information of China (English)

CAO Lian-yang

2016-01-01

MOOC is an abbreviation of Massive Open Online Course. Whether MOOC can be developed for EFL learning in the Chinese context is discussed regarding both the advantages and disadvantages. MOOC provides open access to resources of high quality, systematic set of social interactions and assessment, but still needs to enlarge structured EFL learning courses and exam-ine their effectiveness (Wu & Zhou, 2014). The lack of needs analysis and existence of language obstacles are the defects of MOOC for EFL learning in China.

Point defects and defect clusters examined on the basis of some fundamental experiments

International Nuclear Information System (INIS)

Zuppiroli, L.

1975-01-01

On progressing from the centre of the defect to the surface the theoretical approach to a point defect passes from electronic theories to elastic theory. Experiments by which the point defect can be observed fall into two categories. Those which detect long-range effects: measurement of dimensional variations in the sample; measurement of the mean crystal parameter variation; elastic X-ray scattering near the nodes of the reciprocal lattice (Huang scattering). Those which detect more local effects: low-temperature resistivity measurement; positron capture and annihilation; local scattering far from the reciprocal lattice nodes. Experiments involving both short and long-range effects can always be found. This is the case for example with the dechanneling of α particles by defects. Certain of the experimental methods quoted above apply also to the study of point defect clusters. These methods are illustrated by some of their most striking results which over the last twenty years have refined our knowledge of point defects and defect clusters: length and crystal parameter measurements; diffuse X-ray scattering; low-temperature resistivity measurements; ion emission microscopy; electron microscopy; elastoresistivity [fr

Birth Defects (For Parents)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Birth Defects KidsHealth / For Parents / Birth Defects What's in ... Prevented? Print en español Anomalías congénitas What Are Birth Defects? While still in the womb, some babies ...

Defect of the Eyelids.

Science.gov (United States)

Lu, Guanning Nina; Pelton, Ron W; Humphrey, Clinton D; Kriet, John David

2017-08-01

Eyelid defects disrupt the complex natural form and function of the eyelids and present a surgical challenge. Detailed knowledge of eyelid anatomy is essential in evaluating a defect and composing a reconstructive plan. Numerous reconstructive techniques have been described, including primary closure, grafting, and a variety of local flaps. This article describes an updated reconstructive ladder for eyelid defects that can be used in various permutations to solve most eyelid defects. Copyright © 2017 Elsevier Inc. All rights reserved.

The Role of Lecturers and University Administrators in Promoting New E-Learning Initiatives

Science.gov (United States)

Mncube, Lancelord Siphamandla; Dube, Luyanda; Ngulube, Patrick

2017-01-01

This article examines the role of lecturers in encouraging and supporting students likely to be predisposed to challenges related to incomprehension, incapacity and isolation embedded in the virtual learning environment. This article used a constructivist lens to gain through interviews an understanding into the intuition, thoughts, ideals,…

Decisional Procrastination in Academic Settings: The Role of Metacognitions and Learning Strategies.

Science.gov (United States)

de Palo, Valeria; Monacis, Lucia; Miceli, Silvana; Sinatra, Maria; Di Nuovo, Santo

2017-01-01

Nowadays, university students suffer from a broad range of problems, such as educational underachievement or the inability to control themselves, that lead to procrastination as a consequence. The present research aimed at analyzing the determinants of decisional procrastination among undergraduate students and at assessing a path model in which self regulated learning strategies mediated the relationship between metacognitive beliefs about procrastination and decisional procrastination. 273 students from Southern Italy filled out a questionnaire composed by: the socio-demographic section, the Metacognitive Beliefs About Procrastination Questionnaire, the procrastination subscale of the Melbourne Decision Making Questionnaire, and the Anxiety, the Time Management, and the Information Processing subscales of the Learning and Study Strategies Inventory. Results showed that the relationship between negative and positive metacognitive beliefs about procrastination and decisional procrastination was mediated only by time management and anxiety. Such findings underlined the crucial role played by learning strategies in predicting the tendency to delay decisional situations and in mediating the relationship between metacognitive beliefs about procrastination and decisional procrastination.

Edge dislocations as sinks for sub-nanometric radiation induced defects in α-iron

Science.gov (United States)

Anento, N.; Malerba, L.; Serra, A.

2018-01-01

The role of edge dislocations as sinks for small radiation induced defects in bcc-Fe is investigated by means of atomistic computer simulation. In this work we investigate by Molecular Statics (T = 0K) the interaction between an immobile dislocation line and defect clusters of small sizes invisible experimentally. The study highlights in particular the anisotropy of the interaction and distinguishes between absorbed and trapped defects. When the considered defect intersects the dislocation glide plane and the distance from the dislocation line to the defect is on the range between 2 nm and 4 nm, either total or partial absorption of the cluster takes place leading to the formation of jogs. Residual defects produced during partial absorption pin the dislocation. By the calculation of stress-strain curves we have assessed the strength of those residues as obstacles for the motion of the dislocation, which is reflected on the unpinning stresses and the binding energies obtained. When the defect is outside this range, but on planes close to the dislocation glide plane, instead of absorption we have observed a capture process. Finally, with a view to introducing explicitly in kinetic Monte Carlo models a sink with the shape of a dislocation line, we have summarized our findings on a table presenting the most relevant parameters, which define the interaction of the dislocation with the defects considered.

Formation of topological defects

International Nuclear Information System (INIS)

Vachaspati, T.

1991-01-01

We consider the formation of point and line topological defects (monopoles and strings) from a general point of view by allowing the probability of formation of a defect to vary. To investigate the statistical properties of the defects at formation we give qualitative arguments that are independent of any particular model in which such defects occur. These arguments are substantiated by numerical results in the case of strings and for monopoles in two dimensions. We find that the network of strings at formation undergoes a transition at a certain critical density below which there are no infinite strings and the closed-string (loop) distribution is exponentially suppressed at large lengths. The results are contrasted with the results of statistical arguments applied to a box of strings in dynamical equilibrium. We argue that if point defects were to form with smaller probability, the distance between monopoles and antimonopoles would decrease while the monopole-to-monopole distance would increase. We find that monopoles are always paired with antimonopoles but the pairing becomes clean only when the number density of defects is small. A similar reasoning would also apply to other defects

Photographic guide of selected external defect indicators and associated internal defects in sugar maple

Science.gov (United States)

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for sugar maple. Eleven types of external...

Photographic guide of selected external defect indicators and associated internal defects in yellow-poplar

Science.gov (United States)

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow-poplar. Twelve types of external...

Photographic guide of selected external defect indicators and associated internal defects in yellow birch

Science.gov (United States)

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow birch. Eleven types of external...

Brevican-deficient mice display impaired hippocampal CA1 long-term potentiation but show no obvious deficits in learning and memory

DEFF Research Database (Denmark)

Brakebusch, Cord; Seidenbecher, Constanze I; Asztely, Fredrik

2002-01-01

to be less prominent in mutant than in wild-type mice. Brevican-deficient mice showed significant deficits in the maintenance of hippocampal long-term potentiation (LTP). However, no obvious impairment of excitatory and inhibitory synaptic transmission was found, suggesting a complex cause for the LTP defect....... Detailed behavioral analysis revealed no statistically significant deficits in learning and memory. These data indicate that brevican is not crucial for brain development but has restricted structural and functional roles....

Distribution of defects in wind turbine blades and reliability assessment of blades containing defects

DEFF Research Database (Denmark)

Stensgaard Toft, Henrik; Branner, Kim; Berring, Peter

2009-01-01

on the assumption that one error in the production process tends to trigger several defects. For both models additional information about number, type and size of the defects is included as stochastic variables. The probability of failure for a wind turbine blade will not only depend on variations in the material......In the present paper two stochastic models for the distribution of defects in wind turbine blades are proposed. The first model assumes that the individual defects are completely randomly distributed in the blade. The second model assumes that the defects occur in clusters of different size based...... properties and the load but also on potential defects in the blades. As a numerical example the probability of failure is calculated for the main spar both with and without defects in terms of delaminations. The delaminations increase the probability of failure compared to a perfect blade, but by applying...

The role of feedback in implicit and explicit artificial grammar learning: a comparison between dyslexic and non-dyslexic adults.

Science.gov (United States)

Schiff, Rachel; Sasson, Ayelet; Star, Galit; Kahta, Shani

2017-10-01

The importance of feedback for learning has been firmly established over the past few decades. The question of whether feedback plays a significant role in the statistical learning abilities of adults with dyslexia, however, is currently unresolved. Here, we examined the role of feedback in grammaticality judgment, type of structural knowledge, and confidence rating in both typically developed and dyslexic adults. We implemented two artificial grammar learning experiments: implicit and explicit. The second experiment was directly analogous to the first experiment in all respects except training format: the standard memorization instruction was replaced with an explicit rule-search instruction. Each experiment was conducted with and without performance feedback. While both groups showed significantly improved learning in the feedback-based explicit artificial grammar learning task, only the typically developed adults demonstrated higher levels of conscious structural knowledge. The present study demonstrates that the basis for the grammaticality judgment of adults with dyslexia differs from that of typically developed adults, regardless of increase in the level of explicitness.

Regenerative wound healing in acute degree III mandibular defects in dogs.

Science.gov (United States)

Mardas, Nikos; Kraehenmann, Michael; Dard, Michel

2012-05-01

To evaluate the healing events in degree III furcation defects in dogs following the application of the combination of an enamel matrix derivative with a biphasic calcium phosphate (Emdogain Plus). Seventeen degree III furcation defects, 5 mm high and 4 mm wide, were created in 9 dogs. In both groups, the defects were conditioned with EDTA. One defect was treated with Emdogain Plus (n = 9), while the contralateral defect serving as control remained empty (n = 8). The defects in both groups were fully covered by coronally repositioned flaps. After 5 months of healing, histologic and histometric analysis was preformed. A significant amount of new attachment and bone formation was observed in both control and test specimens. However, in a number of control specimens, ankylosis was also observed. In the control and test groups, respectively, the mean new cementum length was 10.8 ± 2.1 mm and 8.6 ± 3.2 mm; the mean periodontal ligament length was 7.6 ± 3.8 mm and 8.1 ± 4.0 mm. The mean new bone height was 4.4 ± 1.3 mm and 4.3 ± 1.6 mm in the control and test groups, respectively. No statistical differences were found between the two groups in terms of amount of cementum, periodontal ligament, and alveolar bone regeneration. The present study failed to show higher amounts of newly formed cementum and bone following treatment of acute degree III mandibular furcation defects following use of Emdogain Plus compared with a coronally advanced flap. Emdogain Plus seems to have a protective role against ankylosis in this type of defect.

The Role of Transformational Leadership, Organizational Culture and Organizational Learning in Improving the Performance of Iranian Agricultural Faculties

Science.gov (United States)

Abbasi, Enayat; Zamani-Miandashti, Naser

2013-01-01

This empirical research was conducted to investigate the role of transformational leadership, organizational culture and organizational learning in improving the performance of Iranian agricultural faculties and leading them to become learning organizations. The research population consisted of all faculty members of public agricultural faculties…

Work-based learning and role extension: A match made in heaven?

International Nuclear Information System (INIS)

Eddy, Angela

2010-01-01

This paper presents, and discusses the findings from an exploratory study which examined a cohort of postgraduate therapeutic radiographer students' experiences of undertaking work-based learning to support role extension. The findings showed that three themes emerged which impacted on individual experiences: organisational issues, role and practice issues related to competence development and the individual's background and experience. The conclusions are that new models must emerge, and be evaluated, to offer appropriate support to those individuals who demonstrate the skills and ability to progress to advanced and consultant levels. Departments need to deliberate how they can effectively introduce and support role extension, giving specific consideration to study time, the number of higher level practitioners in training, as well as how to offer effective clinical supervision. Collaboration between higher education institutes and departments should enable the development of tripartite agreements to facilitate effective support for the learners.

Investigating Thematic Roles through Implicit Learning: Evidence from Light Verb Constructions

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Eva Wittenberg

2017-06-01

Full Text Available The syntactic structure of a sentence is usually a strong predictor of its meaning: Each argument noun phrase (i.e., Subject and Object should map onto exactly one thematic role (i.e., Agent and Patient, respectively. Some constructions, however, are exceptions to this pattern. This paper investigates how the syntactic structure of an utterance contributes to its construal, using ditransitive English light verb constructions, such as “Nils gave a hug to his brother,” as an example of such mismatches: Hugging is a two-role event, but the ditransitive syntactic structure suggests a three-role event. Data from an eye-tracking experiment and behavioral categorization data reveal that listeners learn to categorize sentences according to the number of thematic roles they convey, independent of their syntax. Light verb constructions, however, seem to form a category of their own, in which the syntactic structure leads listeners down an initial incorrect assignment of thematic roles, from which they only partly recover. These results suggest an automatic influence of syntactic argument structure on semantic interpretation and event construal, even in highly frequent constructions.

Function of TiO2 Lattice Defects toward Photocatalytic Processes: View of Electronic Driven Force

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Huanan Cui

2013-01-01

Full Text Available Oxygen vacancies and Ti-related defects (OTDs are the main lattice defects of TiO2, which have great influence on its photocatalytic activity. To understand the relationship between the defects and photocatalytic activities, detailed discussions based on the electronic driven force provided by these defects are carried out during the three commonly accepted processes in photocatalytic reactions. It is found that these defects inevitably (i influence the energy structure of the pristine TiO2 as the isolate acceptor/donor level or hybrid with the original orbital, (ii provide a disordered short-range force that confuses the charge carriers transferring to surface active sites, (iii act not only as the surface active sites for trapping the charge carriers but also as the main chemisorption sites for O2, H2O, and organic species. These effects of the defects make them one of the key factors that determine the efficiency of heterogeneous photocatalysis. Clarifying the role of the defects will further facilitate the exploration and the construction of high-performance photocatalysts for practical applications.

The role of visualization in learning from computer-based images

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Piburn, Michael D.; Reynolds, Stephen J.; McAuliffe, Carla; Leedy, Debra E.; Birk, James P.; Johnson, Julia K.

2005-05-01

Among the sciences, the practice of geology is especially visual. To assess the role of spatial ability in learning geology, we designed an experiment using: (1) web-based versions of spatial visualization tests, (2) a geospatial test, and (3) multimedia instructional modules built around QuickTime Virtual Reality movies. Students in control and experimental sections were administered measures of spatial orientation and visualization, as well as a content-based geospatial examination. All subjects improved significantly in their scores on spatial visualization and the geospatial examination. There was no change in their scores on spatial orientation. A three-way analysis of variance, with the geospatial examination as the dependent variable, revealed significant main effects favoring the experimental group and a significant interaction between treatment and gender. These results demonstrate that spatial ability can be improved through instruction, that learning of geological content will improve as a result, and that differences in performance between the genders can be eliminated.

System level mechanisms of adaptation, learning, memory formation and evolvability: the role of chaperone and other networks.

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Gyurko, David M; Soti, Csaba; Stetak, Attila; Csermely, Peter

2014-05-01

During the last decade, network approaches became a powerful tool to describe protein structure and dynamics. Here, we describe first the protein structure networks of molecular chaperones, then characterize chaperone containing sub-networks of interactomes called as chaperone-networks or chaperomes. We review the role of molecular chaperones in short-term adaptation of cellular networks in response to stress, and in long-term adaptation discussing their putative functions in the regulation of evolvability. We provide a general overview of possible network mechanisms of adaptation, learning and memory formation. We propose that changes of network rigidity play a key role in learning and memory formation processes. Flexible network topology provides ' learning-competent' state. Here, networks may have much less modular boundaries than locally rigid, highly modular networks, where the learnt information has already been consolidated in a memory formation process. Since modular boundaries are efficient filters of information, in the 'learning-competent' state information filtering may be much smaller, than after memory formation. This mechanism restricts high information transfer to the 'learning competent' state. After memory formation, modular boundary-induced segregation and information filtering protect the stored information. The flexible networks of young organisms are generally in a 'learning competent' state. On the contrary, locally rigid networks of old organisms have lost their 'learning competent' state, but store and protect their learnt information efficiently. We anticipate that the above mechanism may operate at the level of both protein-protein interaction and neuronal networks.

Entanglement entropy in integrable field theories with line defects II. Non-topological defect

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Jiang, Yunfeng

2017-08-01

This is the second part of two papers where we study the effect of integrable line defects on bipartite entanglement entropy in integrable field theories. In this paper, we consider non-topological line defects in Ising field theory. We derive an infinite series expression for the entanglement entropy and show that both the UV and IR limits of the bulk entanglement entropy are modified by the line defect. In the UV limit, we give an infinite series expression for the coefficient in front of the logarithmic divergence and the exact defect g-function. By tuning the defect to be purely transmissive and reflective, we recover correctly the entanglement entropy of the bulk and with integrable boundary respectively.

Death and Rebirth of Atlántida: The Role of Social Learning in ...

African Journals Online (AJOL)

This paper explores the role of social learning in bringing about transformative sustainability processes among individuals and communities. At a time when sustainability is being seriously questioned in terms of what it is and how it can be implemented and evaluated, there are increasing calls to focus instead on ...

Workplace Learning within Teacher Education: The Role of Job Characteristics and Goal Orientation

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Kyndt, Eva; Donche, Vincent; Gijbels, David; Van Petegem, Peter

2014-01-01

Within teacher education, it is widely recognised that internships play a major role in preparing prospective teachers. The current research examines if the learning activities students' undertake in the workplace can be explained by students' goal orientation and their perceptions of the workplace. In addition, it will be investigated…

Defect evolution and impurity migration in Na-implanted ZnO

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Neuvonen, Pekka T.; Vines, Lasse; Venkatachalapathy, Vishnukanthan; Zubiaga, Asier; Tuomisto, Filip; Hallén, Anders; Svensson, Bengt G.; Kuznetsov, Andrej Yu.

2011-11-01

Secondary ion mass spectrometry (SIMS) and positron annihilation spectroscopy (PAS) have been applied to study impurity migration and open volume defect evolution in Na+ implanted hydrothermally grown ZnO samples. In contrast to most other elements, the presence of Na tends to decrease the concentration of open volume defects upon annealing and for temperatures above 600∘C, Na exhibits trap-limited diffusion correlating with the concentration of Li. A dominating trap for the migrating Na atoms is most likely Li residing on Zn site, but a systematic analysis of the data suggests that zinc vacancies also play an important role in the trapping process.

Contribute to quantitative identification of casting defects based on computer analysis of X-ray images

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Z. Ignaszak

2007-12-01

Full Text Available The forecast of structure and properties of casting is based on results of computer simulation of physical processes which are carried out during the casting processes. For the effective using of simulation system it is necessary to validate mathematica-physical models describing process of casting formation and the creation of local discontinues, witch determinate the casting properties.In the paper the proposition for quantitative validation of VP system using solidification casting defects by information sources of II group (methods of NDT was introduced. It was named the VP/RT validation (virtual prototyping/radiographic testing validation. Nowadays identification of casting defects noticeable on X-ray images bases on comparison of X-ray image of casting with relates to the ASTM. The results of this comparison are often not conclusive because based on operator’s subjective assessment. In the paper the system of quantitative identification of iron casting defects on X-ray images and classification this defects to ASTM class is presented. The methods of pattern recognition and machine learning were applied.

Role of N defects in paramagnetic CrN at finite temperatures from first principles

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Mozafari, E.; Alling, B.; Steneteg, P.; Abrikosov, Igor A.

2015-03-01

Simulations of defects in paramagnetic materials at high temperature constitute a formidable challenge to solid-state theory due to the interaction of magnetic disorder, vibrations, and structural relaxations. CrN is a material where these effects are particularly large due to a strong magnetolattice coupling and a tendency for deviations from the nominal 1:1 stoichiometry. In this work, we present a first-principles study of nitrogen vacancies and nitrogen interstitials in CrN at elevated temperature. We report on formation energetics, the geometry of interstitial nitrogen dimers, and the impact on the electronic structure caused by the defects. We find a vacancy formation energy of 2.28 eV with a small effect of temperature, i.e., a formation energy for N interstitial in the form of a -oriented split bond of 3.77 eV with an increase to 3.97 at 1000 K. Vacancies are found to add three electrons, while split-bond interstitial adds one electron to the conduction band. The band gap of defect-free CrN is smeared out due to vibrations, although it is difficult to draw a conclusion about the exact temperature at which the band gap closes from our calculations. However, it is clear that at 900 K there is a nonzero density of electronic states at the Fermi level. At 300 K, our results indicate a border case where the band gap is about to close.

Natural defects and defects created by ionic implantation in zinc tellurium

International Nuclear Information System (INIS)

Roche, J.P.; Dupuy, M.; Pfister, J.C.

1977-01-01

Various defects have been studied in ZnTe crystals by transmission electron microscope and by scanning electron microscope in cathodo-luminescence mode: grain boundaries, sub-grain boundaries, twins. Ionic implants of boron (100 keV - 2x10 14 and 10 15 ions cm -2 ) were made on these crystals followed by isochrone annealing (30 minutes) of zinc under partial pressure at 550, 650 and 750 0 C. The nature of the defects was determined by transmission electron microscope: these are interstitial loops (b=1/3 ) the size of which varies between 20 A (non-annealed sample) and 180A (annealed at 750 0 C). The transmission electron microscope was also used to make concentration profiles of defects depending on depth. It is found that for the same implant (2x10 14 ions.cm -2 ), the defect peak moves towards the exterior of the crystal as the annealing temperature rises (400 - 1000 and 7000 A for the three annealings). These results are explained from a model which allows for the coalescence of defects and considers the surface of the sample as being the principal source of vacancies. During the annealings, the migration of vacancies brings about the gradual annihilation of the implant defects. The adjustment of certain calculation parameters on the computer result in giving 2 eV as energy value for the formation of vacancies [fr

University Student and Teacher Perceptions of Teacher Roles in Promoting Autonomous Language Learning with Technology outside the Classroom

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Lai, Chun; Yeung, Yuk; Hu, Jingjing

2016-01-01

Helping students to become autonomous learners, who actively utilize technologies for learning outside the classroom, is important for successful language learning. Teachers, as significant social agents who shape students' intellectual and social experiences, have a critical role to play. This study examined students' and teachers' perceptions of…

Surface magnetization and the role of pattern defects in various types of ripple patterned films

International Nuclear Information System (INIS)

Colino, Jose M; Arranz, Miguel A; Barbero, Antonio J; Bollero, A; Camarero, J

2016-01-01

We present a detailed study of the magnetic properties of cobalt films with wide-area nanoscale ripple patterns, either on their surface only, or on both the film surface and substrate interface. Angular dependence vectorial-resolved magnetometry measurements and magnetic force microscopy with in situ magnetic field have been used to determine the magnetization reversal processes to correlate them to the different patterned nanostructures. All the samples show well-defined uniaxial magnetic anisotropy with the anisotropy axis lying along the ripple direction. Atomic force microscopy of the different types of pattern reveals various pattern defects: height corrugation and breaks of continuity along the ripple direction, and overlapping ripples and Y-shaped defects (pattern dislocation) across the pattern. In spite of the existence of such customary defects of erosive-regime patterns, the type of low-amplitude, surface-patterned films remarkably behave as a macrospin over almost the whole in-plane angular range (340°), with negligible spread of anisotropy axis or energy. In turn, it is found that high-amplitude surface-patterned films develop an angular distribution of anisotropy axes, probably related to the large distribution of amplitudes in a pattern of short ripples, and a significant distribution of anisotropy fields ΔH k /H k up to 15%. On the other hand, films grow on pre-patterned silicon with a significantly longer mean ripple length, and develop a larger anisotropy energy with H k up to 110 mT, probably because of the double interface effect. The switching fields close to the magnetization easy axis of all types of ripple pattern are not well reproduced by the macrospin approximation, but the observed pattern defects seem to be not responsible for the domain wall pinning that occurs with the field applied along the ripple direction. (paper)

Modeling the relationships among internal defect features and external Appalachian hardwood log defect indicators

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R. Edward. Thomas

2009-01-01

As a hardwood tree grows and develops, surface defects such as branch stubs and wounds are overgrown. Evidence of these defects remain on the log surface for decades and in many instances for the life of the tree. As the tree grows the defect is encapsulated or grown over by new wood. During this process the appearance of the defect in the tree's bark changes. The...