Science.gov

Sample records for activity learners conduct

  1. Does Translation Contribute to Learners' Free Active Vocabulary?

    ERIC Educational Resources Information Center

    Asiyaban, Amir R.; Bagheri, Mohammad S.

    2012-01-01

    This research was conducted to find out whether or not using "translation" technique in vocabulary teaching would have any positive effects on the "free active" vocabulary of Iranian learners of English. To carry out the research, eighty-eight intermediate male and female students were chosen. The participants were divided into…

  2. Learner Activities in a Collaborative CALL Task

    ERIC Educational Resources Information Center

    Leahy, C.

    2008-01-01

    This paper briefly discusses different research approaches in CALL and makes a case for applying grounded theory (GT) to data gathered from an electronic role-play conducted in L2. The article shows that this method can help gain a better understanding of what learners do when engaged in the task. Through the process of open coding, four…

  3. Interactions between and among Heritage Language Learners and Second Language Learners during Collaborative Writing Activities: How Learners Attend to Language

    ERIC Educational Resources Information Center

    Walls, Laura

    2013-01-01

    This study investigates the dynamics in the Spanish classroom between heritage language learner (HLL) dyads, second language learner (L2L) dyads, and mixed HLL-L2L dyads. Specifically, it examines oral, written and embodied discourse that informs our understanding of how learners attend to language. Analysis for this dissertation examined…

  4. Learner-Interface Interaction for Technology-Enhanced Active Learning

    ERIC Educational Resources Information Center

    Sinha, Neelu; Khreisat, Laila; Sharma, Kiron

    2009-01-01

    Neelu Sinha, Laila Khreisat, and Kiron Sharma describe how learner-interface interaction promotes active learning in computer science education. In a pilot study using technology that combines DyKnow software with a hardware platform of pen-enabled HP Tablet notebook computers, Sinha, Khreisat, and Sharma created dynamic learning environments by…

  5. Young Children: Active Learners in a Technological Age.

    ERIC Educational Resources Information Center

    Wright, June L., Ed.; Shade, Daniel D., Ed.

    This book addresses the issues of appropriate use of computers with young children and how children and early childhood educators interact with the computer in early childhood settings. Part 1, "Young Children as Active Learners," contains chapter 1: "Listen to the Children: Observing Young Children's Discoveries with the…

  6. Facebook Activities and the Investment of L2 Learners

    ERIC Educational Resources Information Center

    Shafie, Latisha Asmaak; Yaacob, Aizan; Singh, Paramjit Kaur Karpal

    2016-01-01

    The article discusses the investment of L2 learners in the English language on Facebook that they portrayed through their Facebook activities. It studied four informants consisted of diploma students in a Malaysian university. The study consisted of 14 weeks of online observation and semi-structured interviews. Data were collected from online…

  7. We are what we do: Examining learner-generated content in the anatomy laboratory through the lens of activity theory.

    PubMed

    Doubleday, Alison F; Wille, Sarah J

    2014-01-01

    Video and photography are often used for delivering content within the anatomical sciences. However, instructors typically produce these resources to provide instructional or procedural information. Although the benefits of learner-generated content have been explored within educational research, virtually no studies have investigated the use of learner-generated video and photograph content within anatomy dissection laboratories. This study outlines an activity involving learner-generated video diaries and learner-generated photograph assignments produced during anatomy laboratory sessions. The learner-generated photographs and videos provided instructors with a means of formative assessment and allowed instructors to identify evidence of collaborative behavior in the laboratory. Student questionnaires (n = 21) and interviews (n = 5), as well as in-class observations, were conducted to examine student perspectives on the laboratory activities. The quantitative and qualitative data were examined using the framework of activity theory to identify contradictions between student expectations of, and engagement with, the activity and the actual experiences of the students. Results indicate that learner-generated photograph and video content can act as a rich source of data on student learning processes and can be used for formative assessment, for observing collaborative behavior, and as a starting point for class discussions. This study stresses the idea that technology choice for activities must align with instructional goals. This research also highlights the utility of activity theory as a framework for assessing classroom and laboratory activities, demonstrating that this approach can guide the development of laboratory activities.

  8. Acquisition of Mathematical Language: Suggestions and Activities for English Language Learners

    ERIC Educational Resources Information Center

    Cirillo, Michelle; Bruna, Katherine Richardson; Herbel-Eisenmann, Beth

    2010-01-01

    In this article, we describe aspects of mathematical language that could be problematic to English-language learners, provide recommendations for teaching English-language learners, and suggest activities intended to foster language development in mathematics. (Contains 1 figure.)

  9. Learners' Perceptions of Instructional Design Practice in a Situated Learning Activity

    ERIC Educational Resources Information Center

    Woolf, Nicholas; Quinn, James

    2009-01-01

    This case study investigated learners' perceptions of value from participating in a learning activity designed to model professional instructional design practice. Learners developed instructional design products for a corporate client in the context of a classroom-based course. The findings indicate that learners perceived different kinds of…

  10. Textbook Activities among Heritage and Non-Heritage Portuguese Learners

    ERIC Educational Resources Information Center

    Silva, Glaucia V.

    2011-01-01

    Over the past four decades, scholars have debated the pedagogical and sociolinguistic needs of heritage language learners. It is widely accepted that these learners present several characteristics that are different from those of foreign (or non-heritage) language learners. However, scholars have also pointed to similarities between the two groups…

  11. Does Active Learning Enhance Learner Outcomes? Evidence from Discussion Participation in Online Classes

    ERIC Educational Resources Information Center

    Wilson, Bruce M.; Pollock, Philip H.; Hamann, Kerstin

    2007-01-01

    Discussion is one form of active learning, which has been linked to better learner outcomes. Little is known about the relationship between active learning through discussion and learner outcome in the online environment. Here, we construct an index of active learning online that includes the number of postings a student has read, the number of…

  12. Planning and Conducting Research Activities.

    ERIC Educational Resources Information Center

    Christiansen, Richard L.

    1983-01-01

    Some directions and influences on dental research activities in the near future are discussed. Current challenges include international competition, fellowships, and equipment. Potential research activity includes preventive medicine, epidemiology, chronic illness, the elderly, bioengineering, materials research, nutrition, soft tissue research,…

  13. Promoting Physics Among Female Learners in the Western Cape Through Active Engagement (abstract)

    NASA Astrophysics Data System (ADS)

    Arendse, Gillian J.

    2009-04-01

    In 2006 the author organized a one-day intervention aimed at promoting physics among female learners at the University of Stellenbosch. The activities included an interactive lecture demonstration promoting active engagement, a hands-on session, and short presentations by female physicists addressing issues such as balancing family and career, breaking the stereotypes, and launching a successful career in physics. Each learner was expected to evaluate the program. In 2007 the author joined forces with Hip2B2 (Shuttleworth Foundation) to host a competition among grade-10 learners with the theme, ``promoting creativity through interactivity.'' The author was tasked by the Hip2B2-team to assist with a program for female learners planned for August 2008, coinciding with our national celebration of Women's Day. The event targeted 160 learners and took place in Durban, East London, Cape Town, and Johannesburg. The author shares some of the learners' experiences and personal triumphs.

  14. How Do Distance Learners Use Activities in Self-Instructional Materials?

    ERIC Educational Resources Information Center

    Mishra, Sanjaya; Gaba, Ashok Kumar

    2001-01-01

    Presents results of a study on the use of learning activities in self-instructional materials by distance learners of the Indira Gandhi National Open University (IGNOU). It shows that learners make use of the activities extensively as they have positive perceptions about benefits of Self-Assessment Questions and Terminal Questions given in the…

  15. Investigating Learner Attitudes toward E-Books as Learning Tools: Based on the Activity Theory Approach

    ERIC Educational Resources Information Center

    Liaw, Shu-Sheng; Huang, Hsiu-Mei

    2016-01-01

    This paper investigates the use of e-books as learning tools in terms of learner satisfaction, usefulness, behavioral intention, and learning effectiveness. Based on the activity theory approach, this research develops a research model to understand learner attitudes toward e-books in two physical sizes: 10? and 7?. Results suggest that screen…

  16. Training Learners to Use Quizlet Vocabulary Activities on Mobile Phones in Vietnam with Facebook

    ERIC Educational Resources Information Center

    Tran, Phuong

    2016-01-01

    Mobile phone ownership among university students in Vietnam has reached almost 100%, exceeding that of Internet-capable desktop computers. This has made them increasingly popular to allow learners to carry out learning activities outside of the classroom, but some studies have suggested that learners are not always willing to engage in activities…

  17. A Comparison of Teacher-Rated Classroom Conduct, Social Skills, and Teacher-Child Relationship Quality between Preschool English Learners and Preschool English Speakers

    ERIC Educational Resources Information Center

    Luchtel, Molly; Hughes, Kere; Luze, Gayle; Bruna, Katherine Richardson; Peterson, Carla

    2010-01-01

    This study examined the differences between preschool English learners and preschool English speakers in the areas of classroom conduct, social skills, and teacher-child relationship quality, as rated by their teachers. Data were taken from the Early Head Start Research and Evaluation Project. Students who were English learners were rated…

  18. Beginning Learners' Development of Interactional Competence: Alignment Activity

    ERIC Educational Resources Information Center

    Tecedor, Marta

    2016-01-01

    This study examined the development of interactional competence (Hall, 1993; He & Young, 1998) by beginning learners of Spanish as indexed by their use of alignment moves. Discourse analysis techniques and quantitative data analysis were used to explore how 52 learners expressed alignment and changes in participation patterns in two sets of…

  19. Spoken Language Activation Alters Subsequent Sign Language Activation in L2 Learners of American Sign Language.

    PubMed

    Williams, Joshua T; Newman, Sharlene D

    2017-02-01

    A large body of literature has characterized unimodal monolingual and bilingual lexicons and how neighborhood density affects lexical access; however there have been relatively fewer studies that generalize these findings to bimodal (M2) second language (L2) learners of sign languages. The goal of the current study was to investigate parallel language activation in M2L2 learners of sign language and to characterize the influence of spoken language and sign language neighborhood density on the activation of ASL signs. A priming paradigm was used in which the neighbors of the sign target were activated with a spoken English word and compared the activation of the targets in sparse and dense neighborhoods. Neighborhood density effects in auditory primed lexical decision task were then compared to previous reports of native deaf signers who were only processing sign language. Results indicated reversed neighborhood density effects in M2L2 learners relative to those in deaf signers such that there were inhibitory effects of handshape density and facilitatory effects of location density. Additionally, increased inhibition for signs in dense handshape neighborhoods was greater for high proficiency L2 learners. These findings support recent models of the hearing bimodal bilingual lexicon, which posit lateral links between spoken language and sign language lexical representations.

  20. Learners' Interpersonal Beliefs and Generated Feedback in an Online Role-Playing Peer-Feedback Activity: An Exploratory Study

    ERIC Educational Resources Information Center

    Ching, Yu-Hui; Hsu, Yu-Chang

    2016-01-01

    Peer feedback affords interaction and critical thinking opportunities for learners in online courses. However, various factors prevent learners from taking advantage of these promising benefits. This study explored learners' perceptions of the interpersonal factors in a role-playing peer-feedback activity, and examined the types of peer feedback…

  1. A Development of Game-Based Learning Environment to Activate Interaction among Learners

    NASA Astrophysics Data System (ADS)

    Takaoka, Ryo; Shimokawa, Masayuki; Okamoto, Toshio

    Many studies and systems that incorporate elements such as “pleasure” and “fun” in the game to improve a learner's motivation have been developed in the field of learning environments. However, few are the studies of situations where many learners gather at a single computer and participate in a game-based learning environment (GBLE), and where the GBLE designs the learning process by controlling the interactions between learners such as competition, collaboration, and learning by teaching. Therefore, the purpose of this study is to propose a framework of educational control that induces and activates interaction between learners intentionally to create a learning opportunity that is based on the knowledge understanding model of each learner. In this paper, we explain the design philosophy and the framework of our GBLE called “Who becomes the king in the country of mathematics?” from a game viewpoint and describe the method of learning support control in the learning environment. In addition, we report the results of the learning experiment with our GBLE, which we carried out in a junior high school, and include some comments by a principal and a teacher. From the results of the experiment and some comments, we noticed that a game may play a significant role in weakening the learning relationship among students and creating new relationships in the world of the game. Furthermore, we discovered that learning support control of the GBLE has led to activation of the interaction between learners to some extent.

  2. Active Bone Conduction Prosthesis: Bonebridge(TM).

    PubMed

    Zernotti, Mario E; Sarasty, Andrea Bravo

    2015-10-01

    Introduction Bone conduction implants are indicated for patients with conductive and mixed hearing loss, as well as for patients with single-sided deafness (SSD). The transcutaneous technology avoids several complications of the percutaneous bone conduction implants including skin reaction, skin growth over the abutment, and wound infection. The Bonebridge (MED-EL, Austria) prosthesis is a semi-implantable hearing system: the BCI (Bone Conduction Implant) is the implantable part that contains the Bone Conduction-Floating Mass Transducer (BC-FMT), which applies the vibrations directly to the bone; the external component is the audio processor Amadé BB (MED-EL, Austria), which digitally processes the sound and sends the information through the coil to the internal part. Bonebridge may be implanted through three different approaches: the transmastoid, the retrosigmoid, or the middle fossa approach. Objective This systematic review aims to describe the world́s first active bone conduction implant system, Bonebridge, as well as describe the surgical techniques in the three possible approaches, showing results from implant centers in the world in terms of functional gain, speech reception thresholds and word recognition scores. Data Synthesis The authors searched the MEDLINE database using the key term Bonebridge. They selected only five publications to include in this systematic review. The review analyzes 20 patients that received Bonebridge implants with different approaches and pathologies. Conclusion Bonebridge is a solution for patients with conductive/mixed hearing loss and SSD with different surgical approaches, depending on their anatomy. The system imparts fewer complications than percutaneous bone conduction implants and shows proven benefits in speech discrimination and functional gain.

  3. Learner-Centered Activities from the DVD-Format "Crouching Tiger, Hidden Dragon."

    ERIC Educational Resources Information Center

    Lin, Li-Yun

    This paper demonstrates how Taiwanese English-as-a-Second-Language (ESL) college teachers and students collaborate and negotiate to design various learner-centered activities based on the Chinese film, "Crouching Tiger, Hidden Dragon." These activities are intended to enhance students' listening and speaking abilities. The paper…

  4. What Does Metalinguistic Activity in Learners' Interaction during a Collaborative L2 Writing Task Look Like?

    ERIC Educational Resources Information Center

    Gutierrez, Xavier

    2008-01-01

    This article examines the metalinguistic activity that arose in the interaction of 7 groups of bilingual learners writing collaboratively in their second language (L2), English. A microanalysis of this interaction reveals that metalinguistic activity comprises 3 types of oral production: comments, speech actions, and text reformulations. Text…

  5. The Effects of Pre-Reading Activities on Reading Comprehension of Iranian EFL Learners

    ERIC Educational Resources Information Center

    Moghaddam, Nahid Nemati; Mahmoudi, Asgar

    2016-01-01

    This study investigated the effects of three types of pre-reading activities (movie-watching, vocabulary presentation, and pre-reading summarization) on the reading comprehension of 76 elementary-level EFL Iranian learners. The participants were randomly assigned to one control and three experimental conditions and then a pretest was given to…

  6. Active Learning for Discovery and Innovation in Criminology with Chinese Learners

    ERIC Educational Resources Information Center

    Li, Jessica C. M.; Wu, Joseph

    2015-01-01

    Whereas a great deal of literature based upon the context of Western societies has concluded criminology is an ideal discipline for active learning approach, it remains uncertain if this learning approach is applicable to Chinese learners in the discipline of criminology. This article describes and provides evidence of the benefits of using active…

  7. Investigating the Use of Inquiry & Web-Based Activities with Inclusive Biology Learners

    ERIC Educational Resources Information Center

    Bodzin, Alec M.; Waller, Patricia L.; Edwards, Lana; Darlene Kale, Santoro

    2007-01-01

    A Web-integrated biology program is used to explore how to best assist inclusive high school students to learn biology with inquiry-based activities. Classroom adaptations and instructional strategies teachers may use to assist in promoting biology learning with inclusive learners are discussed.

  8. An Emergent Language Program Framework: Actively Involving Learners in Needs Analysis.

    ERIC Educational Resources Information Center

    Savage, William; Storer, Graeme

    1992-01-01

    Relates the experience of the staff of an aquaculture outreach program in Northeast Thailand in implementing an English for special purposes program. By actively involving learners in both the needs analysis and program design, teachers were able to adapt the program content to the requirements of the students. (15 references) (JL)

  9. Cross-Language Activation in Children's Speech Production: Evidence from Second Language Learners, Bilinguals, and Trilinguals

    ERIC Educational Resources Information Center

    Poarch, Gregory J.; van Hell, Janet G.

    2012-01-01

    In five experiments, we examined cross-language activation during speech production in various groups of bilinguals and trilinguals who differed in nonnative language proficiency, language learning background, and age. In Experiments 1, 2, 3, and 5, German 5- to 8-year-old second language learners of English, German-English bilinguals,…

  10. Flipping the Classroom for English Language Learners to Foster Active Learning

    ERIC Educational Resources Information Center

    Hung, Hsiu-Ting

    2015-01-01

    This paper describes a structured attempt to integrate flip teaching into language classrooms using a WebQuest active learning strategy. The purpose of this study is to examine the possible impacts of flipping the classroom on English language learners' academic performance, learning attitudes, and participation levels. Adopting a…

  11. Fashion Design: Designing a Learner-Active, Multi-Level High School Course

    ERIC Educational Resources Information Center

    Nelson, Diane

    2009-01-01

    A high school fashion design teacher has much in common with the ringmaster of a three-ring circus. The challenges of teaching a hands-on course are to facilitate the entire class and to meet the needs of individual students. When teaching family and consumer sciences, the goal is to have a learner-active classroom. Revamping the high school's…

  12. Synthesizing Technology Adoption and Learners' Approaches towards Active Learning in Higher Education

    ERIC Educational Resources Information Center

    Chan, Kevin; Cheung, George; Wan, Kelvin; Brown, Ian; Luk, Green

    2015-01-01

    In understanding how active and blended learning approaches with learning technologies engagement in undergraduate education, current research models tend to undermine the effect of learners' variations, particularly regarding their styles and approaches to learning, on intention and use of learning technologies. This study contributes to further…

  13. Guidance manual for conducting technology demonstration activities

    SciTech Connect

    Jolley, Robert L.; Morris, Michael I.; Singh, Suman P.N.

    1991-12-01

    This demonstration guidance manual has been prepared to assist Martin Marietta Energy Systems, Inc. (Energy Systems), staff in conducting demonstrations. It is prepared in checklist style to facilitate its use and assumes that Energy Systems personnel have project management responsibility. In addition to a detailed step-by-step listing of procedural considerations, a general checklist, logic flow diagram, and several examples of necessary plans are included to assist the user in developing an understanding of the many complex activities required to manage technology demonstrations. Demonstrations are pilot-scale applications of often innovative technologies to determine the commercial viability of the technologies to perform their designed function. Demonstrations are generally conducted on well-defined problems for which existing technologies or processes are less than satisfactory in terms of effectiveness, cost, and/or regulatory compliance. Critically important issues in demonstration management include, but are not limited to, such factors as communications with line and matrix management and with the US Department of Energy (DOE) and Energy Systems staff responsible for management oversight, budgetary and schedule requirements, regulatory compliance, and safety.

  14. Popular Culture, English Out-of-Class Activities, and Learner Autonomy among Highly Proficient Secondary Students in Hong Kong

    ERIC Educational Resources Information Center

    Chan, Hoi Wing

    2016-01-01

    This paper reports on how and why proficient learners of English in Hong Kong participated in popular culture, out-of-class activities, with an emphasis on their development of learner autonomy. Autonomy in language learning is defined as an individual's ability and responsibility to take charge of his or her own learning [1]. Out-of-class…

  15. Fluency-dependent cortical activation associated with speech production and comprehension in second language learners.

    PubMed

    Shimada, K; Hirotani, M; Yokokawa, H; Yoshida, H; Makita, K; Yamazaki-Murase, M; Tanabe, H C; Sadato, N

    2015-08-06

    This functional magnetic resonance imaging (fMRI) study investigated the brain regions underlying language task performance in adult second language (L2) learners. Specifically, we identified brain regions where the level of activation was associated with L2 fluency levels. Thirty Japanese-speaking adults participated in the study. All participants were L2 learners of English and had achieved varying levels of fluency, as determined by a standardized L2 English proficiency test, the Versant English Test (Pearson Education Inc., 2011). When participants performed the oral sentence building task from the production tasks administered, the dorsal part of the left inferior frontal gyrus (dIFG) showed activation patterns that differed depending on the L2 fluency levels: The more fluent the participants were, the more dIFG activation decreased. This decreased activation of the dIFG might reflect the increased automaticity of a syntactic building process. In contrast, when participants performed an oral story comprehension task, the left posterior superior temporal gyrus (pSTG) showed increased activation with higher fluency levels. This suggests that the learners with higher L2 fluency were actively engaged in post-syntactic integration processing supported by the left pSTG. These data imply that L2 fluency predicts neural resource allocation during language comprehension tasks as well as in production tasks. This study sheds light on the neural underpinnings of L2 learning by identifying the brain regions recruited during different language tasks across different modalities (production vs. comprehension).

  16. Sharing a Small World: Environmental Activities for Young Learners.

    ERIC Educational Resources Information Center

    Zero Population Growth, Inc., Washington, DC.

    This booklet contains a collection of activities developed for pre-K through second grade students. All of the activities in this teacher's guide use an interdisciplinary approach and explore the human connection with all living things and their environment. Contents include: (1) "Sharing Space and Working Together"; (2) "Sharing Resources and…

  17. Cross-language activation in children's speech production: evidence from second language learners, bilinguals, and trilinguals.

    PubMed

    Poarch, Gregory J; van Hell, Janet G

    2012-03-01

    In five experiments, we examined cross-language activation during speech production in various groups of bilinguals and trilinguals who differed in nonnative language proficiency, language learning background, and age. In Experiments 1, 2, 3, and 5, German 5- to 8-year-old second language learners of English, German-English bilinguals, German-English-Language X trilinguals, and adult German-English bilinguals, respectively, named pictures in German and in English; in Experiment 4, 6- to 8-year-old German monolinguals named pictures in German. In both language conditions, cognate status was manipulated. We found that the bidirectional cognate facilitation effect was significant in all groups except the German monolinguals (Experiment 4) and, critically, the child second language learners (Experiment 1) in whom only native language (L1) German had an effect on second language (L2) English. The findings demonstrate how the integration of languages into a child's system follows a developmental path that, at lower levels of proficiency, allows only limited cross-language activation. The results are interpreted against the backdrop of the developing language systems of the children both for early second language learners and for early bi- and trilinguals.

  18. The effect of curricular activities on learner autonomy: the perspective of undergraduate mechanical engineering students

    NASA Astrophysics Data System (ADS)

    Duarte, M.; Leite, C.; Mouraz, A.

    2016-01-01

    This study researches how first-year engineering students perceived the influence of curricular activities on their own learning autonomy, measured with an adaptation of the Personal Responsibility Orientation to Self-direction in Learning Scale (PRO-SDLS). Participants were questioned to assess the influence of the teacher's role. The results indicate that learners' characteristics (motivation and self-efficacy) contribute more to learner autonomy (LA) than the teaching-learning transaction (control and initiative), as in the original PRO-SDLS validation. The most autonomous learners presented higher values in all LA components and dimensions, but the differences were greater in motivation and initiative. The participants with higher LA were not as dependent on the teacher, regarding assessment, the completion of classroom tasks and deadlines. Regardless of the degree of autonomy in learning, all participants viewed teachers as the main source of information. Therefore, LA plays an important role in teaching activities planning. Suggestions for adjustments and more flexible learning scenarios are formulated.

  19. Model Eliciting Activities: Fostering 21st Century Learners

    ERIC Educational Resources Information Center

    Stohlmann, Micah

    2013-01-01

    Real world mathematical modeling activities can develop needed and valuable 21st century skills. The knowledge and skills to become adept at mathematical modeling need to develop over time and students in the elementary grades should have experiences with mathematical modeling. For this to occur elementary teachers need to have positive…

  20. Spoken Language Activation Alters Subsequent Sign Language Activation in L2 Learners of American Sign Language

    ERIC Educational Resources Information Center

    Williams, Joshua T.; Newman, Sharlene D.

    2017-01-01

    A large body of literature has characterized unimodal monolingual and bilingual lexicons and how neighborhood density affects lexical access; however there have been relatively fewer studies that generalize these findings to bimodal (M2) second language (L2) learners of sign languages. The goal of the current study was to investigate parallel…

  1. Thermopower and conductivity activation energies in hydrogenated amorphous silicon

    SciTech Connect

    Dyalsingh, H.M.; Kakalios, J.

    1996-12-31

    The long range fluctuation model has been widely used to account for the difference in activation energies seen experimentally in dark conductivity and thermopower measurements in hydrogenated amorphous silicon. The authors report on a test of this model using measurements of the conductivity and thermoelectric effects carried out in both open and short circuit configurations. While the thermopower activation energy is less than that of the dark conductivity, the short circuit Seebeck conductivity is found to be nearly identical to the dark conductivity in both activation energy and magnitude, consistent with the long range fluctuation model.

  2. The challenge of "teaching" large groups of learners: strategies to increase active participation and learning.

    PubMed

    Nierenberg, D W

    1998-01-01

    While teaching in a tutorial, seminar, or problem-based learning group format may be the most fun and most active/interactive for both learner and faculty mentor, there are situations in medical student education in which various constraints require the use of the "lecture" format. Similar constraints may occur in the field of continuing medical education, or graduate medical education, as well. When this occurs, the faculty mentor can increase the active participation of the learners in the audience by continuously stressing seven key pedagogical (androgogical) principles. These include: 1) begin the learning exercise with a clinical example or anecdote to show the relevance of the material to the student; 2) frequently ask the students whether they have ever seen examples of what you describe in their previous experience with patients, personal experience, experience with relatives, etc.; 3) ask students frequently whether they have heard similar material presented differently in other courses; 4) recruit students to help solve "mystery cases"; 5) show examples of similar material from real life (e.g., patient descriptions, or even excerpts from favorite TV shows); 6) ask students to help summarize key points at the end of the session; and 7) allow, or even encourage, whispering during the class. Using some or all of these techniques can help turn a "lecture format" into a much more fun, interactive, and valuable session that emphasizes "learning" rather than "teaching."

  3. Innovative Strategies for Empowering Your Students to Become Active, Responsible Learners

    NASA Astrophysics Data System (ADS)

    Hufnagel, B.

    2011-09-01

    The economy continues to sputter along, and the repercussions are now hitting hard at publicly-funded colleges and universities, with enrollment increasing and funding decreasing. Funding agencies are starting to look at retention and completion rates as a way to allocate scarce dollars. Improving these rates is also one way to increase the future stream of tuition; students who can't pass introductory classes like ASTRO101 won't enroll and pay tuition for the next level, and they won't complete their degree. So what can you, a mere professor of astronomy, do? Tired of the "What do you want me to know?" questions? Provide your students with learner-centered structures to help them learn more deeply. Do your students resist active-engagement techniques and hate group work? Share empowerment strategies for helping students become active, responsible learners who can thrive in a learner-centered environment. Do you think that it's wrong for the freshman classes to be over-crowded, yet your sophomore classes don't get enough students or don't even exist? After using the proven curriculum of On Course, college and universities across the country have improved their retention across a wide range of disciplines (http://www.OnCourseWorkshop.com/Data.htm). Experience a sample of the fun and engaging activities developed over two decades to help students (1) accept personal responsibility, (2) discover self motivation, (3) master self-management, (4) use interdependence, (5) gain self-awareness, (6) adopt lifelong learning, (7) develop emotional intelligence, and (8) believe in themselves. Since this is only a one-hour workshop, we will focus on choices one and four: to be successful, students need to see themselves as the primary cause of their outcomes and experiences and to build mutually supportive relationships in our classroom and labs. Outcomes: (1) one ASTRO101 Course-ready activity to help students accept personal responsibility; (2) one ASTRO101 Course

  4. Chinese High-School Students in Physics Classroom as Active, Self-Regulated Learners: Cognitive, Motivational and Environmental Aspects

    ERIC Educational Resources Information Center

    Neber, Heinz; He, Jing; Liu, Bang-Xiang; Schofield, Neville

    2008-01-01

    The present study investigates whether Chinese high-school students are self-regulated learners. A social-cognitive model that distinguishes environmental, motivational, and cognitive components of this active approach to learning is described. This provides an appropriate framework for investigating this complex issue with eighth and tenth…

  5. From Passive to Active Learners: The "Lived Experience" of Nurses in a Specialist Nephrology Nursing Education Programme

    ERIC Educational Resources Information Center

    Bridger, Jane

    2007-01-01

    Purpose: This study aims to explore the lived experience of learning for a group of staff nurses in the Middle East, who undertook a post-registration nursing education programme in the speciality of nephrology nursing (the NNP) between 2001 and 2002. The broad-based curriculum seeks to develop the staff nurses into active learners, able to…

  6. Identifying and Enhancing the Strengths of Gifted Learners, K-8: Easy-to-Use Activities and Lessons

    ERIC Educational Resources Information Center

    Maccagnano, Ann Marie

    2007-01-01

    Educators can identify children's strengths early on and gain insight into each student's unique abilities by using the numerous ideas and informal assessments in this exciting guide. Gifted and talented specialist Ann Maccagnano offers K-8 teachers challenging activities and engaging lessons to develop and nurture gifted learners' talents.…

  7. MAI (Multi-Dimensional Activity Based Integrated Approach): A Strategy for Cognitive Development of the Learners at the Elementary Stage

    ERIC Educational Resources Information Center

    Basantia, Tapan Kumar; Panda, B. N.; Sahoo, Dukhabandhu

    2012-01-01

    Cognitive development of the learners is the prime task of each and every stage of our school education and its importance especially in elementary state is quite worth mentioning. Present study investigated the effectiveness of a new and innovative strategy (i.e., MAI (multi-dimensional activity based integrated approach)) for the development of…

  8. Comparison of the Effects of Reflection and Contemplation Activities on Service-Learners' Cognitive and Affective Mindfulness

    ERIC Educational Resources Information Center

    Stewart, Trae; Alrutz, Megan

    2012-01-01

    This study investigates the extent to which service-learners' mindfulness is affected by engagement in reflection (e.g., dialogue) and contemplation activities (e.g., labyrinth tracing). The results are compared within and between treatment groups, while covarying for participants' initial levels of mindfulness. While both dialogue and…

  9. The Impact of Vocabulary Enhancement Activities on Vocabulary Acquisition and Retention among Male and Female EFL Learners in Iran

    ERIC Educational Resources Information Center

    Sharafi-Nejad, Maryam; Raftari, Shohreh; Bijami, Maryam; Khavari, Zahra; Ismail, Shaik Abdul Malik Mohamed; Eng, Lin Siew

    2014-01-01

    In general, incidental vocabulary acquisition is represented as the "picking up" of new vocabularies when students are engaged in a variety of reading, listening, speaking, or writing activities. Research has shown when learners read extensively incidental vocabulary acquisition happens. Many EFL students cannot be involved in reading…

  10. Using Web-Based Instruction to Promote Active Learning: Learners' Perspectives

    ERIC Educational Resources Information Center

    Lee, Lina

    2005-01-01

    This article reports classroom research on learners' perspectives on Web-based instruction that utilizes the "Blackboard" course management system. The Web-based instruction aims to provide and support collaborative learning while fostering learners' autonomy and accountability. The article also provides a description of the course…

  11. Elementary School EFL Learners' Vocabulary Learning: The Effects of Post-Reading Activities

    ERIC Educational Resources Information Center

    Atay, Derin; Kurt, Gokce

    2006-01-01

    As language learning involves the acquisition of thousands of words, teachers and learners alike would like to know how vocabulary learning can be fostered, especially in EFL settings where learners frequently acquire impoverished lexicons, despite years of formal study. Research indicates that reading is important but not sufficient for…

  12. Creative, Kinesthetic Activities to Motivate Young Learners to Communicate: A Conversation with Paula Garrett-Rucks

    ERIC Educational Resources Information Center

    Devall, Kelly Davidson

    2015-01-01

    This article presents a question and answer session in which Paula Garrett-Rucks discusses how creativity and kinesthetics motivate young language learners, the type of characteristics she might consider for different age groups in planning lessons, her views on the goals of world language teachers of young learners, and what a typical lesson…

  13. Active subthreshold dendritic conductances shape the local field potential

    PubMed Central

    Ness, Torbjørn V.; Remme, Michiel W. H.

    2016-01-01

    Key points The local field potential (LFP), the low‐frequency part of extracellular potentials recorded in neural tissue, is often used for probing neural circuit activity. Interpreting the LFP signal is difficult, however.While the cortical LFP is thought mainly to reflect synaptic inputs onto pyramidal neurons, little is known about the role of the various subthreshold active conductances in shaping the LFP.By means of biophysical modelling we obtain a comprehensive qualitative understanding of how the LFP generated by a single pyramidal neuron depends on the type and spatial distribution of active subthreshold currents.For pyramidal neurons, the h‐type channels probably play a key role and can cause a distinct resonance in the LFP power spectrum.Our results show that the LFP signal can give information about the active properties of neurons and imply that preferred frequencies in the LFP can result from those cellular properties instead of, for example, network dynamics. Abstract The main contribution to the local field potential (LFP) is thought to stem from synaptic input to neurons and the ensuing subthreshold dendritic processing. The role of active dendritic conductances in shaping the LFP has received little attention, even though such ion channels are known to affect the subthreshold neuron dynamics. Here we used a modelling approach to investigate the effects of subthreshold dendritic conductances on the LFP. Using a biophysically detailed, experimentally constrained model of a cortical pyramidal neuron, we identified conditions under which subthreshold active conductances are a major factor in shaping the LFP. We found that, in particular, the hyperpolarization‐activated inward current, I h, can have a sizable effect and cause a resonance in the LFP power spectral density. To get a general, qualitative understanding of how any subthreshold active dendritic conductance and its cellular distribution can affect the LFP, we next performed a systematic

  14. Possible conduction mechanisms in coconut-shell activated carbon

    NASA Astrophysics Data System (ADS)

    Daud, W. M.; Badri, M.; Mansor, H.

    1990-02-01

    This work reports on the result of electrical conductivity measurements carried out on coconut-shell activated carbon. The results suggest that the charge carriers moved by variable-range hopping below 200 K, by hopping among localized energy states between 200 K and 385 K, and by percolation through energy states close to the mobility edge above 385 K. In the latter two conduction processes, significant additional frequency-dependent contributions to the conductivity were observed and are tentatively attributed to polarization of unremovable lignin and/or ionic impurities. These explanations are based on the present trends of the electrical transport theory for amorphous semiconductors.

  15. Effect of Two-Tier Diagnostic Tests on Promoting Learners' Conceptual Understanding of Variables in Conducting Scientific Experiments

    ERIC Educational Resources Information Center

    Çil, Emine

    2015-01-01

    Taking a test generally improves the retention of the material tested. This is a phenomenon commonly referred to as testing effect. The present research investigated whether two-tier diagnostic tests promoted student teachers' conceptual understanding of variables in conducting scientific experiments, which is a scientific process skill. In this…

  16. Occupational Safety and Health Activities Conducted across Countries in Asia

    PubMed Central

    Park, Jung-Keun; Khai, Ton T.

    2015-01-01

    Three occupational safety and health (OSH) activities, one international and two national workshops, were documented as part of OSH activities conducted under the International Labor Organization/Korea Partnership Program in the year 2011–2012. This study aimed to provide information on what the three OSH activities were implemented and how they contributed to the improvement of OSH in Asian countries. The international workshop was useful for the participants to understand a variety of information on OSH as well as participatory action-oriented training (PAOT) approaches at the regional and global levels. The two national workshops were practical for participants to strengthen their knowledge and skills on the PAOT at the enterprise and national levels. The study shows that the three OSH activities contributed to the understanding of the participants on OSH and PAOT, and that the activities promoted the improvement of OSH across countries in Asia. PMID:26106515

  17. Occupational Safety and Health Activities Conducted across Countries in Asia.

    PubMed

    Park, Jung-Keun; Khai, Ton T

    2015-06-01

    Three occupational safety and health (OSH) activities, one international and two national workshops, were documented as part of OSH activities conducted under the International Labor Organization/Korea Partnership Program in the year 2011-2012. This study aimed to provide information on what the three OSH activities were implemented and how they contributed to the improvement of OSH in Asian countries. The international workshop was useful for the participants to understand a variety of information on OSH as well as participatory action-oriented training (PAOT) approaches at the regional and global levels. The two national workshops were practical for participants to strengthen their knowledge and skills on the PAOT at the enterprise and national levels. The study shows that the three OSH activities contributed to the understanding of the participants on OSH and PAOT, and that the activities promoted the improvement of OSH across countries in Asia.

  18. Investigative Research: How It Changes Learner Status.

    ERIC Educational Resources Information Center

    Kenny, Brian

    1993-01-01

    What matters about an educational activity is how learners respond to it. This article examines a program concerned with the learners' needs, through the expression of learners' own meanings, and advances the concept of investigative research as a suitable vehicle for more autonomous learning, through a change in learner status. (26 references)…

  19. ATPase activity of the cystic fibrosis transmembrane conductance regulator.

    PubMed

    Li, C; Ramjeesingh, M; Wang, W; Garami, E; Hewryk, M; Lee, D; Rommens, J M; Galley, K; Bear, C E

    1996-11-08

    The gene mutated in cystic fibrosis codes for the cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic AMP-activated chloride channel thought to be critical for salt and water transport by epithelial cells. Plausible models exist to describe a role for ATP hydrolysis in CFTR channel activity; however, biochemical evidence that CFTR possesses intrinsic ATPase activity is lacking. In this study, we report the first measurements of the rate of ATP hydrolysis by purified, reconstituted CFTR. The mutation CFTRG551D resides within a motif conserved in many nucleotidases and is known to cause severe human disease. Following reconstitution the mutant protein exhibited both defective ATP hydrolysis and channel gating, providing direct evidence that CFTR utilizes ATP to gate its channel activity.

  20. Oxidative Regulation of Large Conductance Calcium-Activated Potassium Channels

    PubMed Central

    Tang, Xiang D.; Daggett, Heather; Hanner, Markus; Garcia, Maria L.; McManus, Owen B.; Brot, Nathan; Weissbach, Herbert; Heinemann, Stefan H.; Hoshi, Toshinori

    2001-01-01

    Reactive oxygen/nitrogen species are readily generated in vivo, playing roles in many physiological and pathological conditions, such as Alzheimer's disease and Parkinson's disease, by oxidatively modifying various proteins. Previous studies indicate that large conductance Ca2+-activated K+ channels (BKCa or Slo) are subject to redox regulation. However, conflicting results exist whether oxidation increases or decreases the channel activity. We used chloramine-T, which preferentially oxidizes methionine, to examine the functional consequences of methionine oxidation in the cloned human Slo (hSlo) channel expressed in mammalian cells. In the virtual absence of Ca2+, the oxidant shifted the steady-state macroscopic conductance to a more negative direction and slowed deactivation. The results obtained suggest that oxidation enhances specific voltage-dependent opening transitions and slows the rate-limiting closing transition. Enhancement of the hSlo activity was partially reversed by the enzyme peptide methionine sulfoxide reductase, suggesting that the upregulation is mediated by methionine oxidation. In contrast, hydrogen peroxide and cysteine-specific reagents, DTNB, MTSEA, and PCMB, decreased the channel activity. Chloramine-T was much less effective when concurrently applied with the K+ channel blocker TEA, which is consistent with the possibility that the target methionine lies within the channel pore. Regulation of the Slo channel by methionine oxidation may represent an important link between cellular electrical excitability and metabolism. PMID:11222629

  1. Activities for Challenging Gifted Learners by Increasing Complexity in the Common Core

    ERIC Educational Resources Information Center

    McKeone, Alyssa; Caruso, Lenora; Bettle, Kailyn; Chase, Ashley; Bryson, Bridget; Schneider, Jean S.; Rule, Audrey C.

    2015-01-01

    Gifted learners need opportunities for critical and creative thinking to stretch their minds and imaginations. Strategies for increasing complexity in the four core areas of language arts, mathematics, science, and social studies were addressed using the Common Core and Iowa Core Standards through several methods. Descriptive adjective object…

  2. Mathematics Learning with Multiple Solution Methods: Effects of Types of Solutions and Learners' Activity

    ERIC Educational Resources Information Center

    Große, Cornelia S.

    2014-01-01

    It is commonly suggested to mathematics teachers to present learners different methods in order to solve one problem. This so-called "learning with multiple solution methods" is also recommended from a psychological point of view. However, existing research leaves many questions unanswered, particularly concerning the effects of…

  3. Mediated Vocabulary in Native Speaker-Learner Interactions during an Oral Portfolio Activity

    ERIC Educational Resources Information Center

    Tocaimaza-Hatch, C. Cecilia

    2016-01-01

    This project investigated vocabulary learning from a sociocultural perspective--in particular, the way in which lexical knowledge was mediated in Spanish second language (L2) learners' and native speakers' (NSs') interactions. Nine students who were enrolled in an advanced conversation course completed an oral portfolio assignment consisting of…

  4. Impact of Consciousness-Raising Activities on Young English Language Learners' Grammar Performance

    ERIC Educational Resources Information Center

    Fatemipour, Hamidreza; Hemmati, Shiva

    2015-01-01

    Grammar Consciousness-Raising (GCR) is an approach to teaching of grammar which learners instead of being taught the given rules, experience language data. The data challenge them to rethink, restructure their existing mental grammar and construct an explicit rule to describe the grammatical feature which the data illustrate (Ellis, 2002). And…

  5. The effects of data-driven learning activities on EFL learners' writing development.

    PubMed

    Luo, Qinqin

    2016-01-01

    Data-driven learning has been proved as an effective approach in helping learners solve various writing problems such as correcting lexical or grammatical errors, improving the use of collocations and generating ideas in writing, etc. This article reports on an empirical study in which data-driven learning was accomplished with the assistance of the user-friendly BNCweb, and presents the evaluation of the outcome by comparing the effectiveness of BNCweb and a search engine Baidu which is most commonly used as reference resource by Chinese learners of English as a foreign language. The quantitative results about 48 Chinese college students revealed that the experimental group which used BNCweb performed significantly better in the post-test in terms of writing fluency and accuracy, as compared with the control group which used the search engine Baidu. However, no significant difference was found between the two groups in terms of writing complexity. The qualitative results about the interview revealed that learners generally showed a positive attitude toward the use of BNCweb but there were still some problems of using corpora in the writing process, thus the combined use of corpora and other types of reference resource was suggested as a possible way to counter the potential barriers for Chinese learners of English.

  6. Fostering Active Processing of Instructional Explanations of Learners with High and Low Prior Knowledge

    ERIC Educational Resources Information Center

    Acuna, Santiago R.; Garcia Rodicio, Hector; Sanchez, Emilio

    2011-01-01

    Despite the potential advantages of instructional explanations, evidence indicates that they are usually ineffective. Subsequent work has shown that in order to make instructional explanations effective indeed, one successful strategy is to combine them with indications of the limitations in learners' understanding that they are intended to…

  7. Developing Learners' Second Language Communicative Competence through Active Learning: Clickers or Communicative Approach?

    ERIC Educational Resources Information Center

    Agbatogun, Alaba Olaoluwakotansibe

    2014-01-01

    The purpose of this study was to compare the impact of clickers, the communicative approach and the lecture method on the communicative competence development of learners who were taught English a second language (ESL). Ninety nine pupils from three primary schools participated in the study. Quasi-experimental non-randomised pre-test posttest…

  8. Active Lessons for Active Brains: Teaching Boys and Other Experiential Learners, Grades 3-10

    ERIC Educational Resources Information Center

    James, Abigail Norfleet; Allison, Sandra Boyd; McKenzie, Caitlin Zimmerman

    2011-01-01

    If you're tired of repeating yourself to students who aren't listening, try a little less talk and a lot more action. The authors follow the best-selling "Teaching the Male Brain and Teaching the Female Brain" with this ready-to-use collection of mathematics, language arts, science, and classroom management strategies. Designed for active,…

  9. Conducting polymer transistors making use of activated carbon gate electrodes.

    PubMed

    Tang, Hao; Kumar, Prajwal; Zhang, Shiming; Yi, Zhihui; Crescenzo, Gregory De; Santato, Clara; Soavi, Francesca; Cicoira, Fabio

    2015-01-14

    The characteristics of the gate electrode have significant effects on the behavior of organic electrochemical transistors (OECTs), which are intensively investigated for applications in the booming field of organic bioelectronics. In this work, high specific surface area activated carbon (AC) was used as gate electrode material in OECTs based on the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS). We found that the high specific capacitance of the AC gate electrodes leads to high drain-source current modulation in OECTs, while their intrinsic quasi-reference characteristics make unnecessary the presence of an additional reference electrode to monitor the OECT channel potential.

  10. Hierarchical nanostructured conducting polymer hydrogel with high electrochemical activity

    PubMed Central

    Pan, Lijia; Yu, Guihua; Zhai, Dongyuan; Lee, Hye Ryoung; Zhao, Wenting; Liu, Nian; Wang, Huiliang; Tee, Benjamin C.-K.; Shi, Yi; Cui, Yi; Bao, Zhenan

    2012-01-01

    Conducting polymer hydrogels represent a unique class of materials that synergizes the advantageous features of hydrogels and organic conductors and have been used in many applications such as bioelectronics and energy storage devices. They are often synthesized by polymerizing conductive polymer monomer within a nonconducting hydrogel matrix, resulting in deterioration of their electrical properties. Here, we report a scalable and versatile synthesis of multifunctional polyaniline (PAni) hydrogel with excellent electronic conductivity and electrochemical properties. With high surface area and three-dimensional porous nanostructures, the PAni hydrogels demonstrated potential as high-performance supercapacitor electrodes with high specific capacitance (∼480 F·g-1), unprecedented rate capability, and cycling stability (∼83% capacitance retention after 10,000 cycles). The PAni hydrogels can also function as the active component of glucose oxidase sensors with fast response time (∼0.3 s) and superior sensitivity (∼16.7 μA·mM-1). The scalable synthesis and excellent electrode performance of the PAni hydrogel make it an attractive candidate for bioelectronics and future-generation energy storage electrodes. PMID:22645374

  11. Autonomous Learner Model Resource Book

    ERIC Educational Resources Information Center

    Betts, George T.; Carey, Robin J.; Kapushion, Blanche M.

    2016-01-01

    "Autonomous Learner Model Resource Book" includes activities and strategies to support the development of autonomous learners. More than 40 activities are included, all geared to the emotional, social, cognitive, and physical development of students. Teachers may use these activities and strategies with the entire class, small groups, or…

  12. Conducting-polymer-driven actively shaped propellers and screws

    NASA Astrophysics Data System (ADS)

    Madden, John D.; Schmid, Bryan; Lafontaine, Serge R.; Madden, Peter G. A.; Hover, Franz S.; McLetchie, Karl; Hunter, Ian W.

    2003-07-01

    Conducting polymer actuators are employed to create actively shaped hydrodynamic foils. The active foils are designed to allow control over camber, much like the ailerons of an airplane wing. Control of camber promises to enable variable thrust in propellers and screws, increased maneuverability, and improved stealth. The design and fabrication of the active foils are presented, the forces are measured and operation is demonstrated both in still air and water. The foils have a "wing" span of 240 mm, and an average chord length (width) of 70 mm. The trailing 30 mm of the foil is composed of a thin polypyrrole actuator that curls chordwise to achieve variable camber. The actuator consists of two 30 μm thick sheets of hexafluorophosphate doped polypyrrole separated from each other by a gel electrolyte. A polymer layer encapsulates the entire structure. Potentials are applied between the polymer layers to induce reversible bending by approximately 35 degrees, and generating forces of 0.15 N. These forces and displacements are expected to enable operation in water at flow rates of > 1 m/s and ~ 30 m/s in air.

  13. Three-dimensional numerical simulations for activated hopping conduction

    NASA Astrophysics Data System (ADS)

    Zimmerman, Dan S.; Shegelski, Mark R. A.

    1988-07-01

    We model hopping conduction in a three-dimensional, lightly doped compensated semiconductor using a Miller-Abrahams-type resistor network. A flat density of states of width Δɛ is used. We work with the full expression for the resistances instead of the T-->0 asymptotic form usually employed. We report the first detailed numerical calculations of the overall resistance of a three-dimensional resistor network using this full expression. We find a temperature regime where the hopping conduction has a ratio of activation energy to bandwidth ɛ~3=ɛ3/Δɛ=0.217(8). This value agrees with the analytically determined value calculated by Shegelski and Barrie (SB), and disagrees with results reported by other workers, thereby validating SB's analytic theory and their claim that the full expression for the resistor network should be used in calculations of ɛ~3. An investigation is made into the dependence of ɛ~3 on Δɛ we find, in qualitative agreement with SB, that ɛ~3 decreases with Δɛ and we present improved values for ɛ~3 as a function of Δɛ.

  14. Electrically conductive and optically active porous silicon nanowires.

    PubMed

    Qu, Yongquan; Liao, Lei; Li, Yujing; Zhang, Hua; Huang, Yu; Duan, Xiangfeng

    2009-12-01

    We report the synthesis of vertical silicon nanowire array through a two-step metal-assisted chemical etching of highly doped n-type silicon (100) wafers in a solution of hydrofluoric acid and hydrogen peroxide. The morphology of the as-grown silicon nanowires is tunable from solid nonporous nanowires, nonporous/nanoporous core/shell nanowires, to entirely nanoporous nanowires by controlling the hydrogen peroxide concentration in the etching solution. The porous silicon nanowires retain the single crystalline structure and crystallographic orientation of the starting silicon wafer and are electrically conductive and optically active with visible photoluminescence. The combination of electronic and optical properties in the porous silicon nanowires may provide a platform for novel optoelectronic devices for energy harvesting, conversion, and biosensing.

  15. Transparent electrical conducting films by activated reactive evaporation

    DOEpatents

    Bunshah, R.; Nath, P.

    1982-06-22

    Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation is disclosed. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment. 1 fig.

  16. Transparent electrical conducting films by activated reactive evaporation

    DOEpatents

    Bunshah, Rointan; Nath, Prem

    1982-01-01

    Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment.

  17. Implications of Special Regions to Conducting Human Activities on Mars

    NASA Astrophysics Data System (ADS)

    Rummel, J. D.; Barlow, N. G.; Beaty, D. W.; Jones, M. A.; Hipkin, V.

    2014-12-01

    A MEPAG Science Analysis Group (SAG) has undertaken an analysis of Special Regions (SR) on Mars—regions where indigenous martian life could exist or where Earth microbes, if introduced, could survive and reproduce. The SR-SAG has considered the impact of SR on future human activities on the martian surface. Human exploration requires access to in-situ resources, some of which may be found in SR. Water and oxygen for ISRU are found in the atmosphere, surface/near-surface ice, hydrated minerals, and perchlorates. Water ice is most abundant at latitudes poleward of ~60 degrees, but polar darkness, cold temperatures, and CO2 degassing present hazards to human operations in these regions. Accessible water is more limited toward the equator, though temperature and solar energy conditions become more favorable. The possible presence of liquid water in Recurring Slope Lineae and active gullies leads to their treatment as SR. Fuel for surface operations and propellants for crew ascent could be manufactured from the martian atmosphere and surface materials, but dust in the atmosphere may clog ISRU equipment and perchlorate is toxic to humans. Power may be produced from solar or nuclear energy. Reliance on solar energy limits operations to the equatorial zone where easily accessible ice resources are limited. Nuclear power allows surface operations at a range of latitudes, but waste heat could convert some non-SR into SR. Radiation shielding is necessary for long-term human operations on Mars and could be obtained by deposition of regolith or by water storage in tanks or as ice around habitats, or the use of underground habitats. SR-SAG recognizes that it will be impossible for all human-associated processes and operations to be conducted within entirely closed systems. Protocols need to be established so (1) human missions to Mars will not contaminate SR nor be contaminated by materials from them, and (2) human activities on Mars will avoid converting areas into SR.

  18. Objects prompt authentic scientific activities among learners in a museum programme

    NASA Astrophysics Data System (ADS)

    Achiam, Marianne; Simony, Leonora; Kramer Lindow, Bent Erik

    2016-04-01

    Although the scientific disciplines conduct practical work in different ways, all consider practical work as the essential way of connecting objects and phenomena with ideas and the abstract. Accordingly, practical work is regarded as central to science education as well. We investigate a practical, object-based palaeontology programme at a natural history museum to identify how palaeontological objects prompt scientific activity among upper secondary school students. We first construct a theoretical framework based on an analysis of the programme's palaeontological content. From this, we build our reference model, which considers the specimens used in the programme, possible palaeontological interpretations of these specimens, and the conditions inherent in the programme. We use the reference model to analyse the activities of programme participants, and illustrate how these activities are palaeontologically authentic. Finally, we discuss our findings, examining the mechanism by which the specimens prompt scientific activities. We also discuss our discipline-based approach, and how it allows us to positively identify participants' activities as authentic. We conclude by discussing the implications of our findings.

  19. Small Conductance Ca2+-Activated K+ Channels and Cardiac Arrhythmias

    PubMed Central

    Zhang, Xiao-Dong; Lieu, Deborah K.; Chiamvimonvat, Nipavan

    2015-01-01

    Small conductance Ca2+-activated K+ (SK, KCa2) channels are unique in that they are gated solely by changes in intracellular Ca2+ and hence, function to integrate intracellular Ca2+ and membrane potentials on a beat-to-beat basis. Recent studies have provided evidence for the existence and functional significance of SK channels in the heart. Indeed, our knowledge of cardiac SK channels has been greatly expanded over the past decade. Interests in cardiac SK channels are further driven by recent studies suggesting the critical roles of SK channels in human atrial fibrillation, SK channel as a possible novel therapeutic target in atrial arrhythmias and up-regulation of SK channels in heart failure (HF) in animal models and human HF. However, there remain critical gaps in our knowledge. Specifically, blockade of SK channels in cardiac arrhythmias has been shown to be both anti-arrhythmic and proarrhythmic. This contemporary review will provide an overview of the literature on the role of cardiac SK channels in cardiac arrhythmias and to serve as a discussion platform for the current clinical perspectives. At the translational level, development of SK channel blockers as a new therapeutic target in the treatment of atrial fibrillation and the possible pro-arrhythmic effects merit further considerations and investigations. PMID:25956967

  20. Using What Learners Know.

    ERIC Educational Resources Information Center

    Burns, Mary; Adams, Sharon

    2000-01-01

    This issue of "TAP into Learning" focuses on technology-assisted learning activities for students, in particular on those that use spreadsheets. Articles include: "Using What Learners Know"; "Activity: Grade 7 and 8 Math, Social Studies and Language Arts"; "Managing Growth: Collaborative Decision-Making in Urban Planning"; "Spreadsheets"; "Getting…

  1. 40 CFR 725.238 - Activities conducted outside a structure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Exemptions... certain microorganisms listed in § 725.239 may be conducted without prior review by EPA if all of the... microorganism listed in § 725.239 must be conducted by, or directly under the supervision of, a...

  2. 40 CFR 725.238 - Activities conducted outside a structure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Exemptions... certain microorganisms listed in § 725.239 may be conducted without prior review by EPA if all of the... microorganism listed in § 725.239 must be conducted by, or directly under the supervision of, a...

  3. 40 CFR 725.238 - Activities conducted outside a structure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Exemptions... certain microorganisms listed in § 725.239 may be conducted without prior review by EPA if all of the... microorganism listed in § 725.239 must be conducted by, or directly under the supervision of, a...

  4. 40 CFR 725.238 - Activities conducted outside a structure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Exemptions... certain microorganisms listed in § 725.239 may be conducted without prior review by EPA if all of the... microorganism listed in § 725.239 must be conducted by, or directly under the supervision of, a...

  5. 40 CFR 725.238 - Activities conducted outside a structure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Exemptions... certain microorganisms listed in § 725.239 may be conducted without prior review by EPA if all of the... microorganism listed in § 725.239 must be conducted by, or directly under the supervision of, a...

  6. Adult Learners' Week in Australia.

    ERIC Educational Resources Information Center

    Cross, John

    2002-01-01

    Promotional materials and activities for Australia's Adult Learners Week, which are shaped by a variety of stakeholders , include media strategies and a website. Activities are evaluated using a market research company and website and telephone hotline statistics. (SK)

  7. Communicative Language Teaching: The Learner's View.

    ERIC Educational Resources Information Center

    Nunan, David

    Several studies of the differences in teacher and learner perceptions of the usefulness of certain teaching techniques and activities reveal clear mismatches between learners' and teachers' views of language learning. The differences seem to be due to the sociocultural background and previous learning experiences of the learners and the influence…

  8. Strategy-Based Instruction: A Learner-Focused Approach to Developing Learner Autonomy

    ERIC Educational Resources Information Center

    Nguyen, Le Thi Cam; Gu, Yongqi

    2013-01-01

    This study investigates the effects of strategy-based instruction (SBI) on the promotion of learner autonomy (LA). LA was conceptualized and operationally defined as learner self-initiation and learner self-regulation. An intervention study was conducted with the participation of 37 students in an experimental group, and 54 students in two control…

  9. The Development and Evaluation of an Achievement Test for Measuring the Efficacy of Task-Based Writing Activities to Enhance Iranian EFL Learners' Reading Comprehension

    ERIC Educational Resources Information Center

    Nejad, Ferdows Mohsen; Khosravian, Fereshteh

    2014-01-01

    The present study examined the reliability of an achievement test to measure the efficacy of task-based writing activities to improve Iranian EFL learners' reading comprehension at the intermediate level in a private language institute in Ilam, Iran, namely Alefba language institute. To achieve the goal, the techniques for evaluating reliability…

  10. Effects of an Online Learning Community on Active and Reflective Learners' Learning Performance and Attitudes in a Face-to-Face Undergraduate Course

    ERIC Educational Resources Information Center

    Zhan, Zehui; Xu, Fuyin; Ye, Huiwen

    2011-01-01

    The purpose of this study was to examine the effects of an Online Learning Community (OLC) on active and reflective learners' learning performance and attitude in a face-to-face undergraduate digital design course. 814 freshmen in an introductory digital design course were randomly assigned to one of two treatments: one offered students an OLC,…

  11. Exploring Work-Based Foundation Skills in the ABLE Classroom. Instructional Activities and Resources for the Adult Learner [and] Supplemental Handouts for Modules. Version 1.2.

    ERIC Educational Resources Information Center

    Carman, Priscilla; Van Horn, Barbara; Hamilton, KayLynn; Williams, Mary Kay

    This guide contains activities and resources to help adult learners develop the work-based foundation skills and knowledge areas included on the Foundation Skills Framework wheel (Institute for the Study of Adult Literacy 2000). Its four sections (basic employability skills, basic workplace knowledge, basic workplace skills, and lifelong learning…

  12. The Effects of Pragmatic Consciousness-Raising Activities on the Development of Pragmatic Awareness and Use of Hearsay Evidential Markers for Learners of Japanese as a Foreign Language

    ERIC Educational Resources Information Center

    Narita, Ritsuko

    2009-01-01

    The present study investigates the effectiveness of pragmatic consciousness-raising (PCR) activities in the L2 pragmatic acquisition of hearsay evidential markers by learners of Japanese as a foreign language (JFL). PCR is essentially an inductive approach to facilitating awareness of how language forms are used appropriately in a given context.…

  13. Activation of the human, intermediate-conductance, Ca2+-activated K+ channel by methylxanthines.

    PubMed

    Schrøder, R L; Jensen, B S; Strøbaek, D; Olesen, S P; Christophersen, P

    2000-10-01

    This study demonstrated that the methylxanthines, theophylline, IBMX and caffeine, activate the human, intermediate-conductance, Ca2+-activated K+ channel (hIK) stably expressed in HEK-293 cells. Whole-cell voltage-clamp experiments showed that the hIK current increased reversibly and voltage independently after the addition of methylxanthines. In current-clamp experiments, theophylline dose-dependently hyperpolarised the cell membrane from a resting potential of -18 mV to -56 mV. The methylxanthines did not affect large-conductance (BK) or small-conductance (SK2), Ca2+-activated K+ channels, demonstrating that the effects were not secondary to a rise in intracellular Ca2+. However, the activation of hIK by theophylline required an intracellular [Ca2+] above 30 nM. The hIK current was insensitive to 8-bromoadenosine cyclic 3',5'-monophosphate (8-bromo-cAMP), forskolin, 8-bromoguanosine cyclic 3',5'-monophosphate (8-bromo-cGMP) and sodium nitroprusside. Moreover, in the presence of inhibitors of protein kinase A (PKA) or protein kinase G (PKG) theophylline still activated the current. Finally, mutation of the putative PKA/PKG consensus phosphorylation site (Ser334) had no effect on the theophylline-induced activation of hIK. Since the observed activation is independent of changes in PKA/PKG-phosphorylation and of fluctuations in intracellular Ca2+, we suggest that the methylxanthines interact directly with the hIK protein.

  14. Temperature dependence of dc electrical conductivity of activated carbon-metal oxide nanocomposites. Some insight into conduction mechanisms

    NASA Astrophysics Data System (ADS)

    Barroso-Bogeat, Adrián; Alexandre-Franco, María; Fernández-González, Carmen; Sánchez-González, José; Gómez-Serrano, Vicente

    2015-12-01

    From a commercial activated carbon (AC) and six metal oxide (Al2O3, Fe2O3, SnO2, TiO2, WO3 and ZnO) precursors, two series of AC-metal oxide nanocomposites are prepared by wet impregnation, oven-drying at 120 °C, and subsequent heat treatment at 200 or 850 °C in inert atmosphere. The temperature-dependent dc electrical conductivity of AC and the as-prepared nanocomposites is measured from room temperature up to ca. 200 °C in air atmosphere by the four-probe method. The decrease in conductivity for the hybrid materials as compared to AC is the result of a complex interplay between several factors, including not only the intrinsic conductivity, crystallite size, content and chemical nature of the supported nanoparticles, which ultimately depend on the precursor and heat treatment temperature, but also the adsorption of oxygen and water from the surrounding atmosphere. The conductivity data are discussed in terms of a thermally activated process. In this regard, both AC and the prepared nanocomposites behave as semiconductors, and the temperature-dependent conductivity data have been interpreted on the basis of the classical model proposed by Mott and Davis. Because of its high content of heteroatoms, AC may be considered as a heavily doped semiconductor, so that conduction of thermally excited carriers via acceptor or donor levels is expected to be the dominant mechanism. The activation energies for the hybrid materials suggest that the supported metal oxide nanoparticles strongly modify the electronic band structure of AC by introducing new trap levels in different positions along its band gap. Furthermore, the thermally activated conduction process satisfies the Meyer-Neldel rule, which is likely connected with the shift of the Fermi level due to the introduction of the different metal oxide nanoparticles in the AC matrix.

  15. "Dealing With" Unexpected Learner Contributions in Whole Group Activities: An Examination of Novice Language Teacher Discursive Practices

    ERIC Educational Resources Information Center

    Fagan, Drew S.

    2012-01-01

    The current paper examines the discursive practices of one novice English as a Second Language (ESL) teacher "dealing with" learners' unexpected contributions in whole group classroom interactions during teacher- and learner-initiated sequences-of-talk. The study draws from two fields of research: classroom discourse studies…

  16. Reaching English Language Learners

    ERIC Educational Resources Information Center

    Keenan, Suzanne

    2004-01-01

    In the authors' science classroom, students who are English Language Learners (ELL) seem to struggle less than they do with other content areas. She believes the "handson" nature of science motivates and encourages students to interact with others. This interaction spurs conversation among the students involved in the activity. If a child is…

  17. Calcium-activated potassium conductance noise in snail neurons.

    PubMed

    Westerfield, M; Lux, H D

    1982-11-01

    Current fluctuations were measured in small, 3-6 micrometers-diameter patches of soma membrane in bursting neurons of the snail, Helix pomatia. The fluctuations dramatically increased in magnitude with depolarization of the membrane potential under voltage clamp conditions. Two components of conductance noise were identified in the power spectra calculated from the membrane currents. One component had a corner frequency which increased with depolarization. This component was blocked by intracellular injection of TEA and was relatively insensitive to extracellular calcium levels (as long as the total number of effective divalent cations remained constant). It was identified as fluctuations of the voltage-dependent component of delayed outward current. The second component of conductance noise had a corner frequency which decreased with depolarization. It was relatively unaffected by TEA injection and was reversibly blocked by substitution of extracellular calcium with magnesium, cobalt, or nickel. This second component of noise was identified as fluctuations of the calcium-dependent potassium current. The results suggest that the two components of delayed outward current are conducted through physically distinct channels.

  18. Exploring Shifts in Middle School Learners' Modeling Activity While Generating Drawings, Animations, and Computational Simulations of Molecular Diffusion

    NASA Astrophysics Data System (ADS)

    Wilkerson-Jerde, Michelle H.; Gravel, Brian E.; Macrander, Christopher A.

    2015-04-01

    Modeling and using technology are two practices of particular interest to K-12 science educators. These practices are inextricably linked among professionals, who engage in modeling activity with and across a variety of representational technologies. In this paper, we explore the practices of five sixth-grade girls as they generated models of smell diffusion using drawing, stop-motion animation, and computational simulation during a multi-day workshop. We analyze video, student discourse, and artifacts to address the questions: In what ways did learners' modeling practices, reasoning about mechanism, and ideas about smell shift as they worked across this variety of representational technologies? And, what supports enabled them to persist and progress in the modeling activity? We found that the girls engaged in two distinct modeling cycles that reflected persistence and deepening engagement in the task. In the first, messing about, they focused on describing and representing many ideas related to the spread of smell at once. In the second, digging in, they focused on testing and revising specific mechanisms that underlie smell diffusion. Upon deeper analysis, we found these cycles were linked to the girls' invention of "oogtom," a representational object that encapsulated many ideas from the first cycle and allowed the girls to restart modeling with the mechanistic focus required to construct simulations. We analyze the role of activity design, facilitation, and technological infrastructure in this pattern of engagement over the course of the workshop and discuss implications for future research, curriculum design, and classroom practice.

  19. Sodium conductance and the activation potential in Xenopus laevis eggs.

    PubMed

    Peres, A; Mancinelli, E

    1985-09-01

    Experiments have been performed to identify the membrane permeability changes causing activation potential in Xenopus eggs. The eggs were artificially activated either by pricking or by addition of the Ca2+ ionophore A23187 to the bath. Two different ionic currents appear to control the activation potential: (i) a chloride current which develops after a delay of 30 s to 5 min from the activating stimulus and which, in low external chloride, produces a depolarization and, (ii) a voltage-dependent outward current which begins to flow when the membrane potential is more positive than about +20 mV and tends to hyperpolarize the membrane. The chloride current lasts about 3-4 min; the voltage-dependent outward current is present before activation and disappears more slowly than the Cl- current. Changes in external sodium concentration affect the reversal potential of the outward current before and after the development of the inward Cl- current. We suggest that the chloride current has the role of producing a rapid depolarization necessary to block polyspermy, while the voltage-dependent sodium outward current might prevent the depolarization from reaching excessively high values and help the repolarization phase.

  20. Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on Vm-Fluctuations during Network Activity

    PubMed Central

    Kolind, Jens; Hounsgaard, Jørn; Berg, Rune W.

    2012-01-01

    Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (Vm) and spike timing. The conductance increase is commonly attributed to synaptic conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential. If the spikes arrive at random times the changes in synaptic conductance are therefore stochastic and rapid during intense network activity. In comparison, sub-threshold intrinsic conductances vary smoothly in time. In the present study this discrepancy is investigated using two conductance-based models: a (1) compartment model and a (2) compartment with realistic slow intrinsic conductances. We examine the effects of varying the relative contributions of non-fluctuating intrinsic conductance with fluctuating concurrent inhibitory and excitatory synaptic conductance. For given levels of correlation in the synaptic input we find that the magnitude of the membrane fluctuations uniquely determines the relative contribution of synaptic and intrinsic conductance. We also quantify how Vm-fluctuations vary with synaptic correlations for fixed ratios of synaptic and intrinsic conductance. Interestingly, the levels of Vm -fluctuations and conductance observed experimentally during functional network activity leave little room for intrinsic conductance to contribute. Even without intrinsic conductances the variance in Vm -fluctuations can only be explained by a high degree of correlated firing among presynaptic neurons. PMID:22783184

  1. Empowering Learners

    ERIC Educational Resources Information Center

    Franklin, Pat; Stephens, Claire Gatrell

    2010-01-01

    Turning students into lifelong learners is not easily accomplished. How do school librarians ensure that students have a zeal for learning? How do they encourage, cajole, or entice students to want to learn? The answer lies in empowering students with the skills they need to enjoy researching as well as reading for information and pleasure. This…

  2. Activity Based Learning as Self-Accessing Strategy to Promote Learners' Autonomy

    ERIC Educational Resources Information Center

    Ravi, R.; Xavier, P.

    2007-01-01

    The Activity Based Learning (ABL) is unique and effective to attract out-of -school children to schools. It facilitates readiness for learning, instruction, reinforcement and evaluation. ABL has transformed the classrooms into hubs of activities and meaningful learning. Activity-based learning, naturally leads to cooperative learning. Since group…

  3. Student Activities, Electronic Learners, and the Future: Integrating a Technological Component into Your Role as an Advisor.

    ERIC Educational Resources Information Center

    Simon, Jason Foster

    1996-01-01

    Provides advice to faculty advisers of student organizations on understanding the learning styles, needs, cultures, and strengths of today's "electronic learners." Advisers need to understand technology-related learning patterns and become technologically literate to work with college students. (MDM)

  4. Objects Prompt Authentic Scientific Activities among Learners in a Museum Programme

    ERIC Educational Resources Information Center

    Achiam, Marianne; Simony, Leonora; Lindow, Bent Erik Kramer

    2016-01-01

    Although the scientific disciplines conduct practical work in different ways, all consider practical work as the essential way of connecting objects and phenomena with ideas and the abstract. Accordingly, practical work is regarded as central to science "education" as well. We investigate a practical, object-based palaeontology programme…

  5. 30 CFR 285.614 - When may I begin conducting activities under my approved SAP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... approved SAP? 285.614 Section 285.614 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE... Plans and Information Requirements Activities Under An Approved Sap § 285.614 When may I begin conducting activities under my approved SAP? (a) You may begin conducting the activities approved in your...

  6. 30 CFR 585.614 - When may I begin conducting activities under my approved SAP?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... approved SAP? 585.614 Section 585.614 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 585.614 When may I begin conducting activities under my approved SAP? (a) You may begin conducting the activities...

  7. 30 CFR 585.614 - When may I begin conducting activities under my approved SAP?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... approved SAP? 585.614 Section 585.614 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 585.614 When may I begin conducting activities under my approved SAP? (a) You may begin conducting the activities...

  8. 30 CFR 585.614 - When may I begin conducting activities under my approved SAP?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... approved SAP? 585.614 Section 585.614 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 585.614 When may I begin conducting activities under my approved SAP? (a) You may begin conducting the activities...

  9. The Structural Challenge: A Simple Design-Based Science Activity to Foster Creativity among Kinaesthetic Learners

    ERIC Educational Resources Information Center

    Amir, Nazir; Subramaniam, R.

    2014-01-01

    A suitable way for teachers to present science content and foster creativity in less academically inclined students is by getting them to engage in design-based science activities and guiding them along the way. This study illustrates how a design-and-make activity was carried out with the aim of getting students to showcase their creativity while…

  10. Hippocampus activity differentiates good from poor learners of a novel lexicon.

    PubMed

    Breitenstein, Caterina; Jansen, Andreas; Deppe, Michael; Foerster, Ann-Freya; Sommer, Jens; Wolbers, Thomas; Knecht, Stefan

    2005-04-15

    Language proficiency is a key to academic and workplace success for native and non-native speakers. It is largely unknown, however, why some people pick up languages more easily than others. We used event-related functional magnetic resonance imaging (e-fMRI) to elucidate which brain regions are modulated during the acquisition of a novel lexicon and which of these learning-related activity changes correlated with general semantic language knowledge. Fourteen healthy young subjects learned a novel vocabulary of 45 concrete nouns via an associative learning principle over the course of five blocks during e-fMRI. As a control condition, subjects took part in a structurally identical "No-Learning" condition lacking any learning principle. Overall, increasing vocabulary proficiency was associated with (intercorrelated) modulations of activity within the left hippocampus and the left fusiform gyrus, regions involved in the binding and integration of multimodal stimuli, and with an increasing activation of the left inferior parietal cortex, the presumed neural store of phonological associations. None of these activity changes were observed during the control condition. Furthermore, subjects who showed less suppression of hippocampal activity over learning blocks scored higher on semantic knowledge in their native language and learned the novel vocabulary more efficiently. Our findings indicate that (a) the successful acquisition of a new lexicon depends on correlated amplitude changes between the left hippocampus and neocortical regions and (b) learning-related hippocampus activity is a stable marker of individual differences in the ability to acquire and master vocabularies.

  11. Visible-light active conducting polymer nanostructures with superior photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Ghosh, Srabanti; Kouame, Natalie Amoin; Remita, Samy; Ramos, Laurence; Goubard, Fabrice; Aubert, Pierre-Henri; Dazzi, Alexandre; Deniset-Besseau, Ariane; Remita, Hynd

    2015-12-01

    The development of visible-light responsive photocatalysts would permit more efficient use of solar energy, and thus would bring sustainable solutions to many environmental issues. Conductive polymers appear as a new class of very active photocatalysts under visible light. Among them poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most promising conjugated polymer with a wide range of applications. PEDOT nanostructures synthesized in soft templates via chemical oxidative polymerization demonstrate unprecedented photocatalytic activities for water treatment without the assistance of sacrificial reagents or noble metal co-catalysts and turn out to be better than TiO2 as benchmark catalyst. The PEDOT nanostructures exhibit a narrow band gap (E = 1.69 eV) and are characterized by excellent ability to absorb light in visible and near infrared region. The novel PEDOT-based photocatalysts are very stable with cycling and can be reused without appreciable loss of activity. Interestingly, hollow micrometric vesicular structures of PEDOT are not effective photocatalysts as compared to nanometric spindles suggesting size and shape dependent photocatalytic properties. The visible-light active photocatalytic properties of the polymer nanostructures present promising applications in solar light harvesting and broader fields.

  12. Visible-light active conducting polymer nanostructures with superior photocatalytic activity

    PubMed Central

    Ghosh, Srabanti; Kouame, Natalie Amoin; Remita, Samy; Ramos, Laurence; Goubard, Fabrice; Aubert, Pierre-Henri; Dazzi, Alexandre; Deniset-Besseau, Ariane; Remita, Hynd

    2015-01-01

    The development of visible-light responsive photocatalysts would permit more efficient use of solar energy, and thus would bring sustainable solutions to many environmental issues. Conductive polymers appear as a new class of very active photocatalysts under visible light. Among them poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most promising conjugated polymer with a wide range of applications. PEDOT nanostructures synthesized in soft templates via chemical oxidative polymerization demonstrate unprecedented photocatalytic activities for water treatment without the assistance of sacrificial reagents or noble metal co-catalysts and turn out to be better than TiO2 as benchmark catalyst. The PEDOT nanostructures exhibit a narrow band gap (E = 1.69 eV) and are characterized by excellent ability to absorb light in visible and near infrared region. The novel PEDOT-based photocatalysts are very stable with cycling and can be reused without appreciable loss of activity. Interestingly, hollow micrometric vesicular structures of PEDOT are not effective photocatalysts as compared to nanometric spindles suggesting size and shape dependent photocatalytic properties. The visible-light active photocatalytic properties of the polymer nanostructures present promising applications in solar light harvesting and broader fields. PMID:26657168

  13. Dealing with Disruptive Behavior of Adult Learners

    ERIC Educational Resources Information Center

    Dobmeier, Robert; Moran, Joseph

    2008-01-01

    The adult education literature on disruptive behavior of adult learners was reviewed and a survey on disruptive behavior of adult learners was conducted with adult educators. The findings are synthesized in a conceptual framework for understanding the types and causes of disruptive behavior, which fall into the categories of inattention,…

  14. Adult Learning and Learners. PREL Briefing Paper.

    ERIC Educational Resources Information Center

    Timarong, Alvina; Temaungil, Marianne; Sukrad, Wilma

    A survey of literature on adult learning and learners conducted for Palau Community College (PCC), Koror, Palau, found a lack of literature specific to the United States-affiliated Pacific region. Background information was compiled on development of formal education in Palau. A survey was administered in fall 2001 to adult learners working toward…

  15. Collaborative Syntactic Priming Activities and EFL Learners' Production of Wh-questions

    ERIC Educational Resources Information Center

    McDonough, Kim; Chaikitmongkol, Wanpen

    2010-01-01

    Syntactic priming is the tendency for a speaker to produce a structure that was encountered in recent discourse and is measured by calculating how frequently speakers use the modelled structures as opposed to alternatives. Recent lab-based studies have shown that carrying out syntactic priming activities with trained interlocutors positively…

  16. The Effect of Curricular Activities on Learner Autonomy: The Perspective of Undergraduate Mechanical Engineering Students

    ERIC Educational Resources Information Center

    Duarte, M.; Leite, C.; Mouraz, A.

    2016-01-01

    This study researches how first-year engineering students perceived the influence of curricular activities on their own learning autonomy, measured with an adaptation of the Personal Responsibility Orientation to Self-direction in Learning Scale (PRO-SDLS). Participants were questioned to assess the influence of the teacher's role. The results…

  17. Growing into Greatness: A Study of a Local History Group of Active-Retired Learners

    ERIC Educational Resources Information Center

    Corrigan, Trudy; Byrne, Brid; Harris, Phyllis; Lalor, Maureen; O'Connor, Maura; O'Reilly, Kathleen; Quinn, Frank; Forde, Kathleen

    2005-01-01

    Research in Canada on the learning needs of older people looked at such issues as how to cope with changes in society, the need to make a contribution and the need to be influential. The White Paper on Adult Education "Learning for Life" notes that strategies for active ageing stress the critical importance of access to learning as a key…

  18. Research on the Healthy Lifestyle Model, Active Ageing, and Loneliness of Senior Learners

    ERIC Educational Resources Information Center

    Hung, Jui-Ying; Lu, Kuo-Song

    2014-01-01

    Taiwan has the fastest ageing population in the world. Thus, the government and local policy makers need to formulate policies not just for the nursing and care needs of the aged. They also need to actively promote the need for lifelong learning among seniors in order to achieve elderly-friendly objectives, such as health promotion and delays in…

  19. The Effect of a Timed Reading Activity on EFL Learners: Speed, Comprehension, and Perceptions

    ERIC Educational Resources Information Center

    Chang, Anna C-S

    2010-01-01

    To develop reading fluency, a 13-week timed reading activity was integrated into a normal curriculum with the aim of improving students' reading rates. Participants were 84 college students divided into an experimental and a control group. The test instruments involved pretests and posttests on reading speed and comprehension. Students'…

  20. 30 CFR 285.614 - When may I begin conducting activities under my approved SAP?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... approved SAP? 285.614 Section 285.614 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 285.614 When may I begin conducting activities under my approved SAP? (a) You may begin conducting...

  1. Style Shifts among Japanese Learners before and after Study Abroad in Japan: Becoming Active Social Agents in Japanese

    ERIC Educational Resources Information Center

    Iwasaki, Noriko

    2010-01-01

    Previous studies on L2 Japanese sojourners often reported that learners overuse the plain style or haphazardly mix the plain and polite styles upon return. These styles, which are often associated with formal or informal contexts, also index complex social and situational meanings, and native speakers are reported to shift their styles to create…

  2. Teacher-Made Tactile Science Materials with Critical and Creative Thinking Activities for Learners Including Those with Visual Impairments

    ERIC Educational Resources Information Center

    Teske, Jolene K.; Gray, Phyllis; Kuhn, Mason A.; Clausen, Courtney K.; Smith, Latisha L.; Alsubia, Sukainah A.; Ghayoorad, Maryam; Rule, Audrey C.; Schneider, Jean Suchsland

    2014-01-01

    Gifted students with visual impairments are twice exceptional learners and may not evidence their advanced science aptitudes without appropriate accommodations for learning science. However, effective tactile science teaching materials may be easily made. Recent research has shown that when tactile materials are used with "all" students…

  3. Examining Student Cognitive and Affective Engagement and Reading Instructional Activities: Spanish-Speaking English Learners' Reading Profiles

    ERIC Educational Resources Information Center

    Barber, Ana Taboada; Gallagher, Melissa; Smith, Peet; Buehl, Michelle M.; Beck, Jori S.

    2016-01-01

    Recent research has emphasized the key role of engagement in helping students succeed in school and beyond. Given the academic struggles that many English learners (ELs) face as they transition to middle school, exploring the facets of engagement in middle school ELs is needed. We established reader profiles for eight sixth grade Hispanic ELs and…

  4. Guiding Learners to near Native Fluency in English through an Adaptive Programme of Activities Which Includes Phoneme and Prosody Analysis

    ERIC Educational Resources Information Center

    Lawson, Alistair; Attridge, Ann; Lapok, Paul

    2014-01-01

    Many students of English language find pronunciation difficult to master. This work in progress paper discusses an incremental and iterative approach towards developing requirements for software applications to assist learners with the perception and production of English pronunciation in terms of phonemes and prosody. It was found that prompts…

  5. Using Digital Storytelling as a Language Experience Approach Activity: Integrating English Language Learners into a Museum Field Trip

    ERIC Educational Resources Information Center

    Pappamihiel, N. Eleni; Knight, Jennifer Hatch

    2016-01-01

    Second language learners face countless obstacles in the classroom, including communication and comprehension limitations and difficulty building relationships with peers. Many teachers struggle to build an inclusive classroom environment and ensure all students, especially those with linguistic and other learning disadvantages, are learning. This…

  6. We Are What We Do: Examining Learner-Generated Content in the Anatomy Laboratory through the Lens of Activity Theory

    ERIC Educational Resources Information Center

    Doubleday, Alison F.; Wille, Sarah J.

    2014-01-01

    Video and photography are often used for delivering content within the anatomical sciences. However, instructors typically produce these resources to provide instructional or procedural information. Although the benefits of learner-generated content have been explored within educational research, virtually no studies have investigated the use of…

  7. Learner Personas in CALL

    ERIC Educational Resources Information Center

    Heift, Trude

    2007-01-01

    In examining the titles of this year's conference presentations, the author noticed quite a few papers that focus on learner-specific issues, for instance, papers that address learning styles, learner needs, personality and learning, learner modeling and, more generally, pedagogical issues that deal with individual learner differences in…

  8. Learning from Learners.

    ERIC Educational Resources Information Center

    Matos, Joao Filipe

    This paper is a reflection of the preparation of the Psychology of Mathematics Education Panel (PME26) that discuss the issue of "learning from learners." What it implies to be a learner is formulated in order to reflect upon the way teachers and/or researchers learn from learners. The idea of conceptualizing the notion of "learning from learners"…

  9. Early learner perceptions of the attributes of effective preceptors.

    PubMed

    Huggett, Kathryn N; Warrier, Rugmini; Maio, Anna

    2008-12-01

    Medical education in the US has adapted to the shift of patient care from hospital to ambulatory settings by developing educational opportunities in outpatient settings. Faculty development efforts must acknowledge learners' perspectives to be effective in improving teaching and learning. Clinics provide important and unique learning opportunities, but also present different challenges for preceptors (i.e., physician teachers) and learners. Multiple studies have identified characteristics of effective preceptors of ambulatory care medicine. However, most of these studies were conducted among residents or students with clinical experience. To investigate preclinical, second-year medical students' perceptions of preceptor quality, we conducted an exploratory qualitative study using analysis of student learning journals. The purposive sample included 120 medical students in a private, Midwestern medical school in the United States. Learning journals of 110 students for two semesters were reviewed. Five attributes of an effective preceptor emerged: (1) Demonstrates professional expertise (2) Actively engages students in learning (3) Creates a positive environment for teaching and learning (4) Demonstrates collegiality and professionalism (5) Discusses career-related topics and concerns. Our findings suggest preclinical learners often begin initial clinical experiences with sophisticated definitions of professional expertise, and hold specific expectations for professionalism. These are based on previous coursework and personal experience. These expectations influence their perceptions of effective preceptors and learning experiences. Early clinical experiences can also influence perceptions about career and specialty choice. Improving our understanding of preclinical learners' perceptions of preceptor quality will improve the efficacy of faculty development efforts and learning experiences.

  10. 30 CFR 585.800 - How must I conduct my activities to comply with safety and environmental requirements?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false How must I conduct my activities to comply with... for Activities Conducted Under SAPs, COPs and GAPs § 585.800 How must I conduct my activities to comply with safety and environmental requirements? (a) You must conduct all activities on your lease...

  11. 30 CFR 585.800 - How must I conduct my activities to comply with safety and environmental requirements?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false How must I conduct my activities to comply with... for Activities Conducted Under SAPs, COPs and GAPs § 585.800 How must I conduct my activities to comply with safety and environmental requirements? (a) You must conduct all activities on your lease...

  12. 30 CFR 585.800 - How must I conduct my activities to comply with safety and environmental requirements?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false How must I conduct my activities to comply with... for Activities Conducted Under SAPs, COPs and GAPs § 585.800 How must I conduct my activities to comply with safety and environmental requirements? (a) You must conduct all activities on your lease...

  13. A calcium-permeable cGMP-activated cation conductance in hippocampal neurons

    NASA Technical Reports Server (NTRS)

    Leinders-Zufall, T.; Rosenboom, H.; Barnstable, C. J.; Shepherd, G. M.; Zufall, F.

    1995-01-01

    Whole-cell patch clamp recordings detected a previously unidentified cGMP-activated membrane conductance in cultured rat hippocampal neurons. This conductance is nonselectively permeable for cations and is completely but reversibly blocked by external Cd2+. The Ca2+ permeability of the hippocampal cGMP-activated conductance was examined in detail, indicating that the underlying ion channels display a high relative permeability for Ca2+. The results indicate that hippocampal neurons contain a cGMP-activated membrane conductance that has some properties similar to the cyclic nucleotide-gated channels previously shown in sensory receptor cells and retinal neurons. In hippocampal neurons this conductance similarly could mediate membrane depolarization and Ca2+ fluxes in response to intracellular cGMP elevation.

  14. Sociological Understandings of Conduct for a Noncanonical Activity Theory: Exploring Intersections and Complementarities

    ERIC Educational Resources Information Center

    Sawchuk, Peter H.; Stetsenko, Anna

    2008-01-01

    Following a discussion of activity theory as an approach to human development originally rooted in transformational change, we review the historical context and diverse conceptualizations of social conduct from the field of sociology. The discussion of social conduct is broken into theories of social action, theories of enactment, and contemporary…

  15. 30 CFR 280.10 - What must I do before I may conduct prospecting activities?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OFFSHORE PROSPECTING FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR ON THE OUTER CONTINENTAL SHELF How To... stratigraphic tests, for hard minerals. If you conduct both G&G prospecting activities, you must have a separate... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What must I do before I may conduct...

  16. Exploring Lifelong Learners Engaged in an Astronomy-Related Massively Open Online Course

    NASA Astrophysics Data System (ADS)

    Buxner, Sanlyn; Impey, Chris David; Wenger, Matthew; Formanek, Martin; Romine, James M.

    2016-01-01

    Massively open online courses (MOOCs) are becoming increasingly popular ways to reach diverse lifelong learners all over the world. Although MOOCs resemble more formal classes (e.g. videos of content, quizzes, activities), they are often used by informal audiences from home. Recently, MOOCs have become more utilized by universities to conduct outreach as they explore how to use MOOCs to reach new potential learners. Despite the rapid adaption of MOOCs, little is known about individuals who choose to take a MOOC, how they interact with the course materials, and what motivates them to finish the course.We present results of a study of lifelong learners engaged in an astronomy "101" MOOC. Through analysis of registered learners' behaviors as well as self-reported responses to a survey about science, we were able to characterize a subset of the learners engaged in the MOOC during its first offering. Overall, 25363 learners from over 100 countries registered for the MOOC. Of those, 14900 accessed at least one part of the course. Learners were recruited to complete a survey of their knowledge and attitudes towards science. Of the learner group who opened the course, 2889 individuals completed the survey, 2465 of those were able to be linked to their usage of the MOOC through a unique identifier.Learners represented a wide-range of ages, professions, and previous science experience. The best predictors for MOOC completion were engagement in the first activity and first writing assignment and engagement in the online forum. Learners were very interested in science prior to their registration, had higher basic science knowledge that most undergraduate students enrolled in a parallel astronomy course, and used online searches and science sites to get their information about science. As we reach out to a worldwide audience to learners in these massively open online courses, understanding their motivations and behaviors will be essential. This work is helping us understand and

  17. Enhancing Writing Pedagogy with Learner Corpus Data

    ERIC Educational Resources Information Center

    Cotos, Elena

    2014-01-01

    Learner corpora have become prominent in language teaching and learning, enhancing data-driven learning (DDL) pedagogy by promoting "learning driven data" in the classroom. This study explores the potential of a local learner corpus by investigating the effects of two types of DDL activities, one relying on a native-speaker corpus (NSC)…

  18. Thermal conductivity tensors of the cladding and active layers of interband cascade lasers

    NASA Astrophysics Data System (ADS)

    Zhou, Chuanle; Cui, Boya; Vurgaftman, I.; Canedy, C. L.; Kim, C. S.; Kim, M.; Bewley, W. W.; Merritt, C. D.; Abell, J.; Meyer, J. R.; Grayson, M.

    2014-12-01

    The cross-plane and in-plane thermal conductivities of the W-active stages and InAs/AlSb superlattice optical cladding layer of an interband cascade laser (ICL) were characterized for temperatures ranging from 15 K to 324 K. The in-plane thermal conductivity of the active layer is somewhat larger than the cross-plane value at temperatures above about 30 K, while the thermal conductivity tensor becomes nearly isotropic at the lowest temperatures studied. These results will improve ICL performance simulations and guide the optimization of thermal management.

  19. The Tip of the Iceberg: Factors Affecting Learner Motivation

    ERIC Educational Resources Information Center

    Littlejohn, Andrew

    2008-01-01

    Teachers' informal discussions of learner motivation often emphasize the need to find ways to motivate learners, most usually through "fun" or "dynamic" activities. This paper starts from the assumption, however, that part of the work of the teacher is to avoid the "demotivation" of learners, and that there is a need to consider the overall…

  20. Seeing It Their Way: Learners and Language Curricula.

    ERIC Educational Resources Information Center

    Nunan, David

    The starting point for curriculum planning for second language instruction is the learner, and a curriculum can claim to be learner-centered only if key factors about the learner are made the basis for curriculum design at all stages in the planning and development of learning activities and materials and in the sequencing of learning experiences.…

  1. A volume-activated anion conductance in insulin-secreting cells.

    PubMed

    Best, L; Sheader, E A; Brown, P D

    1996-01-01

    The whole-cell patch-clamp recording technique was used to measure volume-activated currents in K+-free solutions in RINm5F and HIT-T15 insulinoma cells and in dispersed rat islet cells. Cell swelling, induced by intracellular hypertonicity or extracellular hypotonicity, caused activation of an outwardly rectifying conductance which could be subsequently inactivated by hypertonic extracellular solutions. The conductance required adenosine 5'-triphosphate (ATP) in the pipette solution but was Ca2+ independent. Na+ and Cl- substitution studies suggested that the swelling-activated current is Cl- selective with a halide permeability sequence of Br > Cl > I. The conductance was reversibly inhibited by the anion channel inhibitors 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) and by 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB). Further evidence for a volume-activated anion conductance was provided by studies of volume regulation in insulin-secreting cells. When RINm5F cells were exposed to a hypotonic medium, the initial cell swelling was followed by a regulatory volume decrease (RVD). This RVD response was also inhibited by DIDS and by NPPB. These data therefore provide evidence for a volume-activated anion conductance in insulin-secreting cells which could be involved in the RVD following osmotic stress. A possible role for the conductance in hypotonically induced insulin release is also discussed.

  2. 30 CFR 285.1010 - How long may I conduct activities under an Alternate Use RUE?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alternate Use RUE? 285.1010 Section 285.1010 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION... Activities Using Existing OCS Facilities Alternate Use Rue Administration § 285.1010 How long may I conduct activities under an Alternate Use RUE? (a) We will establish on a case-by-case basis, and set forth in...

  3. A large-conductance calcium-activated potassium channel in potato (Solanum tuberosum) tuber mitochondria.

    PubMed

    Koszela-Piotrowska, Izabela; Matkovic, Karolina; Szewczyk, Adam; Jarmuszkiewicz, Wieslawa

    2009-11-11

    In the present study, we describe the existence of a novel potassium channel in the plant [potato (Solanum tuberosum) tuber] mitochondrial inner membrane. We found that substances known to modulate large-conductance calcium-activated potassium channel activity influenced the bioenergetics of potato tuber mitochondria. In isolated mitochondria, Ca2+ and NS1619 {1,3-dihydro-1-[2-hydroxy-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-2H-ben-zimidazole-2-one; a potassium channel opener} were found to depolarize the mitochondrial membrane potential and to stimulate resting respiration. These effects were blocked by iberiotoxin (a potassium channel inhibitor) in a potassium-dependent manner. Additionally, the electrophysiological properties of the large-conductance potassium channel present in the potato tuber inner mitochondrial membrane are described in a reconstituted system, using planar lipid bilayers. After incorporation in 50/450 mM KCl gradient solutions, we recorded large-conductance potassium channel activity with conductance from 502+/-15 to 615+/-12 pS. The probability of channel opening was increased by Ca2+ and reduced by iberiotoxin. Immunological analysis with antibodies raised against the mammalian plasma-membrane large-conductance Ca2+-dependent K+ channel identified a pore-forming alpha subunit and an auxiliary beta2 subunit of the channel in potato tuber mitochondrial inner membrane. These results suggest that a large-conductance calcium-activated potassium channel similar to that of mammalian mitochondria is present in potato tuber mitochondria.

  4. Rectifying conductance substates in a large conductance Ca(2+)- activated K+ channel: evidence for a fluctuating barrier mechanism

    PubMed Central

    1996-01-01

    In this study, we investigated the mechanism underlying the production of inwardly rectifying subconductance states induced in large conductance Ca(2+)-activated K+ channels (maxi K(Ca) channels) by the small, homologous proteins, bovine pancreatic trypsin inhibitor (BPTI) and dendrotoxin-I (DTX). Low-resolution bilayer recordings of BPTI- induced substates display excess noise that is well described by a beta- distribution characteristic of a filtered, two-state process. High- resolution patch recordings of maxi K(Ca) channels from vascular smooth muscle cells confirm that the BPTI-induced substate is actually comprised of rapid, voltage-dependent transitions between the open state and a nearly closed state. Patch recordings of DTX-induced substates also exhibit excess noise consistent with a similar two-state fluctuation process that occurs at rates faster than those measured for the BPTI-induced substate. The results indicate that these examples of ligand-induced substates originate by a fluctuating barrier mechanism that is similar to one class of models proposed by Dani, J.A., and J.A. Fox (1991. J. Theor. Biol. 153: 401-423) to explain subconductance behavior of ion channels. To assess the general impact of such rapid fluctuations on the practical measurement of unitary currents by amplitude histograms, we simulated single-channel records for a linear, three-state scheme of C (closed)-O(open)-S(substate). This simulation defines a range of transition rates relative to filter frequency where rapid fluctuations can lead to serious underestimation of actual unitary current levels. On the basis of these experiments and simulations, we conclude that fluctuating barrier processes and open channel noise may play an important physiological role in the modulation of ion permeation. PMID:8741730

  5. Engineered Ionic Gates for Ion Conduction Based on Sodium and Potassium Activated Nanochannels.

    PubMed

    Liu, Qian; Xiao, Kai; Wen, Liping; Lu, Heng; Liu, Yahui; Kong, Xiang-Yu; Xie, Ganhua; Zhang, Zhen; Bo, Zhishan; Jiang, Lei

    2015-09-23

    In living systems, ion conduction plays a major role in numerous cellular processes and can be controlled by biological ion channels in response to specific environmental stimuli. This article describes biomimetic ionic gates for ion conduction based on sodium and potassium activated nanochannels. The Na(+) activated ionic gate and K(+) activated ionic gate were developed by immobilizing the alkali metal cation-responsive functional molecules, 4'-aminobenzo-15-crown-5 and 4'-aminobenzo-18-crown-6, respectively, onto the conical polyimide nanochannels. When the ionic gate was in the presence of the specific alkali metal cation, positively charged complexes formed between the crown ether and the alkali metal cation. On the basis of the resulting changes in surface charge, wettability and effective pore size, the nanochannel can achieve reversible switching. The switching behaviors of the two complexes differed due to the differences in binding strength between the two complexes. The Na(+) activated ionic gate is able to open and close to control the ion conduction through the nanochannel, and the K(+) activated ionic gate enables selective cation and anion conduction through the nanochannel. The Na(+) and K(+) activated ionic gates show great promise for use in clinical medicine, biosensors and drug delivery based on their high sensitivity and selectivity of being activated, and good stability.

  6. Progressive age-associated activation of JNK associates with conduction disruption in the aged atrium.

    PubMed

    Jones, Sandra A; Lancaster, Matthew K

    2015-03-01

    Connexin43 (Cx43) is critical for maintaining electrical conduction across atrial muscle. During progressive ageing atrial conduction slows associating with increasing susceptibility to arrhythmias. Changes in Cx43 protein expression, or its phosphorylation status, can instigate changes in the conduction of the cardiac action potential. This study investigated whether increased levels of activated c-jun N-terminal kinase (JNK) is responsible for the decline of Cx43 during ageing. Right atria from guinea pigs aged between 1 day and 38 months of age were examined. The area of the intercalated disc increased with age concurrent with a 75% decline in C43 protein expression. An age-dependent increase in activated-JNK correlated with a rise in phosphorylated Cx43, but also slowing of action potential conduction velocity across the atria from 0.38±0.01 m/s at 1 month of age to 0.30±0.01 m/s at 38 months. The JNK activator anisomycin increased activated JNK in myocytes and reduced Cx43 protein expression simulating ageing. The JNK inhibitor SP600125, was found to eradicate almost all trace of Cx43 protein. We conclude that in vivo activation of JNK increases with age leading to the loss of Cx43 protein resulting in impaired conduction and contributing to the increasing risk of atrial arrhythmias with advancing age.

  7. Expanded Perspectives on Autonomous Learners

    ERIC Educational Resources Information Center

    Oxford, Rebecca L.

    2015-01-01

    This paper explores two general perspectives on autonomous learners: psychological and sociocultural. These perspectives introduce a range of theoretically grounded facets of autonomous learners, facets such as the self-regulated learner, the emotionally intelligent learner, the self-determined learner, the mediated learner, the socioculturally…

  8. Techniques for automated local activation time annotation and conduction velocity estimation in cardiac mapping

    PubMed Central

    Cantwell, C.D.; Roney, C.H.; Ng, F.S.; Siggers, J.H.; Sherwin, S.J.; Peters, N.S.

    2015-01-01

    Measurements of cardiac conduction velocity provide valuable functional and structural insight into the initiation and perpetuation of cardiac arrhythmias, in both a clinical and laboratory context. The interpretation of activation wavefronts and their propagation can identify mechanistic properties of a broad range of electrophysiological pathologies. However, the sparsity, distribution and uncertainty of recorded data make accurate conduction velocity calculation difficult. A wide range of mathematical approaches have been proposed for addressing this challenge, often targeted towards specific data modalities, species or recording environments. Many of these algorithms require identification of activation times from electrogram recordings which themselves may have complex morphology or low signal-to-noise ratio. This paper surveys algorithms designed for identifying local activation times and computing conduction direction and speed. Their suitability for use in different recording contexts and applications is assessed. PMID:25978869

  9. Between the Social and the Selfish: Learner Autonomy in Online Environments

    ERIC Educational Resources Information Center

    Lewis, Tim

    2013-01-01

    This paper explores what it means to be an autonomous learner in an online social context. Using distinctions originally drawn by Jürgen Habermas, it argues that classic accounts of learner autonomy as teleological action are inadequate to explain learner activity in group settings. It points out that learners in such settings display attitudes…

  10. Listening to Learners.

    ERIC Educational Resources Information Center

    Ravenhall, Mark

    This booklet looks at the role of learner feedback in the quality improvement process. It suggests how adult and community learning (ACL) providers can adapt and improve their practice to meet the needs of learners in the changed policy context. Chapter 1 explores why providers should listen to learners and finds that listening to learners…

  11. Learners' Interpretations of Recasts

    ERIC Educational Resources Information Center

    Carpenter, Helen; Jeon, K. Seon; MacGregor, David; Mackey, Alison

    2006-01-01

    A number of interaction researchers have claimed that recasts might be ambiguous to learners; that is, instead of perceiving recasts as containing corrective feedback, learners might see them simply as literal or semantic repetitions without any corrective element (Long, in press; Lyster & Ranta, 1997). This study investigates learners'…

  12. Learner and Faculty Support

    ERIC Educational Resources Information Center

    Guan, Sharon; Stanford, Daniel

    2016-01-01

    This chapter identifies effective ways to address learner and faculty support. It introduces methods for building a successful learner support system by providing sufficient resources and proactively addressing learner motivation. It also addresses effective faculty support through institutional policies, resources, training, and course…

  13. 30 CFR 285.800 - How must I conduct my activities to comply with safety and environmental requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Activities Conducted Under SAPs, COPs and GAPs § 285.800 How must I conduct my activities to comply with... compliance with those terms and conditions identified in your approved SAP, COP, or GAP, as required...

  14. 12 CFR 211.29 - Applications by state branches and state agencies to conduct activities not permissible for...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Comptroller imposes a quantitative limitation on the conduct of such activity by the federal branch; (3) Is... conducted, and an estimate of the expected dollar volume associated with the activity; (2) An analysis...

  15. Intracellular Na+ and K+ activities and membrane conductances in the collecting tubule of Amphiuma

    PubMed Central

    1988-01-01

    Membrane potentials and conductances, and intracellular ionic activities were studied in isolated perfused collecting tubules of K+- adapted Amphiuma. Intracellular Na+ (aNai) and K+ (aKi) activities were measured, using liquid ion-exchanger double-barreled microelectrodes. Apical and basolateral membrane conductances were estimated by cable analysis. The effects of inhibition of the apical conductance by amiloride (10(-5) M) and of inhibition of the basolateral Na-K pump by either a low K+ (0.1 mM) bath or by ouabain (10(-4) M) were studied. Under control conditions, aNai was 8.4 +/- 1.9 mM and aKi 56 +/- 3 mM. With luminal amiloride, aNai decreased to 2.2 +/- 0.4 mM and aKi increased to 66 +/- 3 mM. Ouabain produced an increase of aNai to 44 +/- 4 mM, and a decrease of aKi to 22 +/- 6, and similar changes were observed when the tubule was exposed to a low K+ bath solution. During pump inhibition, there was a progressive decrease of the K+-selective basolateral membrane conductance and of the Na+ permeability of the apical membrane. A similar inhibition of both membrane conductances was observed after pump inhibition by low K+ solution. Upon reintroduction of K+, a basolateral membrane hyperpolarization of -23 +/- 4 mV was observed, indicating an immediate reactivation of the electrogenic Na-K pump. However, the recovery of the membrane conductances occurred over a slower time course. These data imply that both membrane conductances are regulated according to the intracellular ionic composition, but that the basolateral K+ conductance is not directly linked to the pump activity. PMID:3235975

  16. 30 CFR 585.1010 - How long may I conduct activities under an Alternate Use RUE?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alternate Use RUE? 585.1010 Section 585.1010 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT... Facilities Alternate Use Rue Administration § 585.1010 How long may I conduct activities under an Alternate Use RUE? (a) We will establish on a case-by-case basis, and set forth in the Alternate Use RUE,...

  17. 30 CFR 285.1010 - How long may I conduct activities under an Alternate Use RUE?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alternate Use RUE? 285.1010 Section 285.1010 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF... Alternate Use Rue Administration § 285.1010 How long may I conduct activities under an Alternate Use RUE? (a) We will establish on a case-by-case basis, and set forth in the Alternate Use RUE, the length of...

  18. 30 CFR 585.1010 - How long may I conduct activities under an Alternate Use RUE?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alternate Use RUE? 585.1010 Section 585.1010 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT... Facilities Alternate Use Rue Administration § 585.1010 How long may I conduct activities under an Alternate Use RUE? (a) We will establish on a case-by-case basis, and set forth in the Alternate Use RUE,...

  19. 42 CFR 455.506 - Activities to be conducted by Medicaid RACs and States.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... States. 455.506 Section 455.506 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS PROGRAM INTEGRITY: MEDICAID Medicaid Recovery Audit Contractors Program § 455.506 Activities to be conducted by Medicaid RACs and States....

  20. 42 CFR 455.506 - Activities to be conducted by Medicaid RACs and States.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... States. 455.506 Section 455.506 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS PROGRAM INTEGRITY: MEDICAID Medicaid Recovery Audit Contractors Program § 455.506 Activities to be conducted by Medicaid RACs and States....

  1. 42 CFR 455.506 - Activities to be conducted by Medicaid RACs and States.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... States. 455.506 Section 455.506 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS PROGRAM INTEGRITY: MEDICAID Medicaid Recovery Audit Contractors Program § 455.506 Activities to be conducted by Medicaid RACs and States....

  2. 42 CFR 455.506 - Activities to be conducted by Medicaid RACs and States.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... States. 455.506 Section 455.506 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS PROGRAM INTEGRITY: MEDICAID Medicaid Recovery Audit Contractors Program § 455.506 Activities to be conducted by Medicaid RACs and States....

  3. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  4. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  5. Dielectric behavior, conduction and EPR active centres in BiVO4 nanoparticles

    NASA Astrophysics Data System (ADS)

    Venkatesan, Rajalingam; Velumani, Subramaniam; Tabellout, Mohamed; Errien, Nicolas; Kassiba, Abdelhadi

    2013-12-01

    Bismuth vanadate (BiVO4) nanomaterials were synthesized by mechano-chemical ball milling method and complementary investigations were devoted to their structures, nanoparticle morphologies and electronic active centres. The dielectric and conductivity behaviour were analysed systematically in wide temperature and frequency ranges to correlate such physical responses with the peculiarities of the samples. Large interfacial polarisations favoured by high specific surfaces of nanoparticles account for a drastic enhancement of the dielectric function in the quasi-static regime. Exhaustive analyses of the dielectric experiments were achieved and account for the main features of dielectric functions and their related relaxation mechanisms. The electrical conductivity is thermally activated with energies in the range 0.1-0.6 eV depending on the sample features. DC conductivity up to 10-3 S/cm was obtained in well crystallized nanoparticles. Vanadium ions reduction was revealed by EPR spectroscopy with higher concentrations of the active centres (V4+) in more agglomerated and amorphous nanopowders. The EPR spectral parameters of V4+ were determined and correlated with the local environments of reduced vanadium ions and the characteristics of their electronic configurations. An insight is also made on the role of active electronic centres (V4+) on the conduction mechanism in nanostructured BiVO4.

  6. 78 FR 78788 - Nondiscrimination in Programs or Activities Conducted by the United States Department of Agriculture

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... activities conducted by the Department. The changes are proposed to clarify the roles and responsibilities of... in 1999 (64 FR 66709, Nov 30, 1999). The changes are proposed to clarify the roles and... compliance purposes, collect, maintain, and annually compile data on the race, ethnicity, and gender of...

  7. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  8. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  9. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  10. Habitual Physical Activity of Classroom Teachers: Does It Relate to Their Conduct of Physical Education Classes?

    ERIC Educational Resources Information Center

    LaMaster, Kathryn; McKenzie, Thom; Marshall, Simon; Sallis, James

    This study used systematic, direct observation of classes over 2 years to investigate whether physical education (PE) teachers' habitual physical activity related to their conduct of PE classes. Participants were 18 fourth and fifth grade classroom teachers employed in a California school district where classroom teachers typically were…

  11. A Context-Aware Ubiquitous Learning Approach to Conducting Scientific Inquiry Activities in a Science Park

    ERIC Educational Resources Information Center

    Hwang, Gwo-Jen; Tsai, Chin-Chung; Chu, Hui-Chun; Kinshuk; Chen, Chieh-Yuan

    2012-01-01

    Fostering students' scientific inquiry competence has been recognised as being an important and challenging objective of science education. To strengthen the understanding of science theories or notations, researchers have suggested conducting some learning activities in the field via operating relevant devices. In a traditional infield scientific…

  12. 12 CFR 7.5008 - Location of a national bank conducting electronic activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Location of a national bank conducting electronic activities. 7.5008 Section 7.5008 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE... because the bank's products or services are accessed through electronic means by customers located in...

  13. 42 CFR 51.31 - Conduct of protection and advocacy activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... to mental health system improvement. Decisions concerning the selection of individuals to receive... 42 Public Health 1 2010-10-01 2010-10-01 false Conduct of protection and advocacy activities. 51.31 Section 51.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  14. Participation in Organized Activities and Conduct Problems in Elementary School: The Mediating Effect of Social Skills

    ERIC Educational Resources Information Center

    Denault, Anne-Sophie; Déry, Michèle

    2015-01-01

    The goal of this study was to test a mediation model in which social skills mediate the relationship between participation in organized activities and conduct problems among elementary school children. Two moderators of these associations were also examined, namely, gender and reception of special education services. A total of 563 children (45%…

  15. Independent activation of ion conduction pores in the double-barreled calcium-activated chloride channel TMEM16A.

    PubMed

    Lim, Novandy K; Lam, Andy K M; Dutzler, Raimund

    2016-11-01

    The TMEM16 proteins constitute a family of membrane proteins with unusual functional breadth, including lipid scramblases and Cl(-) channels. Members of both these branches are activated by Ca(2+), acting from the intracellular side, and probably share a common architecture, which was defined in the recent structure of the lipid scramblase nhTMEM16. The structural features of subunits and the arrangement of Ca(2+)-binding sites in nhTMEM16 suggest that the dimeric protein harbors two locations for catalysis that are independent with respect to both activation and lipid conduction. Here, we ask whether a similar independence is observed in the Ca(2+)-activated Cl(-) channel TMEM16A. For this purpose, we generated concatenated constructs containing subunits with distinct activation and permeation properties. Our biochemical investigations demonstrate the integrity of concatemers after solubilization and purification. During investigation by patch-clamp electrophysiology, the functional behavior of constructs containing either two wild-type (WT) subunits or one WT subunit paired with a second subunit with compromised activation closely resembles TMEM16A. This resemblance extends to ion selectivity, conductance, and the concentration and voltage dependence of channel activation by Ca(2+) Constructs combining subunits with different potencies for Ca(2+) show a biphasic activation curve that can be described as a linear combination of the properties of its constituents. The functional independence is further supported by mutation of a putative pore-lining residue that changes the conduction properties of the mutated subunit. Our results strongly suggest that TMEM16A contains two ion conduction pores that are independently activated by Ca(2+) binding to sites that are embedded within the transmembrane part of each subunit.

  16. Flowable conducting particle networks in redox-active electrolytes for grid energy storage

    DOE PAGES

    Hatzell, K. B.; Boota, M.; Kumbur, E. C.; ...

    2015-01-09

    This paper reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO2+/VO2+ redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage. Charge storage contributionsmore » (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO2+/VO2+ redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s-1) than one based on a non-redox active electrolyte. Additionally, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.« less

  17. Flowable conducting particle networks in redox-active electrolytes for grid energy storage

    SciTech Connect

    Hatzell, K. B.; Boota, M.; Kumbur, E. C.; Gogotsi, Yury G.

    2015-01-09

    This paper reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO2+/VO2+ redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage. Charge storage contributions (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO2+/VO2+ redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s-1) than one based on a non-redox active electrolyte. Additionally, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.

  18. Second language listening difficulties perceived by low-level learners.

    PubMed

    Chang, Anna C-S; Wu, Bill Wen-Pin; Pang, Jerry C-L

    2013-04-01

    The purpose was the develop a questionnaire to identify the specific listening difficulties of second language (L2) learners. Based on previous research, a questionnaire containing 31 items was developed and administered to 1,056 college freshmen. The whole sample was split randomly into two subsamples, each containing 528 cases. Exploratory factor analysis was performed to analyse the first subsample, and six factors were extracted, explaining a total of 57.1% of variance. To test the factor model, confirmatory factor analysis was conducted with the second subsample. Various fit indices were examined. The best fitting model for the data was a 23-item, six-factor model representing text, input channel and surroundings, relevance, listener, speaker, and task. Apart from the listener factor, all components are external ones and deemed to be uncontrollable by listeners. L2 learners must take an active role in listening practice to overcome L2 listening difficulties.

  19. Modeling activity-dependent changes of axonal spike conduction in primary afferent C-nociceptors

    PubMed Central

    Tigerholm, Jenny; Petersson, Marcus E.; Obreja, Otilia; Lampert, Angelika; Carr, Richard; Schmelz, Martin

    2013-01-01

    Action potential initiation and conduction along peripheral axons is a dynamic process that displays pronounced activity dependence. In patients with neuropathic pain, differences in the modulation of axonal conduction velocity by activity suggest that this property may provide insight into some of the pathomechanisms. To date, direct recordings of axonal membrane potential have been hampered by the small diameter of the fibers. We have therefore adopted an alternative approach to examine the basis of activity-dependent changes in axonal conduction by constructing a comprehensive mathematical model of human cutaneous C-fibers. Our model reproduced axonal spike propagation at a velocity of 0.69 m/s commensurate with recordings from human C-nociceptors. Activity-dependent slowing (ADS) of axonal propagation velocity was adequately simulated by the model. Interestingly, the property most readily associated with ADS was an increase in the concentration of intra-axonal sodium. This affected the driving potential of sodium currents, thereby producing latency changes comparable to those observed for experimental ADS. The model also adequately reproduced post-action potential excitability changes (i.e., recovery cycles) observed in vivo. We performed a series of control experiments replicating blockade of particular ion channels as well as changing temperature and extracellular ion concentrations. In the absence of direct experimental approaches, the model allows specific hypotheses to be formulated regarding the mechanisms underlying activity-dependent changes in C-fiber conduction. Because ADS might functionally act as a negative feedback to limit trains of nociceptor activity, we envisage that identifying its mechanisms may also direct efforts aimed at alleviating neuronal hyperexcitability in pain patients. PMID:24371290

  20. [The active middle ear implant for the rehabilitation of sensorineural, mixed and conductive hearing losses].

    PubMed

    Sprinzl, G M; Wolf-Magele, A; Schnabl, J; Koci, V

    2011-09-01

    Active middle ear implants, such as the Vibrant Soundbridge, are used as an important part in the rehabilitation of sensorineural, conductive hearing, or mixed hearing loss. The attachment of the Vibrant Soundbridge at the round window and the usage of the Vibroplasty couplers strongly expanded the application of the Vibrant Soundbridge.The Vibrant Soundbridge is developed for patients who have an intolerance to hearing aids and a moderate to profound sensorineural hearing loss. The VSB also provides an optimal solution for patients with failed middle ear reconstructions or patients with atresia. To capture the improvement with the VSB Implant with different hearing losses a literature analysis was conducted. The functional gain was analyzed for 107 patients with conductive hearing loss and for 214 patients with sensorineural hearing loss out of 14 studies.Patients with conductive and mixed hearing loss resulted in a functional gain from 30 to 58 dB with the VSB. Patients with a pure sensorineural hearing loss showed a functional gain of 23-30 dB. The VSB bone conduction threshold shift was analyzed for all studies conducted in the years between 2000 and 2009. In 11 of the 16 studies there was no significant (p=0.05) change found. In 5 studies, the pre- to post-surgical bone conduction threshold shift was less than 10 dB. None of these studies measured a threshold shift of more than 10 dB.The flexible attachment at either the long process of the incus with sensorineural hearing loss, with an conductive hearing loss at the round window or the use of Vibroplasty couplers at the oval window, head of the stapes or round window makes the VSB an extremely versatile instrument. If patients can't wear conventional hearing aids, had failed middle ear reconstructions or atresia the VSB presents, due to the significant hearing improvement in any type of hearing loss, an ideal solution.

  1. Short-term disruption in regional left ventricular electrical conduction patterns increases interstitial matrix metalloproteinase activity

    PubMed Central

    Zavadzkas, Juozas A.; Rivers, William T.; McLean, Julie E.; Chang, Eileen I.; Bouges, Shenikqua; Matthews, Robert G.; Koval, Christine N.; Stroud, Robert E.; Spinale, Francis G.

    2010-01-01

    Increased matrix metalloproteinase (MMP) abundance occurs with adverse left ventricular (LV) remodeling in a number of cardiac disease states, including those induced by long-standing arrhythmias. However, whether regionally contained aberrant electrical activation of the LV, with consequent dyskinesia, alters interstitial MMP activation remained unknown. Electrical activation of the LV of pigs (n = 10, 30–35 kg) was achieved by pacing (150 beats/min) at left atrial and LV sites such that normal atrioventricular activation (60 min) was followed by regional early LV activation for 60 min within 1.5 cm of the paced site and restoration of normal atrioventricular pacing for 120 min. Regional shortening (piezoelectric crystals) and interstitial MMP activity (microdialysis with MMP fluorogenic substrate) at the LV pacing site and a remote LV site were monitored at 30-min intervals. During aberrant electrical stimulation, interstitial MMP activity at the paced site was increased (122 ± 4%) compared with the remote region (100%, P < 0.05). Restoration of atrioventricular pacing after the 60-min period of aberrant electrical activation normalized segmental shortening (8.5 ± 0.4%), but MMP activity remained elevated (121 ± 6%, P < 0.05). This study demonstrates that despite the restoration of mechanical function, disturbances in electrical conduction, in and of itself, can cause acute increases in regional in vivo MMP activation and, therefore, contribute to myocardial remodeling. PMID:20472759

  2. Short-term disruption in regional left ventricular electrical conduction patterns increases interstitial matrix metalloproteinase activity.

    PubMed

    Mukherjee, Rupak; Zavadzkas, Juozas A; Rivers, William T; McLean, Julie E; Chang, Eileen I; Bouges, Shenikqua; Matthews, Robert G; Koval, Christine N; Stroud, Robert E; Spinale, Francis G

    2010-07-01

    Increased matrix metalloproteinase (MMP) abundance occurs with adverse left ventricular (LV) remodeling in a number of cardiac disease states, including those induced by long-standing arrhythmias. However, whether regionally contained aberrant electrical activation of the LV, with consequent dyskinesia, alters interstitial MMP activation remained unknown. Electrical activation of the LV of pigs (n = 10, 30-35 kg) was achieved by pacing (150 beats/min) at left atrial and LV sites such that normal atrioventricular activation (60 min) was followed by regional early LV activation for 60 min within 1.5 cm of the paced site and restoration of normal atrioventricular pacing for 120 min. Regional shortening (piezoelectric crystals) and interstitial MMP activity (microdialysis with MMP fluorogenic substrate) at the LV pacing site and a remote LV site were monitored at 30-min intervals. During aberrant electrical stimulation, interstitial MMP activity at the paced site was increased (122 +/- 4%) compared with the remote region (100%, P < 0.05). Restoration of atrioventricular pacing after the 60-min period of aberrant electrical activation normalized segmental shortening (8.5 +/- 0.4%), but MMP activity remained elevated (121 +/- 6%, P < 0.05). This study demonstrates that despite the restoration of mechanical function, disturbances in electrical conduction, in and of itself, can cause acute increases in regional in vivo MMP activation and, therefore, contribute to myocardial remodeling.

  3. How Phosphorylation and ATPase Activity Regulate Anion Flux though the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR).

    PubMed

    Zwick, Matthias; Esposito, Cinzia; Hellstern, Manuel; Seelig, Anna

    2016-07-08

    The cystic fibrosis transmembrane conductance regulator (CFTR, ABCC7), mutations of which cause cystic fibrosis, belongs to the ATP-binding cassette (ABC) transporter family and works as a channel for small anions, such as chloride and bicarbonate. Anion channel activity is known to depend on phosphorylation by cAMP-dependent protein kinase A (PKA) and CFTR-ATPase activity. Whereas anion channel activity has been extensively investigated, phosphorylation and CFTR-ATPase activity are still poorly understood. Here, we show that the two processes can be measured in a label-free and non-invasive manner in real time in live cells, stably transfected with CFTR. This study reveals three key findings. (i) The major contribution (≥90%) to the total CFTR-related ATP hydrolysis rate is due to phosphorylation by PKA and the minor contribution (≤10%) to CFTR-ATPase activity. (ii) The mutant CFTR-E1371S that is still conductive, but defective in ATP hydrolysis, is not phosphorylated, suggesting that phosphorylation requires a functional nucleotide binding domain and occurs in the post-hydrolysis transition state. (iii) CFTR-ATPase activity is inversely related to CFTR anion flux. The present data are consistent with a model in which CFTR is in a closed conformation with two ATPs bound. The open conformation is induced by ATP hydrolysis and corresponds to the post-hydrolysis transition state that is stabilized by phosphorylation and binding of chloride channel potentiators.

  4. Learner Development in Language Learning.

    ERIC Educational Resources Information Center

    Wenden, Anita L.

    2002-01-01

    Focuses on learner development, a learner-centered innovation in foreign language-second language instruction that responds to learner diversity by aiming to improve the language learner's ability to learn a language. Describes various ideas that shaped early practice in learner development, and provides an evaluation of the theory and practice in…

  5. Modeling Learner Variability in CALL

    ERIC Educational Resources Information Center

    Heift, Trude

    2008-01-01

    This article describes challenges and benefits of modeling learner variability in Computer-Assisted Language Learning. We discuss the learner model of "E-Tutor," a learner model that addresses learner variability by focusing on certain aspects and/or features of the learner's interlanguage. Moreover, we introduce the concept of phrase descriptors,…

  6. Activation of kinetically distinct synaptic conductances on inhibitory interneurons by electrotonically overlapping afferents.

    PubMed

    Walker, Harrison C; Lawrence, J Josh; McBain, Chris J

    2002-07-03

    Mossy fiber (MF) and CA3 collateral (CL) axons activate common interneurons via synapses comprised of different AMPA receptors to provide feedforward and feedback inhibitory control of the CA3 hippocampal network. Because synapses potentially occur over variable electrotonic distances that distort somatically recorded synaptic currents, it is not known whether the underlying afferent-specific synaptic conductances are associated with different time courses. Using a somatic voltage jump technique to alter the driving force at the site of the synapse, we demonstrate that MF and CL synapses overlap in electrotonic location yet differ in conductance time course. Thus, afferent-specific conductance time courses allow single interneurons to differentially integrate feedforward and feedback information without the need to segregate distinct AMPA receptor subunits to different electrotonic domains.

  7. The Writing of Chinese Characters by CFL Learners: Can Writing on Facebook and Using Machine Translation Help?

    ERIC Educational Resources Information Center

    Zhang, Qi; Lu, Zhouxiang

    2014-01-01

    The current study investigates the applications of the pinyin input system, a Chinese word processing method, for writing on Facebook in order to help CFL (Chinese as a foreign language) learners from two Irish universities to improve their handwriting in Chinese characters on paper. The data were collected from writing activities conducted over…

  8. Characterization of a chloride conductance activated by hyperpolarization in Aplysia neurones.

    PubMed

    Chesnoy-Marchais, D

    1983-09-01

    A voltage-clamp study was made of some properties of the non-synaptic hyperpolarization-activated Cl- conductance recently described in Aplysia neurones loaded with Cl- ions (Chesnoy-Marchais, 1982). The experiments were performed on an identified family of neurones, which present cholinergic responses allowing an easy measurement of the equilibrium potentials of Cl- (ECl) and K+ ions (EK). The Cl- selectivity of the hyperpolarization-activated conductance was deduced from four observations: (1) the extrapolated reversal potential of the hyperpolarization-activated current, Er, was close to the reversal potential of the cholinergic Cl- response, which is the equilibrium potential for Cl- ions, ECl. (2) Modifications of the intracellular or extracellular Cl- concentration induced changes of the reversal potential Er. (3) A prolonged and intense activation of the current lowered the intracellular Cl- concentration. (4) The current persisted after complete substitution of intracellular and extracellular cations by CS+ ions, as well as after replacement of extracellular Na+ ions by Tris. The steady-state Cl- conductance (gss) increases steeply with hyperpolarization. The kinetics of activation and deactivation are exponential and are characterized by the same voltage-dependent time constant (tau), of the order of a few seconds or fractions of seconds. The curves gss(V) and tau (V) can both be fitted by a two-state model in which the rate constants are exponential functions of the membrane potential (e-fold change for 12-16 mV). The Cl- current is much more affected by changes of the intracellular Cl- concentration than predicted simply from the change in Cl- driving force. Both the conductance and the time constant of activation are strongly modified. Modifications of the extracellular Cl- concentration do not always alter the amplitude of the hyperpolarization-activated Cl- current, but systematically affect its kinetics. The hyperpolarization-activated current is

  9. Making Glasses Conduct: Electrochemical Doping of Redox-Active Polymer Thin Films

    NASA Astrophysics Data System (ADS)

    Boudouris, Bryan

    Optoelectronically-active macromolecules have been established as promising materials in myriad organic electronic applications (e.g., organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices). To date, however, the majority of the work surrounding these materials has focused on materials with a great deal of conjugation along their macromolecular backbones and with varying degrees of crystalline structure. Here, we describe an emerging class of macromolecular charge conductors, radical polymers, that: (1) do not contain conjugation and (2) are completely amorphous glasses. Radical polymers contain non-conjugated macromolecular backbones and stable radical sites along the side chains of the electronically-active materials. In contrast to conjugated polymer systems, these materials conduct charge in the solid state through oxidation-reduction (redox) reactions along these pendant groups. Specifically, we demonstrate that controlling the chemical functionality of the pendant groups and the molecular mobility of the macromolecular backbones significantly impacts the charge transport ability of the pristine (i.e., not doped) radical polymers species. Through proper control of these crucial parameters, we show that radical polymers can have electrical conductivity and charge mobility values on par with commonly-used conjugated polymers. Importantly, we also highlight the ability to dope radical polymers with redox-active small molecule species. This doping, in turn, increases the electrical conductivity of the glassy radical polymer thin films in a manner akin to what is observed in traditional conjugated polymer systems. In this way, we establish a means by which to fabricate optically-transparent and colorless thin film glasses capable of conducting charge in a rather rapid manner. We anticipate that these fundamental insights will prove crucial in developing new transparent conducting layers for future electronic applications.

  10. Improving Learners' Research Process Skills

    NASA Astrophysics Data System (ADS)

    Quan, T. K.; Hunter, L.; Kluger-Bell, B.; Seagroves, S.

    2010-12-01

    The Professional Development Program (PDP) supports participants as they design inquiry activities that help learners improve their research process skills. These skills include the cognitive or reasoning skills that scientists and engineers use while doing research; for example, making a testable hypothesis, coordinating results from multiple experiments, or identifying and evaluating tradeoffs. Past work in the PDP indicated that additional support was needed to help participants design instructional activities that would teach these important skills. A new workshop was therefore developed for the 2009 PDP cycle, entitled "Improving Learners' Process Skills." In this workshop, participants worked in small groups to define specific science and engineering skills found in four past PDP activity designs. Participants distinguished between "simple tasks" and "authentic inquiry" activities that learners could perform as demonstration of the skill. Through this new workshop, participants were able to explicitly discuss ways in which individual process skills are unique or inter-related. In addition, by identifying a "simple task," participants were able to pinpoint areas in which their own designs could be improved to better focus on authentic inquiry tasks. In 2010, the workshop was slightly modified to help participants reconnect the research process skills with the activity content. In addition, the idea of using generic and context-specific scaffolds was also introduced. To make the participants feel like they were contributing to the PDP community, four activity designs actively being worked on in the 2010 cycle were used. Based on participant feedback, this "Improving Learners' Process Skills" workshop should be strongly considered for future returning participants.

  11. Neuroactive conducting scaffolds: nerve growth factor conjugation on active ester-functionalized polypyrrole

    PubMed Central

    Lee, Jae Young; Lee, Joo-Woon; Schmidt, Christine E.

    2009-01-01

    Electrically conductive and biologically active scaffolds are desirable for enhancing adhesion, proliferation and differentiation of a number of cell types such as neurons. Hence, the incorporation of neuroactive molecules into electroconductive polymers via a specific and stable method is essential for neuronal tissue engineering applications. Traditional conjugation approaches dramatically impair conductivities and/or stabilities of the scaffolds and ligands. In this study, we developed copolymers (PPy-NSE) of N-hydroxyl succinimidyl ester pyrrole and regular pyrrole, which can be immobilized with nerve growth factor (NGF) without significantly hindering electroconductivity. The presence of active ester groups was confirmed using reflectance infrared spectroscopy and X-ray photoelectron spectroscopy (XPS) from the copolymers prepared from different monomer compositions. We selected PPy-NSE50 (polymerized from a 50 : 50 monomer ratio of pyrrole : pyrrole-NSE) for further modification with NGF because this copolymer retains good conductivity (approx. 8 S cm−1) and presents active ester groups for NGF immobilization. We tethered NGF on the PPy-NSE50 surface, and found that PC12 cells extended neurites similarly to cells cultured in NGF-containing medium. XPS and enzyme-linked immunosorbent assay confirmed that NGF immobilized via the active ester on the PPy-NSE50 film was stable for up to 5 days in phosphate-buffered saline solution. Also, application of an external electrical potential to NGF-immobilized PPy films did not cause a significant release of NGF nor reduce their neurotrophic activity. This novel scaffold, providing electroconductive and neurotrophic activities, has potential for neural applications, such as tissue engineering scaffolds and biosensors. PMID:19068472

  12. Electrical conductivity of activated carbon-metal oxide nanocomposites under compression: a comparison study.

    PubMed

    Barroso-Bogeat, A; Alexandre-Franco, M; Fernández-González, C; Macías-García, A; Gómez-Serrano, V

    2014-12-07

    From a granular commercial activated carbon (AC) and six metal oxide (Al2O3, Fe2O3, SnO2, TiO2, WO3 and ZnO) precursors, two series of AC-metal oxide nanocomposites were prepared by wet impregnation, oven-drying at 120 °C, and subsequent heat treatment at 200 or 850 °C in an inert atmosphere. Here, the electrical conductivity of the resulting products was studied under moderate compression. The influence of the applied pressure, sample volume, mechanical work, and density of the hybrid materials was thoroughly investigated. The DC electrical conductivity of the compressed samples was measured at room temperature by the four-probe method. Compaction assays suggest that the mechanical properties of the nanocomposites are largely determined by the carbon matrix. Both the decrease in volume and the increase in density were relatively small and only significant at pressures lower than 100 kPa for AC and most nanocomposites. In contrast, the bulk electrical conductivity of the hybrid materials was strongly influenced by the intrinsic conductivity, mean crystallite size, content and chemical nature of the supported phases, which ultimately depend on the metal oxide precursor and heat treatment temperature. The supported nanoparticles may be considered to act as electrical switches either hindering or favouring the effective electron transport between the AC cores of neighbouring composite particles in contact under compression. Conductivity values as a rule were lower for the nanocomposites than for the raw AC, all of them falling in the range of semiconductor materials. With the increase in heat treatment temperature, the trend is toward the improvement of conductivity due to the increase in the crystallite size and, in some cases, to the formation of metals in the elemental state and even metal carbides. The patterns of variation of the electrical conductivity with pressure and mechanical work were slightly similar, thus suggesting the predominance of the pressure

  13. Synthesis, characterization and antimicrobial activity of biodegradable conducting polypyrrole-graft-chitosan copolymer

    NASA Astrophysics Data System (ADS)

    Cabuk, Mehmet; Alan, Yusuf; Yavuz, Mustafa; Unal, Halil Ibrahim

    2014-11-01

    In this study, polypyrrole-graft-chitosan (PPy-g-CS) copolymer was chemically synthesized and its structural and morphological properties characterized by FTIR, UV-vis, SEM, XRD, TGA and zeta-potential techniques. The results revealed that there were strong interactions between PPy and CS chains. The electrical conductivity of CS increased to semiconducting range by grafting. The crystallinity and thermal stability of PPy-g-CS copolymer improved when compared to CS. The copolymer was tested against various bacterial and fungal strains at various concentrations and results obtained were compared with the reference antibiotics. The results indicated that the antibacterial activity of PPy-g-CS copolymer was stronger than CS and PPy alone. The antibacterial activity of the PPy-g-CS copolymer observed to increase with rising concentration, and showed stronger activity against bacteria than Penicillin (10 mg), Rifampicin (5 mg) and Trimethoprim (25 mg), whereas showed equipotent activity with Amikacin (30 mg) and Erythromycin (15 mg) antibiotics.

  14. Function and regulation of large conductance Ca(2+)-activated K+ channel in vascular smooth muscle cells.

    PubMed

    Hu, Xiang-Qun; Zhang, Lubo

    2012-09-01

    Large conductance Ca(2+)-activated K(+) (BK(Ca)) channels are abundantly expressed in vascular smooth muscle cells. Activation of BK(Ca) channels leads to hyperpolarization of cell membrane, which in turn counteracts vasoconstriction. Therefore, BK(Ca) channels have an important role in regulation of vascular tone and blood pressure. The activity of BK(Ca) channels is subject to modulation by various factors. Furthermore, the function of BK(Ca) channels are altered in both physiological and pathophysiological conditions, such as pregnancy, hypertension and diabetes, which has dramatic impacts on vascular tone and hemodynamics. Consequently, compounds and genetic manipulation that alter activity and expression of the channel might be of therapeutic interest.

  15. Active control of near-field coupling in conductively coupled microelectromechanical system metamaterial devices

    NASA Astrophysics Data System (ADS)

    Pitchappa, Prakash; Manjappa, Manukumara; Ho, Chong Pei; Qian, You; Singh, Ranjan; Singh, Navab; Lee, Chengkuo

    2016-03-01

    We experimentally report a structurally reconfigurable metamaterial for active switching of near-field coupling in conductively coupled, orthogonally twisted split ring resonators (SRRs) operating in the terahertz spectral region. Out-of-plane reconfigurable microcantilevers integrated into the dark SRR geometry are used to provide active frequency tuning of dark SRR resonance. The geometrical parameters of individual SRRs are designed to have identical inductive-capacitive resonant frequency. This allows for the excitation of classical analogue of electromagnetically induced transparency (EIT) due to the strong conductive coupling between the SRRs. When the microcantilevers are curved up, the resonant frequency of dark SRR blue-shifts and the EIT peak is completely modulated while the SRRs are still conductively connected. EIT modulation contrast of ˜50% is experimentally achieved with actively switchable group delay of ˜2.5 ps. Electrical control, miniaturized size, and readily integrable fabrication process of the proposed structurally reconfigurable metamaterial make it an ideal candidate for the realization of various terahertz communication devices such as electrically controllable terahertz delay lines, buffers, and tunable data-rate channels.

  16. Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance

    PubMed Central

    Carbó Tano, Martín; Vilarchao, María Eugenia

    2015-01-01

    Low-threshold voltage-activated calcium conductances (LT-VACCs) play a substantial role in shaping the electrophysiological attributes of neurites. We have investigated how these conductances affect synaptic integration in a premotor nonspiking (NS) neuron of the leech nervous system. These cells exhibit an extensive neuritic tree, do not fire Na+-dependent spikes, but express an LT-VACC that was sensitive to 250 μM Ni2+ and 100 μM NNC 55-0396 (NNC). NS neurons responded to excitation of mechanosensory pressure neurons with depolarizing responses for which amplitude was a linear function of the presynaptic firing frequency. NNC decreased these synaptic responses and abolished the concomitant widespread Ca2+ signals. Coherent with the interpretation that the LT-VACC amplified signals at the postsynaptic level, this conductance also amplified the responses of NS neurons to direct injection of sinusoidal current. Synaptic amplification thus is achieved via a positive feedback in which depolarizing signals activate an LT-VACC that, in turn, boosts these signals. The wide distribution of LT-VACC could support the active propagation of depolarizing signals, turning the complex NS neuritic tree into a relatively compact electrical compartment. PMID:25972583

  17. Learner Agency

    ERIC Educational Resources Information Center

    Mick, Carola

    2011-01-01

    This article presents first results of an ethnographic research project in a Luxembourgish primary school that accompanied the development of a school project by children from the fifth grade. Analysing the data children themselves collected with Kodak Zi8 cameras in order to document their project activities, it investigates their possibilities…

  18. Cell membrane stretch activates intermediate-conductance Ca2+-activated K+ channels in arterial smooth muscle cells.

    PubMed

    Hayabuchi, Yasunobu; Nakaya, Yutaka; Mawatari, Kazuaki; Inoue, Miki; Sakata, Miho; Kagami, Shoji

    2011-01-01

    The aim of this study is to determine the signal transduction of membrane stretch on intermediate-conductance Ca(2+)-activated K(+) (IKca) channels in rat aorta smooth muscle cells using the patch-clamp technique. To stretch the cell membrane, both suction to the rear end of patch pipette and hypotonic shock were used. In cell-attached and inside-out patch configurations, the open probability of IKca channels increased when 20- to 45-mmHg suction was applied. Hyposmotic swelling efficiently increased IKca channel current. When the Ca(2+)-free solution was superfused, the activation of IKca current by the hyposmotic swelling was reduced. Furthermore, gadolinium (Gd(3+)) attenuated the activation of IKca channels induced by hyposmotic swelling, whereas nicardipine did not. In the experiments with Ca(2+)-free bath solution, pretreatment with GF109203X, a protein kinase C (PKC) inhibitor, completely abolished the stretch-induced activation of IKca currents. The stretch-induced activation of IKca channels was strongly inhibited by cytochalasin D, indicating a role for the F-actin in modulation of IKca channels by changes in cell stretching. These data suggest that cell membrane stretch activates IKca channels. In addition, the activation is associated with extracellular Ca(2+) influx through stretch-activated nonselective cation channels, and is also modulated by the F-actin cytoskeleton and the activation of PKC.

  19. CNTF-Treated Astrocyte Conditioned Medium Enhances Large-Conductance Calcium-Activated Potassium Channel Activity in Rat Cortical Neurons.

    PubMed

    Sun, Meiqun; Liu, Hongli; Xu, Huanbai; Wang, Hongtao; Wang, Xiaojing

    2016-08-01

    Seizure activity is linked to astrocyte activation as well as dysfunctional cortical neuron excitability produced from changes in calcium-activated potassium (KCa) channel function. Ciliary neurotrophic factor-treated astrocyte conditioned medium (CNTF-ACM) can be used to investigate the peripheral effects of activated astrocytes upon cortical neurons. However, CNTF-ACM's effect upon KCa channel activity in cultured cortical neurons has not yet been investigated. Whole-cell patch clamp recordings were performed in rat cortical neurons to evaluate CNTF-ACM's effects upon charybdotoxin-sensitive large-conductance KCa (BK) channel currents and apamin-sensitive small-conductance KCa (SK) channel current. Biotinylation and RT-PCR were applied to assess CNTF-ACM's effects upon the protein and mRNA expression, respectively, of the SK channel subunits SK2 and SK3 and the BK channel subunits BKα1 and BKβ3. An anti-fibroblast growth factor-2 (FGF-2) monoclonal neutralizing antibody was used to assess the effects of the FGF-2 component of CNTF-ACM. CNTF-ACM significantly increased KCa channel current density, which was predominantly attributable to gains in BK channel activity (p < 0.05). CNTF-ACM produced a significant increase in BKα1 and BKβ3 expression (p < 0.05) but had no significant effect upon SK2 or SK3 expression (p > 0.05). Blocking FGF-2 produced significant reductions in KCa channel current density (p > 0.05) as well as BKα1 and BKβ3 expression in CNTF-ACM-treated neurons (p > 0.05). CNTF-ACM significantly enhances BK channel activity in rat cortical neurons and that FGF-2 is partially responsible for these effects. CNTF-induced astrocyte activation results in secretion of neuroactive factors which may affect neuronal excitability and resultant seizure activity in mammalian cortical neurons.

  20. Intrinsic conductances actively shape excitatory and inhibitory postsynaptic responses in olfactory bulb external tufted cells.

    PubMed

    Liu, Shaolin; Shipley, Michael T

    2008-10-08

    The initial synapse in the olfactory system is from olfactory nerve (ON) terminals to postsynaptic targets in olfactory bulb glomeruli. Recent studies have disclosed multiple presynaptic factors that regulate this important linkage, but less is known about the contribution of postsynaptic intrinsic conductances to integration at these synapses. The present study demonstrates voltage-dependent amplification of EPSPs in external tufted (ET) cells in response to monosynaptic (ON) inputs. This amplification is mainly exerted by persistent Na(+) conductance. Larger EPSPs, which bring the membrane potential to a relatively depolarized level, are further boosted by the low-voltage-activated Ca(2+) conductance. In contrast, the hyperpolarization-activated nonselective cation conductance (I(h)) attenuates EPSPs mainly by reducing EPSP duration; this also reduces temporal summation of multiple EPSPs. Regulation of EPSPs by these subthreshold, voltage-dependent conductances can enhance both the signal-to-noise ratio and the temporal summation of multiple synaptic inputs and thus help ET cells differentiate high- and low-frequency synaptic inputs. I(h) can also transform inhibitory inputs to postsynaptic excitation. When the ET cell membrane potential is relatively depolarized, as during a burst of action potentials, IPSPs produce classic inhibition. However, near resting membrane potentials where I(h) is engaged, IPSPs produce rebound bursts of action potentials. ET cells excite GABAergic PG cells. Thus, the transformation of inhibitory inputs to postsynaptic excitation in ET cells may enhance intraglomerular inhibition of mitral/tufted cells, the main output neurons in the olfactory bulb, and hence shape signaling to olfactory cortex.

  1. Novel conductive polypyrrole/zinc oxide/chitosan bionanocomposite: synthesis, characterization, antioxidant, and antibacterial activities

    PubMed Central

    Ebrahimiasl, Saeideh; Zakaria, Azmi; Kassim, Anuar; Basri, Sri Norleha

    2015-01-01

    An antibacterial and conductive bionanocomposite (BNC) film consisting of polypyrrole (Ppy), zinc oxide (ZnO) nanoparticles (NPs), and chitosan (CS) was electrochemically synthesized on indium tin oxide (ITO) glass substrate by electrooxidation of 0.1 M pyrrole in aqueous solution containing appropriate amounts of ZnO NPs uniformly dispersed in CS. This method enables the room temperature electrosynthesis of BNC film consisting of ZnO NPs incorporated within the growing Ppy/CS composite. The morphology of Ppy/ZnO/CS BNC was characterized by scanning electron microscopy. ITO–Ppy/CS and ITO–Ppy/ZnO/CS bioelectrodes were characterized using the Fourier transform infrared technique, X-ray diffraction, and thermogravimetric analysis. The electrical conductivity of nanocomposites was investigated by a four-probe method. The prepared nanocomposites were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay. The results demonstrated that the antioxidant activity of nanocomposites increased remarkably by addition of ZnO NPs. The electrical conductivity of films showed a sudden decrease for lower weight ratios of ZnO NPs (5 wt%), while it was increased gradually for higher ratios (10, 15, and 20 wt%). The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the synthesized BNC is effective against all of the studied bacteria, and its effectiveness is higher for Pseudomonas aeruginosa. The thermal stability and physical properties of BNC films were increased by an increase in the weight ratio of ZnO NPs, promising novel applications for the electrically conductive polysaccharide-based nanocomposites, particularly those that may exploit the antimicrobial nature of Ppy/ZnO/CS BNCs. PMID:25565815

  2. Novel conductive polypyrrole/zinc oxide/chitosan bionanocomposite: synthesis, characterization, antioxidant, and antibacterial activities.

    PubMed

    Ebrahimiasl, Saeideh; Zakaria, Azmi; Kassim, Anuar; Basri, Sri Norleha

    2015-01-01

    An antibacterial and conductive bionanocomposite (BNC) film consisting of polypyrrole (Ppy), zinc oxide (ZnO) nanoparticles (NPs), and chitosan (CS) was electrochemically synthesized on indium tin oxide (ITO) glass substrate by electrooxidation of 0.1 M pyrrole in aqueous solution containing appropriate amounts of ZnO NPs uniformly dispersed in CS. This method enables the room temperature electrosynthesis of BNC film consisting of ZnO NPs incorporated within the growing Ppy/CS composite. The morphology of Ppy/ZnO/CS BNC was characterized by scanning electron microscopy. ITO-Ppy/CS and ITO-Ppy/ZnO/CS bioelectrodes were characterized using the Fourier transform infrared technique, X-ray diffraction, and thermogravimetric analysis. The electrical conductivity of nanocomposites was investigated by a four-probe method. The prepared nanocomposites were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay. The results demonstrated that the antioxidant activity of nanocomposites increased remarkably by addition of ZnO NPs. The electrical conductivity of films showed a sudden decrease for lower weight ratios of ZnO NPs (5 wt%), while it was increased gradually for higher ratios (10, 15, and 20 wt%). The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the synthesized BNC is effective against all of the studied bacteria, and its effectiveness is higher for Pseudomonas aeruginosa. The thermal stability and physical properties of BNC films were increased by an increase in the weight ratio of ZnO NPs, promising novel applications for the electrically conductive polysaccharide-based nanocomposites, particularly those that may exploit the antimicrobial nature of Ppy/ZnO/CS BNCs.

  3. Intracellular Na(+) modulates large conductance Ca(2+)-activated K (+) currents in human umbilical vein endothelial cells.

    PubMed

    Liang, Guo Hua; Kim, Moon Young; Park, Seonghee; Kim, Ji Aee; Choi, Shinkyu; Suh, Suk Hyo

    2008-10-01

    We studied the effects of Na(+) influx on large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels in cultured human umbilical vein endothelial cells (HUVECs) by means of patch clamp and SBFI microfluorescence measurements. In current-clamped HUVECs, extracellular Na(+) replacement by NMDG(+) or mannitol hyperpolarized cells. In voltage-clamped HUVECs, changing membrane potential from 0 mV to negative potentials increased intracellular Na(+) concentration ([Na(+)](i)) and vice versa. In addition, extracellular Na(+) depletion decreased [Na(+)](i). In voltage-clamped cells, BK(Ca) currents were markedly increased by extracellular Na(+) depletion. In inside-out patches, increasing [Na(+)](i) from 0 to 20 or 40 mM reduced single channel conductance but not open probability (NPo) of BK(Ca) channels and decreasing intracellular K(+) concentration ([K(+)](i)) gradually from 140 to 70 mM reduced both single channel conductance and NPo. Furthermore, increasing [Na(+)](i) gradually from 0 to 70 mM, by replacing K(+), markedly reduced single channel conductance and NPo. The Na(+)-Ca(2+) exchange blocker Ni(2+) or KB-R7943 decreased [Na(+)](i) and increased BK(Ca) currents simultaneously, and the Na(+) ionophore monensin completely inhibited BK(Ca) currents. BK(Ca) currents were significantly augmented by increasing extracellular K(+) concentration ([K(+)](o)) from 6 to 12 mM and significantly reduced by decreasing [K(+)](o) from 12 or 6 to 0 mM or applying the Na(+)-K(+) pump inhibitor ouabain. These results suggest that intracellular Na(+) inhibit single channel conductance of BK(Ca) channels and that intracellular K(+) increases single channel conductance and NPo.

  4. Graphene as conductive additives in binderless activated carbon electrodes for power enhancement of supercapacitor

    NASA Astrophysics Data System (ADS)

    Nor, N. S. M.; Deraman, M.; Suleman, M.; Norizam, M. D. M.; Basri, N. H.; Sazali, N. E. S.; Hamdan, E.; Hanappi, M. F. Y. M.; Tajuddin, N. S. M.; Othman, M. A. R.; Shamsudin, S. A.; Omar, R.

    2016-11-01

    Carbon based supercapacitor electrodes from composite of binderless activated carbon and graphene as a conductive additive were fabricated with various amount of graphene (0, 2, 4, 6, 8 and 10 wt%). Graphene was mixed in self-adhesive carbon grains produced from pre-carbonized powder derived from fibers of oil palm empty fruit bunches and converted into green monoliths (GMs). The GMs were carbonized (N2) and activated (CO2) to produce activated carbon monoliths (ACMs) electrodes. Porosity characterizations by nitrogen adsorption-desorption isotherm method shows that the pore characteristics of the ACMs are influenced by the graphene additive. The results of galvanostatic charge-discharge tests carried out on the supercapacitor cells fabricated using these electrodes shows that the addition of graphene additive (even in small amount) decreases the equivalent series resistance and enhances the specific power of the cells but significantly lowers the specific capacitance. The supercapacitor cell constructed with the electrode containing 4 wt % of graphene offers the maximum power (175 W kg-1) which corresponds to an improvement of 55%. These results demonstrate that the addition of graphene as conductive additive in activated carbon electrodes can enhance the specific power of the supercapacitor.

  5. Large-conductance Ca2+-activated potassium channels in secretory neurons.

    PubMed

    Lara, J; Acevedo, J J; Onetti, C G

    1999-09-01

    Large-conductance Ca2+-activated K+ channels (BK) are believed to underlie interburst intervals and contribute to the control of hormone release in several secretory cells. In crustacean neurosecretory cells, Ca2+ entry associated with electrical activity could act as a modulator of membrane K+ conductance. Therefore we studied the contribution of BK channels to the macroscopic outward current in the X-organ of crayfish, and their participation in electrophysiological activity, as well as their sensitivity toward intracellular Ca2+, ATP, and voltage, by using the patch-clamp technique. The BK channels had a conductance of 223 pS and rectified inwardly in symmetrical K+. These channels were highly selective to K+ ions; potassium permeability (PK) value was 2.3 x 10(-13) cm(3) s(-1). The BK channels were sensitive to internal Ca2+ concentration, voltage dependent, and activated by intracellular MgATP. Voltage sensitivity (k) was approximately 13 mV, and the half-activation membrane potentials depended on the internal Ca2+ concentration. Calcium ions (0.3-3 microM) applied to the internal membrane surface caused an enhancement of the channel activity. This activation of BK channels by internal calcium had a KD(0) of 0.22 microM and was probably due to the binding of only one or two Ca2+ ions to the channel. Addition of MgATP (0.01-3 mM) to the internal solution increased steady state-open probability. The dissociation constant for MgATP (KD) was 119 microM, and the Hill coefficient (h) was 0.6, according to the Hill analysis. Ca2+-activated K+ currents recorded from whole cells were suppressed by either adding Cd2+ (0.4 mM) or removing Ca2+ ions from the external solution. TEA (1 mM) or charybdotoxin (100 nM) blocked these currents. Our results showed that both BK and K(ATP) channels are present in the same cell. Even when BK and K(ATP) channels were voltage dependent and modulated by internal Ca2+ and ATP, the profile of sensitivity was quite different for each kind

  6. iPad Acceptance by English Learners in Saudi Arabia

    ERIC Educational Resources Information Center

    Lawrence, Barry A. M.

    2016-01-01

    This study used the Unified Theory of Acceptance and Use of Technology (UTAUT; Venkatesh, Morris, Davis, & Davis, 2003) model to investigate factors predicting the acceptance of iPad tablets by learners of English as a foreign language (EFL) at a technical vocational college in Saudi Arabia. An online survey was conducted on 199 male learners,…

  7. Adult ESL Learner Assessment: Purposes and Tools. ERIC Digest.

    ERIC Educational Resources Information Center

    Burt, Miriam; Keenan, Fran

    Learner assessment is conducted in adult basic education and adult English-as-a-Second-Language (ESL) educational programs for many reasons: to place learners at appropriate instructional levels; to measure ongoing progress; to qualify students for enrollment in academic or job training programs; to verify program effectiveness; and to demonstrate…

  8. Computational Study of Subdural Cortical Stimulation: Effects of Simulating Anisotropic Conductivity on Activation of Cortical Neurons

    PubMed Central

    Seo, Hyeon; Kim, Donghyeon; Jun, Sung Chan

    2015-01-01

    Subdural cortical stimulation (SuCS) is an appealing method in the treatment of neurological disorders, and computational modeling studies of SuCS have been applied to determine the optimal design for electrotherapy. To achieve a better understanding of computational modeling on the stimulation effects of SuCS, the influence of anisotropic white matter conductivity on the activation of cortical neurons was investigated in a realistic head model. In this paper, we constructed pyramidal neuronal models (layers 3 and 5) that showed primary excitation of the corticospinal tract, and an anatomically realistic head model reflecting complex brain geometry. The anisotropic information was acquired from diffusion tensor magnetic resonance imaging (DT-MRI) and then applied to the white matter at various ratios of anisotropic conductivity. First, we compared the isotropic and anisotropic models; compared to the isotropic model, the anisotropic model showed that neurons were activated in the deeper bank during cathodal stimulation and in the wider crown during anodal stimulation. Second, several popular anisotropic principles were adapted to investigate the effects of variations in anisotropic information. We observed that excitation thresholds varied with anisotropic principles, especially with anodal stimulation. Overall, incorporating anisotropic conductivity into the anatomically realistic head model is critical for accurate estimation of neuronal responses; however, caution should be used in the selection of anisotropic information. PMID:26057524

  9. Gating of Recombinant Small-Conductance Ca-activated K+ Channels by Calcium

    PubMed Central

    Hirschberg, Birgit; Maylie, James; Adelman, John P.; Marrion, Neil V.

    1998-01-01

    Small-conductance Ca-activated K+ channels play an important role in modulating excitability in many cell types. These channels are activated by submicromolar concentrations of intracellular Ca2+, but little is known about the gating kinetics upon activation by Ca2+. In this study, single channel currents were recorded from Xenopus oocytes expressing the apamin-sensitive clone rSK2. Channel activity was detectable in 0.2 μM Ca2+ and was maximal above 2 μM Ca2+. Analysis of stationary currents revealed two open times and three closed times, with only the longest closed time being Ca dependent, decreasing with increasing Ca2+ concentrations. In addition, elevated Ca2+ concentrations resulted in a larger percentage of long openings and short closures. Membrane voltage did not have significant effects on either open or closed times. The open probability was ∼0.6 in 1 μM free Ca2+. A lower open probability of ∼0.05 in 1 μM Ca2+ was also observed, and channels switched spontaneously between behaviors. The occurrence of these switches and the amount of time channels spent displaying high open probability behavior was Ca2+ dependent. The two behaviors shared many features including the open times and the short and intermediate closed times, but the low open probability behavior was characterized by a different, long Ca2+-dependent closed time in the range of hundreds of milliseconds to seconds. Small-conductance Ca- activated K+ channel gating was modeled by a gating scheme consisting of four closed and two open states. This model yielded a close representation of the single channel data and predicted a macroscopic activation time course similar to that observed upon fast application of Ca2+ to excised inside-out patches. PMID:9524139

  10. Intermediate-Conductance-Ca2-Activated K Channel Intermediate-Conductance Calcium-Activated Potassium Channel (IKCa1) is Upregulated and Promotes Cell Proliferation in Cervical Cancer

    PubMed Central

    Liu, Ling; Zhan, Ping; Nie, Dan; Fan, Lingye; Lin, Hairui; Gao, Lanyang; Mao, Xiguang

    2017-01-01

    Background Accumulating data point to intermediate-conductance calcium-activated potassium channel (IKCa1) as a key player in controlling cell cycle progression and proliferation of human cancer cells. However, the role that IKCa1 plays in the growth of human cervical cancer cells is largely unexplored. Material/Methods In this study, Western blot analysis, immunohistochemical staining, and RT-PCR were first used for IKCa1protein and gene expression assays in cervical cancer tissues and HeLa cells. Then, IKCa1 channel blocker and siRNA were employed to inhibit the functionality of IKCa1 and downregulate gene expression in HeLa cells, respectively. After these treatments, we examined the level of cell proliferation by MTT method and measured IKCa1 currents by conventional whole-cell patch clamp technique. Cell apoptosis was assessed using the Annexin V-FITC/Propidium Iodide (PI) double-staining apoptosis detection kit. Results We demonstrated that IKCa1 mRNA and protein are preferentially expressed in cervical cancer tissues and HeLa cells. We also showed that the IKCa1 channel blocker, clotrimazole, and IKCa1 channel siRNA can be used to suppress cervical cancer cell proliferation and decrease IKCa1 channel current. IKCa1 downregulation by specific siRNAs induced a significant increase in the proportion of apoptotic cells in HeLa cells. Conclusions IKCa1 is overexpressed in cervical cancer tissues, and IKCa1 upregulation in cervical cancer cell linea enhances cell proliferation, partly by reducing the proportion of apoptotic cells. PMID:28280257

  11. ZnO:H indium-free transparent conductive electrodes for active-matrix display applications

    SciTech Connect

    Chen, Shuming Wang, Sisi

    2014-12-01

    Transparent conductive electrodes based on hydrogen (H)-doped zinc oxide (ZnO) have been proposed for active-matrix (AM) display applications. When fabricated with optimal H plasma power and optimal plasma treatment time, the resulting ZnO:H films exhibit low sheet resistance of 200 Ω/◻ and high average transmission of 85% at a film thickness of 150 nm. The demonstrated transparent conductive ZnO:H films can potentially replace indium-tin-oxide and serve as pixel electrodes for organic light-emitting diodes as well as source/drain electrodes for ZnO-based thin-film transistors. Use of the proposed ZnO:H electrodes means that two photomask stages can be removed from the fabrication process flow for ZnO-based AM backplanes.

  12. Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors

    NASA Astrophysics Data System (ADS)

    Barzegar, Farshad; Dangbegnon, Julien K.; Bello, Abdulhakeem; Momodu, Damilola Y.; Johnson, A. T. Charlie; Manyala, Ncholu

    2015-09-01

    This article is focused on polymer based gel electrolyte due to the fact that polymers are cheap and can be used to achieve extended potential window for improved energy density of the supercapacitor devices when compared to aqueous electrolytes. Electrochemical characterization of a symmetric supercapacitor devices based on activated carbon in different polyvinyl alcohol (PVA) based gel electrolytes was carried out. The device exhibited a maximum energy density of 24 Wh kg-1 when carbon black was added to the gel electrolyte as conductive additive. The good energy density was correlated with the improved conductivity of the electrolyte medium which is favorable for fast ion transport in this relatively viscous environment. Most importantly, the device remained stable with no capacitance lost after 10,000 cycles.

  13. Sensing performance of electrically conductive fabrics and dielectric electro active polymers for parachutes

    NASA Astrophysics Data System (ADS)

    Favini, Eric; Niezrecki, Christopher; Manohar, Sanjeev K.; Willis, David; Chen, Julie; Niemi, Eugene; Desabrais, Kenneth; Charette, Christine

    2011-04-01

    This paper quantifies the sensing capabilities of novel smart materials in an effort to improve the performance, better understand the physics, and enhance the safety of parachutes. Based upon a recent review of actuation technologies for parachute applications, it was surmised that the actuators reviewed could not be used to effectively alter the drag or lift (i.e. geometry, porosity, or air vent openings) of a parachute during flight. However, several materials showed potential for sensing applications within a parachute, specifically electrically conductive fabrics and dielectric electro-active polymers. This paper introduces several new conductive fabrics and provides an evaluation of the sensing performance of these smart materials based upon test results using mechanical testing and digital image correlation for comparison.

  14. Hindi Heritage Language Learners' Performance during OPIs: Characteristics and Pedagogical Implications

    ERIC Educational Resources Information Center

    Ilieva, Gabriela Nik.

    2012-01-01

    The present paper examines the oral performance of Hindi language learners during practice Oral Proficiency Interviews (OPI) conducted during workshops hosted by New York University and sponsored by STARTALK. The most salient characteristics of the heritage language learners' output are compared with the output of foreign language learners who are…

  15. The Effects of Young EFL Learners' Perceptions of Tests on Test Anxiety

    ERIC Educational Resources Information Center

    Aydin, Selami

    2012-01-01

    Studies conducted so far have mainly focused on the relationships between perceptions of tests and test anxiety among adult foreign language learners, while there is a lack of research focusing on young learners on the above-mentioned issue. Thus, this study aims to examine the relationship between test anxiety among young learners who study…

  16. Exploring the Factors Influencing E-Learning of Turkish EFL Learners through TAM

    ERIC Educational Resources Information Center

    Cakir, Recep; Solak, Ekrem

    2014-01-01

    The purpose of this study was to understand the attitude of Turkish EFL learners towards technology and to determine the factors influencing the academic achievement of the learners while using technology. Survey method was used to collect data about technology acceptance of the Turkish Foreign Language Learners. This research was conducted at a…

  17. An Assessment of the Adult Learners' Needs at Gateway Community-Technical College.

    ERIC Educational Resources Information Center

    Luna, Wilson

    A study was conducted to assess the needs of adult learners at Gateway Community-Technical College (GCTC), in North Haven, Connecticut. An extended literature review resulted the choice of the three-part Adult Learner Needs Assessment Survey (ALNAS). In spring 1993, the ALNAS was administered to adult learners in classes at GCTC, resulting in 400…

  18. Electrically conductive PVC layers filled with active carbon containing H+-conducting porous structures of sulfuric acid complexes of cyclams on fabrics

    NASA Astrophysics Data System (ADS)

    Tsivadze, A. Yu.; Fridman, A. Ya.; Morozova, E. M.; Sokolova, N. P.; Voloshchuk, A. M.; Petukhova, G. A.; Bardyshev, I. I.; Gorbunov, A. M.; Novikov, A. K.; Polyakova, I. Ya.; Titova, V. N.; Yavich, A. A.; Petrova, N. V.; Krasil'nikova, O. K.

    2015-07-01

    Electrically conductive PVC layers are synthesized. The layers are filled with active carbons containing porous H+-conductive structures of hydroxyethylcyclam/sulfuric acid complexes crosslinked with cellulose fabric. They are interlaid with layers based on the same structures containing added benzene and hexane adsorbates and solvates. It is found that upon anode or cathode polarization of the layers as H+-conductive electrochemical bridges in air and in the vapor and liquid phases of benzene and hexane, either the electroreduction of H+ to H2 or the electrooxidation of H2O to O2 occurs in the areas of contact between active carbon particles and the complexes. The dependences of rates of H2 and O2 formation on the voltage are studied. The magnitudes of overvoltage and the constants of electrochemical reactions are found to depend on the composition of a layer.

  19. Cell swelling, co-transport activation and potassium conductance in isolated perfused rabbit kidney proximal tubules.

    PubMed Central

    Beck, J S; Potts, D J

    1990-01-01

    1. Isolated, perfused rabbit proximal tubules were used to study the effects of activation of the apical membrane sodium co-transporters, and of the effects of osmotically induced cell swelling, upon cell volume, basolateral membrane potential and apparent partial conductance of potassium. 2. Activation of electrogenic apical sodium co-transport caused a depolarization of the basolateral membrane and a reduction of the basolateral apparent potassium transference number. This was followed by a spontaneous partial recovery of potential and increase in apparent potassium transference number. 3. Stimulation of apical sodium co-transport led to a sustained increase in cell volume. 4. A sustained increase in cell volume (of similar magnitude to that seen after activation of apical membrane sodium co-transporters) was also caused by reduction of bath and perfusate osmolality by removal of 89 mmol l-1 mannitol from both lumen and bath solutions. 5. This reduction in bath and perfusate osmolality also led to a basolateral membrane hyperpolarization and an increase in basolateral apparent potassium transference number. 6. These observations support the possibility that some of the partial recovery of basolateral membrane potential (Vb1) during apical sodium co-transport stimulation is due to a cell volume sensitive change in basolateral potassium conductance. PMID:2213582

  20. Somatic versus Dendritic Resonance: Differential Filtering of Inputs through Non-Uniform Distributions of Active Conductances

    PubMed Central

    Zhuchkova, Ekaterina; Remme, Michiel W. H.; Schreiber, Susanne

    2013-01-01

    Synaptic inputs to neurons are processed in a frequency-dependent manner, with either low-pass or resonant response characteristics. These types of filtering play a key role in the frequency-specific information flow in neuronal networks. While the generation of resonance by specific ionic conductances is well investigated, less attention has been paid to the spatial distribution of the resonance-generating conductances across a neuron. In pyramidal neurons – one of the major excitatory cell-types in the mammalian brain – a steep gradient of resonance-generating h-conductances with a 60-fold increase towards distal dendrites has been demonstrated experimentally. Because the dendritic trees of these cells are large, spatial compartmentalization of resonant properties can be expected. Here, we use mathematical descriptions of spatially extended neurons to investigate the consequences of such a distal, dendritic localization of h-conductances for signal processing. While neurons with short dendrites do not exhibit a pronounced compartmentalization of resonance, i.e. the filter properties of dendrites and soma are similar, we find that neurons with longer dendrites ( space constant) can show distinct filtering of dendritic and somatic inputs due to electrotonic segregation. Moreover, we show that for such neurons, experimental classification as resonant versus nonresonant can be misleading when based on somatic recordings, because for these morphologies a dendritic resonance could easily be undetectable when using somatic input. Nevertheless, noise-driven membrane-potential oscillations caused by dendritic resonance can propagate to the soma where they can be recorded, hence contrasting with the low-pass filtering at the soma. We conclude that non-uniform distributions of active conductances can underlie differential filtering of synaptic input in neurons with spatially extended dendrites, like pyramidal neurons, bearing relevance for the localization

  1. Conceptualizing Learner Support Space.

    ERIC Educational Resources Information Center

    Cates, Ward Mitchell; Bruce, Ronald R.

    2000-01-01

    Discussion of computer-based online help systems for instructional software focuses on three types of learner support: for optimizing use of a computer program; for learning content; and for monitoring and enhancing learning. Proposes a multi-dimensional model of learner-support space defined by the intrusiveness of the delivery methods and…

  2. The Lifelong Learner.

    ERIC Educational Resources Information Center

    Gross, Ronald

    Designed to provide a general guide and stimuli for lifelong learning, this book examines all the positive factors of independent study. Lifelong learning is defined as self-directed growth free from the traditional schooling procedures. Chapters discuss the following: the lifelong learner; profiles of such learners in action; how to be…

  3. The Learner's Permit.

    ERIC Educational Resources Information Center

    Mayhew, Daniel R.

    2003-01-01

    Considers the role and value of an extended learner's period in a graduated driver-licensing system through a review of the literature. Concludes that further research is needed on the safety benefits and optional features of the learner period. (Contains 1 figure, 3 tables, and 41 references.) (AUTHOR/WFA)

  4. Focus on the Learner.

    ERIC Educational Resources Information Center

    Richards, Jack C.

    1988-01-01

    Ways in which curriculum development and methodology in teaching English as a Second Language can take account of learners are discussed. In addition, ways that teachers and researchers can collaborate in the process of developing a learner-center curriculum are examined. (28 references) (LB)

  5. Understanding Oral Learners

    ERIC Educational Resources Information Center

    Moon, W. Jay

    2012-01-01

    A five-year research project of seminary students from various cultural backgrounds revealed that the slight majority of contemporary seminary students studied are oral learners. Oral learners learn best and have their lives most transformed when professors utilize oral teaching and assessment methods. After explaining several preferences of oral…

  6. A Learner Centered Education.

    ERIC Educational Resources Information Center

    Ballard, Florence N.

    This paper proposes a learner-centered educational system, focusing on aspects that are intrinsically associated with the modern educational system, such as the curriculum, school community, parents, learners, and educational support personnel. It examines: primary level preparation (literacy, numeracy, and basic knowledge; examination and…

  7. Improving the EFL Learners' Speaking Ability through Interactive Storytelling

    ERIC Educational Resources Information Center

    Marzuki; Prayogo, Johannes Ananto; Wahyudi, Arwijati

    2016-01-01

    This present research was aimed to improve the EFL learners' speaking ability and their classroom activities through the implementation of Interactive Storytelling Strategy. Therefore, this study was directed to explore the beneficial of Interactive Storytelling that closely related to the EFL learners' everyday activities at their home and…

  8. Activation of the basolateral membrane Cl− conductance essential for electrogenic K+ secretion suppresses electrogenic Cl− secretion

    PubMed Central

    He, Quanhua; Halm, Susan T.; Zhang, Jin; Halm, Dan R.

    2010-01-01

    Adrenaline activates transient Cl−-secretion and sustained K+-secretion across isolated distal colonic mucosa of guinea pig. The Ca++-activated Cl− channel inhibitor CaCCinh-A01 [30μM] significantly reduced electrogenic K+-secretion, detected as short-circuit current (Isc). This inhibition supported the cell model for K+-secretion in which basolateral membrane Cl− channels provide an exit pathway for Cl− entering the cell via Na+/K+/2Cl−-cotransporters. CaCCinh-A01 inhibited both Isc and transepithelial conductance in a concentration dependent manner, IC50 = 6.3μM. GlyH-101, another Cl− channel inhibitor, also reduced sustained adrenaline-activated Isc (IC50 = 9.4μM). Adrenaline activated whole-cell Cl− current in isolated intact colonic crypts, confirmed by ion substitution. This adrenaline-activated whole-cell Cl− current also was inhibited by CaCCinh-A01 or GlyH-101. In contrast to K+-secretion, CaCCinh-A01 augmented the electrogenic Cl−-secretion activated by adrenaline as well as that activated by PGE2. Synergistic Cl−-secretion activated by cholinergic/PGE2 stimulation was insensitive to CaCCinh-A01. Colonic expression of the Ca++-activated Cl− channel protein Tmem16A was supported by RT-PCR detection of Tmem16A-mRNA, by immuno-blot with a Tmem16A-antibody, and by immuno-fluorescence detection in lateral membranes of epithelial cells. Alternative splices of Tmem16A were detected for exons that are involved in channel activation. Inhibition of K+-secretion and augmentation of Cl−-secretion by CaCCinh-A01 supports a common colonic cell model for these two ion secretory processes, such that activation of basolateral membrane Cl− channels contributes to the production of electrogenic K+-secretion and limits the rate of Cl−-secretion. Maximal physiological Cl−-secretion occurs only for synergistic activation mechanisms that close these basolateral membrane Cl− channels. PMID:21169331

  9. 77 FR 43238 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ... Specified Activities; Navy Training Conducted at the Silver Strand Training Complex, San Diego Bay AGENCY... harassment, incidental to conducting training exercises at the Silver Strand Training Complex (SSTC) in the... taking, by harassment, of marine mammals incidental to conducting training exercises at the Navy's...

  10. Spectral, electrical conductivity and biological activity properties of some new azopyrimidine derivatives and their complexes.

    PubMed

    Masoud, Mamdouh S; Khalil, Ekram A; Ramadan, Ahmed M; Gohar, Yousry M; Sweyllam, Amr

    2007-07-01

    The electronic absorption spectra of 5-(o-substituted phenylazo)-6-amino-2-thiouracils and 6-(o-substituted phenylazo)-5-aminouracils containing different substituents are studied at different pH's. The dissociation constants are evaluated and discussed. Phenomenon of tautomerism is more supported by (1)H NMR and (13)C NMR spectra. The electrical conductivity of some ligands and their Co(II), Ni(II) and Cu(II) complexes in the temperature range 293-150K favoured their semiconducting properties where the metal ion forms a bridge to facilitate the flow of the current. The biological activity of some ligands and their complexes are tested against a number of Gram-positive and Gram-negative bacteria. The results showed that some of the compounds have a well considerable activity against some of the organisms.

  11. Molecular heterogeneity of large-conductance calcium-activated potassium channels in canine intracardiac ganglia.

    PubMed

    Selga, Elisabet; Pérez-Serra, Alexandra; Moreno-Asso, Alba; Anderson, Seth; Thomas, Kristen; Desai, Mayurika; Brugada, Ramon; Pérez, Guillermo J; Scornik, Fabiana S

    2013-01-01

    Large conductance calcium-activated potassium (BK) channels are widely expressed in the nervous system. We have recently shown that principal neurons from canine intracardiac ganglia (ICG) express a paxilline- and TEA-sensitive BK current, which increases neuronal excitability. In the present work, we further explore the molecular constituents of the BK current in canine ICG. We found that the β1 and β4 regulatory subunits are expressed in ICG. Single channel voltage-dependence at different calcium concentrations suggested that association of the BKα with a particular β subunit was not enough to explain the channel activity in this tissue. Indeed, we detected the presence of several splice variants of the BKα subunit. In conclusion, BK channels in canine ICG may result from the arrangement of different BKα splice variants, plus accessory β subunits. The particular combinations expressed in canine IC neurons likely rule the excitatory role of BK current in this tissue.

  12. Gain control of synaptic response function in cerebellar nuclear neurons by a calcium activated potassium conductance

    PubMed Central

    Feng, Steven Si; Lin, Risa; Gauck, Volker; Jaeger, Dieter

    2013-01-01

    Small conductance Ca2+ activated potassium (SK) current provides an important modulator of excitatory synaptic transmission, which undergoes plastic regulation via multiple mechanisms. We examined whether inhibitory input processing is also dependent on SK current in the cerebellar nuclei (CN), where inhibition provides the only route of information transfer from the cerebellar cortical Purkinje cells. We employed dynamic clamping in conjunction with computer simulations to address this question. We found that SK current plays a critical role in the inhibitory synaptic control of spiking output. Specifically, regulation of SK current density resulted in a gain control of spiking output, such that low SK current promoted large output signaling for large inhibitory cell input fluctuations due to Purkinje cell synchronization. In contrast, smaller non-synchronized Purkinje cell input fluctuations were not amplified. Regulation of SK density in the CN therefore would likely lead to important consequences for the transmission of synchronized Purkinje cell activity to the motor system. PMID:23605187

  13. Learner-Content-Interface as an Approach for Self-Reliant and Student-Centered Learning

    ERIC Educational Resources Information Center

    Nicolay, Robin; Schwennigcke, Bastian; Sahl, Sarah; Martens, Alke

    2015-01-01

    Conceptualization and implementation of computer supported teaching and training is currently not tailored to the paradigm of learner centration. Many technical solutions lack transparency and consistency regarding the supported learner activities. An insight into learners activities correlated to learning tasks is needed. In this paper we outline…

  14. Beta-adrenoceptor blockade and atrio-ventricular conduction in dogs. Role of intrinsic sympathomimetic activity.

    PubMed

    Giudicelli, J F; Lhoste, F

    1982-01-01

    1 Atrio-ventricular conduction and its modifications induced by six beta-adrenoceptor blocking agents and isoprenaline have been investigated in the anaesthetized dog using the extrastimulus technique and measuring atrial (AERP), nodal (NERP), global (GERP) effective refractory periods as well as global functional refractory period (GFRP). 2 When beta-adrenoceptor blockade was produced by (+/-)-propranolol (beta 1 + beta 2-adrenoceptor blockade) which is devoid of intrinsic sympathomimetic activity (ISA) but has membrane stabilizing effects (MSE), sotalol (beta 1 + beta 2-adrenoceptor blockade, no ISA, no MSE) and atenolol (beta 1-adrenoceptor blockade, no ISA, no MSE), all parameters were significantly increased. When beta-adrenoceptor blockade was achieved with pindolol (beta 1 + beta 2-adrenoceptor blockade) and practolol (beta 1-adrenoceptor blockade) which have ISA but no MSE, all parameters remained unchanged, as was also the case with (+)-propranolol, which has MSE but neither ISA nor beta-adrenolytic properties. 3 Isoprenaline at high doses significantly reduced the refractory periods but when infusion was stopped, marked but reversible conduction depression was observed. 4 It thus appears that beta-adrenoceptor blockade but not MSE is responsible for the onset of atrial and AV-conduction impairment and that ISA affords protection against this impairment.

  15. Conductance and activation energy for electron transport in series and parallel intramolecular circuits.

    PubMed

    Hsu, Liang-Yan; Wu, Ning; Rabitz, Herschel

    2016-11-30

    We investigate electron transport through series and parallel intramolecular circuits in the framework of the multi-level Redfield theory. Based on the assumption of weak monomer-bath couplings, the simulations depict the length and temperature dependence in six types of intramolecular circuits. In the tunneling regime, we find that the intramolecular circuit rule is only valid in the weak monomer coupling limit. In the thermally activated hopping regime, for circuits based on two different molecular units Ma and Mb with distinct activation energies Eact,a > Eact,b, the activation energies of Ma and Mb in series are nearly the same as Eact,a while those in parallel are nearly the same as Eact,b. This study gives a comprehensive description of electron transport through intramolecular circuits from tunneling to thermally activated hopping. We hope that this work can motivate additional studies to design intramolecular circuits based on different types of building blocks, and to explore the corresponding circuit laws and the length and temperature dependence of conductance.

  16. Transparent, conductive, and SERS-active Au nanofiber films assembled on an amphiphilic peptide template

    NASA Astrophysics Data System (ADS)

    Vinod, T. P.; Zarzhitsky, Shlomo; Morag, Ahiud; Zeiri, Leila; Levi-Kalisman, Yael; Rapaport, Hanna; Jelinek, Raz

    2013-10-01

    The use of biological materials as templates for functional molecular assemblies is an active research field at the interface between chemistry, biology, and materials science. We demonstrate the formation of gold nanofiber films on β-sheet peptide domains assembled at the air/water interface. The gold deposition scheme employed a recently discovered chemical process involving spontaneous crystallization and reduction of water-soluble Au(SCN)41- upon anchoring to surface-displayed amine moieties. Here we show that an interlinked network of crystalline Au nanofibers is readily formed upon incubation of the Au(iii) thiocyanate complex with the peptide monolayers. Intriguingly, the resultant films were optically transparent, enabled electrical conductivity, and displayed pronounced surface enhanced Raman spectroscopy (SERS) activity, making the approach a promising avenue for construction of nano-structured films exhibiting practical applications.The use of biological materials as templates for functional molecular assemblies is an active research field at the interface between chemistry, biology, and materials science. We demonstrate the formation of gold nanofiber films on β-sheet peptide domains assembled at the air/water interface. The gold deposition scheme employed a recently discovered chemical process involving spontaneous crystallization and reduction of water-soluble Au(SCN)41- upon anchoring to surface-displayed amine moieties. Here we show that an interlinked network of crystalline Au nanofibers is readily formed upon incubation of the Au(iii) thiocyanate complex with the peptide monolayers. Intriguingly, the resultant films were optically transparent, enabled electrical conductivity, and displayed pronounced surface enhanced Raman spectroscopy (SERS) activity, making the approach a promising avenue for construction of nano-structured films exhibiting practical applications. Electronic supplementary information (ESI) available: AFM analysis of the

  17. Disuse of rat muscle in vivo reduces protein kinase C activity controlling the sarcolemma chloride conductance

    PubMed Central

    Pierno, Sabata; Desaphy, Jean-François; Liantonio, Antonella; De Luca, Annamaria; Zarrilli, Antonia; Mastrofrancesco, Lisa; Procino, Giuseppe; Valenti, Giovanna; Conte Camerino, Diana

    2007-01-01

    Muscle disuse produced by hindlimb unloading (HU) induces severe atrophy and slow-to-fast fibre type transition of the slow-twitch soleus muscle (Sol). After 2 weeks HU, the resting ClC-1 chloride conductance (gCl) of sarcolemma, which controls muscle excitability, increases in Sol toward a value typical of the fast-twitch EDL muscle. After 3 days of HU, the gCl increases as well before initiation of fibre type transition. Since ClC-1 channels are acutely silenced by PKC-dependent phosphorylation, we studied the modulation of gCl by PKC and serine–threonine phosphatase in Sol during HU, using a number of pharmacological tools. We show that a fraction of ClC-1 channels of control Sol are maintained in an inactive state by PKC basal activity, which contributes to the lower gCl in control Sol compared to EDL. After 14 days of HU, PKC/phosphatase manipulation produces effects on Sol gCl that corroborate the partial slow-to-fast transition. After 3 days of HU, the early increase of gCl in Sol is entirely attributable to a reduction of PKC activity and/or activation of phosphatase, maintaining ClC-1 channels in a fully active state. Accordingly, we found that HU reduces expression of PKCα, ɛ, and θ isoenzymes in Sol and EDL muscles and reduces total PKC activity. Moreover, we show that the rheobase current is increased in Sol muscle fibres as soon as after 3 days of HU, most probably in relation to the increased gCl. In conclusion, Sol muscle disuse is characterized by a rapid reduction of PKC activity, which reduces muscle excitability and is likely to contribute to disuse-induced muscle impairment. PMID:17855757

  18. Caffeine-activated large-conductance plasma membrane cation channels in cardiac myocytes: characteristics and significance.

    PubMed

    Zhang, Yu-An; Tuft, Richard A; Lifshitz, Lawrence M; Fogarty, Kevin E; Singer, Joshua J; Zou, Hui

    2007-10-01

    Caffeine-activated, large-conductance, nonselective cation channels (LCCs) have been found in the plasma membrane of isolated cardiac myocytes in several species. However, little is known about the effects of opening these channels. To examine such effects and to further understand the caffeine-activation mechanism, we carried out studies using whole-cell patch-clamp techniques with freshly isolated cardiac myocytes from rats and mice. Unlike previous studies, thapsigargin was used so that both the effect of opening LCCs and the action of caffeine were independent of Ca(2+) release from intracellular stores. These Ca(2+)-permeable LCCs were found in a majority of the cells from atria and ventricles, with a conductance of approximately 370 pS in rat atria. Caffeine and all its direct metabolic products (theophylline, theobromine, and paraxanthine) activated the channel, while isocaffeine did not. Although they share some similarities with ryanodine receptors (RyRs, the openings of which give rise to Ca(2+) sparks), LCCs also showed some different characteristics. With simultaneous Ca(2+) imaging and current recording, the localized fluorescence increase due to Ca(2+) entry through a single opening of an LCC (SCCaFT) was detected. When membrane potential, instead of current, was recorded, SCCaFT-like fluorescence transients (indicating single LCC openings) were found to accompany membrane depolarizations. To our knowledge, this is the first report directly linking membrane potential changes to a single opening of an ion channel. Moreover, these events in cardiac cells suggest a possible additional mechanism by which caffeine and theophylline contribute to the generation of cardiac arrhythmias.

  19. Downregulation of Purkinje Cell Activity by Modulators of Small Conductance Calcium-Activated Potassium Channels In Rat Cerebellum

    PubMed Central

    Karelina, T. V.; Stepanenko, Yu. D.; Abushik, P. A.; Sibarov, D. A.; Antonov, S. M.

    2016-01-01

    Small-conductance calcium-activated potassium channels (SK channels) are widely expressed in CNS tissues. Their functions, however, have not been well studied. Participation of SK channels in Purkinje cell (PC) pacemaker activity has been studied predominantly in vitro. Here we studied for the first time the effects of SK channel activation by NS309 or CyPPA on the PC simple spike frequency in vivo in adult (3 – 6 months) and aged (22 – 28 months) rats using extracellular microelectrode recordings. Both pharmacological agents caused a statistically significant decrease in the PC simple spike frequency. The maximum value of the decrease in the simple spike frequency did not depend on age, whereas a statistically significant inhibition of the spike frequency was achieved faster in aged animals than in adult ones. In experiments on cultured neurons PCs were identified by the expression of calbindin as the PC-specific marker. Registration of transmembrane currents in cerebellar neurons revealed the direct action of NS309 and CyPPA on the SK channels of PC consisted in the enhancement of outward potassium currents and action potential after-hyperpolarization. Thus, SK channel activators can compensate for age-related changes of the autorhythmic functions of the cerebellum. PMID:28050270

  20. Large-conductance calcium-activated potassium current modulates excitability in isolated canine intracardiac neurons

    PubMed Central

    Pérez, Guillermo J.; Desai, Mayurika; Anderson, Seth

    2013-01-01

    We studied principal neurons from canine intracardiac (IC) ganglia to determine whether large-conductance calcium-activated potassium (BK) channels play a role in their excitability. We performed whole cell recordings in voltage- and current-clamp modes to measure ion currents and changes in membrane potential from isolated canine IC neurons. Whole cell currents from these neurons showed fast- and slow-activated outward components. Both current components decreased in the absence of calcium and following 1–2 mM tetraethylammonium (TEA) or paxilline. These results suggest that BK channels underlie these current components. Single-channel analysis showed that BK channels from IC neurons do not inactivate in a time-dependent manner, suggesting that the dynamic of the decay of the fast current component is akin to that of intracellular calcium. Immunohistochemical studies showed that BK channels and type 2 ryanodine receptors are coexpressed in IC principal neurons. We tested whether BK current activation in these neurons occurred via a calcium-induced calcium release mechanism. We found that the outward currents of these neurons were not affected by the calcium depletion of intracellular stores with 10 mM caffeine and 10 μM cyclopiazonic acid. Thus, in canine intracardiac neurons, BK currents are directly activated by calcium influx. Membrane potential changes elicited by long (400 ms) current injections showed a tonic firing response that was decreased by TEA or paxilline. These data strongly suggest that the BK current present in canine intracardiac neurons regulates action potential activity and could increase these neurons excitability. PMID:23195072

  1. Transitioning English Language Learners: Annotated Bibliography

    ERIC Educational Resources Information Center

    Hector-Mason, Anestine; Shaewitz, Dahlia; Sherman, Renee; Brown, Delphinia; Salomon, Erika; Bauman, Emily; Mendieta, Yorkmit; Corley, Mary Ann

    2009-01-01

    On July 17, 2008 the U.S. Department of Education's Office of Vocational and Adult Education (OVAE) awarded a contract to the American Institutes for Research (AIR) to assist OVAE in conducting a descriptive study of instructional and programmatic practices that support the transition of English language learners (TELL) from English as a second…

  2. Ventral striatum and amygdala activity as convergence sites for early adversity and conduct disorder.

    PubMed

    Holz, Nathalie E; Boecker-Schlier, Regina; Buchmann, Arlette F; Blomeyer, Dorothea; Jennen-Steinmetz, Christine; Baumeister, Sarah; Plichta, Michael M; Cattrell, Anna; Schumann, Gunter; Esser, Günter; Schmidt, Martin; Buitelaar, Jan; Meyer-Lindenberg, Andreas; Banaschewski, Tobias; Brandeis, Daniel; Laucht, Manfred

    2016-10-02

    Childhood family adversity (CFA) increases the risk for conduct disorder (CD) and has been associated with alterations in regions of affective processing like ventral striatum (VS) and amygdala. However, no study so far has demonstrated neural converging effects of CFA and CD in the same sample. At age 25 years, functional MRI data during two affective tasks, i.e. a reward (N = 171) and a face-matching paradigm (N = 181) and anatomical scans (N = 181) were acquired in right-handed currently healthy participants of an epidemiological study followed since birth. CFA during childhood was determined using a standardized parent interview. Disruptive behaviors and CD diagnoses during childhood and adolescence were obtained by diagnostic interview (2-19 years), temperamental reward dependence was assessed by questionnaire (15 and 19 years).CFA predicted increased CD and amygdala volume. Both exposure to CFA and CD were associated with a decreased VS response during reward anticipation and blunted amygdala activity during face-matching. CD mediated the effect of CFA on brain activity. Temperamental reward dependence was negatively correlated with CFA and CD and positively with VS activity. These findings underline the detrimental effects of CFA on the offspring's affective processing and support the importance of early postnatal intervention programs aiming to reduce childhood adversity factors.

  3. PLRP-3: Operational Perspectives of Conducting Science-Driven Extravehicular Activity with Communications Latency

    NASA Technical Reports Server (NTRS)

    Miller, Matthew J.; Lim, Darlene S. S.; Brady, Allyson; Cardman, Zena; Bell, Ernest; Garry, Brent; Reid, Donnie; Chappell, Steve; Abercromby, Andrew F. J.

    2016-01-01

    The Pavilion Lake Research Project (PLRP) is a unique platform where the combination of scientific research and human space exploration concepts can be tested in an underwater spaceflight analog environment. The 2015 PLRP field season was performed at Pavilion Lake, Canada, where science-driven exploration techniques focusing on microbialite characterization and acquisition were evaluated within the context of crew and robotic extravehicular activity (EVA) operations. The primary objectives of this analog study were to detail the capabilities, decision-making process, and operational concepts required to meet non-simulated scientific objectives during 5-minute one-way communication latency utilizing crew and robotic assets. Furthermore, this field study served as an opportunity build upon previous tests at PLRP, NASA Desert Research and Technology Studies (DRATS), and NASA Extreme Environment Mission Operations (NEEMO) to characterize the functional roles and responsibilities of the personnel involved in the distributed flight control team and identify operational constraints imposed by science-driven EVA operations. The relationship and interaction between ground and flight crew was found to be dependent on the specific scientific activities being addressed. Furthermore, the addition of a second intravehicular operator was found to be highly enabling when conducting science-driven EVAs. Future human spaceflight activities will need to cope with the added complexity of dynamic and rapid execution of scientific priorities both during and between EVA execution to ensure scientific objectives are achieved.

  4. Mechanism of the activation process for the formation of a surface-conduction electron-emitter

    NASA Astrophysics Data System (ADS)

    Tsukamoto, Takeo; Okuda, Masahiro; Arai, Yutaka; Miyata, Hirokatsu

    2016-01-01

    The major role of the chemical reaction between a silica substrate and deposited carbon in the activation process for the formation of a surface-conduction electron emitter (SCE) is investigated. The SCE emits electrons by the tunneling effect when an electric field is applied across a nanoscale gap. The nanogap is spontaneously formed by the activation process, wherein a pulse voltage is applied between a pair of electrodes, which are separated by a narrow gap inside a vacuum chamber in the presence of hydrocarbons. At the gap, two elemental processes compete; the deposition of carbon by the electron-induced decomposition of hydrocarbons and the consumption of carbon by reaction with the silica substrate. The balance of the dynamics of the two processes, which simply depends on the temperature at the gap, is responsible for the spontaneous determination of the width of the nanogap. The calculation based on the model that involves the two competitive processes agrees with the experimental results on the activation process.

  5. Electrical Conductivity of Rocks and Dominant Charge Carriers. Part 1; Thermally Activated Positive Holes

    NASA Technical Reports Server (NTRS)

    Freund, Friedemann T.; Freund, Minoru M.

    2012-01-01

    The prevailing view in the geophysics community is that the electrical conductivity structure of the Earth's continental crust over the 5-35 km depth range can best be understood by assuming the presence of intergranular fluids and/or of intragranular carbon films. Based on single crystal studies of melt-grown MgO, magma-derived sanidine and anorthosite feldspars and upper mantle olivine, we present evidence for the presence of electronic charge carriers, which derive from peroxy defects that are introduced during cooling, under non-equilibrium conditions, through a redox conversion of pairs of solute hydroxyl arising from dissolution of H2O.The peroxy defects become thermally activated in a 2-step process, leading to the release of defect electrons in the oxygen anion sublattice. Known as positive holes and symbolized by h(dot), these electronic charge carriers are highly mobile. Chemically equivalent to O(-) in a matrix of O(2-) they are highly oxidizing. Being metastable they can exist in the matrix of minerals, which crystallized in highly reduced environments. The h(dot) are highly mobile. They appear to control the electrical conductivity of crustal rocks in much of the 5-35 km depth range.

  6. A Semi-Conductive Copper-Organic Framework with Two Types of Photocatalytic Activity.

    PubMed

    Wu, Zhi-Lei; Wang, Chang-Hong; Zhao, Bin; Dong, Jie; Lu, Feng; Wang, Wei-Hua; Wang, Wei-Chao; Wu, Guang-Jun; Cui, Jian-Zhong; Cheng, Peng

    2016-04-11

    Based on the newly designed ligand 4'-(3,5-dicarboxyphenyl)-4,2':6',4''-terpyridine (DCTP), a unique semi-conductive 3D framework {[Cu(Ι)Cu(ΙΙ)2(DCTP)2]NO3⋅1.5 DMF}n (1) with a narrow band gap of 2.1 eV, was obtained and structurally characterized. DFT calculations with van de Waals correction employed to explore the electronic structure of 1, clearly revealed its semi-conductive behavior. Furthermore, we found that 1 exhibits a superior band alignment with water to produce hydrogen and degrade organic pollutants. Without adding any photosensitizers, 1 displays an efficiently photocatalytic hydrogen production in water based on the photo-generated electrons under UV/Vis light. 1 also exhibits excellent photo-degradation of methyl blue under visible-light owing to the strong oxidization of excited holes. It is the first example of MOFs with doubly photocatalytic activities related to photo-generated electrons and holes, respectively.

  7. Beyond Beginning Learners.

    ERIC Educational Resources Information Center

    Jongsma, Kathy

    2003-01-01

    Discusses materials for middle grade and high school learners. Explains useful resources for teaching struggling writers. Details a publishing tool, a reading comprehension assessment, and a Scholastic Assessment Tests (SAT) preparation text. (PM)

  8. Independence Pending: Teacher Behaviors Preceding Learner Problem Solving

    ERIC Educational Resources Information Center

    Roesler, Rebecca A.

    2017-01-01

    The purposes of the present study were to identify the teacher behaviors that preceded learners' active participation in solving musical and technical problems and describe learners' roles in the problem-solving process. I applied an original model of problem solving to describe the behaviors of teachers and students in 161 rehearsal frames…

  9. Supporting Learners' Appropriation of a Web-Based Learning Curriculum

    ERIC Educational Resources Information Center

    Rasseneur-Coffinet, Dorothée; Smyrniou, Georgia; Tchounikine, Pierre

    2007-01-01

    This article presents an approach and tools that can help learners appropriate a Web-based learning curriculum and become active participants in their learning. The approach is based on a detailed modeling of the curriculum and intends to equip the learners with different computer-based tools facilitating a multiple point of view perception of the…

  10. Practices and Prospects of Learner Autonomy: Teachers' Perceptions

    ERIC Educational Resources Information Center

    Al Asmari, AbdulRahman

    2013-01-01

    Language learning process works through the learners' own reflection on how they learn and it makes learners active in the sense that they learn to analyze their learning strategies. So they start making decisions, e.g., whether to improve them or not, and in which way. Generally, this trait is missing in traditional language teaching process and…

  11. Annotation-Based Learner's Personality Modeling in Distance Learning Context

    ERIC Educational Resources Information Center

    Omheni, Nizar; Kalboussi, Anis; Mazhoud, Omar; Kacem, Ahmed Hadj

    2016-01-01

    Researchers in distance education are interested in observing and modeling learners' personality profiles, and adapting their learning experiences accordingly. When learners read and interact with their reading materials, they do unselfconscious activities like annotation which may be key feature of their personalities. Annotation activity…

  12. Maximising Asian ESL Learners' Communicative Oral English via Drama

    ERIC Educational Resources Information Center

    Gill, Chamkaur

    2016-01-01

    This paper proposes that activities based on a variety of drama-based techniques could be valuable in giving Asian ESL learners opportunities to use communicative spoken English confidently and without restraint during their time in English-language-speaking countries. These learners often get anxious when in situations where they are required to…

  13. Factors Driving Learner Success in Online Professional Development

    ERIC Educational Resources Information Center

    Vu, Phu; Cao, Vien; Vu, Lan; Cepero, Jude

    2014-01-01

    This study examined factors that contributed to the success of online learners in an online professional development course. Research instruments included an online survey and learners' activity logs in an online professional development course for 512 in-service teachers. The findings showed that there were several factors affecting online…

  14. Reading Comprehension Interventions That Enhance Outcomes for English Language Learners with LD, 10/01/98-09/30/02. Final Report.

    ERIC Educational Resources Information Center

    Vaughn, Sharon; Bryant, Diane Pedrotty

    This final report discusses the activities and outcomes of a project that explored the effectiveness of strategies for teaching reading comprehension to English language learners with learning disabilities who are failing to acquire the comprehension skills to learn from print. A series of studies was conducted over a 3-year period that…

  15. A Follow-Up Study of the Facebook Project for Japanese University Students: Has It Been Enhancing Student Interaction, Learner Autonomy, and English Learning?

    ERIC Educational Resources Information Center

    Hamada, Mayumi

    2014-01-01

    This is a follow-up study of the Facebook (FB) project conducted from October 2011 to January 2013. The purpose of the project was to investigate how FB can help Japanese university students improve their English, and determine whether FB can facilitate student interaction and learner autonomy by integrating FB activities into English lessons. In…

  16. Calcium activates the light-dependent conductance in melanopsin-expressing photoreceptors of amphioxus.

    PubMed

    Peinado, Gabriel; Osorno, Tomás; Gomez, María del Pilar; Nasi, Enrico

    2015-06-23

    Melanopsin, the photopigment of the "circadian" receptors that regulate the biological clock and the pupillary reflex in mammals, is homologous to invertebrate rhodopsins. Evidence supporting the involvement of phosphoinositides in light-signaling has been garnered, but the downstream effectors that control the light-dependent conductance remain unknown. Microvillar photoreceptors of the primitive chordate amphioxus also express melanopsin and transduce light via phospholipase-C, apparently not acting through diacylglycerol. We therefore examined the role of calcium in activating the photoconductance, using simultaneous, high time-resolution measurements of membrane current and Ca(2+) fluorescence. The light-induced calcium rise precedes the onset of the photocurrent, making it a candidate in the activation chain. Moreover, photolysis of caged Ca elicits an inward current of similar size, time course and pharmacology as the physiological photoresponse, but with a much shorter latency. Internally released calcium thus emerges as a key messenger to trigger the opening of light-dependent channels in melanopsin-expressing microvillar photoreceptors of early chordates.

  17. Large Conductance Ca2+-Activated K+ Channels Modulate Uterine α1-Adrenergic Sensitivity in Ovine Pregnancy

    PubMed Central

    Hynan, Linda S.; Liu, Xiao-tie; Roy, Timothy

    2014-01-01

    The uteroplacental vasculature is refractory to α-adrenergic stimulation, and large conductance Ca2+-activated K+ channels (BKCa) may contribute. We examined the effects of uterine artery (UA) BKCa inhibition with tetraethylammonium (TEA) on hemodynamic responses to phenylephrine (PE) at 101 to 117 days and 135 to 147 days of ovine gestation, obtaining dose responses for mean arterial pressure (MAP), heart rate (HR), and uteroplacental blood flow (UPBF) and vascular resistance (UPVR) before and during UA TEA infusions. The UA α1-adrenergic receptors (α1-ARs) were assessed. The PE increased MAP and UPVR and decreased HR and UPBF dose dependently at both gestations (P < .001, analysis of variance). The %▵MAP was less at 135 to 147 days before and during TEA infusions (P ≤ .008); however, responses during TEA were greater (P ≤ .002). The PE increased %▵UPVR>>%▵MAP, thus %▵UPBF fell. The TEA enhanced PE-mediated increases in %▵UPVR at 135 to 147 days (P ≤ .03). The UA α1-AR expression was unchanged in pregnancy. Uterine vascular responses to PE exceed systemic vascular responses throughout pregnancy and are attenuated by BKCa activation, suggesting BKCa protect UPBF. PMID:24026311

  18. The large conductance calcium-activated K(+) channel interacts with the small GTPase Rab11b.

    PubMed

    Sokolowski, Sophia; Harvey, Margaret; Sakai, Yoshihisa; Jordan, Amy; Sokolowski, Bernd

    2012-09-21

    The transduction of sound by the receptor or hair cells of the cochlea leads to the activation of ion channels found in the basal and lateral regions of these cells. Thus, the processing of these transduced signals to the central nervous system is tied to the regulation of baso-lateral ion channels. The large conductance calcium-activated potassium or BK channel was revealed to interact with the small GTPase, Rab11b, which is one of many Rabs found in various endosomal pathways. Immunoelectron microscopy showed the colocalization of these two proteins in receptor cells and auditory neurons. Using Chinese hamster ovary cells as a heterologous expression system, Rab11b increased or decreased BK expression, depending on the overexpression or RNAi knockdown of Rab, respectively. Additional mutation analyses, using a yeast two-hybrid assay, suggested that this GTPase moderately interacts within a region of BK exclusive of the N- or C-terminal tails. These data suggest that this small GTPase regulates BK in a slow recycling process through the endocytic compartment and to the plasmalemma.

  19. The large conductance calcium-activated K+ channel interacts with the small GTPase Rab11b

    PubMed Central

    Sokolowski, Sophia; Harvey, Margaret; Sakai, Yoshihisa; Jordan, Amy; Sokolowski, Bernd

    2012-01-01

    The transduction of sound by the receptor or hair cells of the cochlea leads to the activation of ion channels found in the basal and lateral regions of these cells. Thus, the processing of these transduced signals to the central nervous system is tied to the regulation of baso-lateral ion channels. The large conductance calcium-activated potassium or BK channel was revealed to interact with the small GTPase, Rab11b, which is one of many Rabs found in various endosomal pathways. Immunoelectron microscopy showed the colocalization of these two proteins in receptor cells and auditory neurons. Using Chinese hamster ovary cells as a heterologous expression system, Rab11b increased or decreased BK expression, depending on the overexpression or RNAi knockdown of Rab, respectively. Additional mutation analyses, using a yeast two-hybrid assay, suggested that this GTPase moderately interacts within a region of BK exclusive of the N- or C-terminal tails. These data suggest that this small GTPase regulates BK in a slow recycling process through the endocytic compartment and to the plasmalemma. PMID:22935415

  20. Carbon-Based Microbial-Fuel-Cell Electrodes: From Conductive Supports to Active Catalysts.

    PubMed

    Li, Shuang; Cheng, Chong; Thomas, Arne

    2017-02-01

    Microbial fuel cells (MFCs) have attracted considerable interest due to their potential in renewable electrical power generation using the broad diversity of biomass and organic substrates. However, the difficulties in achieving high power densities and commercially affordable electrode materials have limited their industrial applications to date. Carbon materials, which can exhibit a wide range of different morphologies and structures, usually possess physiological activity to interact with microorganisms and are therefore fast-emerging electrode materials. As the anode, carbon materials can significantly promote interfacial microbial colonization and accelerate the formation of extracellular biofilms, which eventually promotes the electrical power density by providing a conductive microenvironment for extracellular electron transfer. As the cathode, carbon-based materials can function as catalysts for the oxygen-reduction reaction, showing satisfying activities and efficiencies nowadays even reaching the performance of Pt catalysts. Here, first, recent advancements on the design of carbon materials for anodes in MFCs are summarized, and the influence of structure and surface functionalization of different types of carbon materials on microorganism immobilization and electrochemical performance is elucidated. Then, synthetic strategies and structures of typical carbon-based cathodes in MFCs are briefly presented. Furthermore, future applications of carbon-electrode-based MFC devices in the energy, environmental, and biological fields are discussed, and the emerging challenges in transferring them from laboratory to industrial scale are described.

  1. Calcium activates the light-dependent conductance in melanopsin-expressing photoreceptors of amphioxus

    PubMed Central

    Peinado, Gabriel; Osorno, Tomás; Gomez, María del Pilar; Nasi, Enrico

    2015-01-01

    Melanopsin, the photopigment of the “circadian” receptors that regulate the biological clock and the pupillary reflex in mammals, is homologous to invertebrate rhodopsins. Evidence supporting the involvement of phosphoinositides in light-signaling has been garnered, but the downstream effectors that control the light-dependent conductance remain unknown. Microvillar photoreceptors of the primitive chordate amphioxus also express melanopsin and transduce light via phospholipase-C, apparently not acting through diacylglycerol. We therefore examined the role of calcium in activating the photoconductance, using simultaneous, high time-resolution measurements of membrane current and Ca2+ fluorescence. The light-induced calcium rise precedes the onset of the photocurrent, making it a candidate in the activation chain. Moreover, photolysis of caged Ca elicits an inward current of similar size, time course and pharmacology as the physiological photoresponse, but with a much shorter latency. Internally released calcium thus emerges as a key messenger to trigger the opening of light-dependent channels in melanopsin-expressing microvillar photoreceptors of early chordates. PMID:26056310

  2. The Large Conductance, Calcium-activated K+ (BK) Channel is regulated by Cysteine String Protein

    PubMed Central

    Kyle, Barry D.; Ahrendt, Eva; Braun, Andrew P.; Braun, Janice E. A.

    2013-01-01

    Large-conductance, calcium-activated-K+ (BK) channels are widely distributed throughout the nervous system, where they regulate action potential duration and firing frequency, along with presynaptic neurotransmitter release. Our recent efforts to identify chaperones that target neuronal ion channels have revealed cysteine string protein (CSPα) as a key regulator of BK channel expression and current density. CSPα is a vesicle-associated protein and mutations in CSPα cause the hereditary neurodegenerative disorder, adult-onset autosomal dominant neuronal ceroid lipofuscinosis (ANCL). CSPα null mice show 2.5 fold higher BK channel expression compared to wild type mice, which is not seen with other neuronal channels (i.e. Cav2.2, Kv1.1 and Kv1.2). Furthermore, mutations in either CSPα's J domain or cysteine string region markedly increase BK expression and current amplitude. We conclude that CSPα acts to regulate BK channel expression, and consequently CSPα-associated changes in BK activity may contribute to the pathogenesis of neurodegenerative disorders, such as ANCL. PMID:23945775

  3. 30 CFR 250.210 - If I conduct ancillary activities, what reporting and data/information retention requirements...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reports that summarize and analyze data or information obtained or derived from your ancillary activities... reporting and data/information retention requirements must I satisfy? 250.210 Section 250.210 Mineral... Activities § 250.210 If I conduct ancillary activities, what reporting and data/information...

  4. 40 CFR 745.230 - Work practice standards for conducting lead-based paint activities: public and commercial...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.230 Work practice standards for conducting lead-based paint activities: public and... lead-based paint activities: public and commercial buildings, bridges and superstructures....

  5. 40 CFR 745.230 - Work practice standards for conducting lead-based paint activities: public and commercial...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.230 Work practice standards for conducting lead-based paint activities: public and... lead-based paint activities: public and commercial buildings, bridges and superstructures....

  6. 40 CFR 745.230 - Work practice standards for conducting lead-based paint activities: public and commercial...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.230 Work practice standards for conducting lead-based paint activities: public and... lead-based paint activities: public and commercial buildings, bridges and superstructures....

  7. 40 CFR 745.230 - Work practice standards for conducting lead-based paint activities: public and commercial...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.230 Work practice standards for conducting lead-based paint activities: public and... lead-based paint activities: public and commercial buildings, bridges and superstructures....

  8. 40 CFR 745.230 - Work practice standards for conducting lead-based paint activities: public and commercial...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.230 Work practice standards for conducting lead-based paint activities: public and... lead-based paint activities: public and commercial buildings, bridges and superstructures....

  9. 77 FR 38082 - Certain Activated Carbon from China; Notice of Commission Determination To Conduct a Full Five...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ... COMMISSION Certain Activated Carbon from China; Notice of Commission Determination To Conduct a Full Five... Activated Carbon From China AGENCY: United States International Trade Commission. ACTION: Notice. SUMMARY... whether revocation of the antidumping duty order on certain activated carbon from China would be likely...

  10. WNK1 Activates Large-Conductance Ca2+-Activated K+ Channels through Modulation of ERK1/2 Signaling

    PubMed Central

    Liu, Yingli; Song, Xiang; Shi, Yanling; Shi, Zhen; Niu, Weihui; Feng, Xiuyan; Gu, Dingying; Bao, Hui-Fang; Ma, He-Ping; Eaton, Douglas C.

    2015-01-01

    With no lysine (WNK) kinases are members of the serine/threonine kinase family. We previously showed that WNK4 inhibits renal large-conductance Ca2+-activated K+ (BK) channel activity by enhancing its degradation through a lysosomal pathway. In this study, we investigated the effect of WNK1 on BK channel activity. In HEK293 cells stably expressing the α subunit of BK (HEK-BKα cells), siRNA-mediated knockdown of WNK1 expression significantly inhibited both BKα channel activity and open probability. Knockdown of WNK1 expression also significantly inhibited BKα protein expression and increased ERK1/2 phosphorylation, whereas overexpression of WNK1 significantly enhanced BKα expression and decreased ERK1/2 phosphorylation in a dose-dependent manner in HEK293 cells. Knockdown of ERK1/2 prevented WNK1 siRNA-mediated inhibition of BKα expression. Similarly, pretreatment of HEK-BKα cells with the lysosomal inhibitor bafilomycin A1 reversed the inhibitory effects of WNK1 siRNA on BKα expression in a dose-dependent manner. Knockdown of WNK1 expression also increased the ubiquitination of BKα channels. Notably, mice fed a high-K+ diet for 10 days had significantly higher renal protein expression levels of BKα and WNK1 and lower levels of ERK1/2 phosphorylation compared with mice fed a normal-K+ diet. These data suggest that WNK1 enhances BK channel function by reducing ERK1/2 signaling-mediated lysosomal degradation of the channel. PMID:25145935

  11. Muscarinic activation of inwardly rectifying K+ conductance reduces EPSPs in rat hippocampal CA1 pyramidal cells

    PubMed Central

    Seeger, Thomas; Alzheimer, Christian

    2001-01-01

    To determine how acetylcholine (ACh) modulates the somatodendritic processing of EPSPs, we performed whole-cell recordings from CA1 pyramidal cells of hippocampal slices and examined the effect of the cholinergic agonist, carbachol (CCh), on α-amino-3-hydroxy-5-methyl isoxazole-4-propionate (AMPA) EPSPs, miniature EPSPs, and EPSP-like waveforms evoked by brief dendritic glutamate pulses (glutamate-evoked postsynaptic potentials, GPSPs). Although CCh is known to enhance the intrinsic excitability of the neuron in several ways, activation of atropine-sensitive (muscarinic) receptors on the apical dendrite or the soma of CA1 pyramidal cells consistently reduced the amplitude of EPSPs and GPSPs. Cholinergic inhibition of evoked and simulated EPSP waveforms displayed considerable voltage dependence, with the amplitude of the postsynaptic potentials progressively declining with membrane hyperpolarization indicating the involvement of an inwardly rectifying current. Extracellular Ba2+ (200 μm) and tertiapin (30 nm), a novel and selective blocker of G protein-activated, inwardly rectifying K+ (GIRK) channels, completely blocked the effect of CCh on GPSP amplitude. Muscarinic reduction of GPSPs was not sensitive to the M1 receptor-preferring antagonist, pirenzepine, but was suppressed by the M2 receptor-preferring antagonist, methoctramine, and by the allosteric M2 receptor antagonist, gallamine. In voltage-clamp recordings, CCh induced an ion current displaying inward rectification in the hyperpolarizing direction, which was identified as a GIRK current based on its sensitivity to low Ba2+ and tertiapin. Its pharmacological profile paralleled that of the cholinergic GPSP reduction. We link the observed reduction of postsynaptic potentials to the cholinergic activation of a GIRK conductance, which serves to partially shunt excitatory synaptic input. PMID:11533131

  12. Exploring Shifts in Middle School Learners' Modeling Activity While Generating Drawings, Animations, and Computational Simulations of Molecular Diffusion

    ERIC Educational Resources Information Center

    Wilkerson-Jerde, Michelle H.; Gravel, Brian E.; Macrander, Christopher A.

    2015-01-01

    Modeling and using technology are two practices of particular interest to K-12 science educators. These practices are inextricably linked among professionals, who engage in modeling activity with and across a variety of representational technologies. In this paper, we explore the practices of five sixth-grade girls as they generated models of…

  13. Design Issues Related to the Evaluation of Learner--Computer Interaction in a Web-Based Environment: Activities v. Tasks

    ERIC Educational Resources Information Center

    Hemard, Dominique

    2006-01-01

    If web-based technology is increasingly becoming the central plank of contemporary teaching and learning processes, there is still too little evidence to suggest that it is delivering purposeful learning activities beyond its widely perceived potential as a learning resource providing content and learning objects. This is due in part to the…

  14. Language-Building Activities and Interaction Variations with Mixed-Ability ESL University Learners in a Content-Based Course

    ERIC Educational Resources Information Center

    Serna Dimas, Héctor Manuel; Ruíz Castellanos, Erika

    2014-01-01

    The preparation of both language-building activities and a variety of teacher/student interaction patterns increase both oral language participation and content learning in a course of manual therapy with mixed-language ability students. In this article, the researchers describe their collaboration in a content-based course in English with English…

  15. Community Resources. Teacher Guidebook and Student Activity Book. Adult Basic Education Project REAL: Relevant Education for Adult Learners.

    ERIC Educational Resources Information Center

    Edgar, S. Keith

    This packet contains both a teacher's guide and a student activity book designed to help adult students locate and use community resources. Both booklets cover the following topics: the public library, Social Security, postal services, use of the telephone and the telephone directory, the newspaper, the Cooperative Extension Service, reference…

  16. You Can Be in a Group and Still Not Cooperate. Collaborative Approaches and Cooperative Learning Activities for Adult Learners.

    ERIC Educational Resources Information Center

    Parma City School District, OH.

    This handbook defines and describes the benefits of both collaborative approaches and cooperative techniques. An introduction uses watercolor marbling as a metaphor for collaborative approaches and cooperative activities. Section I provides research results regarding problems of adult literacy programs, skills employers want, and Bloom's taxonomy.…

  17. Exploring South African Grade 11 Learners' Perceptions of Classroom Inquiry: Validation of a Research Instrument

    ERIC Educational Resources Information Center

    Dudu, Washington T.; Vhurumuku, Elaosi

    2012-01-01

    This paper discusses the adoption and validation of a research instrument, on determining learners' levels of perception of classroom inquiry based on data collected from South African Grade 11 learners. The Learners' Perception of Classroom Inquiry (LPCI) instrument consists only of Likert-type items which rank activities according to how often…

  18. The Effect of Reading on Second-Language Learners' Production in Tasks

    ERIC Educational Resources Information Center

    Collentine, Karina

    2016-01-01

    Tasks provide engaging ways to involve learners in meaningful, real-world activities with the foreign language (FL). Yet selecting classroom tasks suitable to learners' linguistic readiness is challenging, and task-based research is exploring the relationship between learners' overall abilities (e.g., reading, grammatical) and the complexity and…

  19. Comparing Learner Community Behavior in Multiple Presentations of a Massive Open Online Course

    ERIC Educational Resources Information Center

    Gallagher, Silvia Elena; Savage, Timothy

    2016-01-01

    Massive Online Open Courses (MOOCs) can create large scale communities of learners who collaborate, interact and discuss learning materials and activities. MOOCs are often delivered multiple times with similar content to different cohorts of learners. However, research into the differences of learner communication, behavior and expectation between…

  20. Comparing Learner Community Behavior in Multiple Presentations of a Massive Open Online Course

    ERIC Educational Resources Information Center

    Gallagher, Silvia Elena; Savage, Timothy

    2015-01-01

    Massive Online Open Courses (MOOCs) can create large scale communities of learners who collaborate, interact and discuss learning materials and activities. MOOCs are often delivered multiple times with similar content to different cohorts of learners. However, research into the differences of learner communication, behavior and expectation between…

  1. Small Conductance Calcium-Activated Potassium Current is Important in Transmural Repolarization of Failing Human Ventricles

    PubMed Central

    Yu, Chih-Chieh; Corr, Christopher; Shen, Changyu; Shelton, Richard; Yadava, Mrinal; Rhea, Isaac; Straka, Susan; Fishbein, Michael C.; Chen, Zhenhui; Lin, Shien-Fong; Lopshire, John C.; Chen, Peng-Sheng

    2015-01-01

    Background The transmural distribution of apamin-sensitive small conductance Ca2+-activated K+ (SK) current (IKAS) in failing human ventricles remains unclear. Methods and Results We optically mapped left ventricular wedge preparations from 12 failing native hearts and 2 rejected cardiac allografts explanted during transplant surgery. We determined transmural action potential duration (APD) before and after 100 nM apamin administration in all wedges and after sequential administration of apamin, chromanol and E4031 in 4 wedges. Apamin prolonged APD from 363 ms [95% confidence interval (CI), 341 to 385] to 409 [CI, 385 to 434] (p<0.001) in all hearts, and reduced the transmural conduction velocity from 36 cm/s [CI, 30 to 42] to 32 cm/s [CI, 27 to 37] (p=0.001) in 12 native failing hearts at 1000 ms pacing cycle length (PCL). The percent APD prolongation is negatively correlated with baseline APD and positively correlated with PCL. Only one wedge had M-cell islands. The percentages of APD prolongation in the last 4 hearts at 2000 ms PCL after apamin, chromanol and E4031 were 9.1% [CI, 3.9 to 14.2], 17.3% [CI, 3.1 to 31.5] and 35.9% [CI, 15.7 to 56.1], respectively. Immunohistochemical staining of subtype 2 of SK (SK2) protein showed increased expression in intercalated discs of myocytes. Conclusions SK current is important in the transmural repolarization in failing human ventricles. The magnitude of IKAS is positively correlated with the PCL, but negatively correlated with APD when PCL is fixed. There is abundant SK2 protein in the intercalated discs of myocytes. PMID:25908692

  2. Do ePortfolios Contribute to Learners' Reflective Thinking Activities? : A Preliminary Study of Nursing Staff Users.

    PubMed

    Tzeng, Wen-Sheng; Kuo, Kuang-Ming; Talley, Paul C; Chen, Hsiu-Chin; Wang, Jhi-Joung

    2015-09-01

    The purposes of this study are threefold: 1) to find out what characteristics are required for the successful use of ePortfolios; 2) to discover what activities best represent reflective thinking during the use of ePortfolios; and, 3) to investigate the interrelationship between nursing staff users' perceived success levels with ePortfolios and with their reflective thinking activities. Survey methodology was used to gather responses from 78 nurses from a medical center located in southern Taiwan via questionnaires. Factor analysis and canonical correlation analysis were used to analyze the collected data. The results demonstrated that system quality, information quality, and user satisfaction are important variables in successful ePortfolio usage; while habitual action, understanding, reflection, and critical reflection are major variables of reflective thinking. Further, we found a significant relationship exists between the relative success of ePortfolios and reflective thinking activities of ePortfolios users. The subject hospital should pay special attention to important characteristics including system quality, information quality, and user satisfaction when employing ePortfolios to help nursing staff users to achieve their learning goals through this form of reflective thinking.

  3. 78 FR 24161 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ... Specified Activities; Navy Training Conducted at the Silver Strand Training Complex, San Diego Bay AGENCY...) to take marine mammals, by harassment, incidental to conducting training exercises at the Silver Strand Training Complex (SSTC) in the vicinity of San Diego Bay, California. Pursuant to the...

  4. 77 FR 19231 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ... Specified Activities; Navy Training Conducted at the Silver Strand Training Complex, San Diego Bay AGENCY... Authorization (IHA) to take marine mammals, by harassment, incidental to conducting training exercises at the Silver Strand Training Complex (SSTC) in the vicinity of San Diego Bay, California....

  5. Upregulation of the large conductance voltage- and Ca2+-activated K+ channels by Janus kinase 2.

    PubMed

    Hosseinzadeh, Zohreh; Almilaji, Ahmad; Honisch, Sabina; Pakladok, Tatsiana; Liu, GuoXing; Bhavsar, Shefalee K; Ruth, Peter; Shumilina, Ekaterina; Lang, Florian

    2014-06-01

    The iberiotoxin-sensitive large conductance voltage- and Ca(2+)-activated potassium (BK) channels (maxi-K(+)-channels) hyperpolarize the cell membrane thus supporting Ca(2+) entry through Ca(2+)-release activated Ca(2+) channels. Janus kinase-2 (JAK2) has been identified as novel regulator of ion transport. To explore whether JAK2 participates in the regulation of BK channels, cRNA encoding Ca(2+)-insensitive BK channels (BK(M513I+Δ899-903)) was injected into Xenopus oocytes with or without cRNA encoding wild-type JAK2, gain-of-function (V617F)JAK2, or inactive (K882E)JAK2. K(+) conductance was determined by dual electrode voltage clamp and BK-channel protein abundance by confocal microscopy. In A204 alveolar rhabdomyosarcoma cells, iberiotoxin-sensitive K(+) current was determined utilizing whole cell patch clamp. A204 cells were further transfected with JAK2 and BK-channel transcript, and protein abundance was quantified by RT-PCR and Western blotting, respectively. As a result, the K(+) current in BK(M513I+Δ899-903)-expressing oocytes was significantly increased following coexpression of JAK2 or (V617F)JAK2 but not (K882E)JAK2. Coexpression of the BK channel with (V617F)JAK2 but not (K882E)JAK2 enhanced BK-channel protein abundance in the oocyte cell membrane. Exposure of BK-channel and (V617F)JAK2-expressing oocytes to the JAK2 inhibitor AG490 (40 μM) significantly decreased K(+) current. Inhibition of channel insertion by brefeldin A (5 μM) decreased the K(+) current to a similar extent in oocytes expressing the BK channel alone and in oocytes expressing the BK channel and (V617F)JAK2. The iberiotoxin (50 nM)-sensitive K(+) current in rhabdomyosarcoma cells was significantly decreased by AG490 pretreatment (40 μM, 12 h). Moreover, overexpression of JAK2 in A204 cells significantly enhanced BK channel mRNA and protein abundance. In conclusion, JAK2 upregulates BK channels by increasing channel protein abundance in the cell membrane.

  6. Mechanisms of Electrical Activation and Conduction in the Gastrointestinal System: Lessons from Cardiac Electrophysiology.

    PubMed

    Tse, Gary; Lai, Eric Tsz Him; Yeo, Jie Ming; Tse, Vivian; Wong, Sunny Hei

    2016-01-01

    The gastrointestinal (GI) tract is an electrically excitable organ system containing multiple cell types, which coordinate electrical activity propagating through this tract. Disruption in its normal electrophysiology is observed in a number of GI motility disorders. However, this is not well characterized and the field of GI electrophysiology is much less developed compared to the cardiac field. The aim of this article is to use the established knowledge of cardiac electrophysiology to shed light on the mechanisms of electrical activation and propagation along the GI tract, and how abnormalities in these processes lead to motility disorders and suggest better treatment options based on this improved understanding. In the first part of the article, the ionic contributions to the generation of GI slow wave and the cardiac action potential (AP) are reviewed. Propagation of these electrical signals can be described by the core conductor theory in both systems. However, specifically for the GI tract, the following unique properties are observed: changes in slow wave frequency along its length, periods of quiescence, synchronization in short distances and desynchronization over long distances. These are best described by a coupled oscillator theory. Other differences include the diminished role of gap junctions in mediating this conduction in the GI tract compared to the heart. The electrophysiology of conditions such as gastroesophageal reflux disease and gastroparesis, and functional problems such as irritable bowel syndrome are discussed in detail, with reference to ion channel abnormalities and potential therapeutic targets. A deeper understanding of the molecular basis and physiological mechanisms underlying GI motility disorders will enable the development of better diagnostic and therapeutic tools and the advancement of this field.

  7. Mechanisms of Electrical Activation and Conduction in the Gastrointestinal System: Lessons from Cardiac Electrophysiology

    PubMed Central

    Tse, Gary; Lai, Eric Tsz Him; Yeo, Jie Ming; Tse, Vivian; Wong, Sunny Hei

    2016-01-01

    The gastrointestinal (GI) tract is an electrically excitable organ system containing multiple cell types, which coordinate electrical activity propagating through this tract. Disruption in its normal electrophysiology is observed in a number of GI motility disorders. However, this is not well characterized and the field of GI electrophysiology is much less developed compared to the cardiac field. The aim of this article is to use the established knowledge of cardiac electrophysiology to shed light on the mechanisms of electrical activation and propagation along the GI tract, and how abnormalities in these processes lead to motility disorders and suggest better treatment options based on this improved understanding. In the first part of the article, the ionic contributions to the generation of GI slow wave and the cardiac action potential (AP) are reviewed. Propagation of these electrical signals can be described by the core conductor theory in both systems. However, specifically for the GI tract, the following unique properties are observed: changes in slow wave frequency along its length, periods of quiescence, synchronization in short distances and desynchronization over long distances. These are best described by a coupled oscillator theory. Other differences include the diminished role of gap junctions in mediating this conduction in the GI tract compared to the heart. The electrophysiology of conditions such as gastroesophageal reflux disease and gastroparesis, and functional problems such as irritable bowel syndrome are discussed in detail, with reference to ion channel abnormalities and potential therapeutic targets. A deeper understanding of the molecular basis and physiological mechanisms underlying GI motility disorders will enable the development of better diagnostic and therapeutic tools and the advancement of this field. PMID:27303305

  8. Fear conditioning suppresses large-conductance calcium-activated potassium channels in lateral amygdala neurons.

    PubMed

    Sun, P; Zhang, Q; Zhang, Y; Wang, F; Wang, L; Yamamoto, R; Sugai, T; Kato, N

    2015-01-01

    It was previously shown that depression-like behavior is accompanied with suppression of the large-conductance calcium activated potassium (BK) channel in cingulate cortex pyramidal cells. To test whether BK channels are also involved in fear conditioning, we studied neuronal properties of amygdala principal cells in fear conditioned mice. After behavior, we made brain slices containing the amygdala, the structure critically relevant to fear memory. The resting membrane potential in lateral amygdala (LA) neurons obtained from fear conditioned mice (FC group) was more depolarized than in neurons from naïve controls. The frequencies of spikes evoked by current injections were higher in neurons from FC mice, demonstrating that excitability of LA neurons was elevated by fear conditioning. The depolarization in neurons from FC mice was shown to depend on BK channels by using the BK channel blocker charybdotoxin. Suppression of BK channels in LA neurons from the FC group was further confirmed on the basis of the spike width, since BK channels affect the descending phase of spikes. Spikes were broader in the FC group than those in the naïve control in a manner dependent on BK channels. Consistently, quantitative real-time PCR revealed a decreased expression of BK channel mRNA. The present findings suggest that emotional disorder manifested in the forms of fear conditioning is accompanied with BK channel suppression in the amygdala, the brain structure critical to this emotional disorder.

  9. Muscle conduction velocity, strength, neural activity, and morphological changes after eccentric and concentric training.

    PubMed

    Cadore, E L; González-Izal, M; Pallarés, J G; Rodriguez-Falces, J; Häkkinen, K; Kraemer, W J; Pinto, R S; Izquierdo, M

    2014-10-01

    This study compared the effects of concentric and eccentric training on neuromuscular adaptations in young subjects. Twenty-two men and women were assigned to one of two groups: concentric (CON, n = 11) and eccentric (ECC, n = 11) training. Training consisted of 6 weeks of isokinetic exercise, performed twice weekly, starting with two sets of eight repetitions, and progressing to five sets of 10 repetitions. Subjects were tested in strength variables [concentric, eccentric, and isometric peak torque (PT), and rate of force development (RFD)], muscle conduction velocity (CV), neuromuscular activity, vastus lateralis (VL) muscle thickness, and echo intensity as determined by ultrasonography. There were similar increases in the concentric and eccentric PTs in both the CON and ECC groups (P < 0.01), but only the ECC group showed an increase in isometric PT (P < 0.001). Similarly, both groups exhibited increased VL muscle thickness, CV, and RFD, and reduced VL echo intensity (P < 0.05). Significant correlations were observed among the relative changes in the neuromuscular outcomes and training variables (e.g., total work, average PT) (r = 0.68-0.75, P < 0.05). The results showed that both training types similarly improved dynamic PT, CV, RFD, and muscle thickness and quality during the early weeks of training.

  10. Small-conductance Ca2+ -activated K+ channels and cardiac arrhythmias.

    PubMed

    Zhang, Xiao-Dong; Lieu, Deborah K; Chiamvimonvat, Nipavan

    2015-08-01

    Small-conductance Ca2+ -activated K+ (SK, KCa2) channels are unique in that they are gated solely by changes in intracellular Ca2+ and, hence, function to integrate intracellular Ca2+ and membrane potentials on a beat-to-beat basis. Recent studies have provided evidence for the existence and functional significance of SK channels in the heart. Indeed, our knowledge of cardiac SK channels has been greatly expanded over the past decade. Interests in cardiac SK channels are further driven by recent studies suggesting the critical roles of SK channels in human atrial fibrillation, the SK channel as a possible novel therapeutic target in atrial arrhythmias, and upregulation of SK channels in heart failure in animal models and in human heart failure. However, there remain critical gaps in our knowledge. Specifically, blockade of SK channels in cardiac arrhythmias has been shown to be both antiarrhythmic and proarrhythmic. This contemporary review provides an overview of the literature on the role of cardiac SK channels in cardiac arrhythmias and serves as a discussion platform for the current clinical perspectives. At the translational level, development of SK channel blockers as a new therapeutic strategy in the treatment of atrial fibrillation and the possible proarrhythmic effects merit further considerations and investigations.

  11. Skin Conductance at Baseline and Post-Heel Lance Reflects Sympathetic Activation in Neonatal Opiate Withdrawal

    PubMed Central

    Oji-Mmuo, Christiana N.; Michael, Eric J.; McLatchy, Jacqueline; Lewis, Mary M.; Becker, Julie E.; Doheny, Kim Kopenhaver

    2015-01-01

    Aim Skin conductance (SC) provides an objective measure of autonomic system regulation through sympathetic-mediated filling of sweat glands. This study aimed to test the utility of SC to detect sympathetic activation in neonatal abstinence syndrome (NAS). Methods 14 term (mean, SE: 38.8 ± 0.35 weeks gestational age) neonates with chronic prenatal opiate exposure were enrolled. SC (peaks/sec and mean of peaks) were measured at baseline, during heel lance/squeeze (HLS) and recovery from HLS at 24-48 (mean 38) hours of life prior to treatment for NAS. Blinded coders with established reliability assessed neonates using the Modified Finnegan Neonatal Scoring System (MFNSS). Non-parametric tests were used to determine group differences, phase differences from baseline to HLS and HLS to recovery, and associations between MFNSS and SC measures. Results Neonates that would later require morphine treatment for NAS (n = 6) had higher baseline SC mean of peaks than those that did not require treatment (n = 8) (P<0.05). Moreover, there were unique phase differences between groups and SC positively correlated with MFNSS (P< 0.05). Conclusion SC provides early identification of NAS severity. However, a larger sample is needed to determine sensitivity and specificity of SC for early identification of NAS and treatment effectiveness. PMID:26613197

  12. In Situ Measurement of Voltage-Induced Stress in Conducting Polymers with Redox-Active Dopants.

    PubMed

    Sen, Sujat; Kim, Sung Yeol; Palmore, Lia R; Jin, Shenghua; Jadhav, Nitin; Chason, Eric; Palmore, G Tayhas R

    2016-09-14

    Minimization of stress-induced mechanical rupture and delamination of conducting polymer (CP) films is desirable to prevent failure of devices based on these materials. Thus, precise in situ measurement of voltage-induced stress within these films should provide insight into the cause of these failure mechanisms. The evolution of stress in films of polypyrrole (pPy), doped with indigo carmine (IC), was measured in different electrochemical environments using the multibeam optical stress sensor (MOSS) technique. The stress in these films gradually increases to a constant value during voltage cycling, revealing an initial break-in period for CP films. The nature of the ions involved in charge compensation of pPy[IC] during voltage cycling was determined from electrochemical quartz crystal microbalance (EQCM) data. The magnitude of the voltage-induced stress within pPy[IC] at neutral pH correlated with the radius of the hydrated mobile ion in the order Li(+) > Na(+) > K(+). At acidic pH, the IC dopant in pPy[IC] undergoes reversible oxidation and reduction within the range of potentials investigated, providing a secondary contribution to the observed voltage-induced stress. We report on the novel stress response of these polymers due to the presence of pH-dependent redox-active dopants and how it can affect material performance.

  13. Modelling Typical Online Language Learning Activity

    ERIC Educational Resources Information Center

    Montoro, Carlos; Hampel, Regine; Stickler, Ursula

    2014-01-01

    This article presents the methods and results of a four-year-long research project focusing on the language learning activity of individual learners using online tasks conducted at the University of Guanajuato (Mexico) in 2009-2013. An activity-theoretical model (Blin, 2010; Engeström, 1987) of the typical language learning activity was used to…

  14. Factors influencing learner satisfaction with team-based learning among nursing students.

    PubMed

    Roh, Young Sook; Lee, Suk Jeong; Mennenga, Heidi

    2014-12-01

    In this study, learner satisfaction was described, and factors influencing satisfaction with team-based learning were identified. This was a cross-sectional, descriptive survey study. Two separate 2 h team-based, learning sessions, consisting of preparation, readiness assurance, and application, were given to a cohort of 139 second year nursing students in 2010 and 263 students in 2011, respectively. At the end of the learning sessions, participants completed a self-administered questionnaire regarding their learning experience. Nursing students were generally satisfied with team-based learning. Multiple regression analysis revealed that the learning process significantly affected learner satisfaction compared to pre-assignment, course content, peer evaluation, and team activity. According to these results, team-based learning facilitators should organize and conduct team-based learning activities, while also considering instructional design factors, to help students learn effectively.

  15. Intracellular pH regulates basolateral K+ and Cl- conductances in colonic epithelial cells by modulating Ca2+ activation

    PubMed Central

    1991-01-01

    The role of intracellular pH as a modulator of basolateral K+ and Cl- conductances in epithelial cells was studied using digitonin- permeabilized colonic cell layers so that cytosolic pH could be clamped at specific values, while basolateral K+ and Cl- conductances were activated by stepwise increases in intracellular free Ca2+. Increasing the intracellular pH from 6.6 to 8.0 enhanced the sensitivity of both ionic conductances to intracellular Ca2+, but changing extracellular pH had no effect. Maximal K+ and Cl- currents activated by Ca2+ were not affected by changes in intracellular pH, suggesting that protons do not alter the conduction properties of the channels. Hill analysis of the Ca2+ activation process revealed that raising the cytosolic pH from 6.6 to 8.0 reduced the K1/2 for Ca2+ activation. In the absence of Ca2+, changes in intracellular pH did not have a significant effect on the basolateral K+ and Cl- conductances. These results are consistent with the notion that changes in cytosolic pH can modulate basolateral conductances by modifying the action of calcium, perhaps by acting at or near the activation site to provide a mechanism of variable "gain control." PMID:1719125

  16. A Novel Method for Learner Assessment Based on Learner Annotations

    ERIC Educational Resources Information Center

    Noorbehbahani, Fakhroddin; Samani, Elaheh Biglar Beigi; Jazi, Hossein Hadian

    2013-01-01

    Assessment is one of the most essential parts of any instructive learning process which aims to evaluate a learner's knowledge about learning concepts. In this work, a new method for learner assessment based on learner annotations is presented. The proposed method exploits the M-BLEU algorithm to find the most similar reference annotations…

  17. Literacy-Related School Readiness Skills of English Language Learners in Head Start: An Analysis of the School Readiness Survey

    ERIC Educational Resources Information Center

    Park, Yujeong; Gurel, Sungur; Oh, Jihyun; Bettini, Elizabeth A; Leite, Walter

    2015-01-01

    The purpose of this study is to examine the effects of Head Start on early literacy skills relevant to school readiness of English language learners compared to their peers. The comparisons of literacy outcomes were conducted between English language learners and non-English language learners when both groups participated and were not in Head…

  18. The Application of Podcasting as a Motivational Strategy to Iranian EFL Learners of English: A View toward Listening Comprehension

    ERIC Educational Resources Information Center

    Shiri, Saeed

    2015-01-01

    This study was conducted in order to inspect the impact of podcasts as learning and teaching tools on Iranian EFL learners' motivation for listening as well as on their listening comprehension ability. It also investigated the learners' perception towards podcasts. 34 intermediate learners who were homogeneous in terms of listening ability were…

  19. Attitudes of Adult Learners toward the Board of Governors Bachelor of Arts Degree Program at Chicago State University.

    ERIC Educational Resources Information Center

    Thompson-Davenport, Michael A.

    A study was conducted to determine the attitudes of adult learners toward the Board of Governors (BOG) bachelor's degree program at Chicago State University. The study also examined characteristics and types of adult learners, availability and kinds of services adult learners want, relevance of coursework, biases from campus officials toward…

  20. Selectivity filter gating in large-conductance Ca(2+)-activated K+ channels.

    PubMed

    Thompson, Jill; Begenisich, Ted

    2012-03-01

    Membrane voltage controls the passage of ions through voltage-gated K (K(v)) channels, and many studies have demonstrated that this is accomplished by a physical gate located at the cytoplasmic end of the pore. Critical to this determination were the findings that quaternary ammonium ions and certain peptides have access to their internal pore-blocking sites only when the channel gates are open, and that large blocking ions interfere with channel closing. Although an intracellular location for the physical gate of K(v) channels is well established, it is not clear if such a cytoplasmic gate exists in all K(+) channels. Some studies on large-conductance, voltage- and Ca(2+)-activated K(+) (BK) channels suggest a cytoplasmic location for the gate, but other findings question this conclusion and, instead, support the concept that BK channels are gated by the pore selectivity filter. If the BK channel is gated by the selectivity filter, the interactions between the blocking ions and channel gating should be influenced by the permeant ion. Thus, we tested tetrabutyl ammonium (TBA) and the Shaker "ball" peptide (BP) on BK channels with either K(+) or Rb(+) as the permeant ion. When tested in K(+) solutions, both TBA and the BP acted as open-channel blockers of BK channels, and the BP interfered with channel closing. In contrast, when Rb(+) replaced K(+) as the permeant ion, TBA and the BP blocked both closed and open BK channels, and the BP no longer interfered with channel closing. We also tested the cytoplasmically gated Shaker K channels and found the opposite behavior: the interactions of TBA and the BP with these K(v) channels were independent of the permeant ion. Our results add significantly to the evidence against a cytoplasmic gate in BK channels and represent a positive test for selectivity filter gating.

  1. Selectivity filter gating in large-conductance Ca2+-activated K+ channels

    PubMed Central

    Thompson, Jill

    2012-01-01

    Membrane voltage controls the passage of ions through voltage-gated K (Kv) channels, and many studies have demonstrated that this is accomplished by a physical gate located at the cytoplasmic end of the pore. Critical to this determination were the findings that quaternary ammonium ions and certain peptides have access to their internal pore-blocking sites only when the channel gates are open, and that large blocking ions interfere with channel closing. Although an intracellular location for the physical gate of Kv channels is well established, it is not clear if such a cytoplasmic gate exists in all K+ channels. Some studies on large-conductance, voltage- and Ca2+-activated K+ (BK) channels suggest a cytoplasmic location for the gate, but other findings question this conclusion and, instead, support the concept that BK channels are gated by the pore selectivity filter. If the BK channel is gated by the selectivity filter, the interactions between the blocking ions and channel gating should be influenced by the permeant ion. Thus, we tested tetrabutyl ammonium (TBA) and the Shaker “ball” peptide (BP) on BK channels with either K+ or Rb+ as the permeant ion. When tested in K+ solutions, both TBA and the BP acted as open-channel blockers of BK channels, and the BP interfered with channel closing. In contrast, when Rb+ replaced K+ as the permeant ion, TBA and the BP blocked both closed and open BK channels, and the BP no longer interfered with channel closing. We also tested the cytoplasmically gated Shaker K channels and found the opposite behavior: the interactions of TBA and the BP with these Kv channels were independent of the permeant ion. Our results add significantly to the evidence against a cytoplasmic gate in BK channels and represent a positive test for selectivity filter gating. PMID:22371364

  2. Allosteric Gating of a Large Conductance Ca-activated K+ Channel

    PubMed Central

    Cox, D.H.; Cui, J.; Aldrich, R.W.

    1997-01-01

    Large-conductance Ca-activated potassium channels (BK channels) are uniquely sensitive to both membrane potential and intracellular Ca2+. Recent work has demonstrated that in the gating of these channels there are voltage-sensitive steps that are separate from Ca2+ binding steps. Based on this result and the macroscopic steady state and kinetic properties of the cloned BK channel mslo, we have recently proposed a general kinetic scheme to describe the interaction between voltage and Ca2+ in the gating of the mslo channel (Cui, J., D.H. Cox, and R.W. Aldrich. 1997. J. Gen. Physiol. In press.). This scheme supposes that the channel exists in two main conformations, closed and open. The conformational change between closed and open is voltage dependent. Ca2+ binds to both the closed and open conformations, but on average binds more tightly to the open conformation and thereby promotes channel opening. Here we describe the basic properties of models of this form and test their ability to mimic mslo macroscopic steady state and kinetic behavior. The simplest form of this scheme corresponds to a voltage-dependent version of the Monod-Wyman-Changeux (MWC) model of allosteric proteins. The success of voltage-dependent MWC models in describing many aspects of mslo gating suggests that these channels may share a common molecular mechanism with other allosteric proteins whose behaviors have been modeled using the MWC formalism. We also demonstrate how this scheme can arise as a simplification of a more complex scheme that is based on the premise that the channel is a homotetramer with a single Ca2+ binding site and a single voltage sensor in each subunit. Aspects of the mslo data not well fitted by the simplified scheme will likely be better accounted for by this more general scheme. The kinetic schemes discussed in this paper may be useful in interpreting the effects of BK channel modifications or mutations. PMID:9276753

  3. Murine vasa recta pericyte chloride conductance is controlled by calcium, depolarization, and kinase activity

    PubMed Central

    Lin, Hai; Pallone, Thomas L.

    2010-01-01

    We used the whole cell patch-clamp technique to investigate the regulation of descending vasa recta (DVR) pericyte Ca2+-dependent Cl− currents (CaCC) by cytoplasmic Ca2+ concentration ([Ca]CYT), voltage, and kinase activity. Murine CaCC increased with voltage and electrode Ca2+ concentration. The current saturated at [Ca]CYT of ∼1,000 nM and exhibited an EC50 for Ca2+ of ∼500 nM, independent of depolarization potential. Activation time constants were between 100 and 200 ms, independent of electrode Ca2+. Repolarization-related tail currents elicited by stepping from +100 mV to varying test potentials exhibited deactivation time constants of 50–200 ms that increased with voltage when electrode [Ca]CYT was 1,000 nM. The calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7, 30 μM) blocked CaCC. The myosin light chain kinase blockers 1-(5-iodonaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine hydrochloride (ML-7, 1–50 μM) and 1-(5-chloronaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine hydrochloride (ML-9, 10 μM) were similarly effective. Resting pericytes were hyperpolarized by ML-7. Pericytes exposed to ANG II (10 nM) depolarized from a baseline of −50 ± 6 to −29 ± 3 mV and were repolarized to −63 ± 7 mV by exposure to 50 μM ML-7. The Ca2+/calmodulin-dependent kinase inhibitor KN-93 reduced pericyte CaCC only when it was present in the electrode and extracellular buffer from the time of membrane break-in. We conclude that murine DVR pericytes are modulated by [Ca]CYT, membrane potential, and phosphorylation events, suggesting that Ca2+-dependent Cl− conductance may be a target for regulation of vasoactivity and medullary blood flow in vivo. PMID:20686172

  4. Effects of Intermediate-Conductance Ca(2+)-Activated K(+) Channels on Human Endometrial Carcinoma Cells.

    PubMed

    Zhang, Yingli; Feng, Youji; Chen, Lu; Zhu, Jianqing

    2015-06-01

    The objective of this study was to investigate the effect of intermediate-conductance Ca(2+)-activated K(+) (KCa3.1) channels on the cell proliferation, cell cycle, apoptosis, migration, and invasion in endometrial cancer (EC) cells. Human EC cell lines HEC-1-A and Ishikawa were cultured in vitro and transfected with recombinant plasmid containing KCa3.1-targeting shRNA. RT-qPCR and Western blot were used to examine the mRNA and protein expression levels of KCa3.1 channels in transfected cells. In addition, the specific inhibitor of KCa3.1, TRAM-34, was used to examine the effect of KCa3.1 blockage on migration capacity and invasiveness of EC cells using transwell assay. Proliferation and apoptotic rates of EC cells transfected with KCa3.1 shRNA or treated with TRAM-34 were analyzed using MTT, BrdU incorporation assay, and flow cytometry. Expression of cell cycle proteins and metalloproteinase-2 (MMP-2) was evaluated by RT-qPCR and Western blotting. TRAM-34 treatment and KCa3.1 silencing using shRNA dramatically suppressed both the mRNA and protein expression of KCa3.1 channels (P < 0.01) compared with control groups. Blockage of KCa3.1 by TRAM-34 treatment and KCa3.1 shRNA transfection exerted inhibitory effect on cell growth of both EC cell lines, as demonstrated by increased cell population at G0-G1 phase and decreased cell population at S phase. However, both the treatments did not result in significant changes in the apoptotic rate (P > 0.05) compared to controls. Protein expressions of cyclin D1, cyclin E, and survivin were significantly decreased in the experimental groups comparing to control. We showed that TRAM-34 treatment led to significantly inhibited migration, invasion, and MMP-2 expression in HEC-1-A and Ishikawa cells, compared with the control group (P < 0.01). Blockage of KCa3.1 channel activity or expression inhibits cell proliferation and cell cycle progression without inducing apoptosis in EC cells. Moreover, TRAM-34 could reduce the

  5. Multi-ion occupancy alters gating in high-conductance, Ca(2+)-activated K+ channels

    PubMed Central

    1991-01-01

    In this study, single-channel recordings of high-conductance Ca(2+)- activated K+ channels from rat skeletal muscle inserted into planar lipid bilayer were used to analyze the effects of two ionic blockers, Ba2+ and Na+, on the channel's gating reactions. The gating equilibrium of the Ba(2+)-blocked channel was investigated through the kinetics of the discrete blockade induced by Ba2+ ions. Gating properties of Na(+)- blocked channels could be directly characterized due to the very high rates of Na+ blocking/unblocking reactions. While in the presence of K+ (5 mM) in the external solution Ba2+ is known to stabilize the open state of the blocked channel (Miller, C., R. Latorre, and I. Reisin. 1987. J. Gen. Physiol. 90:427-449), we show that the divalent blocker stabilizes the closed-blocked state if permeant ions are removed from the external solution (K+ less than 10 microM). Ionic substitutions in the outer solution induce changes in the gating equilibrium of the Ba(2+)-blocked channel that are tightly correlated to the inhibition of Ba2+ dissociation by external monovalent cations. In permeant ion-free external solutions, blockade of the channel by internal Na+ induces a shift (around 15 mV) in the open probability--voltage curve toward more depolarized potentials, indicating that Na+ induces a stabilization of the closed-blocked state, as does Ba2+ under the same conditions. A kinetic analysis of the Na(+)-blocked channel indicates that the closed- blocked state is favored mainly by a decrease in opening rate. Addition of 1 mM external K+ completely inhibits the shift in the activation curve without affecting the Na(+)-induced reduction in the apparent single-channel amplitude. The results suggest that in the absence of external permeant ions internal blockers regulate the permeant ion occupancy of a site near the outer end of the channel. Occupancy of this site appears to modulate gating primarily by speeding the rate of channel opening. PMID:2056305

  6. Supporting a Learner Community with Software Agents

    ERIC Educational Resources Information Center

    Taurisson, Neil; Tchounikine, Pierre

    2004-01-01

    This paper describes a multi-agent approach that aims at supporting learners involved in a collective activity. We consider pedagogical situations where students have to explicitly define the articulation of their collective work and then achieve the different tasks they have defined. Our objective is to support these students by taking some of…

  7. Motivating Literacy Learners in Today's World

    ERIC Educational Resources Information Center

    Fletcher, J., Ed.; Parkhill, F., Ed.; Gillon, G., Ed.

    2010-01-01

    "Motivating Literacy Learners in Today's World" provides insights into a broad spectrum of children's literacy learning. Motivation is the key theme and the authors show how this can be achieved through reading for pleasure; in writing activities at a number of levels; and through oral language development. Chapters include: (1)…

  8. Goals, the Learner, and the Language Arts.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Teachers, principals, and supervisors need to determine the kinds of learners being taught in the school/class setting. Are pupils good by nature, bad, or neutral? Concepts held pertaining to each pupil assist in determining objectives, learning activities, and evaluation techniques. The Puritans believed that individuals were born evil or sinful.…

  9. Hypermedia Design as Learner Scaffolding

    ERIC Educational Resources Information Center

    Shapiro, Amy M.

    2008-01-01

    A number of available resources offer guidance about hypermedia design strategies, many of which rely on principles of user-centered design. Many recent efforts, however, have focused more on developing "learner-centered" hypermedia. Learner-centered hypermedia is designed to help learners achieve their educational goals, rather than offer mere…

  10. Pituitary adenylate cyclase activating polypeptide (PACAP) dilates cerebellar arteries through activation of large-conductance Ca(2+)-activated (BK) and ATP-sensitive (K ATP) K (+) channels.

    PubMed

    Koide, Masayo; Syed, Arsalan U; Braas, Karen M; May, Victor; Wellman, George C

    2014-11-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a potent vasodilator of numerous vascular beds, including cerebral arteries. Although PACAP-induced cerebral artery dilation is suggested to be cyclic AMP (cAMP)-dependent, the downstream intracellular signaling pathways are still not fully understood. In this study, we examined the role of smooth muscle K(+) channels and hypothesized that PACAP-mediated increases in cAMP levels and protein kinase A (PKA) activity result in the coordinate activation of ATP-sensitive K(+) (KATP) and large-conductance Ca(2+)-activated K(+) (BK) channels for cerebral artery dilation. Using patch-clamp electrophysiology, we observed that PACAP enhanced whole-cell KATP channel activity and transient BK channel currents in freshly isolated rat cerebellar artery myocytes. The increased frequency of transient BK currents following PACAP treatment is indicative of increased intracellular Ca(2+) release events termed Ca(2+) sparks. Consistent with the electrophysiology data, the PACAP-induced vasodilations of cannulated cerebellar artery preparations were attenuated by approximately 50 % in the presence of glibenclamide (a KATP channel blocker) or paxilline (a BK channel blocker). Further, in the presence of both blockers, PACAP failed to cause vasodilation. In conclusion, our results indicate that PACAP causes cerebellar artery dilation through two mechanisms: (1) KATP channel activation and (2) enhanced BK channel activity, likely through increased Ca(2+) spark frequency.

  11. Doing Your Part To Help Your Child Become SMART (Successful, Motivated, Autonomous, Responsible, Thoughtful): Six Workshops on Parenting SMART Learners.

    ERIC Educational Resources Information Center

    Sattes, Beth; Walsh, Jackie; Hickman, Mickey

    A SMART Learner is a lifelong learner who can adapt to rapid change and who possesses characteristics associated with success in and out of school. These workshop materials to help parents help their children become SMART learners provide: information from current research and best practice; learning activities that will actively engage parents in…

  12. Fast activating voltage- and calcium-dependent potassium (BK) conductance promotes bursting in pituitary cells: a dynamic clamp study

    PubMed Central

    Tabak, Joël; Tomaiuolo, Maurizio; Gonzalez-Iglesias, Arturo E.; Milescu, Lorin S.; Bertram, Richard

    2011-01-01

    The electrical activity pattern of endocrine pituitary cells regulates their basal secretion level. Rat somatotrophs and lactotrophs exhibit spontaneous bursting and have high basal levels of hormone secretion, while gonadotrophs exhibit spontaneous spiking and have low basal hormone secretion. It has been proposed that the difference in electrical activity between bursting somatotrophs and spiking gonadotrophs is due to the presence of large conductance potassium (BK) channels on somatotrophs but not on gonadotrophs. This is one example where the role of an ion channel type may be clearly established. We demonstrate here that BK channels indeed promote bursting activity in pituitary cells. Blocking BK channels in bursting lacto-somatotroph GH4C1 cells changes their firing activity to spiking, while further adding an artificial BK conductance via dynamic clamp restores bursting. Importantly, this burst-promoting effect requires a relatively fast BK activation/deactivation, as predicted by computational models. We also show that adding a fast activating BK conductance to spiking gonadotrophs converts the activity of these cells to bursting. Together, our results suggest that differences in BK channel expression may underlie the differences in electrical activity and basal hormone secretion levels among pituitary cell types and that the rapid rate of BK channel activation is key to its role in burst promotion. PMID:22090511

  13. Report: EPA Needs to Conduct Environmental Justice Reviews of Its Programs, Policies, and Activities

    EPA Pesticide Factsheets

    Report #2006-P-00034, September 18, 2006. Our survey results showed that EPA senior management has not sufficiently directed program and regional offices to conduct environment justice reviews in accordance with Executive Order 12898.

  14. 30 CFR 250.208 - If I conduct ancillary activities, what notices must I provide?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and... charge; the specific type(s) of operations you will conduct; and the instrumentation/techniques...

  15. 30 CFR 550.208 - If I conduct ancillary activities, what notices must I provide?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and... charge; the specific type(s) of operations you will conduct; and the instrumentation/techniques...

  16. 30 CFR 550.208 - If I conduct ancillary activities, what notices must I provide?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and... charge; the specific type(s) of operations you will conduct; and the instrumentation/techniques...

  17. 30 CFR 550.208 - If I conduct ancillary activities, what notices must I provide?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and... charge; the specific type(s) of operations you will conduct; and the instrumentation/techniques...

  18. Fragile Identities: Exploring Learner Identity, Learner Autonomy and Motivation through Young Learners' Voices

    ERIC Educational Resources Information Center

    Lamb, Terry Eric

    2011-01-01

    Recent research in the fields of motivation and learner autonomy in language learning has begun to explore their relationships to the construct of identity. This article builds on this through the voices of a group of six learners of French or German in a secondary school in England, over a two-year period. These young learners initially reveal a…

  19. Separate Cl^- Conductances Activated by cAMP and Ca2+ in Cl^--Secreting Epithelial Cells

    NASA Astrophysics Data System (ADS)

    Cliff, William H.; Frizzell, Raymond A.

    1990-07-01

    We studied the cAMP- and Ca2+-activated secretory Cl^- conductances in the Cl^--secreting colonic epithelial cell line T84 using the whole-cell patch-clamp technique. Cl^- and K^+ currents were measured under voltage clamp. Forskolin or cAMP increased Cl^- current 2-15 times with no change in K^+ current. The current-voltage relation for cAMP-activated Cl^- current was linear from -100 to +100 mV and showed no time-dependent changes in current during voltage pulses. Ca2+ ionophores or increased pipette Ca2+ increased both Cl^- and K^+ currents 2-30 times. The Ca2+-activated Cl^- current was outwardly rectified, activated during depolarizing voltage pulses, and inactivated during hyperpolarizing voltage pulses. Addition of ionophore after forskolin further increased Cl^- conductance 1.5-5 times, and the current took on the time-dependent characteristics of that stimulated by Ca2+. Thus, cAMP and Ca2+ activate Cl^- conductances with different properties, implying that these second messengers activate different Cl^- channels or that they induce different conductive and kinetic states in the same Cl^- channel.

  20. Local effect of compression stockings on skin microcirculatory activity through the measurement of skin effective thermal conductivity.

    PubMed

    Grenier, Etienne; Gehin, Claudine; Lun, Bertrand; McAdams, Eric

    2013-01-01

    This paper presents a preliminary study to demonstrate the instantaneous local effect of compression stocking (Class 2) on skin microcirculatory activity. The measurement needs to be carefully performed as the sensor is placed under the garment. To assess the local effect of compression stockings, we use the ambulatory device Hematron located on the calf under the garment. Skin microcirculatory activity is assessed through the skin's effective thermal conductivity measurement. A specific housing for the sensor has been designed to avoid excessive pressure induced by the sensor when squeezed by stockings. The experiment, conducted on ten healthy subjects, comprised two stages: without and with compression stockings. Skin effective thermal conductivity was recorded at three successive positions (supine, sitting and standing). Significant improvement in skin microcirculatory activity was recorded by the Hematron device for the three positions. We have also demonstrated that Hematron sensor can be used under compression stockings.

  1. Induction conductivity and natural gamma logs collected in 15 wells at Camp Stanley Storage Activity, Bexar County, Texas

    USGS Publications Warehouse

    Stanton, Gregory P.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the Camp Stanley Storage Activity conducted electromagnetic induction conductivity and natural gamma logging of 15 selected wells on the Camp Stanley Storage Activity, located in northern Bexar County, Texas, during March 28-30, 2005. In late 2004, a helicopter electromagnetic survey was flown of the Camp Stanley Storage Activity as part of a U.S. Geological Survey project to better define subsurface geologic units, the structure, and the catchment area of the Trinity aquifer. The electromagnetic induction conductivity and natural gamma log data in this report were collected to constrain the calculation of resistivity depth sections and to provide subsurface controls for interpretation of the helicopter electromagnetic data collected for the Camp Stanley Storage Activity. Logs were recorded digitally while moving the probe in an upward direction to maintain proper depth control. Logging speed was no greater than 30 feet per minute. During logging, a repeat section of at least 100 feet was recorded to check repeatability of log responses. Several of the wells logged were completed with polyvinyl chloride casing that can be penetrated by electromagnetic induction fields and allows conductivity measurement. However, some wells were constructed with steel centralizers and stainless steel screen that caused spikes on both conductivity and resulting resistivity log curves. These responses are easily recognizable and appear at regular intervals on several logs.

  2. Supporting Language Learners

    ERIC Educational Resources Information Center

    Cady, Jo Ann; Hodges, Thomas E.; Brown, Clara Lee

    2010-01-01

    English Language Learners (ELLs) have an increasing presence in the nations' classrooms. From 1991 to 2004 the number of ELLs nearly doubled in grades K-12. Furthermore, new forms of accountability have school personnel concerned with the progress--or lack of progress--of the ELLs. "Principles and Standards" also reflects this concern: The Equity…

  3. California's English Learner Students

    ERIC Educational Resources Information Center

    Hill, Laura E.

    2012-01-01

    English Learner (EL) students in California's schools are numerous and diverse, and they lag behind their native-English-speaking peers. Closing the achievement gap for EL students has been a long-standing goal for California educators, and there are some signs of success. Now that EL funding and curriculum issues are receiving a fresh level of…

  4. School Learners & Libraries.

    ERIC Educational Resources Information Center

    Karlsson, Jenni, Ed.

    This document presents papers from a conference held in November 1995 in Durban, KwaZulu-Natal, convened by the Education Policy Unit (EPU) of the University of Natal as part of research concerning the provision of library-based resources for school learners. Following an introduction are two chapters: "Identifying the Inherited Problems in…

  5. Literacy and the Learner.

    ERIC Educational Resources Information Center

    World Education, Inc. Reports, 1987

    1987-01-01

    This journal issue focuses on the learner, looks at why literacy has become a major concern and examines the changes brought about by the mastery of new skills. "Literacy/Illiteracy in an International Perspective" (Carman St. John Hunter) frames the discussion by stressing that literacy and illiteracy are moving targets, not fixed by…

  6. Serving the Online Learner

    ERIC Educational Resources Information Center

    Boettcher, Judith V.

    2007-01-01

    Systems and services for recruiting, advising, and support of online students have seldom been at the top of the list when planning online and distance learning programs. That is now changing: Forces pushing advising and support services into the foreground include recognition of the student learner as "customer" and the increasing…

  7. Gender and Learner Characteristics

    ERIC Educational Resources Information Center

    Hindal, Huda; Reid, Norman; Whitehead, Rex

    2013-01-01

    It is well established that girls and boys perform differently in traditional examinations in most countries. This study looks at a sample of 754 school students in Kuwait (aged about 13) and explores how boys and girls differ in the performance in a range of tests related to learner characteristics. The fundamental question is how boys and girls…

  8. Helping Young Hispanic Learners

    ERIC Educational Resources Information Center

    Garcia, Eugene E.; Jensen, Bryant

    2007-01-01

    Hispanics are the largest and youngest ethnic group in the United States. Moreover, young Hispanic children make up approximately 80 percent of the U.S. English language learner population. They are a heterogeneous group, born both inside and outside the United States and having origins in Mexico, Cuba, Central America, South America, and the…

  9. The Transliterate Learner

    ERIC Educational Resources Information Center

    Bush, Gail

    2012-01-01

    Thomas et al. have defined transliteracy as "the ability to read, write and interact across a range of platforms, tools and media from signing and orality through handwriting, print, TV, radio and film, to digital social networks" (Transliteracy Research Group). The learner who is transliterate builds knowledge, communicates, and interacts across…

  10. Learner Autonomy Revisited

    ERIC Educational Resources Information Center

    Illes, Eva

    2012-01-01

    This article explores whether the perception of learner autonomy that is promoted in language pedagogy is suitable for preparing students to perform successfully in the changed circumstances of the use of English. Recent developments, which include the growing role of English as a lingua franca and computer-mediated communication (CMC), give rise…

  11. Helping Gifted Learners Soar

    ERIC Educational Resources Information Center

    Rakow, Susan

    2012-01-01

    Whenever educators talk about raising achievement, grade-level standards are most frequently the end goal for student learning. But what about students who have already met some, if not all, of those standards and who master material quickly and in-depth? Advanced and gifted learners often languish in our schools because teachers don't have the…

  12. The Savvy Learner

    ERIC Educational Resources Information Center

    Dealtry, Richard

    2004-01-01

    This article defines the cultural nature and scale of change in learning consciousness that has to take place when the organizationally-based adult learner makes the transition from formal prescriptive learning practice to self-owned, self-directed learning. It articulates some of the learning-to-learn process models that introduce, accelerate,…

  13. of Iranian EFL Learners

    ERIC Educational Resources Information Center

    Rashidi, Nasser; Mortazavi, Fariba

    2012-01-01

    This research investigated the relationship between vocabulary learning strategies and vocabulary size of Iranian university EFL students. Participants in the present study were a total of 67 EFL learners, studying at Shiraz Azad University as senior English Translation students. The instruments utilized for data collection were three tests: A…

  14. 75 FR 79342 - Taking and Importing Marine Mammals; Navy Training Activities Conducted Within the Northwest...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... exposing them to sound from mid-frequency or high frequency active sonar (MFAS/HFAS) or to underwater... frequency active sonar (MFAS/HFAS) or underwater detonations. After submitting supplemental...

  15. Carbachol activates a K+ channel of very small conductance in the basolateral membrane of rat pancreatic acinar cells.

    PubMed

    Köttgen, M; Hoefer, A; Kim, S J; Beschorner, U; Schreiber, R; Hug, M J; Greger, R

    1999-10-01

    Secretion of Cl- requires the presence of a K+ conductance to hyperpolarize the cell, and to provide the driving force for Cl- exit via luminal Cl- channels. In the exocrine pancreas Cl- secretion is mediated by an increase in cytosolic Ca2+ ([Ca2+]i). Two types of Ca2+-activated K+ channels could be shown in pancreatic acinar cells of different species. However, there are no data on Ca2+-activated K+ channels in rat pancreatic acini. Here we examine the basolateral K+ conductance of freshly isolated rat pancreatic acinar cells in cell-attached and cell-excised patch-clamp experiments. Addition of carbachol (CCH, 1 micromol/l) to the bath led to the activation of very small conductance K+ channels in cell-attached patches (n=27), producing a noisy macroscopic outward current. The respective outward conductance increased significantly by a factor of 2.1+/-0.1 (n=27). Noise analysis revealed a Lorentzian noise component with a corner frequency (f(c)) of 30.3+/-3.5 Hz (n=19), consistent with channel activity in these patches. The estimated single-channel conductance was 1.5+/-0.4 pS (n=19). In cell-excised patches (inside out) from cells previously stimulated with CCH, channel activity was only observed in the presence of K+ in the bath solution. Under these conditions f(c) was 47.6+/-11.9 Hz (estimated single-channel conductance 1.1+/-0.2 pS, n=20). The current/voltage relationship of the noise showed weak inward rectification and the reversal potential shifted towards E(K+) when Na+ in the bath was replaced by K+. Channel activity in cell-excised patches was slightly reduced by 10 mmol/l Ba2+ (23.6+/-2.1% of the total outward current) and was completely absent when K+ in the bath was replaced by Na+. Reduction of the [Ca2+]i from 1 mmol/l to 1 micromol/l in cell-excised experiments decreased the current by 52.3+/-12.3% (n=5). Expression of K(v)LQT1, one of the possible candidates for a small-conductance K+ channel in rat pancreatic acinar cells, was shown by reverse

  16. 12 CFR 208.72 - What activities may a financial subsidiary conduct?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... activities: (1) Any financial activity listed in § 225.86(a), (b), or (c) of the Board's Regulation Y (12 CFR... 12 Banks and Banking 2 2010-01-01 2010-01-01 false What activities may a financial subsidiary... (12 U.S.C. 24a(b)); and (3) Any activity that the state member bank is permitted to engage in...

  17. 12 CFR 208.72 - What activities may a financial subsidiary conduct?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... activities: (1) Any financial activity listed in § 225.86(a), (b), or (c) of the Board's Regulation Y (12 CFR... 12 Banks and Banking 2 2012-01-01 2012-01-01 false What activities may a financial subsidiary... (12 U.S.C. 24a(b)); and (3) Any activity that the state member bank is permitted to engage in...

  18. 12 CFR 208.72 - What activities may a financial subsidiary conduct?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... activities: (1) Any financial activity listed in § 225.86(a), (b), or (c) of the Board's Regulation Y (12 CFR... 12 Banks and Banking 2 2014-01-01 2014-01-01 false What activities may a financial subsidiary... (12 U.S.C. 24a(b)); and (3) Any activity that the state member bank is permitted to engage in...

  19. 12 CFR 208.72 - What activities may a financial subsidiary conduct?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... activities: (1) Any financial activity listed in § 225.86(a), (b), or (c) of the Board's Regulation Y (12 CFR... 12 Banks and Banking 2 2011-01-01 2011-01-01 false What activities may a financial subsidiary... (12 U.S.C. 24a(b)); and (3) Any activity that the state member bank is permitted to engage in...

  20. 12 CFR 208.72 - What activities may a financial subsidiary conduct?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... activities: (1) Any financial activity listed in § 225.86(a), (b), or (c) of the Board's Regulation Y (12 CFR... 12 Banks and Banking 2 2013-01-01 2013-01-01 false What activities may a financial subsidiary... (12 U.S.C. 24a(b)); and (3) Any activity that the state member bank is permitted to engage in...

  1. Remedial Learners in a Community College Setting Contribute to Their Own Academic Success: Identifying Effective Teaching and Learning Strategies, Delivery Methods and Instructional Technologies for Remedial Learners

    ERIC Educational Resources Information Center

    Bollash, Mary C.

    2013-01-01

    The purpose of this research was to expand on previous research surrounding remedial education at the college level. This research was conducted in four phases and identified common traits for a population of remedial learners and then determined how these common elements, when implemented, positively impacted the academic success for learners in…

  2. 21 CFR 312.87 - Active monitoring of conduct and evaluation of clinical trials.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... clinical trials. 312.87 Section 312.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... and evaluation of clinical trials. For drugs covered under this section, the Commissioner and other agency officials will monitor the progress of the conduct and evaluation of clinical trials and...

  3. 21 CFR 312.87 - Active monitoring of conduct and evaluation of clinical trials.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... clinical trials. 312.87 Section 312.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... and evaluation of clinical trials. For drugs covered under this section, the Commissioner and other agency officials will monitor the progress of the conduct and evaluation of clinical trials and...

  4. 21 CFR 312.87 - Active monitoring of conduct and evaluation of clinical trials.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... clinical trials. 312.87 Section 312.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... and evaluation of clinical trials. For drugs covered under this section, the Commissioner and other agency officials will monitor the progress of the conduct and evaluation of clinical trials and...

  5. 21 CFR 312.87 - Active monitoring of conduct and evaluation of clinical trials.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... clinical trials. 312.87 Section 312.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... and evaluation of clinical trials. For drugs covered under this section, the Commissioner and other agency officials will monitor the progress of the conduct and evaluation of clinical trials and...

  6. 40 CFR 725.235 - Conditions of exemption for activities conducted inside a structure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 725.234(e) is required, the manufacturer, importer, or processor must do one of the following: (1) For research conducted in accordance with the NIH Guidelines, the manufacturer, importer, or processor must... in accordance with § 725.234, the manufacturer, importer, or processor must review and evaluate...

  7. 26 CFR 1.355-3 - Active conduct of a trade or business.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Corporation X is engaged in the manufacture and sale of soap and detergents and also owns investment... years, corporation X has conducted a single business of constructing sewage disposal plants and other... construction of a sewage disposal plant in State M, construction equipment, cash, and other tangible assets....

  8. 26 CFR 1.355-3 - Active conduct of a trade or business.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Corporation X is engaged in the manufacture and sale of soap and detergents and also owns investment... years, corporation X has conducted a single business of constructing sewage disposal plants and other... construction of a sewage disposal plant in State M, construction equipment, cash, and other tangible assets....

  9. 26 CFR 1.355-3 - Active conduct of a trade or business.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... Corporation X is engaged in the manufacture and sale of soap and detergents and also owns investment... years, corporation X has conducted a single business of constructing sewage disposal plants and other... construction of a sewage disposal plant in State M, construction equipment, cash, and other tangible assets....

  10. 26 CFR 1.355-3 - Active conduct of a trade or business.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Corporation X is engaged in the manufacture and sale of soap and detergents and also owns investment... years, corporation X has conducted a single business of constructing sewage disposal plants and other... construction of a sewage disposal plant in State M, construction equipment, cash, and other tangible assets....

  11. 26 CFR 1.355-3 - Active conduct of a trade or business.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Corporation X is engaged in the manufacture and sale of soap and detergents and also owns investment... years, corporation X has conducted a single business of constructing sewage disposal plants and other... construction of a sewage disposal plant in State M, construction equipment, cash, and other tangible assets....

  12. Genetically Programming Interfaces between Active Materials, Conductive Pathway and Current Collector in Li Ion Batteries

    DTIC Science & Technology

    2012-01-01

    assembled into coin cell with metallic lithium as counter electrode. Electrochemical characterization was conducted by galvanostatically cycling the half...encodes either A1, A2, S7, T7 or H7. These DNAs were then introduced into bacteria cells for amplification. Genetic sequencing performed on the

  13. 34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... rehabilitation technology; and (ii) Other scientific research to assist in meeting the employment and independent... Research Center conduct? 350.32 Section 350.32 Education Regulations of the Offices of the Department of... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering...

  14. 34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... rehabilitation technology; and (ii) Other scientific research to assist in meeting the employment and independent... Research Center conduct? 350.32 Section 350.32 Education Regulations of the Offices of the Department of... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering...

  15. Hypotonicity activates a voltage-dependent membrane conductance in N2a neuroblastoma cells.

    PubMed

    Taruno, Akiyuki; Marunaka, Yoshinori

    2017-03-04

    To maintain cellular and bodily homeostasis, cells respond to extracellular stimuli including osmotic stress by activating various ion channels, which have been implicated in many physiological and pathophysiological conditions. However, cellular osmosensory mechanisms remain elusive. Here, we report a novel voltage-dependent current in N2a cells activated by exposure to hypotonic stress. After a hypotonic challenge, N2a cells sequentially develop two distinct currents. The volume-regulated anion channel (VRAC) current emerges first and, after a delay, activation of a previously uncharacterized strongly outwardly rectifying current follows. The latter, delayed current (Id) is insensitive to NPPB, a nonspecific blocker of Cl(-) channels, and intracellular Mg(2+), which inhibits VRAC and swelling-activated TRPM3 and TRPM7 channels. Replacement of extracellular Na(+) with NMDG(+) reduces inward tail currents, suggesting that Id is mediated by cations. Finally, Id shows voltage-dependent activation with slow activation kinetics and half-maximal activation at +76 mV. These pharmacological and biophysical characteristics of Id are distinct from those of known osmotic cell swelling-activated ion channels. In conclusion, our data identify and characterize a novel osmotically-activated, voltage-dependent ion channel in N2a cells.

  16. Antimicrobial activity and cytotoxicity of cotton fabric coated with conducting polymers, polyaniline or polypyrrole, and with deposited silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Maráková, Nela; Humpolíček, Petr; Kašpárková, Věra; Capáková, Zdenka; Martinková, Lenka; Bober, Patrycja; Trchová, Miroslava; Stejskal, Jaroslav

    2017-02-01

    Cotton fabric was coated with conducting polymers, polyaniline or polypyrrole, in situ during the oxidation of respective monomers. Raman and FTIR spectra proved the complete coating of substrates. Polypyrrole content was 19.3 wt.% and that of polyaniline 6.0 wt.%. Silver nanoparticles were deposited from silver nitrate solutions of various concentrations by exploiting the reduction ability of conducting polymers. The content of silver was up to 11 wt.% on polypyrrole and 4 wt.% on polyaniline. The sheet resistivity of fabrics was determined. The conductivity was reduced after deposition of silver. The chemical cleaning reduced the conductivity by less than one order of magnitude for polypyrrole coating, while for polyaniline the decrease was more pronounced. The good antibacterial activity against S. aureus and E. coli and low cytotoxicity of polypyrrole-coated cotton, both with and without deposited silver nanoparticles

  17. Activity-dependent depression of monosynaptic fast IPSCs in hippocampus: contributions from reductions in chloride driving force and conductance.

    PubMed

    Ling, D S; Benardo, L S

    1995-01-23

    Whole-cell recordings techniques were used to record pharmacologically isolated fast inhibitory postsynaptic currents (IPSCs) in CA1 pyramidal neurons from rat hippocampal slices. Repetitive extracellular stimulation up to 10 Hz progressively reduced steady-state fast IPSC amplitude. At low stimulation frequencies (up to 1 Hz), this attenuation was characterized by a positive shift of IPSC reversal potential with no change in IPSC conductance. Above 1 Hz stimulation, fast IPSC depression was associated with changes in both reversal potential and IPSC conductance. Use-dependent depression at low frequencies was prevented when cells were chloride-loaded using cesium chloride based intracellular solutions. These findings suggest that activity-dependent depression of fast IPSCs at low stimulus frequencies results entirely from a reduction in chloride driving force, stemming from intracellular chloride accumulation. Activity-dependent changes in fast IPSC conductance occur only at stimulation rates above 1 Hz.

  18. A monomer is the minimum functional unit required for channel and ATPase activity of the cystic fibrosis transmembrane conductance regulator.

    PubMed

    Ramjeesingh, M; Li, C; Kogan, I; Wang, Y; Huan, L J; Bear, C E

    2001-09-04

    The cystic fibrosis transmembrane conductance regulator (CFTR) normally functions as a phosphorylation-regulated chloride channel on the apical surface of epithelial cells, and lack of this function is the primary cause for the fatal disease cystic fibrosis (CF). Previous studies showed that purified, reconstituted CFTR can function as a chloride channel and, further, that its intrinsic ATPase activity is required to regulate opening and closing of the channel gate. However, these previous studies did not identify the quaternary structure required to mediate conduction and catalysis. Our present studies show that CFTR molecules may self-associate in CHO and Sf9 membranes, as complexes close to the predicted size of CFTR dimers can be captured by chemical cross-linking reagents and detected using nondissociative PAGE. However, CFTR function does not require a multimeric complex for function as we determined that purified, reconstituted CFTR monomers are sufficient to mediate regulated chloride conduction and ATPase activity.

  19. 30 CFR 285.800 - How must I conduct my activities to comply with safety and environmental requirements?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Inspections, and Facility Assessments for Activities Conducted Under SAPs, COPs and GAPs § 285.800 How must I... approved SAP, COP, or GAP, as required under §§ 285.615(c), 285.633(b), or 285.653(c)....

  20. 30 CFR 285.801 - How must I conduct my approved activities to protect marine mammals, threatened and endangered...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... protect marine mammals, threatened and endangered species, and designated critical habitat? 285.801... mammals, threatened and endangered species, and designated critical habitat? (a) You must not conduct any activity under your lease or grant that may affect threatened or endangered species or that may...

  1. 30 CFR 585.801 - How must I conduct my approved activities to protect marine mammals, threatened and endangered...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... protect marine mammals, threatened and endangered species, and designated critical habitat? 585.801... endangered species, and designated critical habitat? (a) You must not conduct any activity under your lease or grant that may affect threatened or endangered species or that may affect designated...

  2. 30 CFR 585.801 - How must I conduct my approved activities to protect marine mammals, threatened and endangered...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... protect marine mammals, threatened and endangered species, and designated critical habitat? 585.801... endangered species, and designated critical habitat? (a) You must not conduct any activity under your lease or grant that may affect threatened or endangered species or that may affect designated...

  3. 30 CFR 585.801 - How must I conduct my approved activities to protect marine mammals, threatened and endangered...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... protect marine mammals, threatened and endangered species, and designated critical habitat? 585.801... endangered species, and designated critical habitat? (a) You must not conduct any activity under your lease or grant that may affect threatened or endangered species or that may affect designated...

  4. 30 CFR 285.801 - How must I conduct my approved activities to protect marine mammals, threatened and endangered...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... protect marine mammals, threatened and endangered species, and designated critical habitat? 285.801... endangered species, and designated critical habitat? (a) You must not conduct any activity under your lease or grant that may affect threatened or endangered species or that may affect designated...

  5. 30 CFR 585.803 - How must I conduct my approved activities to protect essential fish habitats identified and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... protect essential fish habitats identified and described under the Magnuson-Stevens Fishery Conservation... fish habitats identified and described under the Magnuson-Stevens Fishery Conservation and Management Act? (a) If, during the conduct of your approved activities, BOEM finds that essential fish habitat...

  6. 30 CFR 585.803 - How must I conduct my approved activities to protect essential fish habitats identified and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... protect essential fish habitats identified and described under the Magnuson-Stevens Fishery Conservation... fish habitats identified and described under the Magnuson-Stevens Fishery Conservation and Management Act? (a) If, during the conduct of your approved activities, BOEM finds that essential fish habitat...

  7. 30 CFR 585.803 - How must I conduct my approved activities to protect essential fish habitats identified and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... protect essential fish habitats identified and described under the Magnuson-Stevens Fishery Conservation... fish habitats identified and described under the Magnuson-Stevens Fishery Conservation and Management Act? (a) If, during the conduct of your approved activities, BOEM finds that essential fish habitat...

  8. 30 CFR 285.803 - How must I conduct my approved activities to protect essential fish habitats identified and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... protect essential fish habitats identified and described under the Magnuson-Stevens Fishery Conservation... fish habitats identified and described under the Magnuson-Stevens Fishery Conservation and Management Act? (a) If, during the conduct of your approved activities, MMS finds that essential fish habitat...

  9. Feasibility of Conducting a Randomized Trial to Promote Healthy Eating, Active Play and Sustainability Awareness in Early Childhood Curricula

    ERIC Educational Resources Information Center

    Morris, Heather; Skouteris, Helen; Edwards, Susan; Rutherford, Leonie Margaret; Cutter-Mackenzie, Amy; O'Connor, Amanda; Mantilla, Ana; Huang, Terry TK; Lording, Kate Marion; Williams-Smith, Janet

    2016-01-01

    We sought to evaluate the feasibility of conducting a randomized trial to evaluate the efficacy of a preschool/kindergarten curriculum intervention designed to increase 4-year-old children's knowledge of healthy eating, active play and the sustainability consequences of their food and toy choices. Ninety intervention and 65 control parent/child…

  10. Sympathetic nerve activity can be estimated from skin conductance responses - a comment on Henderson et al. (2012).

    PubMed

    Bach, Dominik R

    2014-01-01

    A recent paper by Henderson et al. (2012) claimed that skin sympathetic nerve activity (SSNA) can not be retrieved from skin conductance responses (SCR). Here, I argue that this claim is not supported by the literature, and comment on contemporary approaches of estimating SSNA from SCR using biophysical models.

  11. 30 CFR 280.3 - What requirements must I follow when I conduct prospecting or research activities?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What requirements must I follow when I conduct prospecting or research activities? 280.3 Section 280.3 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE PROSPECTING FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR ON THE...

  12. 30 CFR 280.3 - What requirements must I follow when I conduct prospecting or research activities?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What requirements must I follow when I conduct prospecting or research activities? 280.3 Section 280.3 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE PROSPECTING FOR MINERALS OTHER THAN OIL,...

  13. 20 CFR 670.430 - What entities conduct outreach and admissions activities for the Job Corps program?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What entities conduct outreach and admissions activities for the Job Corps program? 670.430 Section 670.430 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) THE JOB CORPS UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Recruitment, Eligibility,...

  14. 20 CFR 670.430 - What entities conduct outreach and admissions activities for the Job Corps program?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What entities conduct outreach and admissions activities for the Job Corps program? 670.430 Section 670.430 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) THE JOB CORPS UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Recruitment, Eligibility,...

  15. 20 CFR 670.430 - What entities conduct outreach and admissions activities for the Job Corps program?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What entities conduct outreach and admissions activities for the Job Corps program? 670.430 Section 670.430 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR THE JOB CORPS UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Recruitment, Eligibility, Screening,...

  16. M2 Muscarinic Receptors Induce Airway Smooth Muscle Activation via a Dual, Gβγ-mediated Inhibition of Large Conductance Ca2+-activated K+ Channel Activity*

    PubMed Central

    Zhou, Xiao-Bo; Wulfsen, Iris; Lutz, Susanne; Utku, Emine; Sausbier, Ulrike; Ruth, Peter; Wieland, Thomas; Korth, Michael

    2008-01-01

    Airway smooth muscle is richly endowed with muscarinic receptors of the M2 and M3 subtype. Stimulation of these receptors inhibits large conductance calcium-activated K+ (BK) channels, a negative feed back regulator, in a pertussis toxinsensitive manner and thus facilitates contraction. The underlying mechanism, however, is unknown. We therefore studied the activity of bovine trachea BK channels in HEK293 cells expressing the M2 or M3 receptor (M2RorM3R). In M2R- but not M3R-expressing cells, maximal effective concentrations of carbamoylcholine (CCh) inhibited whole cell BK currents by 53%. This M2R-induced inhibition was abolished by pertussis toxin treatment or overexpression of the Gβγ scavenger transducin-α. In inside-out patches, direct application of 300 nm purified Gβγ decreased channel open probability by 55%. The physical interaction of Gβγ with BK channels was confirmed by co-immunoprecipitation. Interestingly, inhibition of phospholipase C as well as protein kinase C activities also reversed the CCh effect but to a smaller (∼20%) extent. Mouse tracheal cells responded similarly to CCh, purified Gβγ and phospholipase C/protein kinase C inhibition as M2R-expressing HEK293 cells. Our results demonstrate that airway M2Rs inhibit BK channels by a dual, Gβγ-mediated mechanism, a direct membrane-delimited interaction, and the activation of the phospholipase C/protein kinase C pathway. PMID:18524769

  17. 34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering...

  18. 34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering...

  19. 34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true What activities must a Rehabilitation Engineering... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering Research Centers Does the Secretary Assist? § 350.32 What activities must a Rehabilitation Engineering...

  20. 34 CFR 350.22 - What activities must a Rehabilitation Research and Training Center conduct?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false What activities must a Rehabilitation Research and... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Research and Training Centers Does the Secretary Assist? § 350.22 What activities must a Rehabilitation Research and...

  1. School Counselors Share Their Favorite Classroom Guidance Activities: Guide to Planning, Conducting, and Processing

    ERIC Educational Resources Information Center

    DeLucia-Waack, J., Ed.; Mercurio, M., Ed.; Colvin, F., Ed.; Korta, S., Ed.; Maertin, K., Ed.; Martin, E., Ed.; Zawadski, L., Ed.

    2014-01-01

    In this book, practicing school counselors have provided more than 60 classroom guidance activities that are presented across the three major ASCA areas in the National Standards for Students: Academic Skills, Personal/Social Skills, and Career Development/College Preparation. Activities are designed to integrate the ASCA Model, Response to…

  2. Tonic nanomolar dopamine enables an activity-dependent phase recovery mechanism that persistently alters the maximal conductance of the hyperpolarization-activated current in a rhythmically active neuron.

    PubMed

    Rodgers, Edmund W; Fu, Jing Jing; Krenz, Wulf-Dieter C; Baro, Deborah J

    2011-11-09

    The phases at which network neurons fire in rhythmic motor outputs are critically important for the proper generation of motor behaviors. The pyloric network in the crustacean stomatogastric ganglion generates a rhythmic motor output wherein neuronal phase relationships are remarkably invariant across individuals and throughout lifetimes. The mechanisms for maintaining these robust phase relationships over the long-term are not well described. Here we show that tonic nanomolar dopamine (DA) acts at type 1 DA receptors (D1Rs) to enable an activity-dependent mechanism that can contribute to phase maintenance in the lateral pyloric (LP) neuron. The LP displays continuous rhythmic bursting. The activity-dependent mechanism was triggered by a prolonged decrease in LP burst duration, and it generated a persistent increase in the maximal conductance (G(max)) of the LP hyperpolarization-activated current (I(h)), but only in the presence of steady-state DA. Interestingly, micromolar DA produces an LP phase advance accompanied by a decrease in LP burst duration that abolishes normal LP network function. During a 1 h application of micromolar DA, LP phase recovered over tens of minutes because, the activity-dependent mechanism enabled by steady-state DA was triggered by the micromolar DA-induced decrease in LP burst duration. Presumably, this mechanism restored normal LP network function. These data suggest steady-state DA may enable homeostatic mechanisms that maintain motor network output during protracted neuromodulation. This DA-enabled, activity-dependent mechanism to preserve phase may be broadly relevant, as diminished dopaminergic tone has recently been shown to reduce I(h) in rhythmically active neurons in the mammalian brain.

  3. Tonic Nanomolar Dopamine Enables an Activity-Dependent Phase Recovery Mechanism That Persistently Alters the Maximal Conductance of the Hyperpolarization-Activated Current in a Rhythmically Active Neuron

    PubMed Central

    Rodgers, Edmund W.; Fu, Jing Jing; Krenz, Wulf-Dieter C.

    2011-01-01

    The phases at which network neurons fire in rhythmic motor outputs are critically important for the proper generation of motor behaviors. The pyloric network in the crustacean stomatogastric ganglion generates a rhythmic motor output wherein neuronal phase relationships are remarkably invariant across individuals and throughout lifetimes. The mechanisms for maintaining these robust phase relationships over the long-term are not well described. Here we show that tonic nanomolar dopamine (DA) acts at type 1 DA receptors (D1Rs) to enable an activity-dependent mechanism that can contribute to phase maintenance in the lateral pyloric (LP) neuron. The LP displays continuous rhythmic bursting. The activity-dependent mechanism was triggered by a prolonged decrease in LP burst duration, and it generated a persistent increase in the maximal conductance (Gmax) of the LP hyperpolarization-activated current (Ih), but only in the presence of steady-state DA. Interestingly, micromolar DA produces an LP phase advance accompanied by a decrease in LP burst duration that abolishes normal LP network function. During a 1 h application of micromolar DA, LP phase recovered over tens of minutes because, the activity-dependent mechanism enabled by steady-state DA was triggered by the micromolar DA-induced decrease in LP burst duration. Presumably, this mechanism restored normal LP network function. These data suggest steady-state DA may enable homeostatic mechanisms that maintain motor network output during protracted neuromodulation. This DA-enabled, activity-dependent mechanism to preserve phase may be broadly relevant, as diminished dopaminergic tone has recently been shown to reduce Ih in rhythmically active neurons in the mammalian brain. PMID:22072689

  4. A summary of lessons learned activities conducted at the OECD Halden Reactor Project

    SciTech Connect

    Hallbert, B.P.

    1997-02-01

    A series of lessons learned studies have been conducted at the OECD Halden Reactor Project. The purpose of these lessons learned reports are to summarize knowledge and experience gained across a number of research project. This paper presents a summary of main issues addressed in four of these lessons learned projects. These are concerned with software development and quality assurance, software reliability, methods for test and evaluation of developed systems, and the evaluation of system design features.

  5. Activation of high and low affinity dopamine receptors generates a closed loop that maintains a conductance ratio and its activity correlate

    PubMed Central

    Krenz, Wulf-Dieter C.; Hooper, Ryan M.; Parker, Anna R.; Prinz, Astrid A.; Baro, Deborah J.

    2013-01-01

    Neuromodulators alter network output and have the potential to destabilize a circuit. The mechanisms maintaining stability in the face of neuromodulation are not well described. Using the pyloric network in the crustacean stomatogastric nervous system, we show that dopamine (DA) does not simply alter circuit output, but activates a closed loop in which DA-induced alterations in circuit output consequently drive a change in an ionic conductance to preserve a conductance ratio and its activity correlate. DA acted at low affinity type 1 receptors (D1Rs) to induce an immediate modulatory decrease in the transient potassium current (IA) of a pyloric neuron. This, in turn, advanced the activity phase of that component neuron, which disrupted its network function and thereby destabilized the circuit. DA simultaneously acted at high affinity D1Rs on the same neuron to confer activity-dependence upon the hyperpolarization activated current (Ih) such that the DA-induced changes in activity subsequently reduced Ih. This DA-enabled, activity-dependent, intrinsic plasticity exactly compensated for the modulatory decrease in IA to restore the IA:Ih ratio and neuronal activity phase, thereby closing an open loop created by the modulator. Activation of closed loops to preserve conductance ratios may represent a fundamental operating principle neuromodulatory systems use to ensure stability in their target networks. PMID:24155696

  6. Hydraulic conductivity of active layer soils in the McMurdo Dry Valleys, Antarctica: Geological legacy controls modern hillslope connectivity

    NASA Astrophysics Data System (ADS)

    Schmidt, Logan M.; Levy, Joseph S.

    2017-04-01

    Spatial variability in the hydraulic and physical properties of active layer soils influences shallow groundwater flow through cold-desert hydrological systems. This study measures the saturated hydraulic conductivity and grain-size distribution of 90 soil samples from the McMurdo Dry Valleys (MDV), Antarctica-primarily from Taylor Valley-to determine what processes affect the spatial distribution of saturated hydraulic conductivity in a simple, mineral-soil-dominated natural hillslope laboratory. We find that the saturated hydraulic conductivity and the grain-size distribution of soils are organized longitudinally within Taylor Valley. Soils sampled down-valley near the coast have a higher percentage of fine-sized sediments (fine sand, silt, clay) and lower saturated hydraulic conductivities than soils collected up-valley near Taylor Glacier (1.3 × 10- 2 vs. 1.2 × 10- 1 cm/s). Soils collected mid-valley have intermediate amounts of fines and saturated hydraulic conductivity values consistent with a hydrogeologic gradient spanning the valley from high inland to low near the coast. These results suggest the organization of modern soil properties within Taylor Valley is a relict signature from past glaciations that have deposited soils of decreasing age toward the mouth of the valley, modified by fluvial activity acting along temporal and microclimate gradients.

  7. Activated STAT1 transcription factors conduct distinct saltatory movements in the cell nucleus.

    PubMed

    Speil, Jasmin; Baumgart, Eugen; Siebrasse, Jan-Peter; Veith, Roman; Vinkemeier, Uwe; Kubitscheck, Ulrich

    2011-12-07

    The activation of STAT transcription factors is a critical determinant of their subcellular distribution and their ability to regulate gene expression. Yet, it is not known how activation affects the behavior of individual STAT molecules in the cytoplasm and nucleus. To investigate this issue, we injected fluorescently labeled STAT1 in living HeLa cells and traced them by single-molecule microscopy. We determined that STAT1 moved stochastically in the cytoplasm and nucleus with very short residence times (<0.03 s) before activation. Upon activation, STAT1 mobility in the cytoplasm decreased ∼2.5-fold, indicating reduced movement of STAT1/importinα/β complexes to the nucleus. In the nucleus, activated STAT1 displayed a distinct saltatory mobility, with residence times of up to 5 s and intermittent diffusive motion. In this manner, activated STAT1 factors can occupy their putative chromatin target sites within ∼2 s. These results provide a better understanding of the timescales on which cellular signaling and regulated gene transcription operate at the single-molecule level.

  8. Guanosine 5'-monophosphate modulates gating of high-conductance Ca2+-activated K+ channels in vascular smooth muscle cells.

    PubMed Central

    Williams, D L; Katz, G M; Roy-Contancin, L; Reuben, J P

    1988-01-01

    Ca2+-activated K+ channels (PKCa channels) account for the predominant K+ permeability of many types of smooth muscle cells. When activated, they oppose depolarization due to Na+ and Ca2+ channel activity. Several vasodilatory agents that increase intracellular cGMP levels (e.g., nitroprusside, adenosine, and atrial natriuretic factor) enhance the activity of these high-conductance PKCa channels in on-cell patches of bovine aortic smooth muscle cells. In addition, dibutyryl-cGMP (1.0 mM) causes a similar increase in channel activity. To pursue the mechanism of channel modulation by these agents, a series of guanine and adenine nucleotides were evaluated by using inside-out excised patches. Whereas cAMP, AMP, ADP, and ATP were ineffective, all of the corresponding guanine nucleotides potentiated PKCa channel activity when tested at a high concentration (500 microM). However, only GMP consistently enhanced channel activity in the 1-100 microM range by increasing the percent open time and frequency of opening of these channels over a wide range of potentials and Ca2+ levels without affecting single-channel conductance. Thus, GMP is a potent modulator of PKCa channels and it, rather than cGMP, may mediate the action of the vasodilators examined in this study. PMID:2848262

  9. Iontophoretic beta-adrenergic stimulation of human sweat glands: possible assay for cystic fibrosis transmembrane conductance regulator activity in vivo.

    PubMed

    Shamsuddin, A K M; Reddy, M M; Quinton, P M

    2008-08-01

    With the advent of numerous candidate drugs for therapy in cystic fibrosis (CF), there is an urgent need for easily interpretable assays for testing their therapeutic value. Defects in the cystic fibrosis transmembrane conductance regulator (CFTR) abolished beta-adrenergic but not cholinergic sweating in CF. Therefore, the beta-adrenergic response of the sweat gland may serve both as an in vivo diagnostic tool for CF and as a quantitative assay for testing the efficacy of new drugs designed to restore CFTR function in CF. Hence, with the objective of defining optimal conditions for stimulating beta-adrenergic sweating, we have investigated the components and pharmacology of sweat secretion using cell cultures and intact sweat glands. We studied the electrical responses and ionic mechanisms involved in beta-adrenergic and cholinergic sweating. We also tested the efficacy of different beta-adrenergic agonists. Our results indicated that in normal subjects the cholinergic secretory response is mediated by activation of Ca(2+)-dependent Cl(-) conductance as well as K(+) conductances. In contrast, the beta-adrenergic secretory response is mediated exclusively by activation of a cAMP-dependent CFTR Cl(-) conductance without a concurrent activation of a K(+) conductance. Thus, the electrochemical driving forces generated by beta-adrenergic agonists are significantly smaller compared with those generated by cholinergic agonists, which in turn reflects in smaller beta-adrenergic secretory responses compared with cholinergic secretory responses. Furthermore, the beta-adrenergic agonists, isoproprenaline and salbutamol, induced sweat secretion only when applied in combination with an adenylyl cyclase activator (forskolin) or a phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine, aminophylline or theophylline). We surmise that to obtain consistent beta-adrenergic sweat responses, levels of intracellular cAMP above that achievable with a beta-adrenergic agonist alone are

  10. Amoxapine inhibition of GABA-stimulated chloride conductance: Investigations of potential sites of activity

    SciTech Connect

    Ikeda, M.; Knapp, R.J.; Yamamura, H.I. ); Malatynska, E. )

    1989-01-01

    Amoxapine inhibits GABA-stimulated chloride conductance by acting on the GABA{sub A}-receptor chloride-ionophore complex which can be studied using membrane vesicles prepared from rat cerebral cortex. Amoxapine produces a right shift in the GABA concentration-response curve for the stimulation of {sup 36}Cl{sup {minus}} uptake into these vesicles with no apparent change in the maximum response. Schild analysis of these data gave a pA{sub 2} value of 5.52 with a slope of 0.79. Amoxapine inhibits the binding of the GABA{sub A} receptor selective antagonist ({sup 3}H)SR 95531 with an IC{sub 50} value of 3.45 {mu}M and a pseudo Hill coefficient of 0.83. In contrast, 10 {mu}M amoxapine inhibits ({sup 3}H) flunitrazepam binding by less than 25% while the benzodiazepine antagonist Ro 15-1788 reduces the amoxapine inhibition of GABA-stimulated chloride conductance only at high concentrations.

  11. Results of the pilot proof of the inquiry activities conducted in the science center

    NASA Astrophysics Data System (ADS)

    Kireš, Marián; BilišÅanská, Mária

    2017-01-01

    The science center SteelPARK Košice offers more than 60 interactive exhibits focused on presenting scientific principles and technical solutions connected to the production and manufacture of steel, research of its properties and its various industrial uses. We are trying to enhance the attractivity of the modern style of the exhibitions and its potential to engage students of ground and middle schools in acquiring new knowledge and capabilities, by means of the inquiry science center. Two laboratory measurements, for 5 three-person teams are provided once a month. During the introductory discussion on the activity, they are asked to answer a series of conceptual questions, which help determine their level of understanding at the beginning of the exercise. The measurements are based in guided inquiry, where the work progress is given a forehand, but the desired result is not. Every activity is focused on developing specific research capabilities. This is being monitored through a self-evaluation card, which every participants is required to fill out immediately after completing the activity. The work is tutored by a lecturer from the students of didactics. During two years and running 15 different activities, we have been able to gather information from more than 6000 students of ground and middle schools. Specific physics measurements, their respective conceptual questions, worksheets and final reports are being presented in this article. We evaluate the present level of conceptual understanding based on the acquired data and give recommendation to teachers on ways to improve the student's capabilities. The teacher, by way of observing the activity, the work of the lecturer and the students, is able to form an understanding of the inquiry activity for their own school practice, for which he/she can use all available methodical and work materials.

  12. Distinct contributions of small and large conductance Ca2+-activated K+ channels to rat Purkinje neuron function

    PubMed Central

    Edgerton, Jeremy R; Reinhart, Peter H

    2003-01-01

    The cerebellum is important for many aspects of behaviour, from posture maintenance and goal-oriented reaching movements to timing tasks and certain forms of learning. In every case, information flowing through the cerebellum passes through Purkinje neurons, which receive input from the two primary cerebellar afferents and generate continuous streams of action potentials that constitute the sole output from the cerebellar cortex to the deep nuclei. The tonic firing behaviour observed in Purkinje neurons in vivo is maintained in brain slices even when synaptic inputs are blocked, suggesting that Purkinje neuron activity relies to a significant extent on intrinsic conductances. Previous research has suggested that the interplay between Ca2+ currents and Ca2+-activated K+ channels (KCa channels) is important for Purkinje cell activity, but how many different KCa channel types are present and what each channel type contributes to cell behaviour remains unclear. In order to better understand the ionic mechanisms that control the behaviour of these neurons, we investigated the effects of different Ca2+ channel and KCa channel antagonists on Purkinje neurons in acute slices of rat cerebellum. Our data show that Ca2+ entering through P-type voltage-gated Ca2+ channels activates both small-conductance (SK) and large-conductance (BK) KCa channels. SK channels play a role in setting the intrinsic firing frequency, while BK channels regulate action potential shape and may contribute to the unique climbing fibre response. PMID:12576503

  13. 40 CFR 725.235 - Conditions of exemption for activities conducted inside a structure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... MICROORGANISMS Exemptions for Research and Development Activities § 725.235 Conditions of exemption for... be associated with the microorganism: (i) Information in its possession or control concerning any significant adverse reaction of persons exposed to the microorganism which may reasonably be associated...

  14. 40 CFR 725.235 - Conditions of exemption for activities conducted inside a structure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... MICROORGANISMS Exemptions for Research and Development Activities § 725.235 Conditions of exemption for... be associated with the microorganism: (i) Information in its possession or control concerning any significant adverse reaction of persons exposed to the microorganism which may reasonably be associated...

  15. 40 CFR 725.235 - Conditions of exemption for activities conducted inside a structure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... MICROORGANISMS Exemptions for Research and Development Activities § 725.235 Conditions of exemption for... be associated with the microorganism: (i) Information in its possession or control concerning any significant adverse reaction of persons exposed to the microorganism which may reasonably be associated...

  16. 40 CFR 725.235 - Conditions of exemption for activities conducted inside a structure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MICROORGANISMS Exemptions for Research and Development Activities § 725.235 Conditions of exemption for... be associated with the microorganism: (i) Information in its possession or control concerning any significant adverse reaction of persons exposed to the microorganism which may reasonably be associated...

  17. 15 CFR 917.42 - Categories of support available for the conducting of Sea Grant activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... have substantial strength in the three basic Sea Grant activities: research, education and training... generally for a single item of research, education and training, or advisory service, but may be renewed... may be in research, education, training, or advisory services. Support for a project is made to...

  18. 42 CFR 51.31 - Conduct of protection and advocacy activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....31 Section 51.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS... individuals with mental illness to address abuse, neglect or other violations of rights. (b) A P&A system shall establish policies and procedures to guide and coordinate advocacy activities. The P&A...

  19. 42 CFR 51.31 - Conduct of protection and advocacy activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....31 Section 51.31 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS... individuals with mental illness to address abuse, neglect or other violations of rights. (b) A P&A system shall establish policies and procedures to guide and coordinate advocacy activities. The P&A...

  20. 30 CFR 585.1010 - How long may I conduct activities under an Alternate Use RUE?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alternate Use RUE? 585.1010 Section 585.1010 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Rights of Use and Easement for Energy- and Marine-Related Activities Using Existing...

  1. New model of cystic fibrosis transmembrane conductance regulator proposes active channel-like conformation.

    PubMed

    Dalton, James; Kalid, Ori; Schushan, Maya; Ben-Tal, Nir; Villà-Freixa, Jordi

    2012-07-23

    The cystic fibrosis transmembrane conductance regulator (CFTR) is an unusual ABC transporter, functioning as a chloride channel critical for fluid homeostasis in multiple organs. Disruption of CFTR function is associated with cystic fibrosis making it an attractive therapeutic target. In addition, CFTR blockers are being developed as potential antidiarrheals. CFTR drug discovery is hampered by the lack of high resolution structural data, and considerable efforts have been invested in modeling the channel structure. Although previously published CFTR models that have been made publicly available mostly agree with experimental data relating to the overall structure, they present the channel in an outward-facing conformation that does not agree with expected properties of a "channel-like" structure. Here, we make available a model of CFTR in such a "channel-like" conformation, derived by a unique modeling approach combining restrained homology modeling and ROSETTA refinement. In contrast to others, the present model is in agreement with expected channel properties such as pore shape, dimensions, solvent accessibility, and experimentally derived distances. We have used the model to explore the interaction of open channel blockers within the pore, revealing a common binding mode and ionic interaction with K95, in agreement with experimental data. The binding-site was further validated using a virtual screening enrichment experiment, suggesting the model might be suitable for drug discovery. In addition, we subjected the model to a molecular dynamics simulation, revealing previously unaddressed salt-bridge interactions that may be important for structure stability and pore-lining residues that may take part in Cl(-) conductance.

  2. Kinetics of activation of the sodium conductance in the squid giant axon.

    PubMed Central

    Keynes, R D; Kimura, J E

    1983-01-01

    The time course of the rise in sodium conductance during positive voltage-clamp pulses was measured in squid giant axons perfused with CsF and immersed in low-sodium solutions. The initial transients were eliminated by subtraction of records made after blocking the sodium channels with tetrodotoxin. The value of tau m as defined by Hodgkin & Huxley (1952) passed through a well defined maximum at a membrane potential of about -35 mV. On fitting the initial inflexion in the rise of INa to the expression mXh instead of m3h, the value of X was found to vary from axon to axon between 2.9 and 4.4, with an average of 3.5. For any given axon, X did not vary significantly with pulse potential. Measurements of tau m were made on approaching each value of the membrane potential both from the negative and from the positive side. The cube law kinetics of the Hodgkin-Huxley equations were closely obeyed. Application of a negative prepulse to -180 mV delayed the rise of conductance by 20 musec at 7 degrees C without obviously changing tau m. Comparisons of the voltage dependence of tau m with that of the time constant tau 1 of the fast relaxation of the asymmetry current measured in the same axon, showed that tau 1 was smaller than tau m except at positive potentials, was less steeply voltage-dependent, and reached its maximum at a more positive potential. PMID:6308231

  3. Activities conducted during the definition phase of the outer planets missions program

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The activities are described of the Meteoroid Science Team for the definition phase of the outer planet missions. Studies reported include: (1) combined zodiacal experiment for the Grand Tour Missions of the outer planets, (2) optical transmission of a honeycomb panel and its effectiveness as a particle impact surface, (3) element identification data from the combined zodiacal OPGT experiment and (4) development of lightweight thermally stable mirrors.

  4. A Ta/W mixed addenda heteropolyacid with excellent acid catalytic activity and proton-conducting property

    NASA Astrophysics Data System (ADS)

    Li, Shujun; Peng, Qingpo; Chen, Xuenian; Wang, Ruoya; Zhai, Jianxin; Hu, Weihua; Ma, Fengji; Zhang, Jie; Liu, Shuxia

    2016-11-01

    A new HPAs H20[P8W60Ta12(H2O)4(OH)8O236]·125H2O (H-1) which comprises a Ta/W mixed addenda heteropolyanion, 20 protons, and 125 crystalline water molecules has been prepared through ion-exchange method. The structure and properties of H-1 have been explored in detail. AC impedance measurements indicate that H-1 is a good solid state proton conducting material at room temperature with a conductivity value of 7.2×10-3 S cm-1 (25 °C, 30% RH). Cyclic voltammograms of H-1 indicate the electrocatalytic activity towards the reduction of nitrite. Hammett acidity constant H0 of H-1 in CH3CN is -2.91, which is the strongest among the present known HPAs. Relatively, H-1 exhibits excellent catalytic activities toward acetal reaction.

  5. New insights into the bactericidal activity of chitosan-Ag bionanocomposite: the role of the electrical conductivity.

    PubMed

    González-Campos, J Betzabé; Mota-Morales, Josué D; Kumar, Siva; Zárate-Triviño, Diana; Hernández-Iturriaga, Montserrat; Prokhorov, Yevgen; Lepe, Milton Vazquez; García-Carvajal, Zaira Y; Sanchez, Isaac C; Luna-Bárcenas, Gabriel

    2013-11-01

    The relationship between electrical conductivity, structure and antibacterial properties of chitosan-silver nanoparticles (CS/AgnP) biocomposites has been analyzed. To test the film's antimicrobial activity, Gram-positive and Gram-negative bacteria were studied. The interactions between silver nanoparticles with chitosan suggest the formation of silver ions which plays a major role in nanocomposite's bactericidal potency. In CS/AgnP biocomposites, the bactericide effectiveness increases by increasing AgnP concentrations up to 3 wt%, which is close to the electrical percolation threshold of ca. 3 wt%. As the AgnP concentration increases above this threshold, the bactericidal potency is greatly diminished. The elucidated correlation between electrical conductivity and antibacterial activity could be useful in the design of other nanocomposites that involve polymeric-based matrices.

  6. Investigating the Washback Effects of Task-Based Instruction on the Iranian EFL Learners' Vocabulary Learning

    ERIC Educational Resources Information Center

    Hamzeh, Alireza

    2016-01-01

    The current research was an attempt to explore the washback impact of task-based instruction (TBI) on EFL Iranian learners' vocabulary development. To this end, conducting an Oxford Placement Test (OPT), 30 out of 72 EFL Iranian learners studying in an English language institute, were randomly selected. Then, they were assigned to experimental (N…

  7. The Influence of In-Situational Coaching on the Reading Success of English Language Learners

    ERIC Educational Resources Information Center

    Hernandez, Esteban F.

    2012-01-01

    The purpose of this study was to evaluate the influence of in-situational coaching on the reading success of English Language Learners. This study was conducted using a quantitative research design to analyze summative assessment data related to the reading success of English Language Learners in a sample from an identified population.…

  8. Investigating the Impact of Explicit Collocation Instruction on ESL Learners' Writing Ability

    ERIC Educational Resources Information Center

    Adhami-O'Brian, Soolmaz

    2014-01-01

    The present study was conducted to explore the impact of explicit collocation instruction on the ESL learners' writing ability. Furthermore, this study was an attempt to find if there is any significant difference between male and female learners on their use of collocations in writing tasks. In so doing, 63 advanced English as a Second Language…

  9. Teachers' Views of the Efficacy of Incorporating the Project Approach into Classroom Practice with Diverse Learners

    ERIC Educational Resources Information Center

    Beneke, Sallee; Ostrosky, Michaelene M.

    2009-01-01

    This study provides preliminary insight into teachers' perspectives on ways that the Project Approach can help to support instruction of learners with a range of strengths and needs, and learners from a variety of cultural, economic, and linguistic backgrounds. Pre- and post-training interviews were conducted with seven preschool teachers who…

  10. The Changing Face of Motivation: A Study of Second Language Learners' Motivation over Time

    ERIC Educational Resources Information Center

    Campbell, Elizabeth; Storch, Neomy

    2011-01-01

    Motivation to learn a second language (L2) is considered a crucial individual factor in explaining success or lack thereof in second language learning. This study examined learners' motivation to learn Chinese as a second language (L2). The study was longitudinal and cross sectional. Interviews were conducted with learners at different year levels…

  11. Relationship between EFL Learners' Autonomy and Speaking Strategies They Use in Conversation Classes

    ERIC Educational Resources Information Center

    Salehi, Hadi; Ebrahimi, Marziyeh; Sattar, Susan; Shojaee, Mohammad

    2015-01-01

    The present study was conducted at Parsayan Language Institute in Isfahan, Iran. The students in pre-intermediate and intermediate classes were examined to investigate the relationship between degrees of learner autonomy, use of strategies for coping with speaking problems and the learners' success in their speaking classes. To determine the…

  12. Does Adding Mathematics to English Language Learners' Timetables Improve Their Acquisition of English?

    ERIC Educational Resources Information Center

    Stacey, Jenny

    2016-01-01

    This enquiry based project set out to find out if adult English language learners, known as ESOL (English for Speakers of Other Languages) learners in the UK, might benefit, in terms of their acquisition of English, from studying maths. This research has been conducted at a medium sized FE college in the East Midlands where I teach. I evaluate…

  13. The Effect of BBC World Clips with and without Subtitles on Intermediate EFL Learners' Vocabulary Development

    ERIC Educational Resources Information Center

    Sirmandi, Effat Heidari; Sardareh, Sedigheh Abbasnasab

    2016-01-01

    This study was conducted to investigate the effect of bimodal subtitled films on vocabulary learning among Iranian EFL learners. To achieve this purpose, 60 male and female intermediate learners who were studying English as a Foreign Language (EFL) in Pardis Memar Institiute in Bandar Abbas, Iran, participated in this study. A standard proficiency…

  14. Review of EFL Learners' Habits in the Use of Pedagogical Dictionaries

    ERIC Educational Resources Information Center

    El-Sayed, Al-Nauman Al-Amin Ali; Siddiek, Ahmed Gumaa

    2013-01-01

    A dictionary is an important device for both: EFL teachers and EFL learners. It is highly needed to conduct effective teaching and learning. Many investigations were carried out to study the foreign language learners' habits in the use of their dictionaries in reading, writing, testing and translating. This paper is shedding light on this issue;…

  15. The Effect of Navigation Tools on Learners' Achievement and Attitude in a Hypermedia Environment.

    ERIC Educational Resources Information Center

    Farrell, Inez H.; Moore, David M.

    2001-01-01

    Describes a study of eighth-grade middle school students that was conducted to determine whether varying the amount of learner control and interactivity through the use of different navigation tools (linear, menu, and search engine) would influence the achievement and attitude of learners of different academic abilities. (Author/LRW)

  16. Promoting "Learner Voice" in VET: Developing Democratic, Transformative Possibilities or Further Entrenching the Status Quo?

    ERIC Educational Resources Information Center

    Angus, Lawrence; Golding, Barry; Foley, Annette; Lavender, Peter

    2013-01-01

    In order to critique the notion of "learner voice" in vocational education and training (VET) policy, this paper draws from a project conducted by the authors on behalf of the Australian National VET Equity Advisory Council (NVEAC). The term "learner voice" is used extensively throughout NVEAC documentation to describe the…

  17. The Influence of Teachers' Anxiety-Reducing Strategies on Learners' Foreign Language Anxiety

    ERIC Educational Resources Information Center

    Alrabai, Fakieh

    2015-01-01

    This quasi-experimental study investigated the effects on learner anxiety of anxiety-reducing strategies utilized by English as a foreign language (EFL) teachers in Saudi Arabia. The study was conducted in two stages. In the first stage, sources of foreign language (FL) anxiety for Saudi learners of English (N = 596) were identified using The…

  18. The Impact of Time-Series Diagnostic Tests on the Writing Ability of Iranian EFL Learners

    ERIC Educational Resources Information Center

    Atashgahi, Bahareh Molazem

    2014-01-01

    This study aimed to show whether administering a battery of time-series diagnostic tests (screening) has any impact on Iranian EFL learners' writing ability. The study was conducted on the intermediate EFL learners at Islamic Azad University North Tehran branch. The researcher administered a homogenizing test in order to exclude the exceptional…

  19. Comparative Effect of Memory and Cognitive Strategies Training on EFL Intermediate Learners' Vocabulary Learning

    ERIC Educational Resources Information Center

    Banisaeid, Maryam

    2013-01-01

    The present study was conducted to compare the effect of memory and cognitive strategies training on vocabulary learning of intermediate proficiency group of Iranian learners of English as a foreign language. It is to check how memory and cognitive strategies training affect word learning of EFL intermediate learners (N = 60) who were homogenized…

  20. The Nature of Language Learners' Beliefs: A Half-Told Story

    ERIC Educational Resources Information Center

    Zhong, Qunyan

    2015-01-01

    Substantial amount of research regarding L2 learners' beliefs has been conducted in recent years. However, not enough attention has been paid to investigating the nature of learners' beliefs; hence our understanding of the construct is contradictory in the sense that early research studies report stability in beliefs, while more recent studies…

  1. Learner Support Requirements for Online Workplace Training in the South African Furniture Industry

    ERIC Educational Resources Information Center

    MacDonald, Iain S.; Bullen, Mark; Kozak, Robert A.

    2010-01-01

    A qualitative research project was conducted to evaluate the suitability of e-learning as a means of delivering training to workplace learners in the South African furniture manufacturing sector. Twenty learners participated in a three-month pilot e-learning course and were monitored throughout. While the study was designed primarily to…

  2. Pedagogical Implications of Score Distribution Pattern and Learner Satisfaction in an Intensive TOEIC Course

    ERIC Educational Resources Information Center

    Kang, Che Chang

    2014-01-01

    The study aimed at investigating TOEIC score distribution patterns and learner satisfaction in an intensive TOEIC course and drew implications for pedagogical practice. A one-group pre-test post-test experiment and a survey on learner satisfaction were conducted on Taiwanese college EFL students (n = 50) in a case study. Results showed that the…

  3. Pragmatic Development of Chinese EFL Learners--A Study on FL Suggestions

    ERIC Educational Resources Information Center

    Gu, Tongqing

    2014-01-01

    While the number of studies on the pragmatic development of nonnative English speakers has been increasing, surprisingly little research has been conducted on the development of the ability of foreign language learners to perform the suggestion speech act, with even less taking Chinese EFL learners as the target group. The present study examines…

  4. Three Facets of Visual and Verbal Learners: Cognitive Ability, Cognitive Style, and Learning Preference.

    ERIC Educational Resources Information Center

    Mayer, Richard E.; Massa, Laura J.

    2003-01-01

    Examines the hypothesis that some people are verbal learners and some people are visual learners. Presented a battery of 14 cognitive measures related to the visualizer-verbalizer dimension to 95 college students and then conducted correlational and factor analyses. Results have implications for how to conceptualize and measure individual…

  5. Sources of Ca2+ for different Ca(2+)-activated K+ conductances in neurones of the rat superior cervical ganglion.

    PubMed Central

    Davies, P J; Ireland, D R; McLachlan, E M

    1996-01-01

    1. The role of various Ca(2+)-activated K+ conductances were investigated using intracellular recording and single-electrode voltage clamp in neurones of superior cervical ganglia isolated in vitro from young adult rats. 2. Following replacement of Ca2+ with Co2+ (2 mM) or the addition of Cd2+ (100 microM), action potential amplitude and half-width either increased or decreased (in different cells), but both the after-hyperpolarization (AHP) and the outward tail current following a suprathreshold voltage step were markedly attenuated (by about 75%). 3. Addition of charybdotoxin (60 nM) or nifedipine (10 microM) increased action potential half-width (by about 25%) but had no significant effect on the AHP or tail current. 4. Addition of apamin (100 nM) or omega-conotoxin GVIA (100 nM) reduced the AHP and tail current (by about 60%) but did not significantly affect the action potential. A prolonged apamin-resistant component of the AHP present in 50% of neurones was blocked by ryanodine (20 microM). 5. Omega-Conotoxin MVIIC (150 nM) and omega agatoxin IVA (200 nM) had no significant effects on the action potential half-width or the AHP. 6. None of the Ca2+ channel blockers affected the prolonged ryanodine-sensitive component of the AHP and tail current. 7. We conclude that, in rat sympathetic neurones, Ca2+ entry via L-type channels selectively activates large conductance Ca(2+)-activated K+ channels (BK type) contributing to action potential repolarization, whereas Ca2+ entry via N-type channels selectively activates small conductance Ca(2+)-activated K+ channels (SK type) contributing to the AHP. Ca2+ entry via R-type Ca2+ channels prolongs the AHP by activating Ca2+ release from intracellular stores. Images Figure 9 PMID:8887749

  6. Epigenetic upregulation of large-conductance Ca2+-activated K+ channel expression in uterine vascular adaptation to pregnancy.

    PubMed

    Chen, Man; Dasgupta, Chiranjib; Xiong, Fuxia; Zhang, Lubo

    2014-09-01

    Our previous study demonstrated that pregnancy increased large-conductance Ca(2+)-activated potassium channel β1 subunit (BKβ1) expression and large-conductance Ca(2+)-activated potassium channel activity in uterine arteries, which were abrogated by chronic hypoxia. The present study tested the hypothesis that promoter methylation/demethylation is a key mechanism in epigenetic reprogramming of BKβ1 expression patterns in uterine arteries. Ovine BKβ1 promoter of 2315 bp spanning from -2211 to +104 of the transcription start site was cloned, and an Sp1-380 binding site that contains CpG dinucleotide in its core binding sequences was identified. Site-directed deletion of the Sp1 site significantly decreased the BKβ1 promoter activity. Estrogen receptor-α bound to the Sp1 site through tethering to Sp1 and upregulated the expression of BKβ1. The Sp1 binding site at BKβ1 promoter was highly methylated in uterine arteries of nonpregnant sheep, and methylation inhibited transcription factor binding and BKβ1 promoter activity. Pregnancy caused a significant decrease in CpG methylation at the Sp1 binding site and increased Sp1 binding to the BKβ1 promoter and BKβ1 mRNA abundance. Chronic hypoxia during gestation abrogated this pregnancy-induced demethylation and upregulation of BKβ1 expression. The results provide evidence of a novel mechanism of promoter demethylation in pregnancy-induced reprogramming of large-conductance Ca(2+)-activated potassium channel expression and function in uterine arteries and suggest new insights of epigenetic mechanisms linking gestational hypoxia to aberrant uteroplacental circulation and increased risk of preeclampsia.

  7. Property of large conductance Ca(2+)-activated K+ channels from Fasciola hepatica incorporated into planar lipid bilayer.

    PubMed

    Jang, Jung Hee; Park, Jin Bong; Kim, Sun Don; Lee, So Yeong; Hong, Sung-Jong; Ryu, Pan Dong

    2012-05-25

    Fasciola hepatica causes biliary epithelial hyperplasia and obstructive jaundice in humans and animals. Using a planar lipid bilayer technique, we further characterized the single channel property of large conductance K(+)-permeable channels that were previously identified from F. hepatica. The single channel conductance was 254.7±17.9 pS under a symmetrical 200/200 mM (cis/trans) KCl gradient. Open state probability (P(o)) varied from channel to channel at a given membrane potential and Ca(2+) concentration, but increased with voltage (-60 to +40 mV) and cis Ca(2+) (1-200 μM). Under a near bi-ionic condition of 200 mM [K(+)](cis)/200 mM [Na(+)](trans), the permeability ratio of K(+) to Na(+) was 5.0. Charybdotoxin (1 μM) inhibited P(o), whereas tetraethylammonium reduced the conductance (K(D)=67.8mM). Taken together, the results show that the single channel properties of the large conductance K(+)-permeable channels in F. hepatica are similar to those of large conductance Ca(2+)-activated K(+) (BK) channels in general, but distinct from typical BK channels in the extent of voltage- and Ca(2+)-dependence, as well as permeability to Na(+). This study further reveals a variant BK channel in F. hepatica that could serve as a new drug target to treat fascioliasis.

  8. Superresolution imaging reveals activity-dependent plasticity of axon morphology linked to changes in action potential conduction velocity.

    PubMed

    Chéreau, Ronan; Saraceno, G Ezequiel; Angibaud, Julie; Cattaert, Daniel; Nägerl, U Valentin

    2017-02-07

    Axons convey information to nearby and distant cells, and the time it takes for action potentials (APs) to reach their targets governs the timing of information transfer in neural circuits. In the unmyelinated axons of hippocampus, the conduction speed of APs depends crucially on axon diameters, which vary widely. However, it is not known whether axon diameters are dynamic and regulated by activity-dependent mechanisms. Using time-lapse superresolution microscopy in brain slices, we report that axons grow wider after high-frequency AP firing: synaptic boutons undergo a rapid enlargement, which is mostly transient, whereas axon shafts show a more delayed and progressive increase in diameter. Simulations of AP propagation incorporating these morphological dynamics predicted bidirectional effects on AP conduction speed. The predictions were confirmed by electrophysiological experiments, revealing a phase of slowed down AP conduction, which is linked to the transient enlargement of the synaptic boutons, followed by a sustained increase in conduction speed that accompanies the axon shaft widening induced by high-frequency AP firing. Taken together, our study outlines a morphological plasticity mechanism for dynamically fine-tuning AP conduction velocity, which potentially has wide implications for the temporal transfer of information in the brain.

  9. The Activation Effect of Hainantoxin-I, a Peptide Toxin from the Chinese Spider, Ornithoctonus hainana, on Intermediate-Conductance Ca2+-Activated K+ Channels

    PubMed Central

    Huang, Pengfei; Zhang, Yiya; Chen, Xinyi; Zhu, Li; Yin, Dazhong; Zeng, Xiongzhi; Liang, Songping

    2014-01-01

    Intermediate-conductance Ca2+-activated K+ (IK) channels are calcium/calmodulin-regulated voltage-independent K+ channels. Activation of IK currents is important in vessel and respiratory tissues, rendering the channels potential drug targets. A variety of small organic molecules have been synthesized and found to be potent activators of IK channels. However, the poor selectivity of these molecules limits their therapeutic value. Venom-derived peptides usually block their targets with high specificity. Therefore, we searched for novel peptide activators of IK channels by testing a series of toxins from spiders. Using electrophysiological experiments, we identified hainantoxin-I (HNTX-I) as an IK-channel activator. HNTX-I has little effect on voltage-gated Na+ and Ca2+ channels from rat dorsal root ganglion neurons and on the heterologous expression of voltage-gated rapidly activating delayed rectifier K+ channels (human ether-à-go-go-related gene; human ERG) in HEK293T cells. Only 35.2% ± 0.4% of the currents were activated in SK channels, and there was no effect on BK channels. We demonstrated that HNTX-I was not a phrenic nerve conduction blocker or acutely toxic. This is believed to be the first report of a peptide activator effect on IK channels. Our study suggests that the activity and selectivity of HNTX-I on IK channels make HNTX-I a promising template for designing new drugs for cardiovascular diseases. PMID:25153257

  10. Electro-active Polymer Actuator Based on Sulfonated Polyimide with Highly Conductive Silver Electrodes Via Self-metallization.

    PubMed

    Song, Jiangxuan; Jeon, Jin-Han; Oh, Il-Kwon; Park, K C

    2011-10-04

    We report here a facile synthesis of high performance electro-active polymer actuator based on a sulfonated polyimide with well-defined silver electrodes via self-metallization. The proposed method greatly reduces fabrication time and cost, and obviates a cation exchange process required in the fabrication of ionic polymer-metal composite actuators. Also, the self-metallized silver electrodes exhibit outstanding metal-polymer adhesion with high conductivity, resulting in substantially larger tip displacements compared with Nafion-based actuators.

  11. Learner Preferences and Achievement Under Differing Amounts of Learner Practice.

    ERIC Educational Resources Information Center

    Schnackenberg, Heidi L.; Sullivan, Howard J.; Leader, Lars F.; Jones, Elizabeth E. K.

    1998-01-01

    Examines the effects of program mode (i.e., a lean program version containing a basic amount of learner practice versus a full mode containing expanded practice) and learner preference (matched or unmatched) for amount of practice on the achievement, time-in-program, and attitudes of university undergraduate students. Students preferred the lean…

  12. Molecular Information of charybdotoxin blockade in the large conductance calcium-activated potassium channel.

    PubMed

    Qiu, Su; Yi, Hong; Liu, Hui; Cao, Zhijian; Wu, Yingliang; Li, Wenxin

    2009-07-01

    The scorpion toxin, charybdotoxin (ChTX), is the first identified peptide inhibitor for the large-conductance Ca2+ and voltage-dependent K+ (BK) channel, and the chemical information of the interaction between ChTX and BK channel remains unclear today. Using combined computational methods, we obtained a ChTX-BK complex structure model, which correlated well with the mutagenesis data. In this complex, ChTX mainly used its beta-sheet domains to associate the BK channel with a conserved pore-blocking Lys27. Another crucial Tyr36 residue of ChTX lied over the loop connecting selectivity filter and S6 helix of BK channel, forming a hydrogen bond with Gly291 of BK channel. Besides, the unique turret region of BK channel was found to be far away from bound ChTX, which could explain the fact that many BK channel blockers show less selectivity over Kv channels. Together, all these information is helpful to reveal the diverse interactions between scorpion toxins and potassium channels and can accelerate the molecular engineering of specific inhibitor design.

  13. Bactericidal activity, eggshell conductance, and hatchability effects of ozone versus formaldehyde disinfection

    SciTech Connect

    Whistler, P.E.; Sheldon, B.W. )

    1989-08-01

    Ozone and formaldehyde were evaluated as disinfectants in a prototype laboratory setter against microorganisms that are naturally present on fertile, freshly laid, broiler hatching eggs. Significantly lower microbial counts of over 2.5 log10 (P less than .05) were observed for water-misted and ozonated (2.83% by weight) eggs or formaldehyde-fumigated (triple strength) eggs than for control and water-misted eggs. Eggshell conductance studies as measured by egg moisture losses in a desiccator showed no significant differences (P greater than .05) among untreated, water misted, ozonated (3.06% by weight) with water mist, or formaldehyde (triple strength)-fumigated eggs. Hatchability was significantly reduced (26.5 to 37.5%) following ozonation (3.03% ozone by weight, 2 h) in comparison with effects of no treatment or water misting. Misting with ozonation was equally as effective as formaldehyde fumigation in reducing microbial counts. However, ozone treatment at the concentrations tested significantly reduced hatchability when compared with results of either no treatment, water misting, or an average hatchability figure for formaldehyde fumigation. These findings indicate that ozone is a good disinfectant yet may adversely affect embryo development when given in the gaseous form.

  14. Detection of Cystic Fibrosis Transmembrane Conductance Regulator Activity in Early-Phase Clinical Trials

    PubMed Central

    Rowe, Steven M.; Accurso, Frank; Clancy, John P.

    2007-01-01

    Advances in our understanding of cystic fibrosis pathogenesis have led to strategies directed toward treatment of underlying causes of the disease rather than treatments of disease-related symptoms. To expedite evaluation of these emerging therapies, early-phase clinical trials require extension of in vivo cystic fibrosis transmembrane conductance regulator (CFTR)–detecting assays to multicenter trial formats, including nasal potential difference and sweat chloride measurements. Both of these techniques can be used to fulfill diagnostic criteria for the disease, and can discriminate various levels of CFTR function. Full realization of these assays in multicenter clinical trials requires identification of sources of nonbiological intra- and intersite variability, and careful attention to study design and statistical analysis of study-generated data. In this review, we discuss several issues important to the performance of these assays, including efforts to identify and address aspects that can contribute to inconsistent and/or potentially erroneous results. Adjunctive means of detecting CFTR including mRNA expression, immunocytochemical localization, and other methods are also discussed. Recommendations are presented to advance our understanding of these biomarkers and to improve their capacity to predict cystic fibrosis outcomes. PMID:17652506

  15. Select clinical recommendations for military medical practitioners conducting humanitarian and civic assistance activities.

    PubMed

    Hollon, Justin R; Hickey, Patrick W

    2010-09-01

    Training and planning for stability, security, transition, and reconstruction, to include humanitarian and civic assistance activities, has taken on new importance for today's military forces. Deployed medical forces providing medical care to local populations are presented with the challenge of limited resources, complex public health needs, and complex cultural and linguistic barriers to care. In this article, we review some of the clinical situations commonly encountered during these operations and provide an evidence-based rationale for proposed courses of action. This report is timely given expanding operations in Afghanistan and the stand-up of the U.S. African Command (AFRICOM).

  16. Pregnancy upregulates large-conductance Ca(2+)-activated K(+) channel activity and attenuates myogenic tone in uterine arteries.

    PubMed

    Hu, Xiang-Qun; Xiao, Daliao; Zhu, Ronghui; Huang, Xiaohui; Yang, Shumei; Wilson, Sean; Zhang, Lubo

    2011-12-01

    Uterine vascular tone significantly decreases whereas uterine blood flow dramatically increases during pregnancy. However, the complete molecular mechanisms remain elusive. We hypothesized that increased Ca(2+)-activated K(+) (BK(Ca)) channel activity contributes to the decreased myogenic tone of uterine arteries in pregnancy. Resistance-sized uterine arteries were isolated from nonpregnant and near-term pregnant sheep. Electrophysiological studies revealed a greater whole-cell K(+) current density in pregnant compared with nonpregnant uterine arteries. Tetraethylammonium and iberiotoxin inhibited K(+) currents to the same extent in uterine arterial myocytes. The BK(Ca) channel current density was significantly increased in pregnant uterine arteries. In accordance, tetraethylammonium significantly increased pressure-induced myogenic tone in pregnant uterine arteries and abolished the difference in myogenic responses between pregnant and nonpregnant uterine arteries. Activation of protein kinase C produced a similar effect to tetraethylammonium by inhibiting BK(Ca) channel activity and increasing myogenic tone in pregnant uterine arteries. Chronic treatment of nonpregnant uterine arteries with physiologically relevant concentrations of 17β-estradiol and progesterone caused a significant increase in the BK(Ca) channel current density. Western blot analyses demonstrated a significant increase of the β1, but not α, subunit of BK(Ca) channels in pregnant uterine arteries. In accordance, steroid treatment of nonpregnant uterine arteries resulted in an upregulation of the β1, but not α, subunit expression. The results indicate that the steroid hormone-mediated upregulation of the β1 subunit and BK(Ca) channel activity may play a key role in attenuating myogenic tone of the uterine artery in pregnancy.

  17. Empirical Studies on Correlations between Lexical Knowledge and English Proficiency of Chinese EFL Learners in Mainland China over the Past Two Decades

    ERIC Educational Resources Information Center

    Zhou, Yao; Dai, Zhongxin

    2016-01-01

    Knowledge of English vocabulary contributes to the learner's proficiency of English as a foreign language, but how the learner's lexical knowledge behaves in the contribution. Researchers in mainland China have conducted studies of various kinds in order to find out how the learner's lexical knowledge correlates with his proficiency. This article…

  18. Solar activity and atmospheric tide effect on the polar conductivity and the vertical electric field in the stratosphere at low latitude

    NASA Astrophysics Data System (ADS)

    Gupta, S. P.

    2004-01-01

    Balloonborne measurements of the polar conductivity and the vertical electric field were carried out over a period of 1984-1994 from Hyderabad, Central India. The conductivity values show positive correlation with solar activity between 20 and 35 km. Between 5 and 20 km the conductivity values show an anti-correlation with solar activity. The vertical electric field does not show solar cycle effect. However, the electric field and the conductivity show a semi-diurnal variation at balloon float altitude.

  19. Modulation of activity and conduction in single dorsal column axons by kilohertz-frequency spinal cord stimulation.

    PubMed

    Crosby, Nathan D; Janik, John J; Grill, Warren M

    2017-01-01

    Kilohertz-frequency spinal cord stimulation (KHF-SCS) is a potential paresthesia-free treatment for chronic pain. However, the effects of KHF-SCS on spinal dorsal column (DC) axons and its mechanisms of action remain unknown. The objectives of this study were to quantify activation and conduction block of DC axons by KHF-SCS across a range of frequencies (1, 5, 10, or 20 kHz) and waveforms (biphasic pulses or sinusoids). Custom platinum electrodes delivered SCS to the T10/T11 dorsal columns of anesthetized male Sprague-Dawley rats. Single DC axons and compound action potentials were recorded during KHF-SCS to evaluate SCS-evoked activity. Responses to KHF-SCS in DC axons included brief onset firing, slowly accommodating asynchronous firing, and conduction block. The effects of KHF-SCS mostly occurred well above motor thresholds, but isolated units were activated at amplitudes shown to reduce behavioral sensitivity in rats. Activity evoked by SCS was similar across a range of frequencies (5-20 kHz) and waveforms (biphasic and sinusoidal). Stimulation at 1-kHz SCS evoked more axonal firing that was also more phase-synchronized to the SCS waveform, but only at amplitudes above motor threshold. These data quantitatively characterize the central nervous system activity that may modulate pain perception and paresthesia, and thereby provide a foundation for continued investigation of the mechanisms of KHF-SCS and its optimization as a therapy for chronic pain. Given the asynchronous and transient nature of DC activity, it is unlikely that the same mechanisms underlying conventional SCS (i.e., persistent, periodic DC activation) apply to KHF-SCS.

  20. Integrating high electrical conductivity and photocatalytic activity in cotton fabric by cationizing for enriched coating of negatively charged graphene oxide.

    PubMed

    Sahito, Iftikhar Ali; Sun, Kyung Chul; Arbab, Alvira Ayoub; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2015-10-05

    Electroconductive textiles have attended tremendous focus recently and researchers are making efforts to increase conductivity of e-textiles, in order to increase the use of such flexible and low cost textile materials. In this study, surface conductivity and photo catalytic activity of standard cotton fabric (SCF) was enhanced by modifying its surface charge, from negative to positive, using Bovine Serum Albumin (BSA) as a cationic agent, to convert it into cationised cotton fabric (CCF). Then, both types of fabrics were dip coated with a simple dip and dry technique for the adsorption of negatively charged graphene oxide (GO) sheets onto its surface. This resulted in 67.74% higher loading amount of GO on the CCF making self-assembly. Finally, this coating was chemically converted by vapor reduction using hydrazine hydrate to reduced graphene oxide (rGO) for restoration of a high electrical conductivity at the fabric surface. Our results revealed that with such high loading of GO, the surface resistance of CCF was only 40Ω/sq as compared to 510Ω/sq of the SCF and a 66% higher photo catalytic activity was also achieved through cationization for improved GO coating. Graphene coated SCF and CCF were characterized using FE-SEM, FTIR, Raman, UV-vis, WAXD, EDX and XPS spectroscopy to ascertain successful reduction of GO to rGO. The effect of BSA treatment on adsorption of cotton fabric was studied using drop shape analyzer to measure contact angle and for thermal and mechanical resistance, the fabric was tested for TGA and tensile strength, respectively. rGO coated fabric also showed slightly improved thermal stability yet a minor loss of strength was observed. The high flexibility, photocatalytic activity and excellent conductivity of this fabric suggests that it can be used as an electrode material for various applications.

  1. Demonized Learners in Sociocultural Theory

    ERIC Educational Resources Information Center

    Chen, Joanna

    2016-01-01

    Within the frameworks of Sociocultural theory, particularly Vygotskian sociocultural theory and ZPD, Lave and Wenger's CoP, and contemporary sociocultural theory, this paper seeks to examine the unfavourable scholarly portrayal of learners and their identities based on learners' behaviours, attitudes, and beliefs about the social element of…

  2. College Centers for Older Learners.

    ERIC Educational Resources Information Center

    Smith, Judith L.

    Across the nation, colleges are discovering a new group of students: retired learners. Special programs are emerging to meet the unique needs and interests of this mature population. This booklet describes these programs under the generic title, College Centers for Older Learners (CCOLs). CCOLs offer a stimulating college environment for older…

  3. The Generative Adolescent Mathematical Learner

    ERIC Educational Resources Information Center

    Lawler, Brian R.

    2010-01-01

    The purpose of this paper is to consider the personal epistemologies of generative adolescent mathematical learners. A generative disposition defined a learner who operated mathematically in ways that reflect an internalized authority for knowing and a constructive orientation to knowledge. Drawing upon the radical constructivist teaching…

  4. Chinese English Learners' Strategic Competence

    ERIC Educational Resources Information Center

    Wang, Dianjian; Lai, Hongling; Leslie, Michael

    2015-01-01

    The present study aims to investigate Chinese English learners' ability to use communication strategies (CSs). The subjects are put in a relatively real English referential communication setting and the analyses of the research data show that Chinese English learners, when encountering problems in foreign language (FL) communication, are…

  5. Assistive Software for Disabled Learners

    ERIC Educational Resources Information Center

    Clark, Sharon; Baggaley, Jon

    2004-01-01

    Previous reports in this series (#32 and 36) have discussed online software features of value to disabled learners in distance education. The current report evaluates four specific assistive software products with useful features for visually and hearing impaired learners: "ATutor", "ACollab", "Natural Voice", and "Just Vanilla". The evaluative…

  6. The Adult Learner: Four Aspects.

    ERIC Educational Resources Information Center

    Lucas, John A., Ed.

    1986-01-01

    Topics concerning the adult learner that are relevant to institutional researchers are addressed in four articles: marketing, predicting success for adult students, enrollment projection, and follow-up studies of adult learners. In "Institutional Research in Support of Marketing the Adult Student," Lydia Jurand notes the importance of…

  7. High Ability and Learner Characteristics

    ERIC Educational Resources Information Center

    Hindal, Huda; Reid, Norman; Whitehead, Rex

    2013-01-01

    The outstandingly able learner has been conceptualised, in terms of test and examination performance, as the learner showing superior academic performance which is markedly better than that of peers and in ways regarded as of value by wider society. In Kuwait, such superior examination performance leads to a classification regarded as being…

  8. Learner Intonation -- A Pilot Study.

    ERIC Educational Resources Information Center

    Backman, Nancy

    This study is concerned with problems in language learners' intonation of English. Ten intonation problems were found in the learner speech of two adult Spanish-speaking males: (1) range of pitch, (2) initial rise, (3) final fall, (4) rise to final stressed syllable, (5) placement of prominence, (6) final rise for questions, (7) total question…

  9. Sensitizing ESL Learners to Genre

    ERIC Educational Resources Information Center

    Swami, Jasti Appa

    2008-01-01

    This article evaluates the efficacy of explicit genre-based instruction by sensitizing the ESL learners to the concept of genre. The main questions addressed are: How does sensitizing ESL learners to the rhetorical move structure of a genre, the communicative purposes of these moves, and linguistic features that realize these moves help them to…

  10. Iranian EFL Learners' Compliment Responses

    ERIC Educational Resources Information Center

    Allami, Hamid; Montazeri, Maryam

    2012-01-01

    The present study aimed at examining the knowledge of Iranian EFL learners in responding to compliments in English, with a focus on the variables of gender, age and educational background. The data were collected through a 24-item English Discourse Completion Task (DCT) to which 40 male and female EFL learners were asked to provide short…

  11. Learner Autonomy and New Technologies.

    ERIC Educational Resources Information Center

    Raya, Manuel Jimenez; Fernandez, Jose Maria Perez

    2002-01-01

    Presents paths for theoretical research and practical procedures that may help teachers make new technology pedagogically relevant. Discusses the need to develop learner autonomy to help students process information in meaningful ways and become independent learners by developing effective learning strategies, transfer skills, and a greater sense…

  12. Profiling Mobile English Language Learners

    ERIC Educational Resources Information Center

    Byrne, Jason; Diem, Robert

    2014-01-01

    The purpose of this study was to use an app-embedded survey to profile language learner demographics. A total of 3,759 EFL language learners from primarily eight L1 backgrounds (French, German, Italian, Japanese, Korean, Russian, Spanish and Thai) responded to the survey embedded within a popular English grammar app. This app has over 500,000…

  13. Effective Instruction for English Learners

    ERIC Educational Resources Information Center

    Calderon, Margarita; Slavin, Robert; Sanchez, Marta

    2011-01-01

    The fastest-growing student population in U.S. schools today is children of immigrants, half of whom do not speak English fluently and are thus labeled English learners. Although the federal government requires school districts to provide services to English learners, it offers states no policies to follow in identifying, assessing, placing, or…

  14. Learner Control in Hypermedia Environments

    ERIC Educational Resources Information Center

    Scheiter, Katharina; Gerjets, Peter

    2007-01-01

    Contrary to system-controlled multimedia learning environments, hypermedia systems are characterized by a high level of interactivity. This interactivity is referred to as learner control in the respective literature. For several reasons this learner control is seen as a major advantage of hypermedia for learning and instruction. For instance,…

  15. Learners' Perceptions and Attitudes: Implications for Willingness to Communicate in an L2 Classroom

    ERIC Educational Resources Information Center

    de Saint Leger, Diane; Storch, Neomy

    2009-01-01

    This paper investigates learners' perceptions of their speaking abilities, of their contributions to oral class activities (whole class and small group discussions) as well as their attitudes towards these activities, and how such perceptions and attitudes influenced the learners' willingness to communicate in the L2. The study employed a range of…

  16. Motivation Classification and Grade Prediction for MOOCs Learners

    PubMed Central

    Xu, Bin; Yang, Dan

    2016-01-01

    While MOOCs offer educational data on a new scale, many educators find great potential of the big data including detailed activity records of every learner. A learner's behavior such as if a learner will drop out from the course can be predicted. How to provide an effective, economical, and scalable method to detect cheating on tests such as surrogate exam-taker is a challenging problem. In this paper, we present a grade predicting method that uses student activity features to predict whether a learner may get a certification if he/she takes a test. The method consists of two-step classifications: motivation classification (MC) and grade classification (GC). The MC divides all learners into three groups including certification earning, video watching, and course sampling. The GC then predicts a certification earning learner may or may not obtain a certification. Our experiment shows that the proposed method can fit the classification model at a fine scale and it is possible to find a surrogate exam-taker. PMID:26884747

  17. Electrospun conducting polymer nanofibers as the active material in sensors and diodes

    NASA Astrophysics Data System (ADS)

    Pinto, Nicholas J.

    2013-03-01

    Polyaniline doped with camphorsulfonic acid (PANi-HCSA) and poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT-PSSA) were electrospun separately to obtain individual nanofibers which were captured on Si/SiO2 substrates and electrically characterized. The fiber resistance was recorded as a function of time in the presence of vapours of aliphatic alcohols of varying sizes. Due to the large surface to volume ratio, uniform diameter and small quantity of active material used in the construction, these sensor responses are very quick. Sensors made from individual fibers also show true saturation upon exposure to and removal of the sensing gas. A Schottky diode was also fabricated using an n-doped Si/SiO2 substrate and a single PANi-HCSA fiber and tested in vacuum and in ammonia gas. The diode response was instantaneous upon exposure to ammonia with nearly complete recovery of the current upon pumping out the ammonia, thereby making it a reusable sensor with rectifying behaviour i.e. multifunctional.

  18. Electrophysiological characterization of Grueneberg ganglion olfactory neurons: spontaneous firing, sodium conductance, and hyperpolarization-activated currents.

    PubMed

    Liu, Cambrian Y; Xiao, Cheng; Fraser, Scott E; Lester, Henry A; Koos, David S

    2012-09-01

    Mammals rely on their acute olfactory sense for their survival. The most anterior olfactory subsystem in the nose, the Grueneberg ganglion (GG), plays a role in detecting alarm pheromone, cold, and urinary compounds. GG neurons respond homogeneously to these stimuli with increases in intracellular [Ca(2+)] or transcription of immediate-early genes. In this electrophysiological study, we used patch-clamp techniques to characterize the membrane properties of GG neurons. Our results offer evidence of functional heterogeneity in the GG. GG neurons fire spontaneously and independently in several stable patterns, including phasic and repetitive single-spike modes of discharge. Whole cell recordings demonstrated two distinct voltage-gated fast-inactivating Na(+) currents with different steady-state voltage dependencies and different sensitivities to tetrodotoxin. Hodgkin-Huxley simulations showed that these Na(+) currents confer dual mechanisms of action potential generation and contribute to different firing patterns. Additionally, GG neurons exhibited hyperpolarization-activated inward currents that modulated spontaneous firing in vitro. Thus, in GG neurons, the heterogeneity of firing patterns is linked to the unusual repertoire of ionic currents. The membrane properties described here will aid the interpretation of chemosensory function in the GG.

  19. Bournonite PbCuSbS3 : Stereochemically Active Lone-Pair Electrons that Induce Low Thermal Conductivity.

    PubMed

    Dong, Yongkwan; Khabibullin, Artem R; Wei, Kaya; Salvador, James R; Nolas, George S; Woods, Lilia M

    2015-10-26

    An understanding of the structural features and bonding of a particular material, and the properties these features impart on its physical characteristics, is essential in the search for new systems that are of technological interest. For several relevant applications, the design or discovery of low thermal conductivity materials is of great importance. We report on the synthesis, crystal structure, thermal conductivity, and electronic-structure calculations of one such material, PbCuSbS3 . Our analysis is presented in terms of a comparative study with Sb2 S3 , from which PbCuSbS3 can be derived through cation substitution. The measured low thermal conductivity of PbCuSbS3 is explained by the distortive environment of the Pb and Sb atoms from the stereochemically active lone-pair s(2) electrons and their pronounced repulsive interaction. Our investigation suggests a general approach for the design of materials for phase-change-memory, thermal-barrier, thermal-rectification and thermoelectric applications, as well as other functions for which low thermal conductivity is purposefully sought.

  20. A highly potent agonist to protease-activated receptor-2 reveals apical activation of the airway epithelium resulting in Ca2+-regulated ion conductance

    PubMed Central

    Sherwood, Cara L.; Daines, Michael O.; Price, Theodore J.; Vagner, Josef

    2014-01-01

    The airway epithelium provides a barrier that separates inhaled air and its various particulates from the underlying tissues. It provides key physiological functions in both sensing the environment and initiating appropriate innate immune defenses to protect the lung. Protease-activated receptor-2 (PAR2) is expressed both apically and basolaterally throughout the airway epithelium. One consequence of basolateral PAR2 activation is the rapid, Ca2+-dependent ion flux that favors secretion in the normally absorptive airway epithelium. However, roles for apically expressed PAR2 activation have not been demonstrated, in part due to the lack of specific, high-potency PAR2 ligands. In the present study, we used the newly developed PAR2 ligand 2at-LIGRLO(PEG3-Pam)-NH2 in combination with well-differentiated, primary cultured airway epithelial cells from wild-type and PAR2−/− mice to examine the physiological role of PAR2 in the conducting airway after apical activation. Using digital imaging microscopy of intracellular Ca2+ concentration changes, we verified ligand potency on PAR2 in primary cultured airway cells. Examination of airway epithelial tissue in an Ussing chamber showed that apical activation of PAR2 by 2at-LIGRLO(PEG3-Pam)-NH2 resulted in a transient decrease in transepithelial resistance that was due to increased apical ion efflux. We determined pharmacologically that this increase in ion conductance was through Ca2+-activated Cl− and large-conductance K+ channels that were blocked with a Ca2+-activated Cl− channel inhibitor and clotrimazole, respectively. Stimulation of Cl− efflux via PAR2 activation at the airway epithelial surface can increase airway surface liquid that would aid in clearing the airway of noxious inhaled agents. PMID:25143347

  1. The influence of moisture on the activation energy of the conductivity of paper-oil insulation of power transformers

    NASA Astrophysics Data System (ADS)

    Kierczyński, Konrad

    2016-09-01

    In the paper presents the influence of moisture content and electric field intensity on the activation energy of the conductivity DC electrical pressboard impregnated with insulating oil in the measuring temperature range of from 20 °C to 80 °C and the electric field intensity range from 10 kV/m to 1000 kV/m. With Arrhenius plots for each of the moisture content and for all seven of the electric field intensity was determined coefficients of determination R2, which are very close to one. This proves the high accuracy of approximation linear experimental results on the Arrhenius plots and highly accurate measurements of conductivity, accurate stabilization and measurements temperature. It was found that the moisture content of range from 1.15% to 6.5% wt. and the electric field intensity does not affect (in the margin of error) on the activation energy value of the DC conductivity, which is (1.0338 +/- 0.02000) eV.

  2. Phosphoinositide interacting regulator of TRP (Pirt) enhances TRPM8 channel activity in vitro via increasing channel conductance

    PubMed Central

    Tang, Min; Wu, Guang-yi; Dong, Xin-zhong; Tang, Zong-xiang

    2016-01-01

    Aim: Pirt is a two-transmembrane domain protein that regulates the function of a variety of ion channels. Our previous study indicated that Pirt acts as a positive endogenous regulator of the TRPM8 channel. The aim of this study was to investigate the mechanism underlying the regulation of TRPM8 channel by Pirt. Methods: HEK293 cells were transfected with TRPM8+Pirt or TRPM8 alone. Menthol (1 mmol/L) was applied through perfusion to induce TRPM8-mediated voltage-dependent currents, which were recorded using a whole-cell recording technique. PIP2 (10 μmol/L) was added into the electrode pipettes (PI was taken as a control). Additionally, cell-attached single-channel recordings were conducted in CHO cells transfected with TRPM8+Pirt or TRPM8 alone, and menthol (1 mmol/L) was added into the pipette solution. Results: Either co-transfection with Pirt or intracellular application of PIP2 (but not PI) significantly enhanced menthol-induced TRPM8 currents. Furthermore, Pirt and PIP2 synergistically modulated menthol-induced TRPM8 currents. Single-channel recordings revealed that co-transfection with Pirt significantly increased the single channel conductance. Conclusion: Pirt and PIP2 synergistically enhance TRPM8 channel activity, and Pirt regulates TRPM8 channel activity by increasing the single channel conductance. PMID:26657057

  3. Imaging the elastic modulus of human platelets during thrombin-induced activation using scanning ion conductance microscopy.

    PubMed

    Rheinlaender, Johannes; Vogel, Sebastian; Seifert, Jan; Schächtele, Marc; Borst, Oliver; Lang, Florian; Gawaz, Meinrad; Schäffer, Tilman E

    2015-02-01

    Platelet activation plays a critical role in haemostasis and thrombosis. It is well-known that platelets generate contractile forces during activation. However, their mechanical material properties have rarely been investigated. Here, we use scanning ion conductance microscopy (SICM) to visualise morphological and mechanical properties of live human platelets at high spatial resolution. We found that their mean elastic modulus decreases during thrombin-induced activation by about a factor of two. We observed a similar softening of platelets during cytochalasin D-induced cytoskeleton depolymerisation. However, thrombin-induced temporal and spatial modulations of the elastic modulus were substantially different from cytochalasin D-mediated changes. We thereby provide new insights into the mechanics of haemostasis and establish SICM as a novel imaging platform for the ex vivo investigation of the mechanical properties of live platelets.

  4. Large-conductance Ca²⁺-activated potassium channel in mitochondria of endothelial EA.hy926 cells.

    PubMed

    Bednarczyk, Piotr; Koziel, Agnieszka; Jarmuszkiewicz, Wieslawa; Szewczyk, Adam

    2013-06-01

    In the present study, we describe the existence of a large-conductance Ca²⁺-activated potassium (BKCa) channel in the mitochondria of the human endothelial cell line EA.hy926. A single-channel current was recorded from endothelial mitoplasts (i.e., inner mitochondrial membrane) using the patch-clamp technique in the mitoplast-attached mode. A potassium-selective current was recorded with a mean conductance equal to 270 ± 10 pS in a symmetrical 150/150 mM KCl isotonic solution. The channel activity, which was determined as the open probability, increased with the addition of calcium ions and the potassium channel opener NS1619. Conversely, the activity of the channel was irreversibly blocked by paxilline and iberiotoxin, BKCa channel inhibitors. The open-state probability was found to be voltage dependent. The substances known to modulate BKCa channel activity influenced the bioenergetics of mitochondria isolated from human endothelial EA.hy926 cells. In isolated mitochondria, 100 μM Ca²⁺, 10 μM NS1619, and 0.5 μM NS11021 depolarized the mitochondrial membrane potential and stimulated nonphosphorylating respiration. These effects were blocked by iberiotoxin and paxilline in a potassium-dependent manner. Under phosphorylating conditions, NS1619-induced, iberiotoxin-sensitive uncoupling diverted energy from ATP synthesis during the phosphorylating respiration of the endothelial mitochondria. Immunological analysis with antibodies raised against proteins of the plasma membrane BKCa channel identified a pore-forming α-subunit and an auxiliary β₂-subunit of the channel in the endothelial mitochondrial inner membrane. In conclusion, we show for the first time that the inner mitochondrial membrane in human endothelial EA.hy926 cells contains a large-conductance calcium-dependent potassium channel with properties similar to those of the surface membrane BKCa channel.

  5. Distribution of High-Conductance Calcium-Activated Potassium Channels in Rat Vestibular Epithelia

    PubMed Central

    Schweizer, Felix E.; Savin, David; Luu, Cindy; Sultemeier, David R.; Hoffman, Larry F.

    2011-01-01

    Voltage- and calcium-activated potassium channels (BK) are important regulators of neuronal excitability. BK channels seem to be crucial for frequency tuning in nonmammalian vestibular and auditory hair cells. However, there are a paucity of data concerning BK expression in mammalian vestibular hair cells. We therefore investigated the localization of BK channels in mammalian vestibular hair cells, specifically in rat vestibular neuroepithelia. We find that only a subset of hair cells in the utricle and the crista ampullaris express BK channels. BK-positive hair cells are located mainly in the medial striolar region of the utricle, where they constitute at most 12% of hair cells, and in the central zone of the horizontal crista. A majority of BK-positive hair cells are encapsulated by a calretinin-positive calyx defining them as type I cells. The remainder are either type I cells encapsulated by a calretinin-negative calyx or type II hair cells. Surprisingly, the number of BK-positive hair cells in the utricle peaks in juvenile rats and declines in early adulthood. BK channels were not found in vestibular afferent dendrites or somata. Our data indicate that BK channel expression in the mammalian vestibular system differs from the expression pattern in the mammalian auditory and the nonmammalian vestibular system. The molecular diversity of vestibular hair cells indicates a functional diversity that has not yet been fully characterized. The predominance of BK-positive hair cells within the medial striola of juvenile animals suggests that they contribute to a scheme of highly lateralized coding of linear head movements during late development. PMID:19731297

  6. Apparent intermediate K conductance channel hyposmotic activation in human lens epithelial cells.

    PubMed

    Lauf, Peter K; Misri, Sandeep; Chimote, Ameet A; Adragna, Norma C

    2008-03-01

    This study explores the nature of K fluxes in human lens epithelial cells (LECs) in hyposmotic solutions. Total ion fluxes, Na-K pump, Cl-dependent Na-K-2Cl (NKCC), K-Cl (KCC) cotransport, and K channels were determined by 85Rb uptake and cell K (Kc) by atomic absorption spectrophotometry, and cell water gravimetrically after exposure to ouabain +/- bumetanide (Na-K pump and NKCC inhibitors), and ion channel inhibitors in varying osmolalities with Na, K, or methyl-d-glucamine and Cl, sulfamate, or nitrate. Reverse transcriptase polymerase chain reaction (RT-PCR), Western blot analyses, and immunochemistry were also performed. In isosmotic (300 mosM) media approximately 90% of the total Rb influx occurred through the Na-K pump and NKCC and approximately 10% through KCC and a residual leak. Hyposmotic media (150 mosM) decreased K(c) by a 16-fold higher K permeability and cell water, but failed to inactivate NKCC and activate KCC. Sucrose replacement or extracellular K to >57 mM, but not Rb or Cs, in hyposmotic media prevented Kc and water loss. Rb influx equaled Kc loss, both blocked by clotrimazole (IC50 approximately 25 microM) and partially by 1-[(2-chlorophenyl) diphenylmethyl]-1H-pyrazole (TRAM-34) inhibitors of the IK channel KCa3.1 but not by other K channel or connexin hemichannel blockers. Of several anion channel blockers (dihydro-indenyl)oxy]alkanoic acid (DIOA), 4-2(butyl-6,7-dichloro-2-cyclopentylindan-1-on-5-yl)oxybutyric acid (DCPIB), and phloretin totally or partially inhibited Kc loss and Rb influx, respectively. RT-PCR and immunochemistry confirmed the presence of KCa3.1 channels, aside of the KCC1, KCC2, KCC3 and KCC4 isoforms. Apparently, IK channels, possibly in parallel with volume-sensitive outwardly rectifying Cl channels, effect regulatory volume decrease in LECs.

  7. Learner characteristics involved in distance learning

    SciTech Connect

    Cernicek, A.T.; Hahn, H.A.

    1991-01-01

    Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

  8. Ten Helpful Ideas for Teaching English to Young Learners

    ERIC Educational Resources Information Center

    Shin, Joan Kang

    2006-01-01

    This article offers ten suggestions for teaching young learners between the age of 7 and 12 based on language-teaching principles. They include supplementing activities with visuals, realia and movement; involving students in making visuals and realia; moving from activity to activity; teaching in themes; using stories and contexts familiar to…

  9. Hypogravity Research and Educational Parabolic Flight Activities Conducted in Barcelona: a new Hub of Innovation in Europe

    NASA Astrophysics Data System (ADS)

    Perez-Poch, Antoni; González, Daniel Ventura; López, David

    2016-12-01

    We report on different research and educational activities related to parabolic flights conducted in Barcelona since 2008. We use a CAP10B single-engine aerobatic aircraft flying out of Sabadell Airport and operating in visual flight conditions providing up to 8 seconds of hypogravity for each parabola. Aside from biomedical experiments being conducted, different student teams have flown in parabolic flights in the framework of the international contest `Barcelona Zero-G Challenge', and have published their results in relevant symposiums and scientific journals. The platform can certainly be a good testbed for a proof-of-concept before accessing other microgravity platforms, and has proved to be excellent for motivational student campaigns.

  10. Studies on the activation energy from the ac conductivity measurements of rubber ferrite composites containing manganese zinc ferrite

    NASA Astrophysics Data System (ADS)

    Hashim, Mohd.; Alimuddin; Kumar, Shalendra; Shirsath, Sagar E.; Mohammed, E. M.; Chung, Hanshik; Kumar, Ravi

    2012-11-01

    Manganese zinc ferrites (MZF) have resistivities between 0.01 and 10 Ω m. Making composite materials of ferrites with either natural rubber or plastics will modify the electrical properties of ferrites. The moldability and flexibility of these composites find wide use in industrial and other scientific applications. Mixed ferrites belonging to the series Mn(1-x)ZnxFe2O4 were synthesized for different ‘x’ values in steps of 0.2, and incorporated in natural rubber matrix (RFC). From the dielectric measurements of the ceramic manganese zinc ferrite and rubber ferrite composites, ac conductivity and activation energy were evaluated. A program was developed with the aid of the LabVIEW package to automate the measurements. The ac conductivity of RFC was then correlated with that of the magnetic filler and matrix by a mixture equation which helps to tailor properties of these composites.

  11. Thermal Cameras in School Laboratory Activities

    ERIC Educational Resources Information Center

    Haglund, Jesper; Jeppsson, Fredrik; Hedberg, David; Schönborn, Konrad J.

    2015-01-01

    Thermal cameras offer real-time visual access to otherwise invisible thermal phenomena, which are conceptually demanding for learners during traditional teaching. We present three studies of students' conduction of laboratory activities that employ thermal cameras to teach challenging thermal concepts in grades 4, 7 and 10-12. Visualization of…

  12. Impedance spectroscopic analysis of composite electrode from activated carbon/conductive materials/ruthenium oxide for supercapacitor applications

    SciTech Connect

    Taer, E.; Awitdrus,; Farma, R.; Deraman, M. Talib, I. A.; Ishak, M. M.; Omar, R.; Dolah, B. N. M.; Basri, N. H.; Othman, M. A. R.; Kanwal, S.

    2015-04-16

    Activated carbon powders (ACP) were produced from the KOH treated pre-carbonized rubber wood sawdust. Different conductive materials (graphite, carbon black and carbon nanotubes (CNTs)) were added with a binder (polivinylidene fluoride (PVDF)) into ACP to improve the supercapacitive performance of the activated carbon (AC) electrodes. Symmetric supercapacitor cells, fabricated using these AC electrodes and 1 molar H{sub 2}SO{sub 4} electrolyte, were analyzed using a standard electrochemical impedance spectroscopy technique. The addition of graphite, carbon black and CNTs was found effective in reducing the cell resistance from 165 to 68, 23 and 49 Ohm respectively, and increasing the specific capacitance of the AC electrodes from 3 to 7, 17, 32 F g{sup −1} respectively. Since the addition of CNTs can produce the highest specific capacitance, CNTs were chosen as a conductive material to produce AC composite electrodes that were added with 2.5 %, 5 % and 10 % (by weight) electro-active material namely ruthenium oxide; PVDF binder and CNTs contents were kept at 5 % by weight in each AC composite produced. The highest specific capacitance of the cells obtained in this study was 86 F g{sup −1}, i.e. for the cell with the resistance of 15 Ohm and composite electrode consists of 5 % ruthenium oxide.

  13. Electrochemical activity and high ionic conductivity of lithium copper pyroborate Li6CuB4O10.

    PubMed

    Strauss, Florian; Rousse, Gwenaëlle; Alves Dalla Corte, Daniel; Ben Hassine, Mohamed; Saubanère, Matthieu; Tang, Mingxue; Vezin, Hervé; Courty, Matthieu; Dominko, Robert; Tarascon, Jean-Marie

    2016-06-01

    In the search for new cathode materials for Li-ion batteries, borate (BO3(3-)) based compounds have gained much interest during the last two decades due to the low molecular weight of the borate polyanions which leads to active materials with increased theoretical capacities. In this context we herein report the electrochemical activity versus lithium and the ionic conductivity of a diborate or pyroborate B2O5(4-) based compound, Li6CuB4O10. By combining various electrochemical techniques with in situ X-ray diffraction, we show that this material can reversibly insert/deinsert limited amounts of lithium (∼0.3 Li(+)) in a potential window ranging from 2.5 to 4.5 V vs. Li(+)/Li(0). We demonstrate, via electron paramagnetic resonance (EPR), that such an electrochemical activity centered near 4.25 V vs. Li(+)/Li(0) is associated with the Cu(3+)/Cu(2+) redox couple, confirmed by density functional theory (DFT) calculations. Another specificity of this compound lies in its different electrochemical behavior when cycled down to 1 V vs. Li(+)/Li(0) which leads to the extrusion of elemental copper via a conversion type reaction as deduced by transmission electron microscopy (TEM). Lastly, we probe the ionic conductivity by means of AC and DC impedance measurements as a function of temperature and show that Li6CuB4O10 undergoes a reversible structural transition around 350 °C, leading to a surprisingly high ionic conductivity of ∼1.4 mS cm(-1) at 500 °C.

  14. Learning Difficulties in English for Rural Learners

    ERIC Educational Resources Information Center

    Singaravelu, G.

    2010-01-01

    The present study illuminates and diagnoses the learning problems of the rural learners in English Grammar at standard VI. Present study may be useful to ameliorate the rural learners for acquiring competencies in English and eliminates the problems of the learners. It paves way to the teachers to diagnose the learning hurdles of the learners and…

  15. Model Learner Outcomes for Service Occupations.

    ERIC Educational Resources Information Center

    Grote, Audrey M.

    This guide to model learner outcomes for service occupations contains four chapters: (1) education values, learner values, philosophy, mission, and goals; (2) introduction, goals, and eight program-level learner outcomes; (3) general learner outcomes and outcomes for housing occupations, child care occupations, cosmetology and personal services,…

  16. Preparing Learners for e-Learning.

    ERIC Educational Resources Information Center

    Piskurich, George M., Ed.

    This book presents methods business organizations and educational institutions can use to prepare their learners to become successful e-learners. "Preparing e-Learners for Self- Directed Learning" (Long) discusses self-direction as a prerequisite to e-learning and gives a list of ways to help enhance learners' self-directedness.…

  17. Mineralocorticoids decrease the activity of the apical small-conductance K channel in the cortical collecting duct.

    PubMed

    Wei, Yuan; Babilonia, Elisa; Sterling, Hyacinth; Jin, Yan; Wang, Wen-Hui

    2005-11-01

    We used the patch-clamp technique to examine the effect of DOCA treatment (2 mg/kg) on the apical small-conductance K (SK) channels, epithelial Na channels (ENaC), and the basolateral 18-pS K channels in the cortical collecting duct (CCD). Treatment of rats with DOCA for 6 days significantly decreased the plasma K from 3.8 to 3.1 meq and reduced the activity of the SK channel, defined as NP(o), from 1.3 in the CCD of control rats to 0.6. In contrast, DOCA treatment significantly increased ENaC activity from 0.01 to 0.53 and the basolateral 18-pS K channel activity from 0.67 to 1.63. Moreover, Western blot analysis revealed that DOCA treatment significantly increased the expression of the nonreceptor type of protein tyrosine kinase (PTK), cSrc, and the tyrosine phosphorylation of ROMK in the renal cortex and outer medulla. The possibility that decreases in apical SK channel activity induced by DOCA treatment were the result of stimulation of PTK activity was further supported by experiments in which inhibition of PTK with herbimycin A significantly increased NP(o) from 0.6 to 2.1 in the CCD from rats receiving DOCA. Also, when rats were fed a high-K (10%) diet, DOCA treatment did not increase the expression of c-Src and decrease the activity of the SK channel in the CCD. We conclude that DOCA treatment decreased the apical SK channel activity in rats on a normal-K diet and that an increase in PTK expression may be responsible for decreased channel activity in the CCD from DOCA-treated rats.

  18. Interaction between 2 extracellular loops influences the activity of the cystic fibrosis transmembrane conductance regulator chloride channel.

    PubMed

    Broadbent, Steven D; Wang, Wuyang; Linsdell, Paul

    2014-10-01

    Activity of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is thought to be controlled by cytoplasmic factors. However, recent evidence has shown that overall channel activity is also influenced by extracellular anions that interact directly with the extracellular loops (ECLs) of the CFTR protein. Very little is known about the structure of the ECLs or how substances interacting with these ECLs might affect CFTR function. We used patch-clamp recording to investigate the accessibility of cysteine-reactive reagents to cysteines introduced throughout ECL1 and 2 key sites in ECL4. Furthermore, interactions between ECL1 and ECL4 were investigated by the formation of disulfide crosslinks between cysteines introduced into these 2 regions. Crosslinks could be formed between R899C (in ECL4) and a number of sites in ECL1 in a manner that was dependent on channel activity, suggesting that the relative orientation of these 2 loops changes on activation. Formation of these crosslinks inhibited channel function, suggesting that relative movement of these ECLs is important to normal channel function. Implications of these findings for the effects of mutations in the ECLs that are associated with cystic fibrosis and interactions with extracellular substances that influence channel activity are discussed.

  19. The influence of hypotonicity on large-conductance calcium-activated potassium channels in human retinal pigment epithelial cells.

    PubMed

    Sheu, Shwu-Jiuan; Wu, Sheng-Nan; Hu, Dan-Ning; Chen, Jane-Fane

    2004-12-01

    The aim of this study was to characterize the effects of hypotonicity on the activity of large-conductance Ca(2+)-activated K+ (BK(Ca)) channels in human retinal pigment epithelial (RPE R-50) cells. Effects of hypotonicity on ion currents were investigated with the aid of the patch-clamp technique. A regulatory volume decrease in response to a hypotonic solution (200 mOsm/L) was observed that could be blunted by paxilline. In whole-cell current recordings, a hypotonic solution (200 mOsm/L) reversibly increased the amplitude of K+ outward currents (I(K)). The increase of I(K) could be reversed by iberiotoxin (200 nM), paxilline (1 microM), or tetrandrine (5 microM), but not by glibenclamide (10 microM), disulphonic acid (DIDS) (100 microM), or dequalinium dichloride (10 microM). In RPE R-50 cells pretreated with thapsigargin, aristolochic acid, or pertussis toxin, the increased amplitude of I(K) in response to hypotonicity was unaltered. In cell-attached patches, an increase in BK(Ca)-channel activity was observed during hypotonicity-induced cell swelling. The enhanced channel activity elicited under this condition was mainly mediated by an increase in the number of long-lived openings. These findings support the evidence for the coupling of volume swelling to the functional activity of BK(Ca) channels.

  20. Purification of charybdotoxine, a specific inhibitor of the high-conductance Ca/sup 2 +/-activated K/sup +/ channel

    SciTech Connect

    Smith, C.; Phillips, M.; Miller, C.

    1986-11-05

    Charybdotoxim is a high-affinity specific inhibitor of the high-conductance Ca/sup 2 +/-activated K/sup +/ channel found in the plasma membranes of many vertebrate cell types. Using Ca/sup 2 +/-activated K/sup +/ channels reconstituted into planar lipid bilayer membranes as an assay, the authors have purified the toxin from the venom of the scorpion Leiurus quinquestriatus by a two-step procedure involving chromatofocusing on SP-Sephadex, followed by reversed-phase high-performance liquid chromatography. Charybdotoxin is shown to be a highly basic protein with a mass of 10 kDa. Under the standard assay conditions, the purified toxin inhibits the Ca/sup 2 +/-activated K/sup +/ channel with an apparent dissociation constant of 3.5 nM. The protein is unusually stable, with inhibitory potency being insensitive to boiling or exposure to organic solvents. The toxin's activity is sensitive to chymotrypsin treatment and to acylation of lysine groups. The protein may be radioiodinated without loss of activity.

  1. Urban school leadership for elementary science education: Meeting the needs of English Language Learners

    NASA Astrophysics Data System (ADS)

    Alarcon, Maricela H.

    Science education reform and state testing accountability call upon principals to become instructional leaders in science. Specifically, elementary school principals must take an active role in science instruction to effectively improve science education for all students including English Language Learners. As such, the research questioned posed in this study centered on How are elementary school principals addressing the academic needs of Latino Spanish-speaking English language learners within science education? This study employed a qualitative research design to identify the factors contributing to the exemplary performance in science, as measured by the Texas Assessment of Knowledge and Skills (TAKS), for English Language Learner students in three high poverty bilingual elementary schools based on a multiple case study. As part of the data collection process, interviews were conducted with three school principals, three science academic support teachers, and two 5th grade bilingual teachers. Additionally, observations were acquired through school principal shadowing. The findings revealed four attributes necessary for effective instructional leadership in science education. First, Positive School Culture was defined as the core that linked the other three instructional leadership attributes and thus increased their effectiveness. Second, Clear Goals and Expectations were set by making science a priority and ensuring that English language learners were transitioning from Spanish to English instruction by the fifth grade. Third, Critical Resourcing involved hiring a science academic support teacher, securing a science classroom on campus, and purchasing bilingual instructional materials. Fourth, principal led and supported Collaboration in which teachers met to discuss student performance based data in addition to curriculum and instruction. These research findings are vital because by implementing these best practices of elementary school principals, educators

  2. Developing Learner Autonomy through Project Work in an ESP Class

    ERIC Educational Resources Information Center

    Díaz Ramírez, Martha Isabel

    2014-01-01

    This article presents the findings of an action research study on developing learner autonomy through project work in an English for Specific Purposes class. The study was conducted at a Colombian regional and public university with environmental engineering undergraduates. The instruments for data collection were field notes, semi-structured…

  3. Learner-Controlled Computing: A Description and Rationale.

    ERIC Educational Resources Information Center

    Milner, Stuart

    Learner controlled instruction in which the student controls the computer (e.g., computer programing) instead of it controlling the student (e.g., drill-and-drill-and-practice) is described. The nature of this mode of computer use is explored, and some examples based on case studies conducted by the author are given. A rationale for learner…

  4. Teaching Life Sciences to Blind and Visually Impaired Learners

    ERIC Educational Resources Information Center

    Fraser, William John; Maguvhe, Mbulaheni Obert

    2008-01-01

    This study reports on the teaching of life sciences (biology) to blind and visually impaired learners in South Africa at 11 special schools with specific reference to the development of science process skills in outcomes-based classrooms. Individual structured interviews were conducted with nine science educators teaching at the different special…

  5. The Educational Trajectories of English Language Learners in Texas

    ERIC Educational Resources Information Center

    Flores, Stella M.; Batalova, Jeanne; Fix, Michael

    2012-01-01

    About 5.3 million English Language Learners (ELLs)--students whose primary language is not English and whose English language skills are not sufficient to keep up with classes conducted only in English--are enrolled in PK-12 public schools across the United States. The number of these students increased dramatically in ten years, from 3.5 million…

  6. Designing Websites for ESL Learners: A Usability Testing Study

    ERIC Educational Resources Information Center

    Liu, Min; Traphagan, Tomoko; Huh, Jin; Koh, Young Ihn; Choi, Gilok; McGregor, Allison

    2008-01-01

    The purpose of this paper is to report on a usability study for ESL websites conducted to gain insights from learners of English as a second language (ESL) as they interacted with specific sites. Five carefully selected ESL sites were tested by 10 different users generating a total of fifty testing sessions. Two major research questions guided the…

  7. Participatory Photography: Can It Help Adult Learners Develop Agency?

    ERIC Educational Resources Information Center

    Yang, Kyung-Hwa

    2014-01-01

    This article draws on a participatory photography project conducted with 10 socioeconomically disadvantaged adult learners for six weeks within the framework of production pedagogy. Throughout the project, the participants took photographs about their lives in response to three prompts that I gave: (1) take photographs of people that are important…

  8. Barriers to Adult Learners of an Isolated Northern Community.

    ERIC Educational Resources Information Center

    Hilts, David J.

    In 1991, a study was conducted to determine perceptions regarding the deterrents to college attendance among adult learners in an isolated northern community. The study consisted of a survey of 40 students at the Fort Nelson campus of Northern Lights College (NLC) in British Columbia, and a follow-up interview of eight of the survey respondents.…

  9. ESL Learners, Writing and the Acquisition of Academic Language.

    ERIC Educational Resources Information Center

    Moore, Rashid A.; Zainuddin, Hanizah

    Most research conducted on the amount of time English language learners (ELLs) require for the acquisition of academic English suggests that 4-10 years are required to be near or on par with fully proficient English (FEP) peers. In this study, data from three administrations (1999, 2000, and 2001) of the FCAT writing test of the Florida Writing…

  10. Developing an Educational Performance Indicator for New Millennium Learners

    ERIC Educational Resources Information Center

    Kang, Myunghee; Heo, Heeok; Jo, Il-Hyun; Shin, Jongho; Seo, Jeonghee

    2011-01-01

    Educational performance based on the learning outcomes of formal schooling in a future knowledge society could be significantly different from that of today. This study investigates the possibilities of developing an educational performance indicator for new-millennium learners (NMLs). The researchers conducted literature reviews, a meeting of…

  11. "Successful Learners": Concept, Children's Views, and Classroom Practice

    ERIC Educational Resources Information Center

    Millar, Rachel; Gillies, Donald

    2013-01-01

    "Successful learners" is one of the four capacities, or purposes, of "Curriculum for Excellence" (CfE). This paper reports on a project which aimed to clarify its meaning, explore children's understanding of the term, and consider possible implications of both for classroom practice. The project was thus conducted in two parts:…

  12. Development of "Learner Roles in Constructive Learning Environment" Scale

    ERIC Educational Resources Information Center

    Bay, Erdal

    2011-01-01

    Introduction: This study aims to develop a scale to determine learner roles in constructive learning environment. Method: This study was conducted with 126 teacher candidates who study in Foreign Languages Department. For this study the teacher candidates were distributed into two groups. In the first group learning environments based on social…

  13. Classroom Instruction that Works with English Language Learners Facilitators Guide

    ERIC Educational Resources Information Center

    Hill, Jane D.; Bjork, Cynthia Linnea

    2008-01-01

    It's much easier to spread the insights and strategies from ASCD's (Association for Supervision and Curriculum Development) best-selling "Classroom Instruction That Works with English Language Learners" to everyone in your school when you have this guide for conducting a workshop or professional development meeting on how to improve the academic…

  14. Meeting the Social Needs of Preschool English Learners

    ERIC Educational Resources Information Center

    Luchtel, Molly; Hughes, Kere; Luze, Gayle; Bruna, Katherine Richardson; Peterson, Carla

    2010-01-01

    This article summarizes the findings of a study that examined the differences between preschool English learners and preschool English speakers in the areas of classroom conduct, social skills, and teacher-child relationship quality, as rated by their teachers. Theoretical and practical implications of the findings for early care and education…

  15. Preparing Teachers for Diverse Learners: Assessing Teacher Candidates' Dispositions

    ERIC Educational Resources Information Center

    Northington, Vera Ann

    2011-01-01

    The National Council for Accreditation for Teacher Education (NCATE) recommended teacher preparation programs measure teacher candidates' disposition toward diverse learners. The conduction of the quantitative cross-sectional survey design utilized the Quick Discrimination Index Survey (QDI), a Likert-type tool that used reversed or negatively…

  16. Learners' Performance in Doing Task with and without Teacher's Presence

    ERIC Educational Resources Information Center

    Rahimpour, Massoud; Zakeri, Elham

    2011-01-01

    Recently task-based language teaching has attracted many researchers', testers' and syllabus designers' attention and consequently a lot of studies are carried out in this field. This study was conducted in the task-based realm too. The main purpose of this study was to investigate the effect of teacher's presence on learners' performance in doing…

  17. Developing an Educational Performance Indicator for New Millennium Learners

    ERIC Educational Resources Information Center

    Kang, Myunghee; Heo, Heeok; Jo, Il-Hyun; Shin, Jongho; Seo, Jeonghee

    2012-01-01

    Educational performance based on the learning outcomes of formal schooling in a future knowledge society could be significantly different from that of today. This study investigates the possibilities of developing an educational performance indicator for new-millennium learners (NMLs). The researchers conducted literature reviews, a meeting of…

  18. Bilingual School Psychologists' Assessment Practices with English Language Learners

    ERIC Educational Resources Information Center

    O'Bryon, Elisabeth C.; Rogers, Margaret R.

    2010-01-01

    This study explored bilingual school psychologists' assessment practices with students identified as English language learners (ELL). One thousand bilingual National Association of School Psychologist members were recruited nationwide, and 276 participated. Among those conducting language proficiency assessments of ELLs, many (58%) use…

  19. Molecular and functional expression of high conductance Ca 2+ activated K+ channels in the eel intestinal epithelium.

    PubMed

    Lionetto, Maria G; Rizzello, Antonia; Giordano, Maria E; Maffia, Michele; De Nuccio, Francesco; Nicolardi, Giuseppe; Hoffmann, Else K; Schettino, Trifone

    2008-01-01

    Several types of K(+) channels have been identified in epithelial cells. Among them high conductance Ca(2+)-activated K(+) channels (BK channels) are of relevant importance for their involvement in regulatory volume decrease (RVD) response following hypotonic stress. The aim of the present work was to investigate the functional and molecular expression of BK in the eel intestine, which is a useful experimental model for cell volume regulation research. In the present paper using rat BK channel-specific primer, a RT-PCR signal of 696 pb cDNA was detected in eel intestine, whole nucleotide sequence showed high similarity (83%) to the alpha subunit of BK channel family. BK channel protein expression was verified by immunoblotting and confocal microscopy, while the functional role of BK channels in epithelial ion transport mechanisms and cell volume regulation was examined by electrophysiological and morphometric analysis on the intact tissue. BK(Ca) channels appeared to be localized along all the plasma membrane of the enterocytes; the apical part of the villi showed the most intense immunostaining. These channels were silent in basal condition, but were activated on both membranes (apical and basolateral) by increasing intracellular Ca(2+) concentration with the Ca(2+) ionophore ionomycin (1 microM). BK(Ca) channels were also activated on both membranes by hypotonic swelling of the epithelium and their inhibition by 100 nM iberiotoxin (specific BK(Ca) inhibitor) abolished the Regulatory Volume Decrease (RVD) of the intestinal cells after hypotonic swelling. In conclusion, our results demonstrated the molecular and functional expression of high conductance Ca(2+) -activated K(+) channels in eel intestine; the physiological role of these channels is mainly related to the RVD response of the epithelial cells following hypotonic swelling.

  20. Reconciling the discrepancies on the involvement of large-conductance Ca(2+)-activated K channels in glioblastoma cell migration.

    PubMed

    Catacuzzeno, Luigi; Caramia, Martino; Sforna, Luigi; Belia, Silvia; Guglielmi, Luca; D'Adamo, Maria Cristina; Pessia, Mauro; Franciolini, Fabio

    2015-01-01

    Glioblastoma (GBM) is the most common and aggressive primary brain tumor, and is notable for spreading so effectively through the brain parenchyma to make complete surgical resection virtually impossible, and prospect of life dismal. Several ion channels have been involved in GBM migration and invasion, due to their critical role in supporting volume changes and Ca(2+) influx occuring during the process. The large-conductance, Ca(2+)-activated K (BK) channels, markedly overexpressed in biopsies of patients with GBMs and in GBM cell lines, have attracted much interest and have been suggested to play a central role in cell migration and invasion as candidate channels for providing the ion efflux and consequent water extrusion that allow cell shrinkage during migration. Available experimental data on the role of BK channel in migration and invasion are not consistent though. While BK channels block typically resulted in inhibition of cell migration or in no effect, their activation would either enhance or inhibit the process. This short review reexamines the relevant available data on the topic, and presents a unifying paradigm capable of reconciling present discrepancies. According to this paradigm, BK channels would not contribute to migration under conditions where the [Ca(2+)] i is too low for their activation. They will instead positively contribute to migration for intermediate [Ca(2+)] i , insufficient as such to activate BK channels, but capable of predisposing them to cyclic activation following oscillatory [Ca(2+)] i increases. Finally, steadily active BK channels because of prolonged high [Ca(2+)] i would inhibit migration as their steady activity would be unsuitable to match the cyclic cell volume changes needed for proper cell migration.