Sample records for corrective feedback cf

  1. Oral Corrective Feedback in Second Language Classrooms

    ERIC Educational Resources Information Center

    Lyster, Roy; Saito, Kazuya; Sato, Masatoshi

    2013-01-01

    This article reviews research on oral corrective feedback (CF) in second language (L2) classrooms. Various types of oral CF are first identified, and the results of research revealing CF frequency across instructional contexts are presented. Research on CF preferences is then reviewed, revealing a tendency for learners to prefer receiving CF more…

  2. Teachers' Choice and Learners' Preference of Corrective Feedback Types

    ERIC Educational Resources Information Center

    Yoshida, Reiko

    2008-01-01

    Corrective feedback (CF) has been investigated in relation to learners' error types that trigger CF and learners' responses to CF. These research findings generally suggest that recasts, the most frequently used type of CF, did not trigger learners' reformulation of their erroneous utterances very frequently. In these studies, however, teachers'…

  3. Corrective Feedback (CF) and English-Major EFL Learners' Ability in Grammatical Error Detection and Correction

    ERIC Educational Resources Information Center

    Asassfeh, Sahail M.

    2013-01-01

    Corrective feedback (CF), the implicit or explicit information learners receive indicating a gap between their current, compared to the desired, performance, has been an area of interest for EFL researchers during the last few decades. This study, conducted on 139 English-major prospective EFL teachers, assessed the impact of two CF types…

  4. The Type and Linguistic Foci of Oral Corrective Feedback in the L2 Classroom: A Meta-Analysis

    ERIC Educational Resources Information Center

    Brown, Dan

    2016-01-01

    Research on corrective feedback (CF), a central focus of second language acquisition (SLA), has increasingly examined how teachers employ CF in second language classrooms. Lyster and Ranta's (1997) seminal study identified six types of CF that teachers use in response to students' errors (recast, explicit correction, elicitation, clarification…

  5. Chinese Secondary EFL Learners' and Teachers' Preferences for Types of Written Corrective Feedback

    ERIC Educational Resources Information Center

    Li, Haishan; He, Qingshun

    2017-01-01

    How learners perceive written corrective feedback (CF) associates with its effectiveness in language learning. This research investigates students' preferences for three types of written CF, i.e., direct, indirect and metalinguistic written CF, and explores the factors that encourage the teachers to employ these CFs in teaching practice. The…

  6. An Integrated Loop Model of Corrective Feedback and Oral English Learning: A Case of International Students in the United States

    ERIC Educational Resources Information Center

    Lee, Eun Jeong

    2017-01-01

    The author in this study introduces an integrated corrective feedback (CF) loop to schematize the interplay between CF and independent practice in L2 oral English learning among advanced-level adult ESL students. The CF loop integrates insights from the Interaction, Output, and Noticing Hypotheses to show how CF can help or harm L2 learners'…

  7. The Effectiveness of Synchronous and Asynchronous Written Corrective Feedback on Grammatical Accuracy in a Computer-Mediated Environment

    ERIC Educational Resources Information Center

    Shintani, Natsuko; Aubrey, Scott

    2016-01-01

    This study extends research on written corrective feedback (CF) by investigating how timing of CF affects grammar acquisition. Specifically, it examined the relative effects of synchronous and asynchronous CF on the accurate use of the hypothetical conditional structure. Participants were 68 intermediate-level students of English at a university…

  8. Corrective Feedback in SLA: Theoretical Relevance and Empirical Research

    ERIC Educational Resources Information Center

    Chen, Jin; Lin, Jianghao; Jiang, Lin

    2016-01-01

    Corrective feedback (CF) refers to the responses or treatments from teachers to a learner's nontargetlike second language (L2) production. CF has been a crucial and controversial topic in the discipline of second language acquisition (SLA). Some SLA theorists believe that CF is harmful to L2 acquisition and should be ruled out completely while…

  9. Exploring the Effects of Teachers' and Learners' Conflicting Beliefs on the Provision of Corrective Feedback during Undisturbed Classroom Interactions

    ERIC Educational Resources Information Center

    Garcia-Ponce, Edgar Emmanuell; Mora-Pablo, Irasema

    2017-01-01

    Extensive research literature suggests that corrective feedback (CF), when effective, has a beneficial impact on the development of learners' interlanguage. This is because CF provides learners with language data concerning the correctness of their utterances and thus pushes their oral production towards greater clarity, accuracy and…

  10. The Differential Effect of Two Types of Direct Written Corrective Feedback on Noticing and Uptake: Reformulation vs. Error Correction

    ERIC Educational Resources Information Center

    Santos, Maria; Lopez-Serrano, Sonia; Manchon, Rosa M.

    2010-01-01

    Framed in a cognitively-oriented strand of research on corrective feedback (CF) in SLA, the controlled three-stage (composition/comparison-noticing/revision) study reported in this paper investigated the effects of two forms of direct CF (error correction and reformulation) on noticing and uptake, as evidenced in the written output produced by a…

  11. Learner Affect in Computerised L2 Oral Grammar Practice with Corrective Feedback

    ERIC Educational Resources Information Center

    Bodnar, Stephen; Cucchiarini, Catia; Penning de Vries, Bart; Strik, Helmer; van Hout, Roeland

    2017-01-01

    Although corrective feedback (CF) has received much interest in the second language acquisition literature, relatively little research has investigated the relationship between CF and learner affect in concrete practice situations. The present study investigates learners' affective states and practice behaviour in a novel context: oral grammar…

  12. The Effectiveness of Written Corrective Feedback and the Impact Lao Learners' Beliefs Have on Uptake

    ERIC Educational Resources Information Center

    Rummel, Stephanie; Bitchener, John

    2015-01-01

    This article presents the results of a study examining the effectiveness of written corrective feedback (CF) on the simple past tense and the impact beliefs may have on students' uptake of the feedback they receive. A seven-week study was carried out with 42 advanced EFL learners in Vientiane, Laos. Students' beliefs about written CF were first…

  13. Teachers' Corrective Feedback in Writing Classes: The Impact of Collaborating with a Peer during the Editing Process on Students' Uptake and Retention

    ERIC Educational Resources Information Center

    Kahyalar, Eda; Yilmaz, Figen

    2016-01-01

    Language teachers devote a lot of time and energy to provide corrective feedback (CF) to help student writers improve the accuracy of their writing. However, regardless of the CF approach adopted, similar types of errors usually appear in students' new pieces of writing. Thus, most teachers have some doubt about the impact of CF, and some see it…

  14. Counterpoint Piece: The Case for Variety in Corrective Feedback Research

    ERIC Educational Resources Information Center

    Lyster, Roy; Ranta, Leila

    2013-01-01

    Goo and Mackey (this issue) outline several apparent design flaws in studies that have compared the impact of different types of corrective feedback (CF). Furthermore, they argue that SLA researchers should stop comparing recasts to other types of CF because they are inherently different kinds of phenomena. Our response to their article addresses…

  15. Learners' Perception of Corrective Feedback in Pair Work

    ERIC Educational Resources Information Center

    Yoshida, Reiko

    2008-01-01

    The present study examines Japanese language learners' perception of corrective feedback (CF) in pair work in relation to their noticing and understanding of their partners' CF and the factors that influence it. This study focuses on three learners, who worked together in pair work. The data collection methods consist of classroom observation,…

  16. Corrective Feedback, Spoken Accuracy and Fluency, and the Trade-Off Hypothesis

    ERIC Educational Resources Information Center

    Chehr Azad, Mohammad Hassan; Farrokhi, Farahman; Zohrabi, Mohammad

    2018-01-01

    The current study was an attempt to investigate the effects of different corrective feedback (CF) conditions on Iranian EFL learners' spoken accuracy and fluency (AF) and the trade-off between them. Consequently, four pre-intermediate intact classes were randomly selected as the control, delayed explicit metalinguistic CF, extensive recast, and…

  17. What Effect Does Reading Academic Articles on Oral Corrective Feedback Have on ESL Teachers?

    ERIC Educational Resources Information Center

    Kamiya, Nobuhiro

    2016-01-01

    This study focuses on four teachers teaching a speaking and listening class at an intensive English program in the United States who read three academic articles on oral corrective feedback (CF). The researcher investigated their stated beliefs and classroom practices of CF as well as their responses to the readings through three classroom…

  18. Providing Graduated Corrective Feedback in an Intelligent Computer-Assisted Language Learning Environment

    ERIC Educational Resources Information Center

    Ai, Haiyang

    2017-01-01

    Corrective feedback (CF), a response to linguistic errors made by second language (L2) learners, has received extensive scholarly attention in second language acquisition. While much of the previous research in the field has focused on whether CF facilitates or impedes L2 development, few studies have examined the efficacy of gradually modifying…

  19. How Do Teachers and Learners Perceive Corrective Feedback in the Japanese Language Classroom?

    ERIC Educational Resources Information Center

    Yoshida, Reiko

    2010-01-01

    This study examined Japanese language teachers' and learners' perceptions of corrective feedback (CF), focusing on the cases in which the learners responded to the teachers' CF. Data were collected from the second-year course of an Australian university for 1 semester by classroom observation and audio recording and stimulated recall interviews.…

  20. Corrective Feedback in L2 Latvian Classrooms: Teacher Perceptions versus the Observed Actualities of Practice

    ERIC Educational Resources Information Center

    Dilans, Gatis

    2016-01-01

    This two-part study aims to investigate teacher perceptions about providing oral corrective feedback (CF) to minority students of Latvian as a second language and compare the perceptions to the actual provision of CF in L2 Latvian classrooms. The survey sample represents sixty-six L2 Latvian teachers while the classroom observations involved 13…

  1. Corrective Feedback in L2 Writing: Theoretical Perspectives, Empirical Insights, and Future Directions

    ERIC Educational Resources Information Center

    Van Beuningen, Catherine

    2010-01-01

    The role of (written) corrective feedback (CF) in the process of acquiring a second language (L2) has been an issue of considerable controversy among theorists and researchers alike. Although CF is a widely applied pedagogical tool and its use finds support in SLA theory, practical and theoretical objections to its usefulness have been raised…

  2. Peer Interaction and Corrective Feedback for Accuracy and Fluency Development: Monitoring, Practice, and Proceduralization

    ERIC Educational Resources Information Center

    Sato, Masatoshi; Lyster, Roy

    2012-01-01

    This quasi-experimental study is aimed at (a) teaching learners how to provide corrective feedback (CF) during peer interaction and (b) assessing the effects of peer interaction and CF on second language (L2) development. Four university-level English classes in Japan participated (N = 167), each assigned to one of four treatment conditions. Of…

  3. Between Learning and Playing? Exploring Learners' Perceptions of Corrective Feedback in an Immersive Game for English Pragmatics

    ERIC Educational Resources Information Center

    Cornillie, Frederik; Clarebout, Geraldine; Desmet, Piet

    2012-01-01

    This paper aims to provide a rationale for the utility of corrective feedback (CF) in digital games designed for language learning, with specific reference to learners' perceptions. Explicit and elaborate CF has the potential to increase learners' understanding of language, but might not be found useful in a game-based learning environment where…

  4. The Written Corrective Feedback Debate: Next Steps for Classroom Teachers and Practitioners

    ERIC Educational Resources Information Center

    Brown, Dan

    2012-01-01

    Language teachers spend much of their time providing corrective feedback on students' writing in hope of helping them improve grammatical accuracy. Turning to research for guidance, however, can leave practitioners with few concrete answers as to the effectiveness of written corrective feedback (CF). Debate in the literature continues, reflecting…

  5. Differential Effects of Focused and Unfocused Written Correction on the Accurate Use of Grammatical Forms by Adult ESL Learners

    ERIC Educational Resources Information Center

    Sheen, Younghee; Wright, David; Moldawa, Anna

    2009-01-01

    Building on Sheen's (2007) study of the effects of written corrective feedback (CF) on the acquisition of English articles, this article investigated whether direct focused CF, direct unfocused CF and writing practice alone produced differential effects on the accurate use of grammatical forms by adult ESL learners. Using six intact adult ESL…

  6. Oral Feedback in Classroom SLA: A Meta-Analysis

    ERIC Educational Resources Information Center

    Lyster, Roy; Saito, Kazuya

    2010-01-01

    To investigate the pedagogical effectiveness of oral corrective feedback (CF) on target language development, we conducted a meta-analysis that focused exclusively on 15 classroom-based studies (N = 827). The analysis was designed to investigate whether CF was effective in classroom settings and, if so, whether its effectiveness varied according…

  7. Written Corrective Feedback in L2 Writing: Connors & Lunsford (1988); Lunsford & Lunsford (2008); Lalande (1982) Dana Ferris

    ERIC Educational Resources Information Center

    Ferris, Dana

    2015-01-01

    Written corrective feedback (CF) has been the most heavily researched topic in second language (L2) writing over the past 20 years. As a recent research timeline article in this journal (Ferris 2012; see also Bitchener & Ferris 2012) shows, studies of error correction in student writing have crossed disciplines (composition and rhetoric,…

  8. Evidence on the Effectiveness of Comprehensive Error Correction in Second Language Writing

    ERIC Educational Resources Information Center

    Van Beuningen, Catherine G.; De Jong, Nivja H.; Kuiken, Folkert

    2012-01-01

    This study investigated the effect of direct and indirect comprehensive corrective feedback (CF) on second language (L2) learners' written accuracy (N = 268). The study set out to explore the value of CF as a revising tool as well as its capacity to support long-term accuracy development. In addition, we tested Truscott's (e.g., 2001, 2007) claims…

  9. Differential Effects of Oral and Written Corrective Feedback in the ESL Classroom

    ERIC Educational Resources Information Center

    Sheen, Younghee

    2010-01-01

    This article examines whether there is any difference between the effect of oral and written corrective feedback (CF) on learners' accurate use of English articles. To this end, the current research presents the results of a quasi-experimental study with a pretest, immediate-posttest, delayed-posttest design, using 12 intact intermediate…

  10. The Noticeability and Effectiveness of Corrective Feedback in Relation to Target Type

    ERIC Educational Resources Information Center

    Kartchava, Eva; Ammar, Ahlem

    2014-01-01

    This quasi-experimental study investigated the noticeability and effectiveness of three corrective feedback (CF) techniques (recasts, prompts and a combination of the two) delivered in the language classroom. The participants were four groups of high-beginner college level francophone learners of English as a second language (ESL) (n = 99) and…

  11. The Influence of Context on Patterns of Corrective Feedback and Learner Uptake: A Comparison of CLIL and Immersion Classrooms

    ERIC Educational Resources Information Center

    Llinares, Ana; Lyster, Roy

    2014-01-01

    This study compares the frequency and distribution of different types of corrective feedback (CF) (recasts, prompts and explicit correction) and learner uptake in 43 hours of classroom interaction at the 4th-5th grade level across three instructional settings: (1) two content and language integrated learning (CLIL) classrooms in Spain with English…

  12. Advanced ESL Students' Prior EFL Education and Their Perceptions of Oral Corrective Feedback

    ERIC Educational Resources Information Center

    Lee, Eun Jeong

    2016-01-01

    The author in this study examines how advanced-level adult English as a Second Language (ESL) students' previous English as a Foreign Language (EFL) classroom experiences influence their perceptions of their teachers' oral corrective feedback (CF). It uses in-depth qualitative data to characterize the participants' prior English learning, and to…

  13. The Effects of Corrective Feedback on Instructed L2 Speech Perception

    ERIC Educational Resources Information Center

    Lee, Andrew H.; Lyster, Roy

    2016-01-01

    To what extent do second language (L2) learners benefit from instruction that includes corrective feedback (CF) on L2 speech perception? This article addresses this question by reporting the results of a classroom-based experimental study conducted with 32 young adult Korean learners of English. An instruction-only group and an instruction + CF…

  14. A Comparison of EFL Teachers' and Students' Attitudes to Oral Corrective Feedback

    ERIC Educational Resources Information Center

    Roothooft, Hanne; Breeze, Ruth

    2016-01-01

    A relatively small number of studies on beliefs about oral corrective feedback (CF) have uncovered a mismatch between teachers' and students' attitudes which is potentially harmful to the language learning process, not only because students may become demotivated when their expectations are not met, but also because teachers appear to be reluctant…

  15. Reading-Writing Integrated Tasks, Comprehensive Corrective Feedback, and EFL Writing Development

    ERIC Educational Resources Information Center

    Zhang, Xiaoyan

    2017-01-01

    The study examines whether there is any difference between the effects of a reading-writing integrated task and comprehensive corrective feedback (CF) on English as a foreign language (EFL) learners' writing development, and whether the input language in the integrated task makes a difference in L2 writing development over time and the language…

  16. Saudi EFL Preparatory Year Students' Perception about Corrective Feedback in Oral Communication

    ERIC Educational Resources Information Center

    Alhaysony, Maha

    2016-01-01

    This study sought to investigate the attitudes of Saudi EFL students towards corrective feedback (henceforth CF) on classroom oral errors. The subjects were 3200 (1223 male and 1977 female) students enrolled in an intensive English language programme in the preparatory year at the University of Ha'il. A questionnaire was the main instrument. This…

  17. Effects of Different Types of Corrective Feedback on Receptive Skills in a Second Language: A Speech Perception Training Study

    ERIC Educational Resources Information Center

    Lee, Andrew H.; Lyster, Roy

    2016-01-01

    This study investigated the effects of different types of corrective feedback (CF) provided during second language (L2) speech perception training. One hundred Korean learners of L2 English, randomly assigned to five groups (n = 20 per group), participated in eight computer-assisted perception training sessions targeting two minimal pairs of…

  18. Corrective Feedback Episodes in Oral Interaction: A Comparison of a CLIL and an EFL Classroom

    ERIC Educational Resources Information Center

    Milla, Ruth; García Mayo, María Pilar

    2014-01-01

    This paper addresses the issue of corrective feedback (CF), a topic widely investigated in the last few decades (Sheen, 2011), and instructional context. We observed and recorded the oral interaction of an intact class of thirty Spanish intermediate-level high-school learners and two teachers in two settings: a traditional form-oriented English as…

  19. Activity Theory in Spanish Mixed Classrooms: Exploring Corrective Feedback as an Artifact

    ERIC Educational Resources Information Center

    Valentín-Rivera, Laura

    2016-01-01

    This study draws upon activity theory to better understand the implications of corrective feedback (CF) as an artifact on (1) the coconstruction of knowledge and (2) the action-oriented decisions of 10 mixed pairs comprising a foreign language learner (FLL) and a heritage language learner (HLL) of Spanish. To this end, the dyads were divided into…

  20. Effects of Form-Focused Instruction and Corrective Feedback on L2 Pronunciation Development of /[alveolar approximant]/ by Japanese Learners of English

    ERIC Educational Resources Information Center

    Saito, Kazuya; Lyster, Roy

    2012-01-01

    Sixty-five Japanese learners of English participated in the current study, which investigated the acquisitional value of form-focused instruction (FFI) with and without corrective feedback (CF) on learners' pronunciation development. All students received a 4-hr FFI treatment designed to encourage them to notice and practice the target feature of…

  1. The Effects of Direct Written Corrective Feedback on Improvement of Grammatical Accuracy of High-Proficient L2 Learners

    ERIC Educational Resources Information Center

    Farrokhi, Farahman; Sattarpour, Simin

    2012-01-01

    The present article reports the findings of a study that explored(1) whether direct written corrective feedback (CF) can help high-proficient L2 learners, who has already achieved a rather high level of accuracy in English, improve in the accurate use of two functions of English articles (the use of "a" for first mention and…

  2. Second Language Writing Research and Written Corrective Feedback in SLA: Intersections and Practical Applications

    ERIC Educational Resources Information Center

    Ferris, Dana R.

    2010-01-01

    For more than a decade now, a great deal of research has been done on the topic of written corrective feedback (CF) in SLA and second language (L2) writing. Nonetheless, what those research efforts really have shown as well as the possible implications for practice remain in dispute. Although L2 writing and SLA researchers often examine similar…

  3. A Reflection on "The Language Learning Potential" of Written CF

    ERIC Educational Resources Information Center

    Bitchener, John

    2012-01-01

    For more than 30 years, different opinions about whether written corrective feedback (CF) is a worthwhile pedagogical practice for L2 learning and acquisition have been voiced. Despite the arguments for and against its potential to help L2 learners acquire the target language and the inconclusive findings across studies that have sought answers to…

  4. The Influence of Academic Articles on an ESL Teacher's Stated Beliefs

    ERIC Educational Resources Information Center

    Kamiya, Nobuhiro; Loewen, Shawn

    2014-01-01

    The current study investigated the relationship between one English as a second language (ESL) teacher's encounters with three academic articles on the topic of oral corrective feedback (CF) and the impact that they had on his stated beliefs regarding CF. The teacher had 14 years of English teaching experience and an MA TESOL degree. Two…

  5. Communicative Focus on Form and Second Language Suprasegmental Learning: Teaching Cantonese Learners to Perceive Mandarin Tones

    ERIC Educational Resources Information Center

    Saito, Kazuya; Wu, Xianghua

    2014-01-01

    The current study examined how form-focused instruction (FFI) with and without corrective feedback (CF) as output enhancement facilitated second language (L2) perception of Mandarin tones at both the phonetic and phonological levels by 41 Cantonese learners of Mandarin. Two experimental groups, FFI only and FFI-CF, received a 90-min FFI treatment…

  6. E-Portfolio as a Corrective Platform towards EFL Students' Overall/Componential Writing Performance

    ERIC Educational Resources Information Center

    Saeedi, Zari; Meihami, Hussein

    2015-01-01

    This paper aims at accentuating and exploring the effect of using electronic portfolio (EP) platform in providing corrective feedback (CF) on EFL students' overall and micro-componential writing performance. Moreover, by conducting a semi-structured interview, the study seeks to obtain students' attitudes towards the use of EP in three aspects,…

  7. Critical Findings: Attempts at Reducing Notification Errors.

    PubMed

    Shahriari, Mona; Liu, Li; Yousem, David M

    2016-11-01

    Ineffective communication of critical findings (CFs) is a patient safety issue. The aim of this study was to assess whether a feedback program for faculty members failing to correctly report CFs would lead to improved compliance. Fifty randomly selected reports were reviewed by the chief of neuroradiology each month for 42 months. Errors included (1) not calling for a CF, (2) not identifying a CF as such, (3) mischaracterizing non-CFs as CFs, and (4) calling for non-CFs. The number of appropriately handled and mishandled reports in each month was recorded. The trend of error reduction after the division chief provided feedback in the subsequent months was evaluated, and the equality of time interval between errors was tested. Among 2,100 reports, 49 (2.3%) were handled inappropriately. Among non-CF reports, 98.97% (1,817 of 1,836) were appropriately not called and not flagged, and 88.64% (234 of 264) of CF reports were called and flagged appropriately. The error rate during the 11th through 32nd months of review (1.28%) was significantly lower than the error rate in the first 10 months of review (3.98%) (P = .001). This benefit lasted for 21 months. Review and giving feedback to radiologists increased their compliance with the CF protocol and decreased deviations from standard operating procedures for about 2 years (from month 10 to month 32). Developing new ideas for improving CF policy compliance may be required at 2- to 3-year intervals to provide continuous quality improvement. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  8. Improving the Grammatical Accuracy of the Spoken English of Indonesian International Kindergarten Students

    ERIC Educational Resources Information Center

    Gozali, Imelda; Harjanto, Ignatius

    2014-01-01

    The need to improve the spoken English of kindergarten students in an international preschool in Surabaya prompted this Classroom Action Research (CAR). It involved the implementation of Form-Focused Instruction (FFI) strategy coupled with Corrective Feedback (CF) in Grammar lessons. Four grammar topics were selected, namely Regular Plural form,…

  9. "Small Talk": Developing Fluency, Accuracy, and Complexity in Speaking

    ERIC Educational Resources Information Center

    Hunter, James

    2012-01-01

    A major issue that continues to challenge language teachers is how to ensure that learners develop accuracy and complexity in their speaking, as well as fluency. Teachers know that too much corrective feedback (CF) can make learners reluctant to speak, while not enough may allow their errors to become entrenched. Furthermore, there is controversy…

  10. Learning a visuomotor rotation: simultaneous visual and proprioceptive information is crucial for visuomotor remapping.

    PubMed

    Shabbott, Britne A; Sainburg, Robert L

    2010-05-01

    Visuomotor adaptation is mediated by errors between intended and sensory-detected arm positions. However, it is not clear whether visual-based errors that are shown during the course of motion lead to qualitatively different or more efficient adaptation than errors shown after movement. For instance, continuous visual feedback mediates online error corrections, which may facilitate or inhibit the adaptation process. We addressed this question by manipulating the timing of visual error information and task instructions during a visuomotor adaptation task. Subjects were exposed to a visuomotor rotation, during which they received continuous visual feedback (CF) of hand position with instructions to correct or not correct online errors, or knowledge-of-results (KR), provided as a static hand-path at the end of each trial. Our results showed that all groups improved performance with practice, and that online error corrections were inconsequential to the adaptation process. However, in contrast to the CF groups, the KR group showed relatively small reductions in mean error with practice, increased inter-trial variability during rotation exposure, and more limited generalization across target distances and workspace. Further, although the KR group showed improved performance with practice, after-effects were minimal when the rotation was removed. These findings suggest that simultaneous visual and proprioceptive information is critical in altering neural representations of visuomotor maps, although delayed error information may elicit compensatory strategies to offset perturbations.

  11. ESKAPE/CF: A Knowledge Acquisition Tool for Expert Systems Using Cognitive Feedback

    DTIC Science & Technology

    1991-03-01

    NAVAL POSTGRADUATE SCHOOL Monterey, California AD-A241 815i!1! lit 1i iill 1111 !! I 1111 ST E * ODTIC OCT22 z 99I; THESIS ESKAPE /CF: A KNOWLEDGE...11. TITLE (include Security Classification) ESKAPE /CF: A KNOWLEDGE ACQUISITION TOOL FOR EXPERT SYSTEMS USING COGNITIVE FEEDBACK (U) e PERSOIAL AUTVR(Yl...tool using Cognitive Feedback ( ESKAPE /CF), based on Lens model techniques which have demonstrated effectiveness in cap- turing policy knowledge. The

  12. Achieving new levels of recall in consent to research by combining remedial and motivational techniques.

    PubMed

    Festinger, David S; Dugosh, Karen L; Marlowe, Douglas B; Clements, Nicolle T

    2014-04-01

    Research supports the efficacy of both a remedial consent procedure (corrected feedback (CF)) and a motivational consent procedure (incentives) for improving recall of informed consent to research. Although these strategies were statistically superior to standard consent, effects were modest and not clinically significant. This study examines a combined incentivised consent and CF procedure that simplifies the cognitive task and increases motivation to learn consent information. We randomly assigned 104 individuals consenting to an unrelated host study to a consent as usual (CAU) condition (n=52) or an incentivised CF (ICF) condition (n=52). All participants were told they would be quizzed on their consent recall following their baseline assessment and at 4 monthly follow-ups. ICF participants were also informed that they would earn $5 for each correct answer and receive CF as needed. Quiz scores in the two conditions did not differ at the first administration (p=0.39, d=0.2); however, ICF scores were significantly higher at each subsequent administration (second: p=0.003, Cohen's d=0.6; third: p<0.0001, d=1.4; fourth: p<0.0001, d=1.6; fifth: p<0.0001, d=1.8). The ICF procedure increased consent recall from 72% to 83%, compared with the CAU condition in which recall decreased from 69% to 59%. This supports the statistical and clinical utility of a combined remedial and motivational consent procedure for enhancing recall of study information and human research protections.

  13. The spatial and temporal representation of a tone on the guinea pig basilar membrane

    NASA Astrophysics Data System (ADS)

    Nilsen, K. E.; Russell, I. J.

    2000-10-01

    School of Biological Sciences, University of Sussex, Falmer Brighton, BN1 9QG, United Kingdom In the mammalian cochlea, the basilar membrane's (BM) mechanical responses are amplified, and frequency tuning is sharpened through active feedback from the electromotile outer hair cells (OHCs). To be effective, OHC feedback must be delivered to the correct region of the BM and introduced at the appropriate time in each cycle of BM displacement. To investigate when OHCs contribute to cochlear amplification, a laser-diode interferometer was used to measure tone-evoked BM displacements in the basal turn of the guinea pig cochlea. Measurements were made at multiple sites acrossthe width of the BM, which are tuned to the same characteristic frequency (CF). In response to CF tones, the largest displacements occur in the OHC region and phase lead those measured beneath the outer pillar cells and adjacent to the spiral ligament by about 90°. Postmortem, responses beneath the OHCs are reduced by up to 65 dB, and all regions across the width of the BM move in unison. We suggest that OHCs amplify BM responses to CF tones when the BM is moving at maximum velocity. In regions of the BM where OHCs contribute to its motion, the responses are compressive and nonlinear. We measured the distribution of nonlinear compressive vibrations along the length of the BM in response to a single frequency tone and estimated that OHC amplification is restricted to a 1.25- to 1.40-mm length of BM centered on the CF place.

  14. Organelle Redox of CF and CFTR-Corrected Airway Epithelia

    PubMed Central

    Schwarzer, Christian; Illek, Beate; Suh, Jung H.; Remington, S. James; Fischer, Horst; Machen, Terry E.

    2014-01-01

    In cystic fibrosis reduced CFTR function may alter redox properties of airway epithelial cells. Redox-sensitive GFP (roGFP1) and imaging microscopy were used to measure redox potentials of cytosol, ER, mitochondria and cell surface of cystic fibrosis nasal epithelial cells and CFTR-corrected cells. We also measured glutathione and cysteine thiol redox states in cell lysates and apical fluids to provide coverage over a range of redox potentials and environments that might be affected by CFTR. As measured with roGFP1, redox potentials at the cell surface (~ -207 ±8 mV) and in the ER (~ -217 ±1 mV) and rates of regulation of the apical fluid and ER lumen following DTT treatment were similar for CF and CFTR-corrected cells. CF and CFTR-corrected cells had similar redox potentials in mitochondria (-344 ±9 mV) and cytosol (-322 ±7 mV). Oxidation of carboxy-dichlorodihydrofluoresceindiacetate and of apical Amplex Red occurred at equal rates in CF and CFTR-corrected cells. Glutathione and cysteine redox couples in cell lysates and apical fluid were equal in CF and CFTR-corrected cells. These quantitative estimates of organelle redox potentials combined with apical and cell measurements using small molecule couples confirmed there were no differences in redox properties of CF and CFTR-corrected cells. PMID:17603939

  15. Specialization of the auditory system for the processing of bio-sonar information in the frequency domain: Mustached bats.

    PubMed

    Suga, Nobuo

    2018-04-01

    For echolocation, mustached bats emit velocity-sensitive orientation sounds (pulses) containing a constant-frequency component consisting of four harmonics (CF 1-4 ). They show unique behavior called Doppler-shift compensation for Doppler-shifted echoes and hunting behavior for frequency and amplitude modulated echoes from fluttering insects. Their peripheral auditory system is highly specialized for fine frequency analysis of CF 2 (∼61.0 kHz) and detecting echo CF 2 from fluttering insects. In their central auditory system, lateral inhibition occurring at multiple levels sharpens V-shaped frequency-tuning curves at the periphery and creates sharp spindle-shaped tuning curves and amplitude tuning. The large CF 2 -tuned area of the auditory cortex systematically represents the frequency and amplitude of CF 2 in a frequency-versus-amplitude map. "CF/CF" neurons are tuned to a specific combination of pulse CF 1 and Doppler-shifted echo CF 2 or 3 . They are tuned to specific velocities. CF/CF neurons cluster in the CC ("C" stands for CF) and DIF (dorsal intrafossa) areas of the auditory cortex. The CC area has the velocity map for Doppler imaging. The DIF area is particularly for Dopper imaging of other bats approaching in cruising flight. To optimize the processing of behaviorally relevant sounds, cortico-cortical interactions and corticofugal feedback modulate the frequency tuning of cortical and sub-cortical auditory neurons and cochlear hair cells through a neural net consisting of positive feedback associated with lateral inhibition. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. An Introduction to X Window Application Development

    DTIC Science & Technology

    1992-03-23

    Acquisition and Policy Evaluation program using Cognitive Feed- back ( ESKAPE /CF) from the SunView windowing system to X Window. The new application...the generic X Window System. This thesis converts an Expert System Knowledge Acquisition and Policy Evaluation program using Cognitive Feedback ( ESKAPE ...15 IV. XESKAPE/CF: THE X WINDOW VERSION OF ESKAPE /CF ........................ 16 A. FUNCTIONAL COMPARISON TO

  17. Finding the sweet spot: Developing, implementing and evaluating a burn out and compassion fatigue intervention for third year medical trainees.

    PubMed

    Tucker, Tara; Bouvette, Maryse; Daly, Shauna; Grassau, Pamela

    2017-12-01

    Medical trainees are at high risk for developing burnout. Introducing trainees to the risks of burnout and supporting identification and proactive responses to their 'warning' signs of compassion fatigue (CF) is critical in building resiliency. The authors developed and evaluated a burnout and CF program for third year trainees at a Canadian Medical School. Of 165 medical trainees who participated in the burnout and CF program, 59 (36%) provided evaluation and feedback of the program and its impact throughout their year. Participation included self-utilization of a validated CF and burnout tool (ProQOL) across three time-points, workshop feedback, and focus group participation. Results highlighted the importance of 1) Recognizing Individual Signs & Symptoms of Stress, CF and Burnout; 2) Normalizing Stress, CF and Burnout for Students and Physicians; 3) Learning to Manage One's Own Stress. A decrease in compassion satisfaction and increase in burnout between beginning and end of third year were found. Further outcomes highlighted the importance of learning, living and surviving CF and burnout in clerkship. Emergent theory reveals the important responsibility educators have to integrate CF and burnout programs into 'the sweet spot' that third year offers, as trainees shift from theoretical to experiential practice as future clinicians. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. 75 FR 22693 - Airworthiness Directives; General Electric Company (GE) CF34-1A, CF34-3A, and CF34-3B Series...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ..., Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England... Directives; General Electric Company (GE) CF34-1A, CF34-3A, and CF34-3B Series Turbofan Engines; Correction... to GE CF34-1A, CF34-3A, and CF34-3B series turbofan engines. The docket number is incorrect in all...

  19. Understanding of safety monitoring in clinical trials by individuals with CF or their parents: A qualitative analysis.

    PubMed

    Kern-Goldberger, Andrew S; Hessels, Amanda J; Saiman, Lisa; Quittell, Lynne M

    2018-03-14

    Recruiting both pediatric and adult participants for clinical trials in CF is currently of paramount importance as numerous new therapies are being developed. However, recruitment is challenging as parents of children with CF and adults with CF cite safety concerns as a principal barrier to enrollment. In conjunction with the CF Foundation (CFF) Data Safety Monitoring Board (DSMB), a pilot brochure was developed to inform patients and parents of the multiple levels of safety monitoring; the CFF simultaneously created an infographic representing the safety monitoring process. This study explores the attitudes and beliefs of CF patients and families regarding safety monitoring and clinical trial participation, and elicits feedback regarding the educational materials. Semi-structured interviews were conducted using a pre-tested interview guide and audio-recorded during routine CF clinic visits. Participants included 5 parents of children with CF <16years old; 5 adolescents and young adults with CF 16-21years old; and 5 adults with CF ≥22years old from pediatric and adult CF centers. The study team performed systematic text condensation analysis of the recorded interviews using an iterative process. Four major thematic categories with subthemes emerged as supported by exemplar quotations: attitudes toward clinical trials, safety values, conceptualizing the safety monitoring process, and priorities for delivery of patient education. Participant feedback was used to revise the pilot brochure; text was shortened, unfamiliar words clarified (e.g., "pipeline"), abbreviations eliminated, and redundancy avoided. Qualitative analysis of CF patient and family interviews provided insights into barriers to participation in clinical trials, safety concerns, perspectives on safety monitoring and educational priorities. We plan a multicenter study to determine if the revised brochure reduces knowledge, attitude and practice barriers regarding participation in CF clinical trials. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  20. Enhanced IL-1{beta}-induced IL-8 production in cystic fibrosis lung epithelial cells is dependent of both mitogen-activated protein kinases and NF-{kappa}B signaling

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

    Muselet-Charlier, Celine; Universite Pierre et Marie Curie-Paris 6, Paris, UMR-S719, F-75012; Roque, Telma

    2007-06-01

    Transcription nuclear factor-{kappa}B (NF-{kappa}B) is hyperactivated in cystic fibrosis (CF) lung epithelial cells, and participates in exaggerated IL-8 production in the CF lung. We recently found that rapid activation of NF-{kappa}B occurred in a CF lung epithelial IB3-1 cell line (CF cells) upon IL-1{beta} stimulation, which was not observed in its CFTR-corrected lung epithelial S9 cell line (corrected cells). To test whether other signaling pathways such as that of mitogen-activated protein kinases (MAPKs) could be involved in IL-1{beta}-induced IL-8 production of CF cells, we investigated ERK1/2, JNK, and p38MAP signaling compared to NF-{kappa}B. Within 30 min, exposure to IL-1{beta} causedmore » high activation of NF-{kappa}B, ERK1/2, p38MAP but not JNK in CF cells compared to corrected cells. Treatment of IL-1{beta}-stimulated CF cells with a series of chemical inhibitors of NF-{kappa}B, ERK1/2, and p38MAP, when used separately, reduced slightly IL-8 production. However, when used together, these inhibitors caused a blockade in IL-1{beta}-induced IL-8 production in CF cells. Understanding of the cross-talk between NF-{kappa}B and MAPKs signaling in CF lung epithelial cells may help in developing new therapeutics to reduce lung inflammation in patients with CF.« less

  1. Increased (/sup 125/I)trypsin-binding in serum from cystic fibrosis patients

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

    Cox, K.L.; Frates, R.C. Jr.; Sheikholislam, B.M.

    1982-01-01

    The capacities of normal and cystic fibrosis (CF) sera to bind to exogenous human (/sup 125/I)trypsin were compared. Sera from eight older CF patients bound significantly more exogenous human (/sup 125/I)trypsin than did sera from eight normal subjects (p less than 0.001). Disregarding the increased trypsin-binding (TB) of CF sera, serum immunoreactive trypsinogen (SIRT) levels were not detectable in these eight older CF patients. However, when SIRT levels were corrected for TB, four CF patients had normal SIRT concentrations and four had low but detectable SIRT levels. As compared to five normal newborns' sera, serum from a newborn with CFmore » had normal TB and the SIRT levels were very high. In conclusion, increased TB in CF serum lowers results of SIRT assays. Therefore, unless SIRT levels are corrected for TB, results obtained from currently available SIRT kits may be invalid.« less

  2. Correcting a Metacognitive Error: Feedback Increases Retention of Low-Confidence Correct Responses

    ERIC Educational Resources Information Center

    Butler, Andrew C.; Karpicke, Jeffrey D.; Roediger, Henry L., III

    2008-01-01

    Previous studies investigating posttest feedback have generally conceptualized feedback as a method for correcting erroneous responses, giving virtually no consideration to how feedback might promote learning of correct responses. Here, the authors show that when correct responses are made with low confidence, feedback serves to correct this…

  3. Correction of the F508del-CFTR protein processing defect in vitro by the investigational drug VX-809

    PubMed Central

    Van Goor, Fredrick; Hadida, Sabine; Grootenhuis, Peter D. J.; Burton, Bill; Stack, Jeffrey H.; Straley, Kimberly S.; Decker, Caroline J.; Miller, Mark; McCartney, Jason; Olson, Eric R.; Wine, Jeffrey J.; Frizzell, Ray A.; Ashlock, Melissa; Negulescu, Paul A.

    2011-01-01

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene that impair the function of CFTR, an epithelial chloride channel required for proper function of the lung, pancreas, and other organs. Most patients with CF carry the F508del CFTR mutation, which causes defective CFTR protein folding and processing in the endoplasmic reticulum, resulting in minimal amounts of CFTR at the cell surface. One strategy to treat these patients is to correct the processing of F508del-CFTR with small molecules. Here we describe the in vitro pharmacology of VX-809, a CFTR corrector that was advanced into clinical development for the treatment of CF. In cultured human bronchial epithelial cells isolated from patients with CF homozygous for F508del, VX-809 improved F508del-CFTR processing in the endoplasmic reticulum and enhanced chloride secretion to approximately 14% of non-CF human bronchial epithelial cells (EC50, 81 ± 19 nM), a level associated with mild CF in patients with less disruptive CFTR mutations. F508del-CFTR corrected by VX-809 exhibited biochemical and functional characteristics similar to normal CFTR, including biochemical susceptibility to proteolysis, residence time in the plasma membrane, and single-channel open probability. VX-809 was more efficacious and selective for CFTR than previously reported CFTR correctors. VX-809 represents a class of CFTR corrector that specifically addresses the underlying processing defect in F508del-CFTR. PMID:21976485

  4. A mechanism accounting for the low cellular level of linoleic acid in cystic fibrosis and its reversal by DHA.

    PubMed

    Al-Turkmani, M Rabie; Andersson, Charlotte; Alturkmani, Ragheed; Katrangi, Waddah; Cluette-Brown, Joanne E; Freedman, Steven D; Laposata, Michael

    2008-09-01

    Specific fatty acid alterations have been described in the blood and tissues of cystic fibrosis (CF) patients. The principal alterations include decreased levels of linoleic acid (LA) and docosahexaenoic acid (DHA). We investigated the potential mechanisms of these alterations by studying the cellular uptake of LA and DHA, their distribution among lipid classes, and the metabolism of LA in a human bronchial epithelial cell model of CF. CF (antisense) cells demonstrated decreased levels of LA and DHA compared with wild type (WT, sense) cells expressing normal CFTR. Cellular uptake of LA and DHA was higher in CF cells compared with WT cells at 1 h and 4 h. Subsequent incorporation of LA and DHA into most lipid classes and individual phospholipids was also increased in CF cells. The metabolic conversion of LA to n-6 metabolites, including 18:3n-6 and arachidonic acid, was upregulated in CF cells, indicating increased flux through the n-6 pathway. Supplementing CF cells with DHA inhibited the production of LA metabolites and corrected the n-6 fatty acid defect. In conclusion, the evidence suggests that low LA level in cultured CF cells is due to its increased metabolism, and this increased LA metabolism is corrected by DHA supplementation.

  5. Sphingolipids as targets for inhalation treatment of cystic fibrosis.

    PubMed

    Becker, Katrin Anne; Riethmüller, Joachim; Seitz, Aaron P; Gardner, Aaron; Boudreau, Ryan; Kamler, Markus; Kleuser, Burkhard; Schuchman, Edward; Caldwell, Charles C; Edwards, Michael J; Grassmé, Heike; Brodlie, Malcolm; Gulbins, Erich

    2018-04-24

    Studies over the past several years have demonstrated the important role of sphingolipids in cystic fibrosis (CF), chronic obstructive pulmonary disease and acute lung injury. Ceramide is increased in airway epithelial cells and alveolar macrophages of CF mice and humans, while sphingosine is dramatically decreased. This increase in ceramide results in chronic inflammation, increased death of epithelial cells, release of DNA into the bronchial lumen and thereby an impairment of mucociliary clearance; while the lack of sphingosine in airway epithelial cells causes high infection susceptibility in CF mice and possibly patients. The increase in ceramide mediates an ectopic expression of β1-integrins in the luminal membrane of CF epithelial cells, which results, via an unknown mechanism, in a down-regulation of acid ceramidase. It is predominantly this down-regulation of acid ceramidase that results in the imbalance of ceramide and sphingosine in CF cells. Correction of ceramide and sphingosine levels can be achieved by inhalation of functional acid sphingomyelinase inhibitors, recombinant acid ceramidase or by normalization of β1-integrin expression and subsequent re-expression of endogenous acid ceramidase. These treatments correct pulmonary inflammation and prevent or treat, respectively, acute and chronic pulmonary infections in CF mice with Staphylococcus aureus and mucoid or non-mucoid Pseudomonas aeruginosa. Inhalation of sphingosine corrects sphingosine levels only and seems to mainly act against the infection. Many antidepressants are functional inhibitors of the acid sphingomyelinase and were designed for systemic treatment of major depression. These drugs could be repurposed to treat CF by inhalation. Copyright © 2018. Published by Elsevier B.V.

  6. Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT.

    PubMed

    Ciet, Pierluigi; Serra, Goffredo; Bertolo, Silvia; Spronk, Sandra; Ros, Mirco; Fraioli, Francesco; Quattrucci, Serena; Assael, M Baroukh; Catalano, Carlo; Pomerri, Fabio; Tiddens, Harm A W M; Morana, Giovanni

    2016-03-01

    To date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults. Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated. MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100% (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease. Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations). PROPELLER MRI does not match CT sensitivity to assess CF lung disease. PROPELLER MRI has lower sensitivity than CT to detect severe bronchiectasis. PROPELLER MRI has good to very good intra- and inter-observer variability. PROPELLER MRI can be used for short-term follow-up studies in CF.

  7. Scalable Low-Power Deep Machine Learning with Analog Computation

    DTIC Science & Technology

    2013-07-19

    transimpedance amplifier (TIA) that measures the output current 7 V Cf Vbias MP1 MN1 Vdd = 3 V 2.5 V 2.6 V + − Vox = 4.4 V 0.1 V + − 7 V Cf Vbias MP1 MN1 Vddt... amplifier . The amplifier has Cf as its feedback capacitor and the FG voltage Vfg as its input. The two MUXs at the sources of MP1 and MP2 control the...as a simple operational transconductor amplifier (OTA), converts voltage Vout to output current Iout. Vref determines the nominal voltage of Vout

  8. Theoretical studies on atmospheric chemistry of HFE-245mc and perfluoro-ethyl formate: Reaction with OH radicals, atmospheric fate of alkoxy radical and global warming potential

    NASA Astrophysics Data System (ADS)

    Lily, Makroni; Baidya, Bidisha; Chandra, Asit K.

    2017-02-01

    Theoretical studies have been performed on the kinetics, mechanism and thermochemistry of the hydrogen abstraction reactions of CF3CF2OCH3 (HFE-245mc) and CF3CF2OCHO with OH radical using DFT based M06-2X method. IRC calculation shows that both hydrogen abstraction reactions proceed via weakly bound hydrogen-bonded complex preceding to the formation of transition state. The rate coefficients calculated by canonical transition state theory along with Eckart's tunnelling correction at 298 K: k1(CF3CF2OCH3 + OH) = 1.09 × 10-14 and k2(CF3CF2OCHO + OH) = 1.03 × 10-14 cm3 molecule-1 s-1 are in very good agreement with the experimental values. The atmospheric implications of CF3CF2OCH3 and CF3CF2OCHO are also discussed.

  9. 75 FR 1017 - Airworthiness Directives; General Electric Company (GE) CF34-1A, CF34-3A, and CF34-3B Series...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-08

    ...) fan blades within compliance times specified in the AD, inspecting the fan blade abradable rub strip on certain engines for wear, inspecting the fan blades on certain engines for cracks, inspecting the.... This ad supersedure requires the same actions but corrects the effectivity for certain fan blades...

  10. Feedback-related brain activity predicts learning from feedback in multiple-choice testing.

    PubMed

    Ernst, Benjamin; Steinhauser, Marco

    2012-06-01

    Different event-related potentials (ERPs) have been shown to correlate with learning from feedback in decision-making tasks and with learning in explicit memory tasks. In the present study, we investigated which ERPs predict learning from corrective feedback in a multiple-choice test, which combines elements from both paradigms. Participants worked through sets of multiple-choice items of a Swahili-German vocabulary task. Whereas the initial presentation of an item required the participants to guess the answer, corrective feedback could be used to learn the correct response. Initial analyses revealed that corrective feedback elicited components related to reinforcement learning (FRN), as well as to explicit memory processing (P300) and attention (early frontal positivity). However, only the P300 and early frontal positivity were positively correlated with successful learning from corrective feedback, whereas the FRN was even larger when learning failed. These results suggest that learning from corrective feedback crucially relies on explicit memory processing and attentional orienting to corrective feedback, rather than on reinforcement learning.

  11. Comparing Explicit Exemplar-Based and Rule-Based Corrective Feedback: Introducing Analogy-Based Corrective Feedback

    ERIC Educational Resources Information Center

    Thomas, Kavita E.

    2018-01-01

    This study introduces an approach to providing corrective feedback to L2 learners termed analogy-based corrective feedback that is motivated by analogical learning theories and syntactic alignment in dialogue. Learners are presented with a structurally similar synonymous version of their output where the erroneous form is corrected, and they must…

  12. A Comparison of Answer until Correct Feedback and Knowledge of Correct Response Feedback under Two Conditions of Contextualization.

    ERIC Educational Resources Information Center

    Clariana, Roy B.

    1990-01-01

    Discussion of various types of feedback used in computer-assisted instruction focuses on a study of low-ability eleventh graders that compared the effectiveness of answer until correct (AUC) feedback with knowledge of correct response (KCR) feedback. Achievement data on posttests as well as time data are analyzed. (11 references) (LRW)

  13. Transepithelial nasal potential difference (NPD) measurements in cystic fibrosis (CF).

    PubMed

    Sands, Dorota

    2013-01-01

    The main underlying physiologic abnormality in cystic fibrosis (CF) is dysfunction of the CF transmembrane conductance regulator (CFTR), which results in abnormal transport of sodium and chloride across epithelial surfaces. CFTR function could be tested in vivo using measurements of nasal transepithelial potential difference (PD). Nasal measurements show characteristic features of CF epithelia, including hyperpolarized baseline readings (basal PD), excessive depolarization in response to sodium channel inhibitors, such as amiloride (ΔAmiloride), and little or no chloride (Cl-) secretion in response to isoproterenol in a chloride-free solution (ΔCl- free-isoproterenol). PD test is applied for CF diagnosis and monitoring of new therapeutic modulations and corrections.

  14. US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis

    PubMed Central

    Olivier, Kenneth N; Saiman, Lisa; Daley, Charles L; Herrmann, Jean-Louis; Nick, Jerry A; Noone, Peadar G; Bilton, Diana; Corris, Paul; Gibson, Ronald L; Hempstead, Sarah E; Koetz, Karsten; Sabadosa, Kathryn A; Sermet-Gaudelus, Isabelle; Smyth, Alan R; van Ingen, Jakko; Wallace, Richard J; Winthrop, Kevin L; Marshall, Bruce C; Haworth, Charles S

    2016-01-01

    Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease such as cystic fibrosis (CF). Pulmonary disease caused by NTM has emerged as a major threat to the health of individuals with CF but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened an expert panel of specialists to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM pulmonary disease in individuals with CF. Nineteen experts were invited to participate in the recommendation development process. Population, Intervention, Comparison, Outcome (PICO) methodology and systematic literature reviews were employed to inform draft recommendations. An anonymous voting process was used by the committee to reach consensus. All committee members were asked to rate each statement on a scale of: 0, completely disagree, to 9, completely agree; with 80% or more of scores between 7 and 9 being considered ‘good’ agreement. Additionally, the committee solicited feedback from the CF communities in the USA and Europe and considered the feedback in the development of the final recommendation statements. Three rounds of voting were conducted to achieve 80% consensus for each recommendation statement. Through this process, we have generated a series of pragmatic, evidence-based recommendations for the screening, investigation, diagnosis and treatment of NTM infection in individuals with CF as an initial step in optimising management for this challenging condition. PMID:26666259

  15. Computer-Mediated Corrective Feedback and the Development of L2 Grammar

    ERIC Educational Resources Information Center

    Sauro, Shannon

    2009-01-01

    This paper reports on a study that investigated the impact of two types of computer-mediated corrective feedback on the development of adult learners' L2 knowledge: (1) corrective feedback that reformulates the error in the form of recasts, and (2) corrective feedback that supplies the learner with metalinguistic information about the nature of…

  16. The Effects of Corrective Feedback on Chinese Learners' Writing Accuracy: A Quantitative Analysis in an EFL Context

    ERIC Educational Resources Information Center

    Wang, Xin

    2017-01-01

    Scholars debate whether corrective feedback contributes to improving L2 learners' grammatical accuracy in writing performance. Some researchers take a stance on the ineffectiveness of corrective feedback based on the impracticality of providing detailed corrective feedback for all L2 learners and detached grammar instruction in language…

  17. On the derivation of selection functions from redshift survey data

    NASA Technical Reports Server (NTRS)

    Strauss, Michael A.; Yahil, Amos; Davis, Marc

    1991-01-01

    A previously unrecognized effect is described in the derivation of luminosity functions and selection functions from existing redshift survey data, due to binning of quoted magnitudes and diameters. Corrections are made for this effect in the Center for Astrophysics (CfA) and Southern Sky (SSRS) Redshift Surveys. The correction makes subtle but systematic changes in the derived density fields of the CfA survey, especially within 2000 km/s of the Local Group. The effect on the density field of the SSRS survey is negligible.

  18. The Use of Online Corrective Feedback in Academic Writing by L1 Malay Learners

    ERIC Educational Resources Information Center

    Yoke, Soo Kum; Rajendran, Cecilia Bai; Sain, Noridah; Kamaludin, Puteri Nur Hidayah; Nawi, Sofwah Md; Yusof, Suhaili

    2013-01-01

    Conventional corrective feedback has been widely practiced but has been said to be tedious, stressful and time consuming. As such, the focus of this study is to investigate the use of an alternative method to giving corrective feedback namely, an online corrective feedback through e-mail. In order to examine if this innovative form of corrective…

  19. Evaluating Corrective Feedback Self-Efficacy Changes among Counselor Educators and Site Supervisors

    ERIC Educational Resources Information Center

    Motley, Veronica; Reese, Mary Kate; Campos, Peter

    2014-01-01

    Analysis of pretest-posttest scores on the Corrective Feedback Self-Efficacy Instrument (Page & Hulse-Killacky, [Page, B. J., 1999]) following a supervision workshop indicated a significant positive relationship between workshop training and supervisors' feedback self-efficacy in giving corrective feedback. Furthermore, the association…

  20. Perspectives of adolescent girls with cystic fibrosis and parents on disease-specific sexual and reproductive health education.

    PubMed

    Kazmerski, Traci M; Hill, Kelsey; Prushinskaya, Olga; Nelson, Eliza; Greenberg, Jonathan; Pitts, Sarah Ab; Borrero, Sonya; Miller, Elizabeth; Sawicki, Gregory S

    2018-04-26

    Adolescent girls with cystic fibrosis (CF) face significant disease-specific sexual and reproductive health (SRH) concerns that are not typically addressed in routine clinical care. Additionally, there is a paucity of developmentally appropriate CF-specific SRH educational resources for this population. The goal of this study was to explore patient and parent attitudes toward SRH educational resources for adolescent girls with CF. Adolescent girls ages 13-18 years with CF and parents of daughters ages 10-18 years with CF completed individual, semi-structured interviews regarding their experiences and preferences around CF-specific SRH education and care. To facilitate discussion, participants provided feedback on the format and design of existing SRH educational resources. Qualitative analysis was conducted using a thematic analysis approach. We interviewed 26 participants (14 parents and 12 patients). The majority reported they had never discussed SRH in the CF care setting. All participants preferred a comprehensive, online patient educational resource complemented by real patient stories and interactive components. Participants noted that such resources should create a sense of normalcy and community around CF and female SRH. Most desired more frequent communication around SRH between adolescent girls with CF and their healthcare providers as a way to promote SRH knowledge, decision making, and health outcomes. Adolescent girls with CF and their parents desire an online patient educational resource that normalizes SRH and enhances patient-provider communication around these topics. Creation of developmentally appropriate resources would facilitate improved health outcomes around this aspect of comprehensive care in CF. © 2018 Wiley Periodicals, Inc.

  1. US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis.

    PubMed

    Floto, R Andres; Olivier, Kenneth N; Saiman, Lisa; Daley, Charles L; Herrmann, Jean-Louis; Nick, Jerry A; Noone, Peadar G; Bilton, Diana; Corris, Paul; Gibson, Ronald L; Hempstead, Sarah E; Koetz, Karsten; Sabadosa, Kathryn A; Sermet-Gaudelus, Isabelle; Smyth, Alan R; van Ingen, Jakko; Wallace, Richard J; Winthrop, Kevin L; Marshall, Bruce C; Haworth, Charles S

    2016-01-01

    Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease such as cystic fibrosis (CF). Pulmonary disease caused by NTM has emerged as a major threat to the health of individuals with CF but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened an expert panel of specialists to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM pulmonary disease in individuals with CF. Nineteen experts were invited to participate in the recommendation development process. Population, Intervention, Comparison, Outcome (PICO) methodology and systematic literature reviews were employed to inform draft recommendations. An anonymous voting process was used by the committee to reach consensus. All committee members were asked to rate each statement on a scale of: 0, completely disagree, to 9, completely agree; with 80% or more of scores between 7 and 9 being considered 'good' agreement. Additionally, the committee solicited feedback from the CF communities in the USA and Europe and considered the feedback in the development of the final recommendation statements. Three rounds of voting were conducted to achieve 80% consensus for each recommendation statement. Through this process, we have generated a series of pragmatic, evidence-based recommendations for the screening, investigation, diagnosis and treatment of NTM infection in individuals with CF as an initial step in optimising management for this challenging condition. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Lost in translation? How adults living with Cystic Fibrosis understand treatment recommendations from their healthcare providers, and the impact on adherence to therapy.

    PubMed

    Pakhale, S; Baron, J; Armstrong, M; Tasca, G; Gaudet, E; Aaron, S D; Cameron, W; Balfour, L

    2016-08-01

    This study builds on the limited research documenting Cystic Fibrosis (CF) patients' understanding of treatment recommendations and how this may impact adherence to therapy. We surveyed adults with CF and their healthcare professional (HCP) to capture treatment recommendations provided by the HCP, and patients' knowledge, and frequency of performance, of these recommendations. We classified CF participants' understanding of treatment recommendations (correct/incorrect) as compared to the actual recommendations made by the HCP. We computed CF participants' adherence in relation to HCP treatment recommendations and to their own understanding of treatment recommendations (adherent/non-adherent). Complete HCP and patient data were available for 42 participants. The recommended treatment frequency was correctly understood by 0%-87.8% of CF participants. Adherence to HCP treatment recommendations ranged from 0 to 68.3% (mean 45.4%±21.5), and rates were low (<33%) for acapella, percussion/postural drainage, tobramycin nebulization and insulin. Participants' adherence was greater when calculated in relation to participants' understanding of treatment recommendations (62.4%±25.1) than when calculated in relation to actual HCP treatment recommendations (45.4%±21.5%) (p=0.009). Adults with CF misunderstand treatment recommendations; this likely affects treatment adherence. Interventions to ensure HCPs use effective communication strategies are needed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Prenatal detection of fetal triploidy from cell-free DNA testing in maternal blood.

    PubMed

    Nicolaides, Kypros H; Syngelaki, Argyro; del Mar Gil, Maria; Quezada, Maria Soledad; Zinevich, Yana

    2014-01-01

    To investigate potential performance of cell-free DNA (cfDNA) testing in maternal blood in detecting fetal triploidy. Plasma and buffy coat samples obtained at 11-13 weeks' gestation from singleton pregnancies with diandric triploidy (n=4), digynic triploidy (n=4), euploid fetuses (n=48) were sent to Natera, Inc. (San Carlos, Calif., USA) for cfDNA testing. Multiplex polymerase chain reaction amplification of cfDNA followed by sequencing of single nucleotide polymorphic loci covering chromosomes 13, 18, 21, X, and Y was performed. Sequencing data were analyzed using the NATUS algorithm which identifies copy number for each of the five chromosomes. cfDNA testing provided a result in 44 (91.7%) of the 48 euploid cases and correctly predicted the fetal sex and the presence of two copies each of chromosome 21, 18 and 13. In diandric triploidy, cfDNA testing identified multiple paternal haplotypes (indicating fetal trisomy 21, trisomy 18 and trisomy 13) suggesting the presence of either triploidy or dizygotic twins. In digynic triploidy the fetal fraction corrected for maternal weight and gestational age was below the 0.5th percentile. cfDNA testing by targeted sequencing and allelic ratio analysis of single nucleotide polymorphisms covering chromosomes 21, 18, 13, X, and Y can detect diandric triploidy and raise the suspicion of digynic triploidy. © 2013 S. Karger AG, Basel.

  4. The Value of a Focused Approach to Written Corrective Feedback

    ERIC Educational Resources Information Center

    Bitchener, John; Knoch, Ute

    2009-01-01

    Investigations into the most effective ways to provide ESL learners with written corrective feedback have often been overly comprehensive in the range of error categories examined. As a result, clear conclusions about the efficacy of such feedback have not been possible. On the other hand, oral corrective feedback studies have produced clear,…

  5. Relationship between Counseling Students' Childhood Memories and Current Negative Self-Evaluations When Receiving Corrective Feedback

    ERIC Educational Resources Information Center

    Stroud, Daniel; Olguin, David; Marley, Scott

    2016-01-01

    This article entails a study focused on the relationship between counseling students' negative childhood memories of receiving corrective feedback and current negative self-evaluations when receiving similar feedback in counselor education programs. Participants (N = 186) completed the Corrective Feedback Instrument-Revised (CFI-R; Hulse-Killacky…

  6. Written Corrective Feedback in IELTS Writing Task 2: Teachers' Priorities, Practices, and Beliefs

    ERIC Educational Resources Information Center

    Pearson, William S.

    2018-01-01

    Teacher corrective feedback is widely recognised as integral in supporting developing L2 writers. The potentially high pressure IELTS test preparation classroom presents a context where feedback has not yet been extensively studied. Consequently, teachers' approaches to corrective feedback on Writing Task 2, the essay component of IELTS Writing,…

  7. The Effects of Writing Anxiety and Motivation on EFL College Students' Self-Evaluative Judgments of Corrective Feedback.

    PubMed

    Tsao, Jui-Jung; Tseng, Wen-Ta; Wang, Chaochang

    2017-04-01

    Feedback is regarded as a way to foster students' motivation and to ensure linguistic accuracy. However, mixed findings are reported in the research on written corrective feedback because of its multifaceted nature and its correlations with learners' individual differences. It is necessary, therefore, to conduct further research on corrective feedback from the student's perspective and to examine how individual differences in terms of factors such as writing anxiety and motivation predict learners' self-evaluative judgments of both teacher-corrected and peer-corrected feedback. For this study, 158 Taiwanese college sophomores participated in a survey that comprised three questionnaires. Results demonstrated that intrinsic motivation and different types of writing anxiety predicted English as foreign language learners' evaluative judgments of teacher and peer feedback. The findings have implications for English-writing instruction.

  8. Self-efficacy: empowering parents of children with cystic fibrosis.

    PubMed

    McDonald, Catherine M; Haberman, Diane; Brown, Natalie

    2013-09-01

    Can parent engagement in the development and delivery of educational materials for cystic fibrosis (CF) promote increased self-efficacy and confidence in self-management skills? Standard therapies for a child with CF frequently involve pulmonary treatment, medications, and behavioral and nutritional interventions. Parents report that the prescribed CF care can be overwhelming. Previous research at this pediatric CF Center indicated the parental perception of the difficulty in managing CF-related nutrition therapy. Parents' nutrition knowledge was an initial target of this continuous quality improvement (CQI) project with a long-range aim of increasing children's median body mass index (BMI) percentiles for patients at this pediatric CF center. The local CF Parent Advisory Council, CF parents and staff collaborated on this family-centered CQI project. A CF parent website with weekly email newsletters and a facebook page were developed and evolved with input from parents. Parental feedback was gathered through electronic surveys, written questionnaires, focus groups and informal interviews. A convenience sample of parents participated in pre- and post-intervention surveys to determine change in self-confidence in effectively managing their children's CF treatment regimens. Results were also compared with responses from a larger previous survey. Parental knowledge of nutrition facts and medical nutrition therapy for CF did not increase significantly over the course of the CQI project. Surveyed parents reported increased confidence in their self-management skills. Although mean BMI percentiles have increased at this center, they remain below the national average. Parent-driven educational strategies provide an opportunity to promote reliable CF-related information in parent-preferred formats that enhance self-management skills in caring for children with CF. Parental confidence to follow CF center recommendations increased between 2004 and 2011. Although many factors may impact confidence, parent satisfaction with the creation of electronic resources and engagement in the CQI process were intangible, but important outcomes. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  9. Learning from Feedback: Spacing and the Delay-Retention Effect

    ERIC Educational Resources Information Center

    Smith, Troy A.; Kimball, Daniel R.

    2010-01-01

    Most modern research on the effects of feedback during learning has assumed that feedback is an error correction mechanism. Recent studies of feedback-timing effects have suggested that feedback might also strengthen initially correct responses. In an experiment involving cued recall of trivia facts, we directly tested several theories of…

  10. Written Corrective Feedback: Student Preferences and Teacher Feedback Practices

    ERIC Educational Resources Information Center

    Irwin, Bradley

    2017-01-01

    This case study explores the intricate interaction between students' preferences for written corrective feedback and actual teacher feedback practices in a second year academic EFL writing class in a Japanese university. Specific institutional and instructional details establish the context in which written feedback is being provided. A…

  11. Reactivation of the chloroplast CF1-ATPase beta subunit by trace amounts of the CF1 alpha subunit suggests a chaperonin-like activity for CF1 alpha.

    PubMed

    Avni, A; Avital, S; Gromet-Elhanan, Z

    1991-04-25

    Incubation of tobacco and lettuce thylakoids with 2 M LiCl in the presence of MgATP removes the beta subunit from their CF1-ATPase (CF1 beta) together with varying amounts of the CF1 alpha subunit (CF1 alpha). These 2 M LiCl extracts, as with the one obtained from spinach thylakoids (Avital, S., and Gromet-Elhanan, Z. (1991) J. Biol. Chem. 266, 7067-7072), could form active hybrid ATPases when reconstituted into inactive beta-less Rhodospirillum rubrum chromatophores. Pure CF1 beta fractions that have been isolated from these extracts could not form such active hybrids by themselves, but could do so when supplemented with trace amounts (less than 5%) of CF1 alpha. A mitochondrial F1-ATPase alpha subunit was recently reported to be a heat-shock protein, having two amino acid sequences that show a highly conserved identity with sequences found in molecular chaperones (Luis, A. M., Alconada, A., and Cuezva, J. M. (1990) J. Biol. Chem. 265, 7713-7716). These sequences are also conserved in CF1 alpha isolated from various plants, but not in F1 beta subunits. The above described reactivation of CF1 beta by trace amounts of CF1 alpha could thus be due to a chaperonin-like function of CF1 alpha, which involves the correct, active folding of isolated pure CF1 beta.

  12. Nuclease-mediated double-strand break (DSB) enhancement of small fragment homologous recombination (SFHR) gene modification in human-induced pluripotent stem cells (hiPSCs).

    PubMed

    Sargent, R Geoffrey; Suzuki, Shingo; Gruenert, Dieter C

    2014-01-01

    Recent developments in methods to specifically modify genomic DNA using sequence-specific endonucleases and donor DNA have opened the door to a new therapeutic paradigm for cell and gene therapy of inherited diseases. Sequence-specific endonucleases, in particular transcription activator-like (TAL) effector nucleases (TALENs), have been coupled with polynucleotide small/short DNA fragments (SDFs) to correct the most common mutation in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene, a 3-base-pair deletion at codon 508 (delF508), in induced pluripotent stem (iPS) cells. The studies presented here describe the generation of candidate TALENs and their co-transfection with wild-type (wt) CFTR-SDFs into CF-iPS cells homozygous for the delF508 mutation. Using an allele-specific PCR (AS-PCR)-based cyclic enrichment protocol, clonal populations of corrected CF-iPS cells were isolated and expanded.

  13. Accurate quantitative CF-LIBS analysis of both major and minor elements in alloys via iterative correction of plasma temperature and spectral intensity

    NASA Astrophysics Data System (ADS)

    Shuxia, ZHAO; Lei, ZHANG; Jiajia, HOU; Yang, ZHAO; Wangbao, YIN; Weiguang, MA; Lei, DONG; Liantuan, XIAO; Suotang, JIA

    2018-03-01

    The chemical composition of alloys directly determines their mechanical behaviors and application fields. Accurate and rapid analysis of both major and minor elements in alloys plays a key role in metallurgy quality control and material classification processes. A quantitative calibration-free laser-induced breakdown spectroscopy (CF-LIBS) analysis method, which carries out combined correction of plasma temperature and spectral intensity by using a second-order iterative algorithm and two boundary standard samples, is proposed to realize accurate composition measurements. Experimental results show that, compared to conventional CF-LIBS analysis, the relative errors for major elements Cu and Zn and minor element Pb in the copper-lead alloys has been reduced from 12%, 26% and 32% to 1.8%, 2.7% and 13.4%, respectively. The measurement accuracy for all elements has been improved substantially.

  14. Beyond hypercorrection: remembering corrective feedback for low-confidence errors.

    PubMed

    Griffiths, Lauren; Higham, Philip A

    2018-02-01

    Correcting errors based on corrective feedback is essential to successful learning. Previous studies have found that corrections to high-confidence errors are better remembered than low-confidence errors (the hypercorrection effect). The aim of this study was to investigate whether corrections to low-confidence errors can also be successfully retained in some cases. Participants completed an initial multiple-choice test consisting of control, trick and easy general-knowledge questions, rated their confidence after answering each question, and then received immediate corrective feedback. After a short delay, they were given a cued-recall test consisting of the same questions. In two experiments, we found high-confidence errors to control questions were better corrected on the second test compared to low-confidence errors - the typical hypercorrection effect. However, low-confidence errors to trick questions were just as likely to be corrected as high-confidence errors. Most surprisingly, we found that memory for the feedback and original responses, not confidence or surprise, were significant predictors of error correction. We conclude that for some types of material, there is an effortful process of elaboration and problem solving prior to making low-confidence errors that facilitates memory of corrective feedback.

  15. Macronutrient intake in preschoolers with cystic fibrosis and the relationship between macronutrients and growth.

    PubMed

    Filigno, Stephanie S; Robson, Shannon M; Szczesniak, Rhonda D; Chamberlin, Leigh A; Baker, Meredith A; Sullivan, Stephanie M; Kroner, John; Powers, Scott W

    2017-07-01

    Adequate nutrition is essential for growth in children with cystic fibrosis (CF). The new CF Foundation Clinical Practice Guidelines bring attention to monitoring macronutrient intake as well as total energy. Dietary intake of 75 preschool children with CF and pancreatic insufficiency was examined and compared to the Clinical Practice Guidelines. Regression analyses examined relationships between macronutrient intake and growth. Approximately 45% of children met the 110% minimum recommended dietary allowance (RDA) recommendation. Children consumed 35.3% (6.1) of total daily energy intake from fat, 12.7% (1.7) from protein, and 52.0% (6.1) from carbohydrates. Percent energy from protein was associated with height growth. Many preschoolers with CF are not meeting nutrition benchmarks for total energy and fat. To optimize nutrition early, dietary monitoring with frequent individualized feedback is needed. Optimizing intake of macronutrients that promote growth, especially fat and protein, should be a primary clinical target. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  16. Can false memories be corrected by feedback in the DRM paradigm?

    PubMed

    McConnell, Melissa D; Hunt, R Reed

    2007-07-01

    Normal processes of comprehension frequently yield false memories as an unwanted by-product. The simple paradigm now known as the Deese/Roediger-McDermott (DRM) paradigm takes advantage of this fact and has been used to reliably produce false memory for laboratory study. Among the findings from past research is the difficulty of preventing false memories in this paradigm. The purpose of the present experiments was to examine the effectiveness of feedback in correcting false memories. Two experiments were conducted, in which participants recalled DRM lists and either received feedback on their performance or did not. A subsequent recall test was administered to assess the effect of feedback. The results showed promising effects of feedback: Feedback enhanced both error correction and the propagation of correct recall. The data replicated other data of studies that have shown substantial error perseveration following feedback. These data also provide new information on the occurrence of errors following feedback. The results are discussed in terms of the activation-monitoring theory of false memory.

  17. Theoretical insight into OH- and Cl-initiated oxidation of CF3OCH(CF3)2 and CF3OCF2CF2H & fate of CF3OC(X•)(CF3)2 and CF3OCF2CF2X• radicals (X=O, O2)

    PubMed Central

    Bai, Feng-Yang; Ma, Yuan; Lv, Shuang; Pan, Xiu-Mei; Jia, Xiu-Juan

    2017-01-01

    In this study, the mechanistic and kinetic analysis for reactions of CF3OCH(CF3)2 and CF3OCF2CF2H with OH radicals and Cl atoms have been performed at the CCSD(T)//B3LYP/6-311++G(d,p) level. Kinetic isotope effects for reactions CF3OCH(CF3)2/CF3OCD(CF3)2 and CF3OCF2CF2H/CF3OCF2CF2D with OH and Cl were estimated so as to provide the theoretical estimation for future laboratory investigation. All rate constants, computed by canonical variational transition state theory (CVT) with the small-curvature tunneling correction (SCT), are in reasonable agreement with the limited experimental data. Standard enthalpies of formation for the species were also calculated. Atmospheric lifetime and global warming potentials (GWPs) of the reaction species were estimated, the large lifetimes and GWPs show that the environmental impact of them cannot be ignored. The organic nitrates can be produced by the further oxidation of CF3OC(•)(CF3)2 and CF3OCF2CF2• in the presence of O2 and NO. The subsequent decomposition pathways of CF3OC(O•)(CF3)2 and CF3OCF2CF2O• radicals were studied in detail. The derived Arrhenius expressions for the rate coefficients over 230–350 K are: k T(1) = 5.00 × 10−24T3.57 exp(−849.73/T), k T(2) = 1.79 × 10−24T4.84 exp(−4262.65/T), kT(3) = 1.94 × 10−24 T4.18 exp(−884.26/T), and k T(4) = 9.44 × 10−28T5.25 exp(−913.45/T) cm3 molecule−1 s−1. PMID:28067283

  18. Theoretical insight into OH- and Cl-initiated oxidation of CF3OCH(CF3)2 and CF3OCF2CF2H & fate of CF3OC(X•)(CF3)2 and CF3OCF2CF2X• radicals (X=O, O2)

    NASA Astrophysics Data System (ADS)

    Bai, Feng-Yang; Ma, Yuan; Lv, Shuang; Pan, Xiu-Mei; Jia, Xiu-Juan

    2017-01-01

    In this study, the mechanistic and kinetic analysis for reactions of CF3OCH(CF3)2 and CF3OCF2CF2H with OH radicals and Cl atoms have been performed at the CCSD(T)//B3LYP/6-311++G(d,p) level. Kinetic isotope effects for reactions CF3OCH(CF3)2/CF3OCD(CF3)2 and CF3OCF2CF2H/CF3OCF2CF2D with OH and Cl were estimated so as to provide the theoretical estimation for future laboratory investigation. All rate constants, computed by canonical variational transition state theory (CVT) with the small-curvature tunneling correction (SCT), are in reasonable agreement with the limited experimental data. Standard enthalpies of formation for the species were also calculated. Atmospheric lifetime and global warming potentials (GWPs) of the reaction species were estimated, the large lifetimes and GWPs show that the environmental impact of them cannot be ignored. The organic nitrates can be produced by the further oxidation of CF3OC(•)(CF3)2 and CF3OCF2CF2• in the presence of O2 and NO. The subsequent decomposition pathways of CF3OC(O•)(CF3)2 and CF3OCF2CF2O• radicals were studied in detail. The derived Arrhenius expressions for the rate coefficients over 230-350 K are: k T(1) = 5.00 × 10-24T3.57 exp(-849.73/T), k T(2) = 1.79 × 10-24T4.84 exp(-4262.65/T), kT(3) = 1.94 × 10-24 T4.18 exp(-884.26/T), and k T(4) = 9.44 × 10-28T5.25 exp(-913.45/T) cm3 molecule-1 s-1.

  19. Increased folding and channel activity of a rare cystic fibrosis mutant with CFTR modulators

    PubMed Central

    Grove, Diane E.; Houck, Scott A.

    2011-01-01

    Cystic fibrosis (CF) is a lethal recessive genetic disease caused by mutations in the CFTR gene. The gene product is a PKA-regulated anion channel that is important for fluid and electrolyte transport in the epithelia of lung, gut, and ducts of the pancreas and sweat glands. The most common CFTR mutation, ΔF508, causes a severe, but correctable, folding defect and gating abnormality, resulting in negligible CFTR function and disease. There are also a large number of rare CF-related mutations where disease is caused by CFTR misfolding. Yet the extent to which defective biogenesis of these CFTR mutants can be corrected is not clear. CFTRV232D is one such mutant that exhibits defective folding and trafficking. CFTRΔF508 misfolding is difficult to correct, but defective biogenesis of CFTRV232D is corrected to near wild-type levels by small-molecule folding correctors in development as CF therapeutics. To determine if CFTRV232D protein is competent as a Cl− channel, we utilized single-channel recordings from transfected human embryonic kidney (HEK-293) cells. After PKA stimulation, CFTRV232D channels were detected in patches with a unitary Cl− conductance indistinguishable from that of CFTR. Yet the frequency of detecting CFTRV232D channels was reduced to ∼20% of patches compared with 60% for CFTR. The folding corrector Corr-4a increased the CFTRV232D channel detection rate and activity to levels similar to CFTR. CFTRV232D-corrected channels were inhibited with CFTRinh-172 and stimulated fourfold by the CFTR channel potentiator VRT-532. These data suggest that CF patients with rare mutations that cause CFTR misfolding, such as CFTRV232D, may benefit from treatment with folding correctors and channel potentiators in development to restore CFTRΔF508 function. PMID:21642448

  20. Pedagogical Knowledge Base Underlying EFL Teachers' Provision of Oral Corrective Feedback in Grammar Instruction

    ERIC Educational Resources Information Center

    Atai, Mahmood Reza; Shafiee, Zahra

    2017-01-01

    The present study investigated the pedagogical knowledge base underlying EFL teachers' provision of oral corrective feedback in grammar instruction. More specifically, we explored the consistent thought patterns guiding the decisions of three Iranian teachers regarding oral corrective feedback on grammatical errors. We also examined the potential…

  1. EFL Students' Preferences toward the Lecturer's Corrective Feedback in Business Letters Writing

    ERIC Educational Resources Information Center

    Sanu, La Ode

    2016-01-01

    This study aimed to investigate the students' preferences toward the lecturer's corrective feedback in the business letter writing and their reasons why they preferred particular corrective feedback types. A case study was used by involving 15 EFL students who enrolled in the Business Correspondence Course. The questionnaire and interview were…

  2. Characterization of nasal potential difference in cftr knockout and F508del-CFTR mice.

    PubMed

    Saussereau, Emilie Lyne; Roussel, Delphine; Diallo, Siradiou; Debarbieux, Laurent; Edelman, Aleksander; Sermet-Gaudelus, Isabelle

    2013-01-01

    Treatments designed to correct cystic fibrosis transmembrane conductance regulator (CFTR) defects must first be evaluated in preclinical experiments in the mouse model of cystic fibrosis (CF). Mice nasal mucosa mimics the bioelectric defect seen in humans. The use of nasal potential difference (V(TE)) to assess ionic transport is a powerful test evaluating the restoration of CFTR function. Nasal V(TE) in CF mice must be well characterized for correct interpretation. We performed V(TE) measurements in large-scale studies of two mouse models of CF--B6;129 cftr knockout and FVB F508del-CFTR--and their respective wild-type (WT) littermates. We assessed the repeatability of the test for cftr knockout mice and defined cutoff points distinguishing between WT and F508del-CFTR mice. We determined the typical V(TE) values for CF and WT mice and demonstrated the existence of residual CFTR activity in F508del-CFTR mice. We characterized intra-animal variability in B6;129 mice and defined the cutoff points for F508del-CFTR chloride secretion rescue. Hyperpolarization of more than -2.15 mV after perfusion with a low-concentration Cl(-) solution was considered to indicate a normal response. These data will make it possible to interpret changes in nasal V(TE) in mouse models of CF, in future preclinical studies.

  3. Non-invasive measurement of liver and pancreas fibrosis in patients with cystic fibrosis.

    PubMed

    Friedrich-Rust, Mireen; Schlueter, Nina; Smaczny, Christina; Eickmeier, Olaf; Rosewich, Martin; Feifel, Kirstin; Herrmann, Eva; Poynard, Thierry; Gleiber, Wolfgang; Lais, Christoph; Zielen, Stefan; Wagner, Thomas O F; Zeuzem, Stefan; Bojunga, Joerg

    2013-09-01

    Patients with cystic fibrosis (CF) have a relevant morbidity and mortality caused by CF-related liver-disease. While transient elastography (TE) is an established elastography method in hepatology centers, Acoustic-Radiation-Force-Impulse (ARFI)-Imaging is a novel ultrasound-based elastography method which is integrated in a conventional ultrasound-system. The aim of the present study was to evaluate the prevalence of liver-fibrosis in patients with CF using TE, ARFI-imaging and fibrosis blood tests. 106 patients with CF were prospectively included in the present study and received ARFI-imaging of the left and right liver-lobe, ARFI of the pancreas TE of the liver and laboratory evaluation. The prevalence of liver-fibrosis according to recently published best practice guidelines for CFLD was 22.6%. Prevalence of significant liver-fibrosis assessed by TE, ARFI-right-liver-lobe, ARFI-left-liver-lobe, Fibrotest, Fibrotest-corrected-by-haptoglobin was 17%, 24%, 40%, 7%, and 16%, respectively. The best agreement was found for TE, ARFI-right-liver-lobe and Fibrotest-corrected-by-haptoglobin. Patients with pancreatic-insufficiency had significantly lower pancreas-ARFI-values as compared to patients without. ARFI-imaging and TE seem to be promising non-invasive methods for detection of liver-fibrosis in patients with CF. Copyright © 2013 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  4. Impact of Feedback on Three Phases of Performance Monitoring

    PubMed Central

    Appelgren, Alva; Penny, William; Bengtsson, Sara L

    2013-01-01

    We investigated if certain phases of performance monitoring show differential sensitivity to external feedback and thus rely on distinct mechanisms. The phases of interest were: the error phase (FE), the phase of the correct response after errors (FEC), and the phase of correct responses following corrects (FCC). We tested accuracy and reaction time (RT) on 12 conditions of a continuous-choice-response task; the 2-back task. External feedback was either presented or not in FE and FEC, and delivered on 0%, 20%, or 100% of FCC trials. The FCC20 was matched to FE and FEC in the number of sounds received so that we could investigate when external feedback was most valuable to the participants. We found that external feedback led to a reduction in accuracy when presented on all the correct responses. Moreover, RT was significantly reduced for FCC100, which in turn correlated with the accuracy reduction. Interestingly, the correct response after an error was particularly sensitive to external feedback since accuracy was reduced when external feedback was presented during this phase but not for FCC20. Notably, error-monitoring was not influenced by feedback-type. The results are in line with models suggesting that the internal error-monitoring system is sufficient in cognitively demanding tasks where performance is ∼ 80%, as well as theories stipulating that external feedback directs attention away from the task. Our data highlight the first correct response after an error as particularly sensitive to external feedback, suggesting that important consolidation of response strategy takes place here. PMID:24217138

  5. Evaluating Preference for Graphic Feedback on Correct versus Incorrect Performance

    ERIC Educational Resources Information Center

    Sigurdsson, Sigurdur O.; Ring, Brandon M.

    2013-01-01

    The current study evaluated preferences of undergraduate students for graphic feedback on percentage of incorrect performance versus feedback on percentage of correct performance. A total of 108 participants were enrolled in the study and received graphic feedback on performance on 12 online quizzes. One half of participants received graphic…

  6. Corrective Feedback, Learner Uptake, and Feedback Perception in a Chinese as a Foreign Language Classroom

    ERIC Educational Resources Information Center

    Fu, Tingfeng; Nassaji, Hossein

    2016-01-01

    The role of corrective feedback in second language classrooms has received considerable research attention in the past few decades. However, most of this research has been conducted in English-teaching settings, either ESL or EFL. This study examined teacher feedback, learner uptake as well as learner and teacher perception of feedback in an adult…

  7. Teacher Cognition in Corrective Feedback in Japan

    ERIC Educational Resources Information Center

    Mori, Reiko

    2011-01-01

    Based on qualitative data, the current study explored how the knowledge and beliefs of two EFL professionals shaped their corrective feedback practices. The two teachers teaching in Japan had in common two main agendas that they kept in mind as they provided or opted not to provide corrective feedback. They aimed to teach the language and to…

  8. An Investigation on the Use of Oral Corrective Feedback in Turkish EFL Classrooms

    ERIC Educational Resources Information Center

    Öztürk, Gökhan

    2016-01-01

    This classroom research study investigates corrective feedback implications in a sample of Turkish EFL classrooms. The types of corrective feedback, their distribution and the reasons of error ignorance were the foci. Four speaking classes in the English preparatory program of a Turkish state university were video-recorded for 12 hours in total…

  9. Using Track Changes and Word Processor to Provide Corrective Feedback to Learners in Writing

    ERIC Educational Resources Information Center

    AbuSeileek, A. F.

    2013-01-01

    This study investigated the effect of computer-mediated corrective feedback types in an English as a foreign language (EFL) intact class over time. The participants were 64 English majors who were assigned randomly into three treatment conditions that gave and received computer-mediated corrective feedback while writing (track changes, word…

  10. Feedback That Corrects and Contrasts Students' Erroneous Solutions with Expert Ones Improves Expository Instruction for Conceptual Change

    ERIC Educational Resources Information Center

    Asterhan, Christa S. C.; Dotan, Aviv

    2018-01-01

    In the present study, we examined the effects of feedback that corrects and contrasts a student's own erroneous solutions with the canonical, correct one (CEC&C feedback) on learning in a conceptual change task. Sixty undergraduate students received expository instruction about natural selection, which presented the canonical, scientifically…

  11. The Effects of Computer-Mediated Synchronous and Asynchronous Direct Corrective Feedback on Writing: A Case Study

    ERIC Educational Resources Information Center

    Shintani, Natsuko

    2016-01-01

    This case study investigated the characteristics of computer-mediated synchronous corrective feedback (SCF, provided while students wrote) and asynchronous corrective feedback (ACF, provided after students had finished writing) in an EFL writing task. The task, designed to elicit the use of the hypothetical conditional, was completed by two…

  12. Epidemiology and genetics of cystic fibrosis in Asia: In preparation for the next-generation treatments.

    PubMed

    Singh, Meenu; Rebordosa, Cristina; Bernholz, Juliane; Sharma, Neeraj

    2015-11-01

    Cystic fibrosis (CF) in the Asian population is less frequently reported due to under-diagnosis and lack of centralized CF patient registries. Clinical studies on CF cases from Asia have documented a severe course of the disease. The spectrum of the cystic fibrosis transmembrane conductance regulator (CFTR) variants in this population is quite heterogeneous. In total, 166 variants have been reported on approximately 3700 Asian CF chromosomes. The frequency of F508del among Asians is low compared with Caucasians. Recent in vitro studies have shown promise of small molecule correction and potentiation of 45 different CFTR variants. Of these variants, 16 (including G551D and F508del) have also been observed among Asian CF individuals. We suggest undertaking molecular studies extensively to annotate CFTR variants that will help Asian CF individuals to benefit from the precision medicine gaining momentum in the Western countries. © 2015 Asian Pacific Society of Respirology.

  13. Deleterious impact of hyperglycemia on cystic fibrosis airway ion transport and epithelial repair.

    PubMed

    Bilodeau, Claudia; Bardou, Olivier; Maillé, Émilie; Berthiaume, Yves; Brochiero, Emmanuelle

    2016-01-01

    Cystic fibrosis (CF)-related diabetes (CFRD) is associated with faster pulmonary function decline. Thus, we evaluated the impact of hyperglycemia on airway epithelial repair and transepithelial ion transport, which are critical in maintaining lung integrity and function. Non-CF and CF airway epithelial cells were exposed to low (LG) or high (HG) glucose before ion current and wound repair rate measurements. CFTR and K+ currents decreased after HG treatments. HG also reduced the wound healing rates of non-CF and CF cell monolayers. Although CFTR correction with VRT-325 accelerated the healing rates of CF cells monolayers under LG conditions, this improvement was significantly abrogated under HG conditions. Our data highlights a deleterious impact of hyperglycemia on ion transport and epithelial repair functions, which could contribute to the deterioration in lung function in CFRD patients. HG may also interfere with the beneficial effects of CFTR rescue on airway epithelial repair. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  14. Learning versus correct models: influence of model type on the learning of a free-weight squat lift.

    PubMed

    McCullagh, P; Meyer, K N

    1997-03-01

    It has been assumed that demonstrating the correct movement is the best way to impart task-relevant information. However, empirical verification with simple laboratory skills has shown that using a learning model (showing an individual in the process of acquiring the skill to be learned) may accelerate skill acquisition and increase retention more than using a correct model. The purpose of the present study was to compare the effectiveness of viewing correct versus learning models on the acquisition of a sport skill (free-weight squat lift). Forty female participants were assigned to four learning conditions: physical practice receiving feedback, learning model with model feedback, correct model with model feedback, and learning model without model feedback. Results indicated that viewing either a correct or learning model was equally effective in learning correct form in the squat lift.

  15. Testing Moderating Detection Systems with {sup 252}Cf-Based Reference Neutron Fields

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

    Hertel, Nolan E.; Sweezy, Jeremy; Sauber, Jeremiah S.

    Calibration measurements were carried out on a probe designed to measure ambient dose equivalent in accordance with ICRP Pub 60 recommendations. It consists of a cylindrical {sup 3}He proportional counter surrounded by a 25-cm-diameter spherical polyethylene moderator. Its neutron response is optimized for dose rate measurements of neutrons between thermal energies and 20 MeV. The instrument was used to measure the dose rate in four separate neutron fields: unmoderated {sup 252}Cf, D{sub 2}O-moderated {sup 252}Cf, polyethylene-moderated {sup 252}Cf, and WEP neutron howitzer with {sup 252}Cf at its center. Dose equivalent measurements were performed at source-detector centerline distances from 50 tomore » 200 cm. The ratio of air-scatter- and room-return-corrected ambient dose equivalent rates to ambient dose equivalent rates calculated with the code MCNP are tabulated.« less

  16. How you provide corrective feedback makes a difference: the motivating role of communicating in an autonomy-supporting way.

    PubMed

    Mouratidis, Athanasios; Lens, Willy; Vansteenkiste, Maarten

    2010-10-01

    We relied on self-determination theory (SDT; Deci & Ryan, 2000) to investigate to what extent autonomy-supporting corrective feedback (i.e., feedback that coaches communicate to their athletes after poor performance or mistakes) is associated with athletes' optimal motivation and well-being. To test this hypothesis, we conducted a cross-sectional study with 337 (67.1% males) Greek adolescent athletes (age M = 15.59, SD = 2.37) from various sports. Aligned with SDT, we found through path analysis that an autonomy-supporting versus controlling communication style was positively related to future intentions to persist and well-being and negatively related to ill-being. These relations were partially mediated by the perceived legitimacy of the corrective feedback (i.e., the degree of acceptance of corrective feedback), and, in turn, by intrinsic motivation, identified regulation, and external regulation for doing sports. Results indicate that autonomy-supporting feedback can be still motivating even in cases in which such feedback conveys messages of still too low competence.

  17. Assessing Feedback in a Mobile Videogame.

    PubMed

    Brand, Leah; Beltran, Alicia; Hughes, Sheryl; O'Connor, Teresia; Baranowski, Janice; Nicklas, Theresa; Chen, Tzu-An; Dadabhoy, Hafza R; Diep, Cassandra S; Buday, Richard; Baranowski, Tom

    2016-06-01

    Player feedback is an important part of serious games, although there is no consensus regarding its delivery or optimal content. "Mommio" is a serious game designed to help mothers motivate their preschoolers to eat vegetables. The purpose of this study was to assess optimal format and content of player feedback for use in "Mommio." The current study posed 36 potential "Mommio" gameplay feedback statements to 20 mothers using a Web survey and interview. Mothers were asked about the meaning and helpfulness of each feedback statement. Several themes emerged upon thematic analysis, including identifying an effective alternative in the case of corrective feedback, avoiding vague wording, using succinct and correct grammar, avoiding provocation of guilt, and clearly identifying why players' game choice was correct or incorrect. Guidelines are proposed for future feedback statements.

  18. TALEN-mediated generation and genetic correction of disease-specific human induced pluripotent stem cells.

    PubMed

    Ramalingam, Sivaprakash; Annaluru, Narayana; Kandavelou, Karthikeyan; Chandrasegaran, Srinivasan

    2014-01-01

    Generation and precise genetic correction of patient-derived hiPSCs have great potential in regenerative medicine. Such targeted genetic manipulations can now be achieved using gene-editing nucleases. Here, we report generation of cystic fibrosis (CF) and Gaucher's disease (GD) hiPSCs respectively from CF (homozygous for CFTRΔF508 mutation) and Type II GD [homozygous for β-glucocerebrosidase (GBA) 1448T>C mutation] patient fibroblasts, using CCR5- specific TALENs. Site-specific addition of loxP-flanked Oct4/Sox2/Klf4/Lin28/Nanog/eGFP gene cassette at the endogenous CCR5 site of patient-derived disease-specific primary fibroblasts induced reprogramming, giving rise to both monoallele (heterozygous) and biallele CCR5-modified hiPSCs. Subsequent excision of the donor cassette was done by treating CCR5-modified CF and GD hiPSCs with Cre. We also demonstrate site-specific correction of sickle cell disease (SCD) mutations at the endogenous HBB locus of patient-specific hiPSCs [TNC1 line that is homozygous for mutated β- globin alleles (βS/βS)], using HBB-specific TALENs. SCD-corrected hiPSC lines showed gene conversion of the mutated βS to the wild-type βA in one of the HBB alleles, while the other allele remained a mutant phenotype. After excision of the loxP-flanked DNA cassette from the SCD-corrected hiPSC lines using Cre, we obtained secondary heterozygous βS/βA hiPSCs, which express the wild-type (βA) transcript to 30-40% level as compared to uncorrected (βS/βS) SCD hiPSCs when differentiated into erythroid cells. Furthermore, we also show that TALEN-mediated generation and genetic correction of disease-specific hiPSCs did not induce any off-target mutations at closely related sites.

  19. Feedback in action within bedside teaching encounters: a video ethnographic study.

    PubMed

    Rizan, Chantelle; Elsey, Christopher; Lemon, Thomas; Grant, Andrew; Monrouxe, Lynn V

    2014-09-01

    Feedback associated with teaching activities is often synonymous with reflection on action, which comprises the evaluative assessment of performance out of its original context. Feedback in action (as correction during clinical encounters) is an underexplored, complementary resource facilitating students' understanding and learning. The purpose of this study was to explore the interactional patterns and correction modalities utilised in feedback sequences between doctors and students within general practice-based bedside teaching encounters (BTEs). A qualitative video ethnographic approach was used. Participants were recorded in their natural settings to allow interactional practices to be contextually explored. We examined 12 BTEs recorded across four general practices and involving 12 patients, four general practitioners and four medical students (209 minutes and 20 seconds of data) taken from a larger corpus. Data analysis was facilitated by Transana video analysis software and informed by previous conversation analysis research in ordinary conversation, classrooms and health care settings. A range of correction strategies across a spectrum of underlying explicitness were identified. Correction strategies classified at extreme poles of this scale (high or low explicitness) were believed to be less interactionally effective. For example, those using abrupt closing of topics (high explicitness) or interactional ambiguity (low explicitness) were thought to be less effective than embedded correction strategies that enabled the student to reach the correct answer with support. We believe that educators who are explicitly taught linguistic strategies for how to manage feedback in BTEs might manage learning more effectively. For example, clinicians might maximise learning moments during BTEs by avoiding abrupt or ambiguous feedback practices. Embedded correction strategies can enhance student participation by guiding students towards the correct answer. Clinician corrections can sensitively manage student face-saving by minimising the exposure of student error to patients. Furthermore, we believe that the effective practices highlighted by our analysis might facilitate successful transformation of feedback in action into feedback for action. © 2014 John Wiley & Sons Ltd.

  20. Emerging Critical Meta-Awareness among Black and Latina/o Youth during Corrective Feedback Practices in Urban English Language Arts Classrooms

    ERIC Educational Resources Information Center

    Martinez, Danny C.

    2017-01-01

    This article addresses teachers' uptake of Black and Latina/o youth linguistic repertoires within the official space of an English Language Arts (ELA) classroom and how youth respond to corrective feedback that is focused on the form of their messages, rather than their function. Corrective feedback offered by one Latina teacher indexed larger…

  1. The Potential of Automated Corrective Feedback to Remediate Cohesion Problems in Advanced Students' Writing

    ERIC Educational Resources Information Center

    Strobl, Carola

    2017-01-01

    This study explores the potential of a feedback environment using simple string-based pattern matching technology for the provision of automated corrective feedback on cohesion problems. Thirty-eight high-frequent problems, including non-target like use of connectives and co-references were addressed providing both direct and indirect feedback.…

  2. Assessing the residual CFTR gene expression in human nasal epithelium cells bearing CFTR splicing mutations causing cystic fibrosis

    PubMed Central

    Masvidal, Laia; Igreja, Susana; Ramos, Maria D; Alvarez, Antoni; de Gracia, Javier; Ramalho, Anabela; Amaral, Margarida D; Larriba, Sara; Casals, Teresa

    2014-01-01

    The major purpose of the present study was to quantify correctly spliced CFTR transcripts in human nasal epithelial cells from cystic fibrosis (CF) patients carrying the splicing mutations c.580-1G>T (712-1G>T) and c.2657+5G>A (2789+5G>A) and to assess the applicability of this model in CFTR therapeutic approaches. We performed the relative quantification of CFTR mRNA by reverse transcription quantitative PCR (RT-qPCR) of these splicing mutations in four groups (wild type, CF-F508del controls, CF patients and CF carriers) of individuals. In addition, in vitro assays using minigene constructs were performed to evaluate the effect of a new CF complex allele c.[2657+5G>A; 2562T>G]. Ex vivo qPCR data show that the primary consequence of both mutations at the RNA level is the skipping of their neighboring exon (6 and 16, respectively). The CFTR minigenes results mimicked the ex vivo data, as exon 16 skipping is the main aberrant transcript, and the correctly spliced transcript level was observed in a similar proportion when the c.2657+5G>A mutation is present. In summary, we provide evidence that ex vivo quantitative transcripts analysis using RT/qPCR is a robust technology that could be useful for measuring the efficacy of therapeutic approaches that attempt to achieve an increase in CFTR gene expression. PMID:24129438

  3. Some gating potentiators, including VX-770, diminish ΔF508-CFTR functional expression

    PubMed Central

    Veit, Guido; Avramescu, Radu G.; Perdomo, Doranda; Phuan, Puay-Wah; Bagdany, Miklos; Apaja, Pirjo M.; Borot, Florence; Szollosi, Daniel; Wu, Yu-Sheng; Finkbeiner, Walter E.; Hegedus, Tamas; Verkman, Alan S.; Lukacs, Gergely L.

    2015-01-01

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane regulator (CFTR) that result in reduced anion conductance at the apical membrane of secretory epithelia. Treatment of CF patients carrying the G551D gating mutation with the potentiator VX-770 (ivacaftor) largely restores channel activity and has shown substantial clinical benefit. However, most CF patients carry the ΔF508 mutation, which impairs CFTR folding, processing, function, and stability. Studies in homozygous ΔF508 CF patients indicated little clinical benefit of monotherapy with the investigational corrector VX-809 (lumacaftor) or VX-770, whereas combination clinical trials show limited but significant improvements in lung function. We show that VX-770, as well as most other potentiators, reduces the correction efficacy of VX-809 and another investigational corrector, VX-661. To mimic the administration of VX-770 alone or in combination with VX-809, we examined its long-term effect in immortalized and primary human respiratory epithelia. VX-770 diminished the folding efficiency and the metabolic stability of ΔF508-CFTR at the endoplasmic reticulum (ER) and post-ER compartments, respectively, causing reduced cell surface ΔF508-CFTR density and function. VX-770–induced destabilization of ΔF508-CFTR was influenced by second-site suppressor mutations of the folding defect and was prevented by stabilization of the nucleotide-binding domain 1 (NBD1)–NBD2 interface. The reduced correction efficiency of ΔF508-CFTR, as well as of two other processing mutations in the presence of VX-770, suggests the need for further optimization of potentiators to maximize the clinical benefit of corrector-potentiator combination therapy in CF. PMID:25101887

  4. Some gating potentiators, including VX-770, diminish ΔF508-CFTR functional expression.

    PubMed

    Veit, Guido; Avramescu, Radu G; Perdomo, Doranda; Phuan, Puay-Wah; Bagdany, Miklos; Apaja, Pirjo M; Borot, Florence; Szollosi, Daniel; Wu, Yu-Sheng; Finkbeiner, Walter E; Hegedus, Tamas; Verkman, Alan S; Lukacs, Gergely L

    2014-07-23

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane regulator (CFTR) that result in reduced anion conductance at the apical membrane of secretory epithelia. Treatment of CF patients carrying the G551D gating mutation with the potentiator VX-770 (ivacaftor) largely restores channel activity and has shown substantial clinical benefit. However, most CF patients carry the ΔF508 mutation, which impairs CFTR folding, processing, function, and stability. Studies in homozygous ΔF508 CF patients indicated little clinical benefit of monotherapy with the investigational corrector VX-809 (lumacaftor) or VX-770, whereas combination clinical trials show limited but significant improvements in lung function. We show that VX-770, as well as most other potentiators, reduces the correction efficacy of VX-809 and another investigational corrector, VX-661. To mimic the administration of VX-770 alone or in combination with VX-809, we examined its long-term effect in immortalized and primary human respiratory epithelia. VX-770 diminished the folding efficiency and the metabolic stability of ΔF508-CFTR at the endoplasmic reticulum (ER) and post-ER compartments, respectively, causing reduced cell surface ΔF508-CFTR density and function. VX-770-induced destabilization of ΔF508-CFTR was influenced by second-site suppressor mutations of the folding defect and was prevented by stabilization of the nucleotide-binding domain 1 (NBD1)-NBD2 interface. The reduced correction efficiency of ΔF508-CFTR, as well as of two other processing mutations in the presence of VX-770, suggests the need for further optimization of potentiators to maximize the clinical benefit of corrector-potentiator combination therapy in CF. Copyright © 2014, American Association for the Advancement of Science.

  5. Sensitivity of chloride efflux vs. transepithelial measurements in mixed CF and normal airway epithelial cell populations.

    PubMed

    Illek, Beate; Lei, Dachuan; Fischer, Horst; Gruenert, Dieter C

    2010-01-01

    While the Cl(-) efflux assays are relatively straightforward, their ability to assess the efficacy of phenotypic correction in cystic fibrosis (CF) tissue or cells may be limited. Accurate assessment of therapeutic efficacy, i.e., correlating wild type CF transmembrane conductance regulator (CFTR) levels with phenotypic correction in tissue or individual cells, requires a sensitive assay. Radioactive chloride ((36)Cl) efflux was compared to Ussing chamber analysis for measuring cAMP-dependent Cl(-) transport in mixtures of human normal (16HBE14o-) and cystic fibrosis (CF) (CFTE29o- or CFBE41o-, respectively) airway epithelial cells. Cell mixtures with decreasing amounts of 16HBE14o- cells were evaluated. Efflux and Ussing chamber studies on mixed populations of normal and CF airway epithelial cells showed that, as the number of CF cells within the population was progressively increased, the cAMP-dependent Cl(-) decreased. The (36)Cl efflux assay was effective for measuring Cl(-) transport when ≥ 25% of the cells were normal. If < 25% of the cells were phenotypically wild-type (wt), the (36)Cl efflux assay was no longer reliable. Polarized CFBE41o- cells, also homozygous for the ΔF508 mutation, were used in the Ussing chamber studies. Ussing analysis detected cAMP-dependent Cl(-) currents in mixtures with ≥1% wild-type cells indicating that Ussing analysis is more sensitive than (36)Cl efflux analysis for detection of functional CFTR. Assessment of CFTR function by Ussing analysis is more sensitive than (36)Cl efflux analysis. Ussing analysis indicates that cell mixtures containing 10% 16HBE14o- cells showed 40-50% of normal cAMP-dependent Cl(-) transport that drops off exponentially between 10-1% wild-type cells. Copyright © 2010 S. Karger AG, Basel.

  6. Assessing Feedback in a Mobile Videogame

    PubMed Central

    Brand, Leah; Beltran, Alicia; Hughes, Sheryl; O'Connor, Teresia; Baranowski, Janice; Nicklas, Theresa; Chen, Tzu-An; Dadabhoy, Hafza R.; Diep, Cassandra S.; Buday, Richard

    2016-01-01

    Abstract Background: Player feedback is an important part of serious games, although there is no consensus regarding its delivery or optimal content. “Mommio” is a serious game designed to help mothers motivate their preschoolers to eat vegetables. The purpose of this study was to assess optimal format and content of player feedback for use in “Mommio.” Materials and Methods: The current study posed 36 potential “Mommio” gameplay feedback statements to 20 mothers using a Web survey and interview. Mothers were asked about the meaning and helpfulness of each feedback statement. Results: Several themes emerged upon thematic analysis, including identifying an effective alternative in the case of corrective feedback, avoiding vague wording, using succinct and correct grammar, avoiding provocation of guilt, and clearly identifying why players' game choice was correct or incorrect. Conclusions: Guidelines are proposed for future feedback statements. PMID:27058403

  7. Advances in Collaborative Filtering

    NASA Astrophysics Data System (ADS)

    Koren, Yehuda; Bell, Robert

    The collaborative filtering (CF) approach to recommenders has recently enjoyed much interest and progress. The fact that it played a central role within the recently completed Netflix competition has contributed to its popularity. This chapter surveys the recent progress in the field. Matrix factorization techniques, which became a first choice for implementing CF, are described together with recent innovations. We also describe several extensions that bring competitive accuracy into neighborhood methods, which used to dominate the field. The chapter demonstrates how to utilize temporal models and implicit feedback to extend models accuracy. In passing, we include detailed descriptions of some the central methods developed for tackling the challenge of the Netflix Prize competition.

  8. Critical Mechanisms for the Formation of Extreme Arctic Sea-Ice Extent in the Summers of 2007 and 1996

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

    Dong, Xiquan; Zib, Benjamin J.; Xi, Baike

    A warming Arctic climate is undergoing significant e 21 nvironmental change, most evidenced by the reduction of Arctic sea-ice extent during the summer. In this study, we examine two extreme anomalies of September sea-ice extent in 2007 and 1996, and investigate the impacts of cloud fraction (CF), atmospheric precipitable water vapor (PWV), downwelling longwave flux (DLF), surface air temperature (SAT), pressure and winds on the sea-ice variation in 2007 and 1996 using both satellite-derived sea-ice products and MERRA reanalysis. The area of the Laptev, East Siberian and West Chukchi seas (70-90oN, 90-180oE) has experienced the largest variation in sea-ice extentmore » from year-to-year and defined here as the Area Of Focus (AOF). The record low September sea-ice extent in 2007 was associated with positive anomalies 30 of CF, PWV, DLF, and SAT over the AOF. Persistent anti-cyclone positioned over the Beaufort Sea coupled with low pressure over Eurasia induced easterly zonal and southerly meridional winds. In contrast, negative CF, PWV, DLF and SAT anomalies, as well as opposite wind patterns to those in 2007, characterized the 1996 high September sea-ice extent. Through this study, we hypothesize the following positive feedbacks of clouds, water vapor, radiation and atmospheric variables on the sea-ice retreat during the summer 2007. The record low sea-ice extent during the summer 2007 is initially triggered by the atmospheric circulation anomaly. The southerly winds across the Chukchi and East Siberian seas transport warm, moist air from the north Pacific, which is not only enhancing sea-ice melt across the AOF, but also increasing clouds. The positive cloud feedback results in higher SAT and more sea-ice melt. Therefore, 40 more water vapor could be evaporated from open seas and higher SAT to form more clouds, which will enhance positive cloud feedback. This enhanced positive cloud feedback will then further increase SAT and accelerate the sea-ice retreat during the summer 2007.« less

  9. The Effect Of Different Corrective Feedback Methods on the Outcome and Self Confidence of Young Athletes

    PubMed Central

    Tzetzis, George; Votsis, Evandros; Kourtessis, Thomas

    2008-01-01

    This experiment investigated the effects of three corrective feedback methods, using different combinations of correction, or error cues and positive feedback for learning two badminton skills with different difficulty (forehand clear - low difficulty, backhand clear - high difficulty). Outcome and self-confidence scores were used as dependent variables. The 48 participants were randomly assigned into four groups. Group A received correction cues and positive feedback. Group B received cues on errors of execution. Group C received positive feedback, correction cues and error cues. Group D was the control group. A pre, post and a retention test was conducted. A three way analysis of variance ANOVA (4 groups X 2 task difficulty X 3 measures) with repeated measures on the last factor revealed significant interactions for each depended variable. All the corrective feedback methods groups, increased their outcome scores over time for the easy skill, but only groups A and C for the difficult skill. Groups A and B had significantly better outcome scores than group C and the control group for the easy skill on the retention test. However, for the difficult skill, group C was better than groups A, B and D. The self confidence scores of groups A and C improved over time for the easy skill but not for group B and D. Again, for the difficult skill, only group C improved over time. Finally a regression analysis depicted that the improvement in performance predicted a proportion of the improvement in self confidence for both the easy and the difficult skill. It was concluded that when young athletes are taught skills of different difficulty, different type of instruction, might be more appropriate in order to improve outcome and self confidence. A more integrated approach on teaching will assist coaches or physical education teachers to be more efficient and effective. Key pointsThe type of the skill is a critical factor in determining the effectiveness of the feedback types.Different instructional methods of corrective feedback could have beneficial effects in the outcome and self-confidence of young athletesInstructions focusing on the correct cues or errors increase performance of easy skills.Positive feedback or correction cues increase self-confidence of easy skills but only the combination of error and correction cues increase self confidence and outcome scores of difficult skills. PMID:24149905

  10. Disease phenotype of a ferret CFTR-knockout model of cystic fibrosis

    PubMed Central

    Sun, Xingshen; Sui, Hongshu; Fisher, John T.; Yan, Ziying; Liu, Xiaoming; Cho, Hyung-Ju; Joo, Nam Soo; Zhang, Yulong; Zhou, Weihong; Yi, Yaling; Kinyon, Joann M.; Lei-Butters, Diana C.; Griffin, Michelle A.; Naumann, Paul; Luo, Meihui; Ascher, Jill; Wang, Kai; Frana, Timothy; Wine, Jeffrey J.; Meyerholz, David K.; Engelhardt, John F.

    2010-01-01

    Cystic fibrosis (CF) is a recessive disease that affects multiple organs. It is caused by mutations in CFTR. Animal modeling of this disease has been challenging, with species- and strain-specific differences in organ biology and CFTR function influencing the emergence of disease pathology. Here, we report the phenotype of a CFTR-knockout ferret model of CF. Neonatal CFTR-knockout ferrets demonstrated many of the characteristics of human CF disease, including defective airway chloride transport and submucosal gland fluid secretion; variably penetrant meconium ileus (MI); pancreatic, liver, and vas deferens disease; and a predisposition to lung infection in the early postnatal period. Severe malabsorption by the gastrointestinal (GI) tract was the primary cause of death in CFTR-knockout kits that escaped MI. Elevated liver function tests in CFTR-knockout kits were corrected by oral administration of ursodeoxycholic acid, and the addition of an oral proton-pump inhibitor improved weight gain and survival. To overcome the limitations imposed by the severe intestinal phenotype, we cloned 4 gut-corrected transgenic CFTR-knockout kits that expressed ferret CFTR specifically in the intestine. One clone passed feces normally and demonstrated no detectable ferret CFTR expression in the lung or liver. The animals described in this study are likely to be useful tools for dissecting CF disease pathogenesis and developing treatments. PMID:20739752

  11. Disease phenotype of a ferret CFTR-knockout model of cystic fibrosis.

    PubMed

    Sun, Xingshen; Sui, Hongshu; Fisher, John T; Yan, Ziying; Liu, Xiaoming; Cho, Hyung-Ju; Joo, Nam Soo; Zhang, Yulong; Zhou, Weihong; Yi, Yaling; Kinyon, Joann M; Lei-Butters, Diana C; Griffin, Michelle A; Naumann, Paul; Luo, Meihui; Ascher, Jill; Wang, Kai; Frana, Timothy; Wine, Jeffrey J; Meyerholz, David K; Engelhardt, John F

    2010-09-01

    Cystic fibrosis (CF) is a recessive disease that affects multiple organs. It is caused by mutations in CFTR. Animal modeling of this disease has been challenging, with species- and strain-specific differences in organ biology and CFTR function influencing the emergence of disease pathology. Here, we report the phenotype of a CFTR-knockout ferret model of CF. Neonatal CFTR-knockout ferrets demonstrated many of the characteristics of human CF disease, including defective airway chloride transport and submucosal gland fluid secretion; variably penetrant meconium ileus (MI); pancreatic, liver, and vas deferens disease; and a predisposition to lung infection in the early postnatal period. Severe malabsorption by the gastrointestinal (GI) tract was the primary cause of death in CFTR-knockout kits that escaped MI. Elevated liver function tests in CFTR-knockout kits were corrected by oral administration of ursodeoxycholic acid, and the addition of an oral proton-pump inhibitor improved weight gain and survival. To overcome the limitations imposed by the severe intestinal phenotype, we cloned 4 gut-corrected transgenic CFTR-knockout kits that expressed ferret CFTR specifically in the intestine. One clone passed feces normally and demonstrated no detectable ferret CFTR expression in the lung or liver. The animals described in this study are likely to be useful tools for dissecting CF disease pathogenesis and developing treatments.

  12. The Italian National External quality assessment program in molecular genetic testing: results of the VII round (2010-2011).

    PubMed

    Censi, F; Tosto, F; Floridia, G; Marra, M; Salvatore, M; Baffico, A M; Grasso, M; Melis, M A; Pelo, E; Radice, P; Ravani, A; Rosatelli, C; Resta, N; Russo, S; Seia, M; Varesco, L; Falbo, V; Taruscio, D

    2013-01-01

    Since 2001 the Istituto Superiore di Sanità established a quality assurance programme for molecular genetic testing that covers four pathologies: Cystic Fibrosis (CF), Beta Thalassemia (BT), Fragile X Syndrome (FX), and Familial Adenomatous Polyposis Coli (APC). Since 2009 this activity is an institutional activity and participation is open to both public and private laboratories. Seven rounds have been performed until now and the eighth is in progress. Laboratories receive 4 DNA samples with mock clinical indications. They analyze the samples using their routine procedures. A panel of assessors review the raw data and the reports; all data are managed through a web utility. In 2010 the number of participants was 43, 17, 15, 5 for CF, BT, FX, APC schemes respectively. Genotyping results were correct in 96%, 98.5%, 100%, and 100% of CF, BT, FX, and APC samples, respectively. Interpretation was correct in 74%, 91%, 88%, and 60% of CF, BT, FX, and APC reports, respectively; however in most of them it was not complete but a referral to genetic counseling was given. Reports were satisfactory in more than 60% of samples in all schemes. This work presents the 2010 results in detail comparing our data with those from other European schemes.

  13. The Effect of Direct and Indirect Corrective Feedback on Iranian EFL Learners' Spelling Errors

    ERIC Educational Resources Information Center

    Ghandi, Maryam; Maghsoudi, Mojtaba

    2014-01-01

    The aim of the current study was to investigate the impact of indirect corrective feedback on promoting Iranian high school students' spelling accuracy in English (as a foreign language). It compared the effect of direct feedback with indirect feedback on students' written work dictated by their teacher from Chicken Soup for the Mother and…

  14. New Supervisors' Struggles and Successes with Corrective Feedback

    ERIC Educational Resources Information Center

    Borders, L. DiAnne; Welfare, Laura E.; Sackett, Corrine R.; Cashwell, Craig

    2017-01-01

    Seven doctoral supervisors described their experiences giving corrective feedback, including events when constructive feedback and confrontation did and did not go well. Findings reveal their thoughts and feelings before, during, and after each event. The authors suggest several specific pedagogical directions for facilitating supervisor…

  15. Information needs of parents of infants diagnosed with cystic fibrosis: Results of a pilot study.

    PubMed

    Edwards, Danielle J; Wicking, Kristin; Smyth, Wendy; Shields, Linda; Douglas, Tonia

    2018-01-01

    This study investigated the information needs, priorities and information-seeking behaviours of parents of infants recently diagnosed with cystic fibrosis (CF) following newborn screening, by piloting the 'Care of Cystic Fibrosis Families Survey'. The questionnaires were posted to eligible parents ( n = 66) attending CF clinics in hospitals in two Australian states; reply-paid envelopes were provided for return of the questionnaires. Twenty-six were returned (response rate 39.4%). The most common questions to which parents required answers during their initial education period related to what CF is, how it is treated and how to care for their child. Parents preferred face-to-face consultations to deliver information, and yet all reported using the Internet to search for more information at some point during the education period. Many parents provided negative feedback about being given their child's CF diagnosis via telephone. The timing, content and method of information delivery can all affect the initial education experience. We can deliver education to better suit the information needs and priorities for education of parents of infants recently diagnosed with CF. The Care of Cystic Fibrosis Families Survey was successfully piloted and recommendations for amendments have been made for use in a larger study across Australia.

  16. Can corrective feedback improve recognition memory?

    PubMed

    Kantner, Justin; Lindsay, D Stephen

    2010-06-01

    An understanding of the effects of corrective feedback on recognition memory can inform both recognition theory and memory training programs, but few published studies have investigated the issue. Although the evidence to date suggests that feedback does not improve recognition accuracy, few studies have directly examined its effect on sensitivity, and fewer have created conditions that facilitate a feedback advantage by encouraging controlled processing at test. In Experiment 1, null effects of feedback were observed following both deep and shallow encoding of categorized study lists. In Experiment 2, feedback robustly influenced response bias by allowing participants to discern highly uneven base rates of old and new items, but sensitivity remained unaffected. In Experiment 3, a false-memory procedure, feedback failed to attenuate false recognition of critical lures. In Experiment 4, participants were unable to use feedback to learn a simple category rule separating old items from new items, despite the fact that feedback was of substantial benefit in a nearly identical categorization task. The recognition system, despite a documented ability to utilize controlled strategic or inferential decision-making processes, appears largely impenetrable to a benefit of corrective feedback.

  17. When more is less: Feedback effects in perceptual category learning ☆

    PubMed Central

    Maddox, W. Todd; Love, Bradley C.; Glass, Brian D.; Filoteo, J. Vincent

    2008-01-01

    Rule-based and information-integration category learning were compared under minimal and full feedback conditions. Rule-based category structures are those for which the optimal rule is verbalizable. Information-integration category structures are those for which the optimal rule is not verbalizable. With minimal feedback subjects are told whether their response was correct or incorrect, but are not informed of the correct category assignment. With full feedback subjects are informed of the correctness of their response and are also informed of the correct category assignment. An examination of the distinct neural circuits that subserve rule-based and information-integration category learning leads to the counterintuitive prediction that full feedback should facilitate rule-based learning but should also hinder information-integration learning. This prediction was supported in the experiment reported below. The implications of these results for theories of learning are discussed. PMID:18455155

  18. Efficacy of Error for the Correction of Initially Incorrect Assumptions and of Feedback for the Affirmation of Correct Responding: Learning in the Classroom

    ERIC Educational Resources Information Center

    Brosvic, Gary M.; Epstein, Michael L.; Cook, Michael J.; Dihoff, Roberta E.

    2005-01-01

    Participants completed 5 classroom examinations during which the timing of knowledge of results (no feedback: Scantron form; delayed feedback: end-of-test, 24 hour delay; immediate feedback: educator, response form) and iterative responding (1 response, up to 4 responses) were manipulated. At the end of the semester, each participant completed a…

  19. Feedback on students' clinical reasoning skills during fieldwork education

    PubMed Central

    de Beer, Marianne; Mårtensson, Lena

    2015-01-01

    Background/aim Feedback on clinical reasoning skills during fieldwork education is regarded as vital in occupational therapy students' professional development. The nature of supervisors' feedback however, could be confirmative and/or corrective and corrective feedback could be with or without suggestions on how to improve. The aim of the study was to evaluate the impact of supervisors' feedback on final-year occupational therapy students' clinical reasoning skills through comparing the nature of feedback with the students' subsequent clinical reasoning ability. Method A mixed-method approach with a convergent parallel design was used combining the collection and analysis of qualitative and quantitative data. From focus groups and interviews with students, data were collected and analysed qualitatively to determine how the students experienced the feedback they received from their supervisors. By quantitatively comparing the final practical exam grades with the nature of the feedback, their fieldwork End-of-Term grades and average academic performance it became possible to merge the results for comparison and interpretation. Results Students' clinical reasoning skills seem to be improved through corrective feedback if accompanied by suggestions on how to improve, irrespective of their average academic performance. Supervisors were inclined to underrate high performing students and overrate lower performing students. Conclusions Students who obtained higher grades in the final practical examinations received more corrective feedback with suggestions on how to improve from their supervisors. Confirmative feedback alone may not be sufficient for improving the clinical reasoning skills of students. PMID:26256854

  20. Molecular typing of Burkholderia cepacia complex isolated from patients attending an Italian Cystic Fibrosis Centre.

    PubMed

    Teri, Antonio; Sottotetti, Samantha; Biffi, Arianna; Girelli, Daniela; D'Accico, Monica; Arghittu, Milena; Colombo, Carla; Corti, Fabiola; Pizzamiglio, Giovanna; Cariani, Lisa

    2018-04-01

    Bacteria from the Burkholderia cepacia complex (Bcc) are capable of causing severe infections in patients with cystic fibrosis (CF). Bcc infection is often extremely difficult to treat due to its intrinsic resistance to multiple antibiotics. In addition, it seems to speed up the decline of lung function and is considered a contraindication for lung transplantation in CF. This study investigates the species of the Bcc strains recovered from chronically infected CF subjects by means of: isolation, identification methods and complete recA nucleotide sequences of 151 samples. Molecular typing showed that B. cenocepacia III is the dominant strain found in the group of subjects being treated at the Milan CF Centre (Italy) and that the infection is chronically maintained by the same species. Defining species by means of molecular analysis yields important information for the clinician in order to establish the most appropriate therapy and implement correct measures for prevention of transmission among CF subjects.

  1. Multimodal Strategies Allowing Corrective Feedback to Be Softened during Webconferencing-Supported Interactions

    ERIC Educational Resources Information Center

    Wigham, Ciara R.; Vidal, Julie

    2016-01-01

    This paper focuses on corrective feedback and examines how trainee-teachers use different semiotic resources to soften feedback sequences during synchronous online interactions. The ISMAEL corpus of webconferencing-supported L2 interactions in French provided data for this qualitative study. Using multimodal transcriptions, the analysis describes…

  2. Error correcting mechanisms during antisaccades: contribution of online control during primary saccades and offline control via secondary saccades.

    PubMed

    Bedi, Harleen; Goltz, Herbert C; Wong, Agnes M F; Chandrakumar, Manokaraananthan; Niechwiej-Szwedo, Ewa

    2013-01-01

    Errors in eye movements can be corrected during the ongoing saccade through in-flight modifications (i.e., online control), or by programming a secondary eye movement (i.e., offline control). In a reflexive saccade task, the oculomotor system can use extraretinal information (i.e., efference copy) online to correct errors in the primary saccade, and offline retinal information to generate a secondary corrective saccade. The purpose of this study was to examine the error correction mechanisms in the antisaccade task. The roles of extraretinal and retinal feedback in maintaining eye movement accuracy were investigated by presenting visual feedback at the spatial goal of the antisaccade. We found that online control for antisaccade is not affected by the presence of visual feedback; that is whether visual feedback is present or not, the duration of the deceleration interval was extended and significantly correlated with reduced antisaccade endpoint error. We postulate that the extended duration of deceleration is a feature of online control during volitional saccades to improve their endpoint accuracy. We found that secondary saccades were generated more frequently in the antisaccade task compared to the reflexive saccade task. Furthermore, we found evidence for a greater contribution from extraretinal sources of feedback in programming the secondary "corrective" saccades in the antisaccade task. Nonetheless, secondary saccades were more corrective for the remaining antisaccade amplitude error in the presence of visual feedback of the target. Taken together, our results reveal a distinctive online error control strategy through an extension of the deceleration interval in the antisaccade task. Target feedback does not improve online control, rather it improves the accuracy of secondary saccades in the antisaccade task.

  3. Development of Field Methodology and Processes for Task Analysis and Training Feedback

    DTIC Science & Technology

    1978-10-31

    To evaluate technical ability and/or pco ad~nil- 2064 5. If part is in. notifies Shop Pffice t-e Job status is tration of shop supply elemnt and...Pepairs are ct- Dieted within a reasonable tnie frare consistent with prevailing conditions and pablispied standards, 5. Corpletion cf work must be

  4. The Context Matters: Outcome Probability and Expectation Mismatch Modulate the Feedback Negativity When Self-Evaluation of Response Correctness Is Possible

    PubMed Central

    Leue, Anja; Cano Rodilla, Carmen; Beauducel, André

    2015-01-01

    Individuals typically evaluate whether their performance and the obtained feedback match. Previous research has shown that feedback negativity (FN) depends on outcome probability and feedback valence. It is, however, less clear to what extent previous effects of outcome probability on FN depend on self-evaluations of response correctness. Therefore, we investigated the effects of outcome probability on FN amplitude in a simple go/no-go task that allowed for the self-evaluation of response correctness. We also investigated effects of performance incompatibility and feedback valence. In a sample of N = 22 participants, outcome probability was manipulated by means of precues, feedback valence by means of monetary feedback, and performance incompatibility by means of feedback that induced a match versus mismatch with individuals' performance. We found that the 100% outcome probability condition induced a more negative FN following no-loss than the 50% outcome probability condition. The FN following loss was more negative in the 50% compared to the 100% outcome probability condition. Performance-incompatible loss resulted in a more negative FN than performance-compatible loss. Our results indicate that the self-evaluation of the correctness of responses should be taken into account when the effects of outcome probability and expectation mismatch on FN are investigated. PMID:26783525

  5. The Context Matters: Outcome Probability and Expectation Mismatch Modulate the Feedback Negativity When Self-Evaluation of Response Correctness Is Possible.

    PubMed

    Leue, Anja; Cano Rodilla, Carmen; Beauducel, André

    2015-01-01

    Individuals typically evaluate whether their performance and the obtained feedback match. Previous research has shown that feedback negativity (FN) depends on outcome probability and feedback valence. It is, however, less clear to what extent previous effects of outcome probability on FN depend on self-evaluations of response correctness. Therefore, we investigated the effects of outcome probability on FN amplitude in a simple go/no-go task that allowed for the self-evaluation of response correctness. We also investigated effects of performance incompatibility and feedback valence. In a sample of N = 22 participants, outcome probability was manipulated by means of precues, feedback valence by means of monetary feedback, and performance incompatibility by means of feedback that induced a match versus mismatch with individuals' performance. We found that the 100% outcome probability condition induced a more negative FN following no-loss than the 50% outcome probability condition. The FN following loss was more negative in the 50% compared to the 100% outcome probability condition. Performance-incompatible loss resulted in a more negative FN than performance-compatible loss. Our results indicate that the self-evaluation of the correctness of responses should be taken into account when the effects of outcome probability and expectation mismatch on FN are investigated.

  6. Internet-Mediated Corrective Feedback for Digital Natives

    ERIC Educational Resources Information Center

    Saadat, Mahboobeh; Mehrpour, Saeed; Khajavi, Yaser

    2016-01-01

    In this article, the authors examine different ways of using the Internet to receive feedback, and discuss advantages of language learners' use of the Internet to improve their own writing. In effect, the article elaborates on how Internet-mediated corrective feedback (IMCF) can be used as an efficient tool by language learners to become competent…

  7. Comparative Effects of Ability and Feedback Form in Computer-Assisted Instruction.

    ERIC Educational Resources Information Center

    Clariana, Roy B.; Smith, Lana J.

    A study involving 50 experimental and 99 control subjects (graduate education majors) was undertaken to assess the interchangeability of knowledge of correct response feedback (KRC) and answer until correct feedback (AUC) in computer-assisted instruction. P. L. Smith's model (1988) suggests that AUC in better for high-ability students. W. Dick and…

  8. ESLl Teachers' Knowledge of and Experience with Written Corrective Feedback

    ERIC Educational Resources Information Center

    Cao, Peihong

    2017-01-01

    Written Corrective Feedback (WCF) in writing classes is fundamental to interactions between teachers and students about students' writing and to help students further improve their writing. As one of the main feedback sources, teachers' cognition (e.g., teachers' thoughts, knowledge, and beliefs) needs to be probed to properly understand teachers…

  9. Novel short chain fatty acids restore chloride secretion in cystic fibrosis

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

    Nguyen, Toan D.; Kim, Ug-Sung; Perrine, Susan P.

    2006-03-31

    Phenylalanine deletion at position 508 of the cystic fibrosis transmembrane conductance regulator ({delta}F508-CFTR), the most common mutation in cystic fibrosis (CF), causes a misfolded protein exhibiting partial chloride conductance and impaired trafficking to the plasma membrane. 4-Phenylbutyrate corrects defective {delta}F508-CFTR trafficking in vitro, but is not clinically efficacious. From a panel of short chain fatty acid derivatives, we showed that 2,2-dimethyl-butyrate (ST20) and {alpha}-methylhydrocinnamic acid (ST7), exhibiting high oral bioavailability and sustained plasma levels, correct the {delta}F508-CFTR defect. Pre-incubation ({>=}6 h) of CF IB3-1 airway cells with {>=}1 mM ST7 or ST20 restored the ability of 100 {mu}M forskolin tomore » stimulate an {sup 125}I{sup -} efflux. This efflux was fully inhibited by NPPB, DPC, or glibenclamide, suggesting mediation through CFTR. Partial inhibition by DIDS suggests possible contribution from an additional Cl{sup -} channel regulated by CFTR. Thus, ST7 and ST20 offer treatment potential for CF caused by the {delta}F508 mutation.« less

  10. Corrective Feedback via E-Mail on the Correct Use of Past Tense among Iranian EFL Learners

    ERIC Educational Resources Information Center

    Alipanahi, Fatemeh; Mahmoodi, Ra'na

    2015-01-01

    This study explores the differential effect of two types of corrective feedback strategies--explicit and implicit--on the acquisition and retention of correct past form of irregular verbs by Iranian English as Foreign Language (EFL) learners. Sixty out of 80 pre-intermediate EFL learners were selected as the participants, based on their…

  11. Task-dependent vestibular feedback responses in reaching.

    PubMed

    Keyser, Johannes; Medendorp, W Pieter; Selen, Luc P J

    2017-07-01

    When reaching for an earth-fixed object during self-rotation, the motor system should appropriately integrate vestibular signals and sensory predictions to compensate for the intervening motion and its induced inertial forces. While it is well established that this integration occurs rapidly, it is unknown whether vestibular feedback is specifically processed dependent on the behavioral goal. Here, we studied whether vestibular signals evoke fixed responses with the aim to preserve the hand trajectory in space or are processed more flexibly, correcting trajectories only in task-relevant spatial dimensions. We used galvanic vestibular stimulation to perturb reaching movements toward a narrow or a wide target. Results show that the same vestibular stimulation led to smaller trajectory corrections to the wide than the narrow target. We interpret this reduced compensation as a task-dependent modulation of vestibular feedback responses, tuned to minimally intervene with the task-irrelevant dimension of the reach. These task-dependent vestibular feedback corrections are in accordance with a central prediction of optimal feedback control theory and mirror the sophistication seen in feedback responses to mechanical and visual perturbations of the upper limb. NEW & NOTEWORTHY Correcting limb movements for external perturbations is a hallmark of flexible sensorimotor behavior. While visual and mechanical perturbations are corrected in a task-dependent manner, it is unclear whether a vestibular perturbation, naturally arising when the body moves, is selectively processed in reach control. We show, using galvanic vestibular stimulation, that reach corrections to vestibular perturbations are task dependent, consistent with a prediction of optimal feedback control theory. Copyright © 2017 the American Physiological Society.

  12. Repurposing tromethamine as inhaled therapy to treat CF airway disease

    PubMed Central

    Alaiwa, Mahmoud H. Abou; Launspach, Janice L.; Sheets, Kelsey A.; Rivera, Jade A.; Gansemer, Nicholas D.; Taft, Peter J.; Thorne, Peter S.; Welsh, Michael J.; Stoltz, David A.

    2016-01-01

    In cystic fibrosis (CF), loss of CF transmembrane conductance regulator (CFTR) anion channel activity causes airway surface liquid (ASL) pH to become acidic, which impairs airway host defenses. One potential therapeutic approach is to correct the acidic pH in CF airways by aerosolizing HCO3– and/or nonbicarbonate pH buffers. Here, we show that raising ASL pH with inhaled HCO3– increased pH. However, the effect was transient, and pH returned to baseline values within 30 minutes. Tromethamine (Tham) is a buffer with a long serum half-life used as an i.v. formulation to treat metabolic acidosis. We found that Tham aerosols increased ASL pH in vivo for at least 2 hours and enhanced bacterial killing. Inhaled hypertonic saline (7% NaCl) is delivered to people with CF in an attempt to promote mucus clearance. Because an increased ionic strength inhibits ASL antimicrobial factors, we added Tham to hypertonic saline and applied it to CF sputum. We found that Tham alone and in combination with hypertonic saline increased pH and enhanced bacterial killing. These findings suggest that aerosolizing the HCO3–-independent buffer Tham, either alone or in combination with hypertonic saline, might be of therapeutic benefit in CF airway disease. PMID:27390778

  13. Assessment of the atmospheric loss processes initiated by OH radicals and sunlight, and the radiative efficiency for a series of hydrofluoroolefins, CF3(CF2)x=1,3,5CHCH2.

    PubMed

    González, Sergio; Jiménez, Elena; Albaladejo, José

    2016-05-01

    Hydrofluoroolefins (HFOs) of the type CF3(CF2)x≥0CHCH2, are currently being suggested as substitutes of some hydrofluorocarbons (HFCs). In this work, an assessment of the atmospheric removal of CF3(CF2)x=1,3,5CHCH2, initiated by reaction with hydroxyl (OH) radicals and UV solar radiation is addressed. For that purpose, the rate coefficients for the OH + CF3(CF2)x=1,3,5CHCH2 reaction, kOH(T = 263-358 K), were determined by the pulsed laser photolysis-laser induced fluorescence technique. A slightly negative temperature dependence of kOH was observed, obtaining Ea/R (in K) values of -124 ± 15, -128 ± 6 and -160 ± 10, for CF3CF2CHCH2, CF3(CF2)3CHCH2 and CF3(CF2)5CHCH2, respectively. The estimated atmospheric lifetimes are around 8 days, considering that HFOs are well-mixed in the troposphere. Furthermore, an evaluation of the long-wave and short-wave absorption process of these HFOs have been carried out by determining the UV (191-367 nm) and IR (4000-500 cm(-1)) absorption cross sections at 298 K. Based on the obtained UV absorption cross sections, no photolysis of CF3(CF2)x=1,3,5CHCH2 is expected in the troposphere (λ > 290 nm). These species strongly absorb IR radiation in the atmospheric IR window. Despite the strong absorption in the IR region, the lifetime corrected radiative efficiencies are low (0.033 W m(-2) ppb(-1) for CF3(CF2)3CHCH2 and 0.039 Wm(-2) ppb(-1) for CF3(CF2)5CHCH2). Calculation of GWPs for these species has been performed as a function of the horizon time, providing values higher than unity for a short-period term, decreasing dramatically for longer periods. Therefore, it is concluded that emissions of these species do not affect the radiative forcing of climate, making them suitable replacements of large-GWP HFCs. Copyright © 2016. Published by Elsevier Ltd.

  14. Understanding Written Corrective Feedback in Second-Language Grammar Acquisition

    ERIC Educational Resources Information Center

    Wagner, Jason Paul; Wulf, Douglas J.

    2016-01-01

    Written Corrective Feedback (WCF) is used extensively in second-language (L2) writing classrooms despite controversy over its effectiveness. This study examines indirect WCF, an instructional procedure that flags L2 students' errors with editing symbols that guide their corrections. WCF practitioners assume that this guidance will lead to…

  15. Written Corrective Feedback and Peer Review in the BYOD Classroom

    ERIC Educational Resources Information Center

    Ferreira, Daniel

    2013-01-01

    Error correction in the English as a Foreign Language (EFL) writing curriculum is a practice both teachers and students agree is important for writing proficiency development (Ferris, 2004; Van Beuningen, De Jong, & Kuiken, 2012; Vyatkina, 2010, 2011). Research suggests student dependency on teacher corrective feedback yields few long-term…

  16. Correcting false memories: Errors must be noticed and replaced.

    PubMed

    Mullet, Hillary G; Marsh, Elizabeth J

    2016-04-01

    Memory can be unreliable. For example, after reading The new baby stayed awake all night, people often misremember that the new baby cried all night (Brewer, 1977); similarly, after hearing bed, rest, and tired, people often falsely remember that sleep was on the list (Roediger & McDermott, 1995). In general, such false memories are difficult to correct, persisting despite warnings and additional study opportunities. We argue that errors must first be detected to be corrected; consistent with this argument, two experiments showed that false memories were nearly eliminated when conditions facilitated comparisons between participants' errors and corrective feedback (e.g., immediate trial-by-trial feedback that allowed direct comparisons between their responses and the correct information). However, knowledge that they had made an error was insufficient; unless the feedback message also contained the correct answer, the rate of false memories remained relatively constant. On the one hand, there is nothing special about correcting false memories: simply labeling an error as "wrong" is also insufficient for correcting other memory errors, including misremembered facts or mistranslations. However, unlike these other types of errors--which often benefit from the spacing afforded by delayed feedback--false memories require a special consideration: Learners may fail to notice their errors unless the correction conditions specifically highlight them.

  17. Intestinal CFTR expression alleviates meconium ileus in cystic fibrosis pigs

    PubMed Central

    Stoltz, David A.; Rokhlina, Tatiana; Ernst, Sarah E.; Pezzulo, Alejandro A.; Ostedgaard, Lynda S.; Karp, Philip H.; Samuel, Melissa S.; Reznikov, Leah R.; Rector, Michael V.; Gansemer, Nicholas D.; Bouzek, Drake C.; Alaiwa, Mahmoud H. Abou; Hoegger, Mark J.; Ludwig, Paula S.; Taft, Peter J.; Wallen, Tanner J.; Wohlford-Lenane, Christine; McMenimen, James D.; Chen, Jeng-Haur; Bogan, Katrina L.; Adam, Ryan J.; Hornick, Emma E.; Nelson, George A.; Hoffman, Eric A.; Chang, Eugene H.; Zabner, Joseph; McCray, Paul B.; Prather, Randall S.; Meyerholz, David K.; Welsh, Michael J.

    2013-01-01

    Cystic fibrosis (CF) pigs develop disease with features remarkably similar to those in people with CF, including exocrine pancreatic destruction, focal biliary cirrhosis, micro-gallbladder, vas deferens loss, airway disease, and meconium ileus. Whereas meconium ileus occurs in 15% of babies with CF, the penetrance is 100% in newborn CF pigs. We hypothesized that transgenic expression of porcine CF transmembrane conductance regulator (pCFTR) cDNA under control of the intestinal fatty acid–binding protein (iFABP) promoter would alleviate the meconium ileus. We produced 5 CFTR–/–;TgFABP>pCFTR lines. In 3 lines, intestinal expression of CFTR at least partially restored CFTR-mediated anion transport and improved the intestinal phenotype. In contrast, these pigs still had pancreatic destruction, liver disease, and reduced weight gain, and within weeks of birth, they developed sinus and lung disease, the severity of which varied over time. These data indicate that expressing CFTR in intestine without pancreatic or hepatic correction is sufficient to rescue meconium ileus. Comparing CFTR expression in different lines revealed that approximately 20% of wild-type CFTR mRNA largely prevented meconium ileus. This model may be of value for understanding CF pathophysiology and testing new preventions and therapies. PMID:23676501

  18. Outbreak of Corynebacterium pseudodiphtheriticum Infection in Cystic Fibrosis Patients, France

    PubMed Central

    Bittar, Fadi; Cassagne, Carole; Bosdure, Emmanuelle; Stremler, Nathalie; Dubus, Jean-Christophe; Sarles, Jacques; Reynaud-Gaubert, Martine; Raoult, Didier

    2010-01-01

    An increasing body of evidence indicates that nondiphtheria corynebacteria may be responsible for respiratory tract infections. We report an outbreak of Corynebacterium pseudodiphtheriticum infection in children with cystic fibrosis (CF). To identify 18 C. pseudodiphtheriticum strains isolated from 13 French children with CF, we used molecular methods (partial rpoB gene sequencing) and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. Clinical symptoms were exhibited by 10 children (76.9%), including cough, rhinitis, and lung exacerbations. The results of MALDI-TOF identification matched perfectly with those obtained from molecular identification. Retrospective analysis of sputum specimens by using specific real-time PCR showed that ≈20% of children with CF were colonized with these bacteria, whereas children who did not have CF had negative test results. Our study reemphasizes the conclusion that correctly identifying bacteria at the species level facilitates detection of an outbreak of new or emerging infections in humans. PMID:20678316

  19. Cystic fibrosis carriership and tuberculosis: hints toward an evolutionary selective advantage based on data from the Brazilian territory.

    PubMed

    Bosch, Lander; Bosch, Barbara; De Boeck, Kris; Nawrot, Tim; Meyts, Isabelle; Vanneste, Dominique; Le Bourlegat, Cleonice Alexandre; Croda, Julio; da Silva Filho, Luiz Vicente Ribeiro Ferreira

    2017-05-12

    The reason why Cystic Fibrosis (CF) is the most common fatal genetic disease among Caucasians has been incompletely studied. We aimed at deepening the hypothesis that CF carriers have a relative protection against Mycobacterium tuberculosis (Mtb) infection. Applying spatial epidemiology, we studied the link between CF carriership rate and tuberculosis (TB) incidence in Brazil. We corrected for 5 potential environmental and 2 immunological confounders in this relation: monthly income, sanitary provisions, literacy rates, racial composition and population density along with AIDS incidence rates and diabetes mellitus type 2. Smoking data were incomplete and not available for analysis. A significant, negative correlation between CF carriership rate and TB incidence, independent of any of the seven confounders was found. We provide exploratory support for the hypothesis that carrying a single CFTR mutation arms against Mtb infections.

  20. Best practices in the treatment of early cystic fibrosis lung disease.

    PubMed

    Proesmans, Marijke

    2017-02-01

    For many years, management of cystic fibrosis (CF) lung disease was focused on symptomatic treatment of chronic lung infection, which is characterized by cough and sputum production, leading to progressive lung damage. With increasing survival and better knowledge of the pathogenesis of CF lung disease, it has become clear that treatment has to start very early because lung damage occurs in young patients, often before obvious symptoms appear. The arrival of new cystic fibrosis transmembrane conductance-regulator (CFTR)-correcting therapies will bring more opportunities to prevent the disease, apart from only treating chronic lung infection. In this review, a summary of the current knowledge of early CF lung disease is provided, based on animal model studies, as well as on data obtained from well structured follow-up programs after newborn screening (NBS). The most important clinical guidelines for treating young CF patients are also summarized.

  1. The Effects of Two Methods of Error Correction on L2 Writing: The Case of Acquisition of the Spanish Preterite and Imperfect

    ERIC Educational Resources Information Center

    Munoz, Carlos A.

    2011-01-01

    Very often, second language (L2) writers commit the same type of errors repeatedly, despite being corrected directly or indirectly by teachers or peers (Semke, 1984; Truscott, 1996). Apart from discouraging teachers from providing error correction feedback, this also makes them hesitant as to what form of corrective feedback to adopt. Ferris…

  2. Peer Response to L2 Student Writing: Patterns and Expectations

    ERIC Educational Resources Information Center

    Abdalla Salih, Abdel Rahman

    2013-01-01

    This paper reports the corrective feedback patterns in L2 writing and the student writers' preferences for peer feedback. The study examines the actual focus of peer review and the types of corrective feedback provided in L2 composing process. Sixteen L2 matriculation students at a Malaysian university took part in five peer review sessions,…

  3. Learners' Beliefs about Corrective Feedback in the Language Classroom: Perspectives from Two International Contexts

    ERIC Educational Resources Information Center

    Kartchava, Eva

    2016-01-01

    This study compared the beliefs college-level students hold about corrective feedback in different learning contexts: English as a second language (Canada, n = 197) and English as a foreign language (Russia, n = 224). The participants completed a 40-item questionnaire that dealt with various aspects of feedback found in the literature. While the…

  4. SPECTRAL CORRECTION FACTORS FOR CONVENTIONAL NEUTRON DOSE METERS USED IN HIGH-ENERGY NEUTRON ENVIRONMENTS-IMPROVED AND EXTENDED RESULTS BASED ON A COMPLETE SURVEY OF ALL NEUTRON SPECTRA IN IAEA-TRS-403.

    PubMed

    Oparaji, U; Tsai, Y H; Liu, Y C; Lee, K W; Patelli, E; Sheu, R J

    2017-06-01

    This paper presents improved and extended results of our previous study on corrections for conventional neutron dose meters used in environments with high-energy neutrons (En > 10 MeV). Conventional moderated-type neutron dose meters tend to underestimate the dose contribution of high-energy neutrons because of the opposite trends of dose conversion coefficients and detection efficiencies as the neutron energy increases. A practical correction scheme was proposed based on analysis of hundreds of neutron spectra in the IAEA-TRS-403 report. By comparing 252Cf-calibrated dose responses with reference values derived from fluence-to-dose conversion coefficients, this study provides recommendations for neutron field characterization and the corresponding dose correction factors. Further sensitivity studies confirm the appropriateness of the proposed scheme and indicate that (1) the spectral correction factors are nearly independent of the selection of three commonly used calibration sources: 252Cf, 241Am-Be and 239Pu-Be; (2) the derived correction factors for Bonner spheres of various sizes (6"-9") are similar in trend and (3) practical high-energy neutron indexes based on measurements can be established to facilitate the application of these correction factors in workplaces. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Structural learning in feedforward and feedback control.

    PubMed

    Yousif, Nada; Diedrichsen, Jörn

    2012-11-01

    For smooth and efficient motor control, the brain needs to make fast corrections during the movement to resist possible perturbations. It also needs to adapt subsequent movements to improve future performance. It is important that both feedback corrections and feedforward adaptation need to be made based on noisy and often ambiguous sensory data. Therefore, the initial response of the motor system, both for online corrections and adaptive responses, is guided by prior assumptions about the likely structure of perturbations. In the context of correcting and adapting movements perturbed by a force field, we asked whether these priors are hard wired or whether they can be modified through repeated exposure to differently shaped force fields. We found that both feedback corrections to unexpected perturbations and feedforward adaptation to a new force field changed, such that they were appropriate to counteract the type of force field that participants had experienced previously. We then investigated whether these changes were driven by a common mechanism or by two separate mechanisms. Participants experienced force fields that were either temporally consistent, causing sustained adaptation, or temporally inconsistent, causing little overall adaptation. We found that the consistent force fields modified both feedback and feedforward responses. In contrast, the inconsistent force field modified the temporal shape of feedback corrections but not of the feedforward adaptive response. These results indicate that responses to force perturbations can be modified in a structural manner and that these modifications are at least partly dissociable for feedback and feedforward control.

  6. Structural learning in feedforward and feedback control

    PubMed Central

    Diedrichsen, Jörn

    2012-01-01

    For smooth and efficient motor control, the brain needs to make fast corrections during the movement to resist possible perturbations. It also needs to adapt subsequent movements to improve future performance. It is important that both feedback corrections and feedforward adaptation need to be made based on noisy and often ambiguous sensory data. Therefore, the initial response of the motor system, both for online corrections and adaptive responses, is guided by prior assumptions about the likely structure of perturbations. In the context of correcting and adapting movements perturbed by a force field, we asked whether these priors are hard wired or whether they can be modified through repeated exposure to differently shaped force fields. We found that both feedback corrections to unexpected perturbations and feedforward adaptation to a new force field changed, such that they were appropriate to counteract the type of force field that participants had experienced previously. We then investigated whether these changes were driven by a common mechanism or by two separate mechanisms. Participants experienced force fields that were either temporally consistent, causing sustained adaptation, or temporally inconsistent, causing little overall adaptation. We found that the consistent force fields modified both feedback and feedforward responses. In contrast, the inconsistent force field modified the temporal shape of feedback corrections but not of the feedforward adaptive response. These results indicate that responses to force perturbations can be modified in a structural manner and that these modifications are at least partly dissociable for feedback and feedforward control. PMID:22896725

  7. Comparison of meaning and graphophonemic feedback strategies for guided reading instruction of children with language delays.

    PubMed

    Kouri, Theresa A; Selle, Carrie A; Riley, Sarah A

    2006-08-01

    Guided reading is a common practice recommended for children in the early stages of literacy development. While experts agree that oral reading facilitates literacy skills, controversy exists concerning which corrective feedback strategies are most effective. The purpose of this study was to compare feedback procedures stemming from 2 different theoretical perspectives on literacy development. Fourteen children with specific language impairment (SLI) and 21 with typically developing language read aloud 2 stories to an adult examiner who presented corrective feedback prompts when reading miscues (errors) occurred. One type of feedback based on whole language principles emphasized meaning aspects of a text. The other type consisted of graphophonemic (GP) word-decoding strategies. Before reading, participants were provided instruction on 5 key words taken from each story text. This instruction emphasized either meaning or GP aspects of specific key words. Story comprehension questions followed readings. Findings indicated that more miscued words were corrected overall through the use of GP feedback cues; however, some meaning-based instructional advantages were indicated for key word identifications for children with SLI. Higher story comprehension scores were yielded in the GP condition for both groups. Both meaning-based and phonemic key word reviews, prior to oral reading, appear to be effective strategies for children with SLI. The use of GP word-decoding cues may be more effective than meaning-based cues for facilitating correction of reading miscues during children's oral readings. Further research findings are discussed along with clinical implications for using corrective feedback procedures.

  8. The Effects of Different Levels of Performance Feedback on "TOEFL iBT"® Reading Practice Test Performance. TOEFL iBT Research Report. TOEFL iBT-29. ETS Research Report. RR-17-31

    ERIC Educational Resources Information Center

    Sawaki, Yasuyo

    2017-01-01

    The purpose of the present study is to examine whether performance on the "TOEFL iBT"® Reading practice test is affected by 3 different levels of feedback provided to learners upon completion of reading exercises: (a) correctness of learner response (the knowledge of correct results [KCR] feedback), (b) KCR feedback and rationales for…

  9. The Effect of Error Correction Feedback on the Collocation Competence of Iranian EFL Learners

    ERIC Educational Resources Information Center

    Jafarpour, Ali Akbar; Sharifi, Abolghasem

    2012-01-01

    Collocations are one of the most important elements in language proficiency but the effect of error correction feedback of collocations has not been thoroughly examined. Some researchers report the usefulness and importance of error correction (Hyland, 1990; Bartram & Walton, 1991; Ferris, 1999; Chandler, 2003), while others showed that error…

  10. A Three-Stage Model for Implementing Focused Written Corrective Feedback

    ERIC Educational Resources Information Center

    Chong, Sin Wang

    2017-01-01

    This article aims to show how the findings from written corrective feedback (WCF) research can be applied in practice. One particular kind of WCF--focused WCF--is brought into the spotlight. The article first summarizes major findings from focused WCF research to reveal the potential advantages of correcting a few preselected language items…

  11. Error Correcting Mechanisms during Antisaccades: Contribution of Online Control during Primary Saccades and Offline Control via Secondary Saccades

    PubMed Central

    Bedi, Harleen; Goltz, Herbert C.; Wong, Agnes M. F.; Chandrakumar, Manokaraananthan; Niechwiej-Szwedo, Ewa

    2013-01-01

    Errors in eye movements can be corrected during the ongoing saccade through in-flight modifications (i.e., online control), or by programming a secondary eye movement (i.e., offline control). In a reflexive saccade task, the oculomotor system can use extraretinal information (i.e., efference copy) online to correct errors in the primary saccade, and offline retinal information to generate a secondary corrective saccade. The purpose of this study was to examine the error correction mechanisms in the antisaccade task. The roles of extraretinal and retinal feedback in maintaining eye movement accuracy were investigated by presenting visual feedback at the spatial goal of the antisaccade. We found that online control for antisaccade is not affected by the presence of visual feedback; that is whether visual feedback is present or not, the duration of the deceleration interval was extended and significantly correlated with reduced antisaccade endpoint error. We postulate that the extended duration of deceleration is a feature of online control during volitional saccades to improve their endpoint accuracy. We found that secondary saccades were generated more frequently in the antisaccade task compared to the reflexive saccade task. Furthermore, we found evidence for a greater contribution from extraretinal sources of feedback in programming the secondary “corrective” saccades in the antisaccade task. Nonetheless, secondary saccades were more corrective for the remaining antisaccade amplitude error in the presence of visual feedback of the target. Taken together, our results reveal a distinctive online error control strategy through an extension of the deceleration interval in the antisaccade task. Target feedback does not improve online control, rather it improves the accuracy of secondary saccades in the antisaccade task. PMID:23936308

  12. Quantitative analysis of Al-Si alloy using calibration free laser induced breakdown spectroscopy (CF-LIBS)

    NASA Astrophysics Data System (ADS)

    Shakeel, Hira; Haq, S. U.; Aisha, Ghulam; Nadeem, Ali

    2017-06-01

    The quantitative analysis of the standard aluminum-silicon alloy has been performed using calibration free laser induced breakdown spectroscopy (CF-LIBS). The plasma was produced using the fundamental harmonic (1064 nm) of the Nd: YAG laser and the emission spectra were recorded at 3.5 μs detector gate delay. The qualitative analysis of the emission spectra confirms the presence of Mg, Al, Si, Ti, Mn, Fe, Ni, Cu, Zn, Sn, and Pb in the alloy. The background subtracted and self-absorption corrected emission spectra were used for the estimation of plasma temperature as 10 100 ± 300 K. The plasma temperature and self-absorption corrected emission lines of each element have been used for the determination of concentration of each species present in the alloy. The use of corrected emission intensities and accurate evaluation of plasma temperature yield reliable quantitative analysis up to a maximum 2.2% deviation from reference sample concentration.

  13. Dating groundwater with trifluoromethyl sulfurpentafluoride (SF 5CF3), sulfur hexafluoride (SF6), CF 3Cl (CFC-13), and CF2Cl2 (CFC-12)

    USGS Publications Warehouse

    Busenberg, E.; Plummer, Niel

    2008-01-01

    [1] A new groundwater dating procedure using the transient atmospheric signal of the environmental tracers SF5CF3, CFC-13, SF6, and CFC-12 was developed. The analytical procedure determines concentrations of the four tracers in air and water samples. SF 5CF3 and CFC-13 can be used to date groundwaters in some environments where the CFCs and SF6 have previously failed because these new tracers have increasing atmospheric input functions, no known terrigenic source, and are believed to be stable under reducing conditions. SF5CF3 has a dating range from 1970 to modern; the mixing ratio (mole fraction) in North American air has increased from the detection limit of 0.005 parts per trillion (ppt) to the 2006 mole fraction of about 0.16 ppt. No evidence was found for degradation of SF5CF3 in laboratory anaerobic systems. The solubility of SF5CF3 was measured in water from 1 to 35??C. Groundwater samples that contained large amounts of terrigenic SF6 did not contain terrigenic SF 5CF3. CFC-13 is a trace atmospheric gas with a dating range in groundwater of about 1965 to modem. CFC-13 has been used primarily in very low-temperature refrigeration; thus groundwater environments are less likely to be contaminated with nonatmospheric sources as compared to other widely used CFCs. Because of the low solubility of SF5CF3 and CFC-13 in water, an excess air correction must be applied to the apparent ages. The new dating procedure was tested in water samples from wells and springs from Maryland, Virginia, and West Virginia.

  14. Tumor Cell-Free DNA Copy Number Instability Predicts Therapeutic Response to Immunotherapy.

    PubMed

    Weiss, Glen J; Beck, Julia; Braun, Donald P; Bornemann-Kolatzki, Kristen; Barilla, Heather; Cubello, Rhiannon; Quan, Walter; Sangal, Ashish; Khemka, Vivek; Waypa, Jordan; Mitchell, William M; Urnovitz, Howard; Schütz, Ekkehard

    2017-09-01

    Purpose: Chromosomal instability is a fundamental property of cancer, which can be quantified by next-generation sequencing (NGS) from plasma/serum-derived cell-free DNA (cfDNA). We hypothesized that cfDNA could be used as a real-time surrogate for imaging analysis of disease status as a function of response to immunotherapy and as a more reliable tool than tumor biomarkers. Experimental Design: Plasma cfDNA sequences from 56 patients with diverse advanced cancers were prospectively collected and analyzed in a single-blind study for copy number variations, expressed as a quantitative chromosomal number instability (CNI) score versus 126 noncancer controls in a training set of 23 and a blinded validation set of 33. Tumor biomarker concentrations and a surrogate marker for T regulatory cells (Tregs) were comparatively analyzed. Results: Elevated CNI scores were observed in 51 of 56 patients prior to therapy. The blinded validation cohort provided an overall prediction accuracy of 83% (25/30) and a positive predictive value of CNI score for progression of 92% (11/12). The combination of CNI score before cycle (Cy) 2 and 3 yielded a correct prediction for progression in all 13 patients. The CNI score also correctly identified cases of pseudo-tumor progression from hyperprogression. Before Cy2 and Cy3, there was no significant correlation for protein tumor markers, total cfDNA, or surrogate Tregs. Conclusions: Chromosomal instability quantification in plasma cfDNA can serve as an early indicator of response to immunotherapy. The method has the potential to reduce health care costs and disease burden for cancer patients following further validation. Clin Cancer Res; 23(17); 5074-81. ©2017 AACR . ©2017 American Association for Cancer Research.

  15. Lipid-protein nanodiscs for cell-free production of integral membrane proteins in a soluble and folded state: comparison with detergent micelles, bicelles and liposomes.

    PubMed

    Lyukmanova, E N; Shenkarev, Z O; Khabibullina, N F; Kopeina, G S; Shulepko, M A; Paramonov, A S; Mineev, K S; Tikhonov, R V; Shingarova, L N; Petrovskaya, L E; Dolgikh, D A; Arseniev, A S; Kirpichnikov, M P

    2012-03-01

    Production of integral membrane proteins (IMPs) in a folded state is a key prerequisite for their functional and structural studies. In cell-free (CF) expression systems membrane mimicking components could be added to the reaction mixture that promotes IMP production in a soluble form. Here lipid-protein nanodiscs (LPNs) of different lipid compositions (DMPC, DMPG, POPC, POPC/DOPG) have been compared with classical membrane mimicking media such as detergent micelles, lipid/detergent bicelles and liposomes by their ability to support CF synthesis of IMPs in a folded and soluble state. Three model membrane proteins of different topology were used: homodimeric transmembrane (TM) domain of human receptor tyrosine kinase ErbB3 (TM-ErbB3, 1TM); voltage-sensing domain of K(+) channel KvAP (VSD, 4TM); and bacteriorhodopsin from Exiguobacterium sibiricum (ESR, 7TM). Structural and/or functional properties of the synthesized proteins were analyzed. LPNs significantly enhanced synthesis of the IMPs in a soluble form regardless of the lipid composition. A partial disintegration of LPNs composed of unsaturated lipids was observed upon co-translational IMP incorporation. Contrary to detergents the nanodiscs resulted in the synthesis of ~80% active ESR and promoted correct folding of the TM-ErbB3. None of the tested membrane mimetics supported CF synthesis of correctly folded VSD, and the protocol of the domain refolding was developed. The use of LPNs appears to be the most promising approach to CF production of IMPs in a folded state. NMR analysis of (15)N-Ile-TM-ErbB3 co-translationally incorporated into LPNs shows the great prospects of this membrane mimetics for structural studies of IMPs produced by CF systems. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Clinical application of dual photon absorptiometry (DPA) at the lumbar spine (LS) in the diagnosis of osteoporosis

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

    Wahner, H.W.; Dunn, W.L.; Riggs, B.L.

    This study evaluates the effectiveness of DPA to separate patients with osteoporosis (greater than 2 spinal fractures, normal Ca, P, absence of drugs, and metabolic bone disease) from a normal population. Performance criteria for the instrument have been described previously. Data was obtained from a prospective study of 105 normal women, 75 patients with osteoporosis and a retrospective study of 300 patients with osteoporosis seen in 1982/83. The results were as follows: (1) Area density (gm/cm/sup 2/) was found superior to mass (gm) due to the occasional problem to clearly identify the boundaries of L1-4. (2) Separation of the twomore » populations was best when L1-L4,L2-L4, L3 alone or 10 paths over the mid lumbar area were used. One pass was not acceptable. (3) Compression fractures (CF) in the LS showed an increase in area density initially but area density may be undistinguishable from intact vertebrae later. To correct for this loss of bone area a factor predicting the area of lumbar vertebrae and based on patients actual height and weight was introduced and tested. (4) In the retrospective study a negative correlation was found between number of thoracic spine CF and bone mineral values in the LS. (5) A fracture threshold value of BM defined as the level below which 95% of all patients with CF were found was determined to be 0.98 g/cm2. Sixty-five percent of patients with two or more spinal CF could be separated from the normal population (outside 2SD). By using a correction factor for height loss this could be further increased to about 70%. CF in the LS may falsely elevate bone mineral values.« less

  17. Role of Contact Force Sensing in Catheter Ablation of Cardiac Arrhythmias: Evolution or History Repeating Itself?

    PubMed

    Ariyarathna, Nilshan; Kumar, Saurabh; Thomas, Stuart P; Stevenson, William G; Michaud, Gregory F

    2018-06-01

    Adequate catheter-tissue contact facilitates efficient heat energy transfer to target tissue. Tissue contact is thus critical to achieving lesion transmurality and success of radiofrequency (RF) ablation procedures, a fact recognized more than 2 decades ago. The availability of real-time contact force (CF)-sensing catheters has reinvigorated the field of ablation biophysics and optimized lesion formation. The ability to measure and display CF came with the promise of dramatic improvement in safety and efficacy; however, CF quality was noted to have just as important an influence on lesion formation as absolute CF quantity. Multiple other factors have emerged as key elements influencing effective lesion formation, including catheter stability, lesion contiguity and continuity, lesion density, contact homogeneity across a line of ablation, spatiotemporal dynamics of contact governed by cardiac and respiratory motion, contact directionality, and anatomic wall thickness, in addition to traditional ablation indices of power and RF duration. There is greater appreciation of surrogate markers as a guide to lesion formation, such as impedance fall, loss of pace capture, and change in unipolar electrogram morphology. In contrast, other surrogates such as tactile feedback, catheter motion, and electrogram amplitude are notably poor predictors of actual contact and lesion formation. This review aims to contextualize the role of CF sensing in lesion formation with respect of the fundamental principles of biophysics of RF ablation and summarize the state-of-the-art evidence behind the role of CF in optimizing lesion formation. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  18. Corrective Feedback and Student Uptakes in English Immersion Classrooms in Japan: Is the Counter-Balance Hypothesis Valid?

    ERIC Educational Resources Information Center

    Sakurai, Shogo

    2014-01-01

    There are a number of studies on teachers' corrective feedback and students' uptakes in immersion settings, but the majority is carried out in the North American context. Based on limited data, "the counter­-balance hypothesis" was proposed by Lyster and Mori (2006) to explain distributions of teacher feedback and students' uptakes in…

  19. Corrective Feedback and Second Language Acquisition: Differential Contributions of Implicit and Explicit Knowledge

    ERIC Educational Resources Information Center

    Ebadi, Mandana Rohollahzadeh; Saad, Mohd Rashid Mohd; Abedalaziz, Nabil

    2014-01-01

    The issue of error correction remains controversial in recent years due to the different positions of interface toward implicit and explicit knowledge of ESL learners. This study looks at the impacts of implicit corrective feedback in the form of recast on implicit and explicit knowledge of adult ESL learners. In an experimental study,…

  20. On Written Corrective Feedback in L2 Writing

    ERIC Educational Resources Information Center

    Shao, Xu

    2015-01-01

    Truscott (1996) questions the practicability of grammar correction, and he believes that written corrective feedback (WCF) is not only a waste of time, but even harmful to the students as well. This has led to a great deal of discussion and research on WCF in second-language (L2) writing. Ferris (1999) is the representative opponent of Truscott's…

  1. State Counting for Excited Bands of the Fractional Quantum Hall Effect: Exclusion Rules for Bound Excitons

    NASA Astrophysics Data System (ADS)

    Coimbatore Balram, Ajit; Wójs, Arkadiusz; Jain, Jainendra

    2014-03-01

    Exact diagonalization studies have revealed that the energy spectrum of interacting electrons in the lowest Landau level splits, non-perturbatively, into bands. The theory of nearly free composite fermions (CFs) has been shown to be valid for the lowest band, and thus to capture the low temperature physics, but it over-predicts the number of states for the excited bands. We explain the state counting of higher bands in terms of composite fermions with an infinitely strong short range interaction between a CF particle and a CF hole. This interaction, the form of which we derive from the microscopic CF theory, eliminates configurations containing certain tightly bound CF excitons. With this modification, the CF theory reproduces, for all well-defined excited bands, an exact counting for ν > 1 / 3 , and an almost exact counting for ν <= 1 / 3 . The resulting insight clarifies that the corrections to the nearly free CF theory are not thermodynamically significant at sufficiently low temperatures, thus providing a microscopic explanation for why it has proved successful for the analysis of the various properties of the CF Fermi sea. NSF grants DMR-1005536 and DMR-0820404, Polish NCN grant 2011/01/B/ST3/04504 and EU Marie Curie Grant PCIG09-GA-2011-294186, Research Computing and Cyberinfrastructure, PSU and Wroclaw Centre for Networking and Supercomputing

  2. Investigating the Effects of Three Types of Corrective Feedback on the Acquisition of English Wh-Question Forms by Iranian EFL Learners

    ERIC Educational Resources Information Center

    Rassaei, Ehsan; Moinzadeh, Ahmad

    2011-01-01

    The current research examines the immediate and delayed effects of three types of corrective feedback, namely recasts, metalinguistic feedback, and clarification requests, on the acquisition of English wh-question forms by Iranian EFL learners. To this end, 134 Iranian EFL learners comprising 4 intact classes participated in the study. Learners in…

  3. A physics investigation of deadtime losses in neutron counting at low rates with Cf252

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

    Evans, Louise G; Croft, Stephen

    2009-01-01

    {sup 252}Cf spontaneous fission sources are used for the characterization of neutron counters and the determination of calibration parameters; including both neutron coincidence counting (NCC) and neutron multiplicity deadtime (DT) parameters. Even at low event rates, temporally-correlated neutron counting using {sup 252}Cf suffers a deadtime effect. Meaning that in contrast to counting a random neutron source (e.g. AmLi to a close approximation), DT losses do not vanish in the low rate limit. This is because neutrons are emitted from spontaneous fission events in time-correlated 'bursts', and are detected over a short period commensurate with their lifetime in the detector (characterizedmore » by the system die-away time, {tau}). Thus, even when detected neutron events from different spontaneous fissions are unlikely to overlap in time, neutron events within the detected 'burst' are subject to intrinsic DT losses. Intrinsic DT losses for dilute Pu will be lower since the multiplicity distribution is softer, but real items also experience self-multiplication which can increase the 'size' of the bursts. Traditional NCC DT correction methods do not include the intrinsic (within burst) losses. We have proposed new forms of the traditional NCC Singles and Doubles DT correction factors. In this work, we apply Monte Carlo neutron pulse train analysis to investigate the functional form of the deadtime correction factors for an updating deadtime. Modeling is based on a high efficiency {sup 3}He neutron counter with short die-away time, representing an ideal {sup 3}He based detection system. The physics of dead time losses at low rates is explored and presented. It is observed that new forms are applicable and offer more accurate correction than the traditional forms.« less

  4. Mechanism-based corrector combination restores ΔF508-CFTR folding and function

    PubMed Central

    Okiyoneda, Tsukasa; Veit, Guido; Dekkers, Johanna F.; Bagdany, Miklos; Soya, Naoto; Xu, Haijin; Roldan, Ariel; Verkman, Alan S.; Kurth, Mark; Simon, Agnes; Hegedus, Tamas; Beekman, Jeffrey M.; Lukacs, Gergely L.

    2013-01-01

    The most common cystic fibrosis (CF) mutation, ΔF508 in the nucleotide binding domain-1 (NBD1), impairs CFTR coupled-domain folding, plasma membrane (PM) expression, function and stability. VX-809, a promising investigational corrector of ΔF508-CFTR misprocessing, has limited clinical benefit and incompletely understood mechanism, hampering drug development. Based on the effect of second site suppressor mutations, robust ΔF508-CFTR correction likely requires stabilization of NBD1 and the membrane spanning domains (MSDs)-NBD1 interface, both established primary conformational defects. Here, we elucidated the molecular targets of available correctors; class-I stabilizes the NBD1-MSD1/2 interface, class-II targets NBD2, and only chemical chaperones, surrogates of class-III correctors, stabilize the human ΔF508-NBD1. While VX-809 can correct missense mutations primarily destabilizing the NBD1-MSD1/2 interface, functional PM expression of ΔF508-CFTR also requires compounds that counteract the NBD1 and NBD2 stability defects in CF bronchial epithelial cells and intestinal organoids. Thus, structure-guided corrector combination represents an effective approach for CF therapy. PMID:23666117

  5. Cystic Fibrosis Gene Therapy in the UK and Elsewhere

    PubMed Central

    Pytel, Kamila M.; Alton, Eric W.F.W.

    2015-01-01

    Abstract The cystic fibrosis transmembrane conductance regulator (CFTR) gene was identified in 1989. This opened the door for the development of cystic fibrosis (CF) gene therapy, which has been actively pursued for the last 20 years. Although 26 clinical trials involving approximately 450 patients have been carried out, the vast majority of these trials were short and included small numbers of patients; they were not designed to assess clinical benefit, but to establish safety and proof-of-concept for gene transfer using molecular end points such as the detection of recombinant mRNA or correction of the ion transport defect. The only currently published trial designed and powered to assess clinical efficacy (defined as improvement in lung function) administered AAV2-CFTR to the lungs of patients with CF. The U.K. Cystic Fibrosis Gene Therapy Consortium completed, in the autumn of 2014, the first nonviral gene therapy trial designed to answer whether repeated nonviral gene transfer (12 doses over 12 months) can lead to clinical benefit. The demonstration that the molecular defect in CFTR can be corrected with small-molecule drugs, and the success of gene therapy in other monogenic diseases, is boosting interest in CF gene therapy. Developments are discussed here. PMID:25838137

  6. Assessment of fetal sex chromosome aneuploidy using directed cell-free DNA analysis.

    PubMed

    Nicolaides, Kypros H; Musci, Thomas J; Struble, Craig A; Syngelaki, Argyro; Gil, M M

    2014-01-01

    To examine the performance of chromosome-selective sequencing of cell-free (cf) DNA in maternal blood for assessment of fetal sex chromosome aneuploidies. This was a case-control study of 177 stored maternal plasma samples, obtained before fetal karyotyping at 11-13 weeks of gestation, from 59 singleton pregnancies with fetal sex chromosome aneuploidies (45,X, n = 49; 47,XXX, n = 6; 47,XXY, n = 1; 47,XYY, n = 3) and 118 with euploid fetuses (46,XY, n = 59; 46,XX, n = 59). Digital analysis of selected regions (DANSR™) on chromosomes 21, 18, 13, X and Y was performed and the fetal-fraction optimized risk of trisomy evaluation (FORTE™) algorithm was used to estimate the risk for non-disomic genotypes. Performance was calculated at a risk cut-off of 1:100. Analysis of cfDNA provided risk scores for 172 (97.2%) samples; 4 samples (45,X, n = 2; 46,XY, n = 1; 46,XX, n = 1) had an insufficient fetal cfDNA fraction for reliable testing and 1 case (47,XXX) failed laboratory quality control metrics. The classification was correct in 43 (91.5%) of 47 cases of 45,X, all 5 of 47,XXX, 1 of 47,XXY and 3 of 47,XYY. There were no false-positive results for monosomy X. Analysis of cfDNA by chromosome-selective sequencing can correctly classify fetal sex chromosome aneuploidy with reasonably high sensitivity. © 2013 S. Karger AG, Basel.

  7. Spectral correction factors for conventional neutron dosemeters used in high-energy neutron environments.

    PubMed

    Lee, K W; Sheu, R J

    2015-04-01

    High-energy neutrons (>10 MeV) contribute substantially to the dose fraction but result in only a small or negligible response in most conventional moderated-type neutron detectors. Neutron dosemeters used for radiation protection purpose are commonly calibrated with (252)Cf neutron sources and are used in various workplace. A workplace-specific correction factor is suggested. In this study, the effect of the neutron spectrum on the accuracy of dose measurements was investigated. A set of neutron spectra representing various neutron environments was selected to study the dose responses of a series of Bonner spheres, including standard and extended-range spheres. By comparing (252)Cf-calibrated dose responses with reference values based on fluence-to-dose conversion coefficients, this paper presents recommendations for neutron field characterisation and appropriate correction factors for responses of conventional neutron dosemeters used in environments with high-energy neutrons. The correction depends on the estimated percentage of high-energy neutrons in the spectrum or the ratio between the measured responses of two Bonner spheres (the 4P6_8 extended-range sphere versus the 6″ standard sphere). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. The Effect of Written Corrective Feedback on Omani Students' Accuracy in the Use of English Prepositions

    ERIC Educational Resources Information Center

    Al Ajmi, Ahmed Ali Saleh

    2015-01-01

    A quasi-experimental study was conducted to examine the effectiveness of providing written corrective feedback (WCF) to Arab speakers of English on ten uses of English prepositions. Arab speakers commonly find it difficult to correctly use English prepositions, mainly due to the differences between the two languages (e.g. Ortega, 2009). Examples…

  9. The Effect of Different Types of Corrective Feedback on ESL Student Writing

    ERIC Educational Resources Information Center

    Bitchener, John; Young, Stuart; Cameron, Denise

    2005-01-01

    Debate about the value of providing corrective feedback on L2 writing has been prominent in recent years as a result of Truscott's [Truscott, J. (1996). The case against grammar correction in L2 writing classes. Language Learning, 46, 327-369] claim that it is both ineffective and harmful and should therefore be abandoned. A growing body of…

  10. Heart Rate Dependency of Large Artery Stiffness.

    PubMed

    Tan, Isabella; Spronck, Bart; Kiat, Hosen; Barin, Edward; Reesink, Koen D; Delhaas, Tammo; Avolio, Alberto P; Butlin, Mark

    2016-07-01

    Carotid-femoral pulse wave velocity (cfPWV) quantifies large artery stiffness, it is used in hemodynamic research and is considered a useful cardiovascular clinical marker. cfPWV is blood pressure (BP) dependent. Intrinsic heart rate (HR) dependency of cfPWV is unknown because increasing HR is commonly accompanied by increasing BP. This study aims to quantify cfPWV dependency on acute, sympathovagal-independent changes in HR, independent of BP. Individuals (n=52, age 40-93 years, 11 female) with in situ cardiac pacemakers or cardioverter defibrillators were paced at 60, 70, 80, 90, and 100 bpm. BP and cfPWV were measured at each HR. Both cfPWV (mean [95% CI], 0.31 [0.26-0.37] m/s per 10 bpm; P<0.001) and central aortic diastolic pressure (3.78 [3.40-4.17] mm Hg/10 bpm; P<0.001) increased with HR. The HR effect on cfPWV was isolated by correcting the BP effects by 3 different methods: (1) statistically, by a linear mixed model; (2) mathematically, using an exponential relationship between BP and cross-sectional lumen area; and (3) using measured BP dependency of cfPWV derived from changes in BP induced by orthostatic changes (seated and supine) in a subset of subjects (n=17). The BP-independent effects of HR on cfPWV were quantified as 0.20 [0.11-0.28] m/s per 10 bpm (P<0.001, method 1), 0.16 [0.11-0.22] m/s per 10 bpm (P<0.001, method 2), and 0.16 [0.11-0.21] m/s per 10 bpm (P<0.001, method 3). With a mean HR dependency in the range of 0.16 to 0.20 m/s per 10 bpm, cfPWV may be considered to have minimal physiologically relevant changes for small changes in HR, but larger differences in HR must be considered as contributing to significant differences in cfPWV. © 2016 American Heart Association, Inc.

  11. Plasma cell-free mitochondrial DNA declines in response to prolonged moderate aerobic exercise.

    PubMed

    Shockett, Penny E; Khanal, Januka; Sitaula, Alina; Oglesby, Christopher; Meachum, William A; Castracane, V Daniel; Kraemer, Robert R

    2016-01-01

    Increased plasma cell-free mitochondrial DNA (cf-mDNA), a damage-associated molecular pattern (DAMP) produced by cellular injury, contributes to neutrophil activation/inflammation in trauma patients and arises in cancer and autoimmunity. To further understand relationships between cf-mDNA released by tissue injury, inflammation, and health benefits of exercise, we examined cf-mDNA response to prolonged moderate aerobic exercise. Seven healthy moderately trained young men (age = 22.4 ± 1.2) completed a treadmill exercise trial for 90 min at 60% VO2 max and a resting control trial. Blood was sampled immediately prior to exercise (0 min = baseline), during (+18, +54 min), immediately after (+90 min), and after recovery (R40). Plasma was analyzed for cf-mDNA, IL-6, and lactate. A significant difference in cf-mDNA response was observed between exercise and control trials, with cf-mDNA levels reduced during exercise at +54 and +90 (with or without plasma volume shift correction). Declines in cf-mDNA were accompanied by increased lactate and followed by an increase in IL-6, suggesting a temporal association with muscle stress and inflammatory processes. Our novel finding of cf-mDNA decline with prolonged moderate treadmill exercise provides evidence for increased clearance from or reduced release of cf-mDNA into the blood with prolonged exercise. These studies contrast with previous investigations involving exhaustive short-term treadmill exercise, in which no change in cf-mDNA levels were reported, and contribute to our understanding of differences between exercise- and trauma-induced inflammation. We propose that transient declines in cf-mDNA may induce health benefits, by reducing systemic inflammation. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  12. Computer-Based Feedback and Goal Intervention: Learning Effects

    ERIC Educational Resources Information Center

    Valdez, Alfred

    2012-01-01

    This study investigated how a goal intervention influences the learning effects gained from feedback when acquiring concepts and rules pertaining to the topic of descriptive statistics. Three feedback conditions; knowledge of correct response feedback (KCRF), principle-based feedback (PBF), and no-feedback (NF), were crossed with two goal…

  13. Mutations of Cystic Fibrosis Transmembrane Conductance Regulator Gene Cause a Monocyte-Selective Adhesion Deficiency.

    PubMed

    Sorio, Claudio; Montresor, Alessio; Bolomini-Vittori, Matteo; Caldrer, Sara; Rossi, Barbara; Dusi, Silvia; Angiari, Stefano; Johansson, Jan E; Vezzalini, Marzia; Leal, Teresinha; Calcaterra, Elisa; Assael, Baroukh M; Melotti, Paola; Laudanna, Carlo

    2016-05-15

    Cystic fibrosis (CF) is a common genetic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Persistent lung inflammation, characterized by increasing polymorphonuclear leukocyte recruitment, is a major cause of the decline in respiratory function in patients with CF and is a leading cause of morbidity and mortality. CFTR is expressed in various cell types, including leukocytes, but its involvement in the regulation of leukocyte recruitment is unknown. We evaluated whether CF leukocytes might present with alterations in cell adhesion and migration, a key process governing innate and acquired immune responses. We used ex vivo adhesion and chemotaxis assays, flow cytometry, immunofluorescence, and GTPase activity assays in this study. We found that chemoattractant-induced activation of β1 and β2 integrins and of chemotaxis is defective in mononuclear cells isolated from patients with CF. In contrast, polymorphonuclear leukocyte adhesion and chemotaxis were normal. The functionality of β1 and β2 integrins was restored by treatment of CF monocytes with the CFTR-correcting drugs VRT325 and VX809. Moreover, treatment of healthy monocytes with the CFTR inhibitor CFTR(inh)-172 blocked integrin activation by chemoattractants. In a murine model of lung inflammation, we found that integrin-independent migration of CF monocytes into the lung parenchyma was normal, whereas, in contrast, integrin-dependent transmigration into the alveolar space was impaired. Finally, signal transduction analysis showed that, in CF monocytes, chemoattractant-triggered activation of RhoA and CDC42 Rho small GTPases (controlling integrin activation and chemotaxis, respectively) was strongly deficient. Altogether, these data highlight the critical regulatory role of CFTR in integrin activation by chemoattractants in monocytes and identify CF as a new, cell type-selective leukocyte adhesion deficiency disease, providing new insights into CF pathogenesis.

  14. Inhibition by TNF-alpha and IL-4 of cationic lipid mediated gene transfer in cystic fibrosis tracheal gland cells.

    PubMed

    Bastonero, Sonia; Gargouri, Myriem; Ortiou, Sandrine; Guéant, Jean-Louis; Merten, Marc D

    2005-11-01

    In vivo, tracheal gland serous cells highly express the cystic fibrosis transmembrane conductance regulator (cftr) gene. This gene is mutated in the lethal monogenic disease cystic fibrosis (CF). Clinical trials in which the human CFTR cDNA was delivered to the respiratory epithelia of CF patients have resulted in weak and transient gene expression. As CF is characterized by mucus inspissation, airway infection, and severe inflammation, we tested the hypothesis that inflammation and especially two cytokines involved in the Th1/Th2 inflammatory response, interleukin 4 (IL-4) and TNFalpha, could inhibit gene transfer efficiency using a model of human CF tracheal gland cells (CF-KM4) and Lipofectamine reagent as a transfection reagent. The specific secretory defects of CF-KM4 cells were corrected by Lipofectamine-mediated human CFTR gene transfer. However, this was altered when cells were pre-treated with IL-4 and TNFalpha. Inhibition of luciferase reporter gene expression by IL-4 and TNFalpha pre-treated CF-KM4 cells was measured by activity and real-time RT-PCR. Both cytokines induced similar and synergistic inhibition of transgene expression and activity. This cytokine-mediated inhibition could be prevented by anti-inflammatory agents such as glucocorticoids but not by non-steroidal (NSAI) agents. This data suggests that an inflammatory context generated by IL-4 and TNFalpha can inhibit human CFTR gene transfer in CF tracheal gland cells and that glucocorticoids may have a protecting action. Copyright (c) 2005 John Wiley & Sons, Ltd.

  15. To What Extent Do Learners Benefit from Indirect Written Corrective Feedback? A Study Targeting Learners of Different Proficiency and Heritage Language Status

    ERIC Educational Resources Information Center

    Park, Eun Sung; Song, Sunhee; Shin, Yu Kyoung

    2016-01-01

    Should teachers spend hours correcting students' errors, or should they simply underline the errors, leaving it up to the students to self-correct them? The current study examines the utility of indirect feedback on learners' written output. Journal entries from students enrolled in intact second language (L2) Korean classes (n = 40) were…

  16. "Why Are These Underlined?" Depth of Processing and Type of Written Corrective Feedback in L2 Spanish Compositions

    ERIC Educational Resources Information Center

    Caras, Allison Marie

    2017-01-01

    There is an ongoing debate as to whether written corrective feedback (WCF) is effective for the improvement of adult second language (L2) writers' accuracy. Ever since Truscott (1996, 1999) began arguing against grammar correction in L2 writing courses, researchers have challenged his position (i.e. below). Although most of these studies show WCF…

  17. Test-Retest Variability in Lesion SUV and Lesion SUR in 18F-FDG PET: An Analysis of Data from Two Prospective Multicenter Trials.

    PubMed

    Hofheinz, Frank; Apostolova, Ivayla; Oehme, Liane; Kotzerke, Jörg; van den Hoff, Jörg

    2017-11-01

    Quantitative assessment of radio- and chemotherapy response with 18 F-FDG whole-body PET has attracted increasing interest in recent years. In most published work, SUV has been used for this purpose. In the context of therapy response assessment, the reliability of lesion SUVs, notably their test-retest stability, thus becomes crucial. However, a recent study demonstrated substantial test-retest variability (TRV) in SUVs. The purpose of the present study was to investigate whether the tumor-to-blood SUV ratio (SUR) can improve TRV in tracer uptake. Methods: 73 patients with advanced non-small cell lung cancer from the prospective multicenter trials ACRIN 6678 ( n = 34) and MK-0646-008 ( n = 39) were included in this study. All patients underwent two 18 F-FDG PET/CT investigations on two different days (time difference, 3.6 ± 2.1 d; range, 1-7 d) before therapy. For each patient, up to 7 tumor lesions were evaluated. For each lesion, SUV max and SUV peak were determined. Blood SUV was determined as the mean value of a 3-dimensional aortic region of interest that was delineated on the attenuation CT image and transferred to the PET image. SURs were computed as the ratio of tumor SUV to blood SUV and were uptake time-corrected to 75 min after injection. TRV was quantified as 1.96 multiplied by the root-mean-square deviation of the fractional paired differences in SUV and SUR. The combined effect of blood normalization and uptake time correction was inspected by considering R TRV (TRV SUR /TRV SUV ), a ratio reflecting the reduction in the TRV in SUR relative to SUV. R TRV was correlated with the group-averaged-value difference (δ) in CF mean (δCF mean ) of the quantity δCF = |CF - 1|, where CF is the numeric factor that converts individual ratios of paired SUVs into corresponding SURs. This correlation analysis was performed by successively increasing a threshold value δCF min and computing δCF mean and R TRV for the remaining subgroup of patients/lesions with δCF ≥ δCF min Results: The group-averaged TRV SUV and TRV SUR were 32.1 and 29.0, respectively, which correspond to a reduction of variability in SUR by an R TRV factor of 0.9 in comparison to SUV. This rather marginal improvement can be understood to be a consequence of the atypically low intrasubject variability in blood SUV and uptake time and the accordingly small δCF values in the investigated prospective study groups. In fact, subgroup analysis with increasing δCF min thresholds revealed a pronounced negative correlation (Spearman ρ = -0.99, P < 0.001) between R TRV and δCF mean , where R TRV ≈ 0.4 in the δCF min = 20% subgroup, corresponding to a more than 2-fold reduction of TRV SUR compared with TRV SUV Conclusion: Variability in blood SUV and uptake time has been identified as a causal factor in the TRV in lesion SUV. Therefore, TRV in lesion uptake measurements can be reduced by replacing SUV with SUR as the uptake measure. The improvement becomes substantial for the level of variability in blood SUV and uptake time typically observed in the clinical context. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  18. The Tumor Necrosis Factor α (-308 A/G) Polymorphism Is Associated with Cystic Fibrosis in Mexican Patients

    PubMed Central

    Sanchez-Dominguez, Celia N.; Reyes-Lopez, Miguel A.; Bustamante, Adriana; Cerda-Flores, Ricardo M.; Villalobos-Torres, Maria del C.; Gallardo-Blanco, Hugo L.; Rojas-Martinez, Augusto; Martinez-Rodriguez, Herminia G.; Barrera-Saldaña, Hugo A.; Ortiz-Lopez, Rocio

    2014-01-01

    Environmental and genetic factors may modify or contribute to the phenotypic differences observed in multigenic and monogenic diseases, such as cystic fibrosis (CF). An analysis of modifier genes can be helpful for estimating patient prognosis and directing preventive care. The aim of this study is to determine the association between seven genetic variants of four modifier genes and CF by comparing their corresponding allelic and genotypic frequencies in CF patients (n = 81) and control subjects (n = 104). Genetic variants of MBL2 exon 1 (A, B, C and D), the IL-8 promoter (−251 A/T), the TNFα promoter (TNF1/TNF2), and SERPINA1 (PI*Z and PI*S) were tested in CF patients and control subjects from northeastern Mexico by PCR-RFLP. Results The TNF2 allele (P = 0.012, OR 3.43, 95% CI 1.25–9.38) was significantly associated with CF under the dominant and additive models but was not associated with CF under the recessive model. This association remained statistically significant after adjusting for multiple tests using the Bonferroni correction (P = 0.0482). The other tested variants and genotypes did not show any association with the disease. Conclusion An analysis of seven genetic variants of four modifier genes showed that one variant, the TNF2 allele, appears to be significantly associated with CF in Mexican patients. PMID:24603877

  19. Effect of Immediate Feedback and Revision on Psychometric Properties of Open-Ended Sentence- Completion Items. ETS GRE Board Research Report No. 03-15. ETS RR-08-16

    ERIC Educational Resources Information Center

    Attali, Yigal; Powers, Don; Hawthorn, John

    2008-01-01

    Registered examinees for the GRE® General Test answered open-ended sentence-completion items. For half of the items, participants received immediate feedback on the correctness of their answers and up to two opportunities to revise their answers. A significant feedback-and-revision effect was found. Participants were able to correct many of their…

  20. Effects of two types of intra-team feedback on developing a shared mental model in Command & Control teams.

    PubMed

    Rasker, P C; Post, W M; Schraagen, J M

    2000-08-01

    In two studies, the effect of two types of intra-team feedback on developing a shared mental model in Command & Control teams was investigated. A distinction is made between performance monitoring and team self-correction. Performance monitoring is the ability of team members to monitor each other's task execution and give feedback during task execution. Team self-correction is the process in which team members engage in evaluating their performance and in determining their strategies after task execution. In two experiments the opportunity to engage in performance monitoring, respectively team self-correction, was varied systematically. Both performance monitoring as well as team self-correction appeared beneficial in the improvement of team performance. Teams that had the opportunity to engage in performance monitoring, however, performed better than teams that had the opportunity to engage in team self-correction.

  1. Learning feedback and feedforward control in a mirror-reversed visual environment.

    PubMed

    Kasuga, Shoko; Telgen, Sebastian; Ushiba, Junichi; Nozaki, Daichi; Diedrichsen, Jörn

    2015-10-01

    When we learn a novel task, the motor system needs to acquire both feedforward and feedback control. Currently, little is known about how the learning of these two mechanisms relate to each other. In the present study, we tested whether feedforward and feedback control need to be learned separately, or whether they are learned as common mechanism when a new control policy is acquired. Participants were trained to reach to two lateral and one central target in an environment with mirror (left-right)-reversed visual feedback. One group was allowed to make online movement corrections, whereas the other group only received visual information after the end of the movement. Learning of feedforward control was assessed by measuring the accuracy of the initial movement direction to lateral targets. Feedback control was measured in the responses to sudden visual perturbations of the cursor when reaching to the central target. Although feedforward control improved in both groups, it was significantly better when online corrections were not allowed. In contrast, feedback control only adaptively changed in participants who received online feedback and remained unchanged in the group without online corrections. Our findings suggest that when a new control policy is acquired, feedforward and feedback control are learned separately, and that there may be a trade-off in learning between feedback and feedforward controllers. Copyright © 2015 the American Physiological Society.

  2. Learning feedback and feedforward control in a mirror-reversed visual environment

    PubMed Central

    Kasuga, Shoko; Telgen, Sebastian; Ushiba, Junichi; Nozaki, Daichi

    2015-01-01

    When we learn a novel task, the motor system needs to acquire both feedforward and feedback control. Currently, little is known about how the learning of these two mechanisms relate to each other. In the present study, we tested whether feedforward and feedback control need to be learned separately, or whether they are learned as common mechanism when a new control policy is acquired. Participants were trained to reach to two lateral and one central target in an environment with mirror (left-right)-reversed visual feedback. One group was allowed to make online movement corrections, whereas the other group only received visual information after the end of the movement. Learning of feedforward control was assessed by measuring the accuracy of the initial movement direction to lateral targets. Feedback control was measured in the responses to sudden visual perturbations of the cursor when reaching to the central target. Although feedforward control improved in both groups, it was significantly better when online corrections were not allowed. In contrast, feedback control only adaptively changed in participants who received online feedback and remained unchanged in the group without online corrections. Our findings suggest that when a new control policy is acquired, feedforward and feedback control are learned separately, and that there may be a trade-off in learning between feedback and feedforward controllers. PMID:26245313

  3. Inhibition of NFkappaB by the natural product Withaferin A in cellular models of Cystic Fibrosis inflammation.

    PubMed

    Maitra, Rangan; Porter, Melissa A; Huang, Shan; Gilmour, Brian P

    2009-05-13

    Cystic Fibrosis (CF) is one of the most common autosomal genetic disorders in humans. This disease is caused by mutations within a single gene, coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The phenotypic hallmark of CF is chronic lung infection and associated inflammation from opportunistic microbes such as Pseudomonas aeruginosa (PA), Haemophilus influenzae, and Staphylococcus aureus. This eventually leads to deterioration of lung function and death in most CF patients. Unfortunately, there is no approved therapy for correcting the genetic defect causal to the disease. Hence, controlling inflammation and infection in CF patients are critical to disease management. Accordingly, anti-inflammatory agents and antibiotics are used to manage chronic inflammation and infection in CF patients. However, most of the anti-inflammatory agents in CF have severe limitations due to adverse side effects, and resistance to antibiotics is becoming an even more prominent problem. Thus, new agents that can be used to control chronic inflammation in CF are needed in the absence of a cure for the disease. Activation of the transcription factor NFkappaB through Toll-like receptors (TLR) following bacterial infection is principally involved in regulating lung inflammation in CF. NFkappaB regulates the transcription of several genes that are involved in inflammation, anti-apoptosis and anti-microbial activity, and hyper-activation of this transcription factor leads to a potent inflammatory response. Thus, NFkappaB is a potential anti-inflammatory drug target in CF. Screening of several compounds from natural sources in an in vitro model of CF-related inflammation wherein NFkappaB is activated by filtrates of a clinically isolated strain of PA (PAF) led us to Withaferin A (WFA), a steroidal lactone from the plant Withania Somnifera L. Dunal. Our data demonstrate that WFA blocks PAF-induced activation of NFkappaB as determined using reporter assays, IL-8 measurements and high-content fluorescent imaging of NFkappaB subunit p65 translocation. Since the airways of CF patients can be specifically targeted for delivery of therapeutics, we propose that WFA should be further studied as an anti-inflammatory agent in models of CF related inflammation mediated by NFkappaB.

  4. An Investigation into Effectiveness of Peer Feedback

    ERIC Educational Resources Information Center

    Lin, Grace Hui Chin; Chien, Paul Shih Chieh

    2009-01-01

    Copious researches argue the effectiveness of peer-correction in writing courses (e.g., Connor & Asenavage, 1994). Also, Coit (2004) mentions using peer feedback for correcting articles through a student-centered environment is a beneficial pedagogy to extend learners' academic-style writing practice. Therefore, this study focused on…

  5. Erratum: Correction to: On the relative strength of radiative feedbacks under climate variability and change

    NASA Astrophysics Data System (ADS)

    Colman, Robert; Hanson, Lawson

    2018-06-01

    Two errors were discovered in the calculation of decadal feedbacks under RCP8.5: (i) cloud short wave (SW) and total feedbacks were miscalculated; and (ii) surface albedo and SW water vapour feedbacks were swapped when calculating regressions with climate change feedbacks.

  6. Learning new vocabulary in German: the effects of inferring word meanings, type of feedback, and time of test.

    PubMed

    Carpenter, Shana K; Sachs, Riebana E; Martin, Beth; Schmidt, Kristian; Looft, Ruxandra

    2012-02-01

    In the present study, introductory-level German students read a simplified story and learned the meanings of new German words by reading English translations in marginal glosses versus trying to infer (i.e., guess) their translations. Students who inferred translations were given feedback in English or in German, or no feedback at all. Although immediate retention of new vocabulary was better for students who used marginal glosses, students who inferred word meanings and then received English feedback forgot fewer translations over time. Plausible but inaccurate inferences (i.e., those that made sense in the context) were more likely to be corrected by students who received English feedback as compared with German feedback, providing support for the beneficial effects of mediating information. Implausible inaccurate inferences, however, were more likely to be corrected on the delayed vocabulary test by students who received German feedback as compared with English feedback, possibly because of the additional contextual support provided by German feedback.

  7. Characterizing and Modeling the Cost of Rework in a Library of Reusable Software Components

    NASA Technical Reports Server (NTRS)

    Basili, Victor R.; Condon, Steven E.; ElEmam, Khaled; Hendrick, Robert B.; Melo, Walcelio

    1997-01-01

    In this paper we characterize and model the cost of rework in a Component Factory (CF) organization. A CF is responsible for developing and packaging reusable software components. Data was collected on corrective maintenance activities for the Generalized Support Software reuse asset library located at the Flight Dynamics Division of NASA's GSFC. We then constructed a predictive model of the cost of rework using the C4.5 system for generating a logical classification model. The predictor variables for the model are measures of internal software product attributes. The model demonstrates good prediction accuracy, and can be used by managers to allocate resources for corrective maintenance activities. Furthermore, we used the model to generate proscriptive coding guidelines to improve programming, practices so that the cost of rework can be reduced in the future. The general approach we have used is applicable to other environments.

  8. A Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) Quantitative Analysis Method Based on the Auto-Selection of an Internal Reference Line and Optimized Estimation of Plasma Temperature.

    PubMed

    Yang, Jianhong; Li, Xiaomeng; Xu, Jinwu; Ma, Xianghong

    2018-01-01

    The quantitative analysis accuracy of calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is severely affected by the self-absorption effect and estimation of plasma temperature. Herein, a CF-LIBS quantitative analysis method based on the auto-selection of internal reference line and the optimized estimation of plasma temperature is proposed. The internal reference line of each species is automatically selected from analytical lines by a programmable procedure through easily accessible parameters. Furthermore, the self-absorption effect of the internal reference line is considered during the correction procedure. To improve the analysis accuracy of CF-LIBS, the particle swarm optimization (PSO) algorithm is introduced to estimate the plasma temperature based on the calculation results from the Boltzmann plot. Thereafter, the species concentrations of a sample can be calculated according to the classical CF-LIBS method. A total of 15 certified alloy steel standard samples of known compositions and elemental weight percentages were used in the experiment. Using the proposed method, the average relative errors of Cr, Ni, and Fe calculated concentrations were 4.40%, 6.81%, and 2.29%, respectively. The quantitative results demonstrated an improvement compared with the classical CF-LIBS method and the promising potential of in situ and real-time application.

  9. VX-809 corrects folding defects in cystic fibrosis transmembrane conductance regulator protein through action on membrane-spanning domain 1

    PubMed Central

    Ren, Hong Yu; Grove, Diane E.; De La Rosa, Oxana; Houck, Scott A.; Sopha, Pattarawut; Van Goor, Fredrick; Hoffman, Beth J.; Cyr, Douglas M.

    2013-01-01

    Cystic fibrosis (CF) is a fatal genetic disorder associated with defective hydration of lung airways due to the loss of chloride transport through the CF transmembrane conductance regulator protein (CFTR). CFTR contains two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory domain, and its channel assembly requires multiple interdomain contacts. The most common CF-causing mutation, F508del, occurs in NBD1 and results in misfolding and premature degradation of F508del-CFTR. VX-809 is an investigational CFTR corrector that partially restores CFTR function in people who are homozygous for F508del-CFTR. To identify the folding defect(s) in F508del-CFTR that must be repaired to treat CF, we explored the mechanism of VX-809 action. VX-809 stabilized an N-terminal domain in CFTR that contains only MSD1 and efficaciously restored function to CFTR forms that have missense mutations in MSD1. The action of VX-809 on MSD1 appears to suppress folding defects in F508del-CFTR by enhancing interactions among the NBD1, MSD1, and MSD2 domains. The ability of VX-809 to correct F508del-CFTR is enhanced when combined with mutations that improve F508del-NBD1 interaction with MSD2. These data suggest that the use of VX-809 in combination with an additional CFTR corrector that suppresses folding defects downstream of MSD1 may further enhance CFTR function in people with F508del-CFTR. PMID:23924900

  10. VX-809 corrects folding defects in cystic fibrosis transmembrane conductance regulator protein through action on membrane-spanning domain 1.

    PubMed

    Ren, Hong Yu; Grove, Diane E; De La Rosa, Oxana; Houck, Scott A; Sopha, Pattarawut; Van Goor, Fredrick; Hoffman, Beth J; Cyr, Douglas M

    2013-10-01

    Cystic fibrosis (CF) is a fatal genetic disorder associated with defective hydration of lung airways due to the loss of chloride transport through the CF transmembrane conductance regulator protein (CFTR). CFTR contains two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory domain, and its channel assembly requires multiple interdomain contacts. The most common CF-causing mutation, F508del, occurs in NBD1 and results in misfolding and premature degradation of F508del-CFTR. VX-809 is an investigational CFTR corrector that partially restores CFTR function in people who are homozygous for F508del-CFTR. To identify the folding defect(s) in F508del-CFTR that must be repaired to treat CF, we explored the mechanism of VX-809 action. VX-809 stabilized an N-terminal domain in CFTR that contains only MSD1 and efficaciously restored function to CFTR forms that have missense mutations in MSD1. The action of VX-809 on MSD1 appears to suppress folding defects in F508del-CFTR by enhancing interactions among the NBD1, MSD1, and MSD2 domains. The ability of VX-809 to correct F508del-CFTR is enhanced when combined with mutations that improve F508del-NBD1 interaction with MSD2. These data suggest that the use of VX-809 in combination with an additional CFTR corrector that suppresses folding defects downstream of MSD1 may further enhance CFTR function in people with F508del-CFTR.

  11. Computer-Mediated Corrective Feedback and Language Accuracy in Telecollaborative Exchanges

    ERIC Educational Resources Information Center

    Vinagre, Margarita; Munoz, Beatriz

    2011-01-01

    Recent studies illustrate the potential that intercultural telecollaborative exchanges entail for language development through the use of corrective feedback from collaborating partners (Kessler, 2009; Lee, 2008; Sauro, 2009; Ware & O'Dowd, 2008). We build on this growing body of research by presenting the findings of a three-month-long…

  12. Levofloxacin pharmacokinetics in adult cystic fibrosis.

    PubMed

    Lee, Carlton K K; Boyle, Michael P; Diener-West, Marie; Brass-Ernst, Lois; Noschese, Michelle; Zeitlin, Pamela L

    2007-03-01

    Cystic fibrosis (CF) patients have enhanced renal clearance of aminoglycosides and several beta-lactams and require higher dosages. Levofloxacin is a fluoroquinolone with extensive renal elimination and enhanced penetration into lungs and Pseudomonas aeruginosa (PA) biofilms. We studied the preliminary pharmacokinetic and pharmacodynamic (PK/PD) relationship of levofloxacin in CF. Twelve patients at least 18 years old with a mild-to-moderate pulmonary exacerbation and fluoroquinolone-sensitive PA colonization received oral levofloxacin, 500 mg qd, for 14 days. Steady-state serum concentrations were collected after 3 to 7 days, and sputum samples for PA densities were collected before and after levofloxacin. PK/PD relationships for reducing PA sputum densities were evaluated. When compared to published data on non-CF patients, CF patients had similar area under the curve for 24 h (AUC(24)), total clearance, volume of distribution, maximum serum concentration (Cpmax), and elimination half-life: mean, 7.33 microg x h/mL/kg (SD, 1.70); 2.43 mL/min/kg (SD, 0.74); 1.33 L/kg (SD, 0.37); 7.06 microg/mL (SD, 2.35); and 6.44 h (SD, 1.1), respectively. Time to reach maximum serum concentration (Tmax) in CF was longer: mean, 2.20 h (SD, 0.99) vs 1.1 h (SD, 0.4) [p < 0.01]. Preliminary PK/PD analysis failed to demonstrate trends for decreasing PA sputum densities with increasing Cpmax/minimum inhibitory concentration (MIC) ratio and AUC(24)/MIC ratio. CF levofloxacin pharmacokinetics corrected for body weight are similar to non-CF, except for Tmax. Standard levofloxacin dosing (especially monotherapy) is unlikely to produce maximum therapeutic effectiveness. Additional levofloxacin studies in CF are necessary to evaluate its sputum concentrations; the benefits of higher daily dosages (>/= 750 mg); and establish PK/PD targets for managing PA pulmonary infections.

  13. Attention and memory impairments in pediatric patients with cystic fibrosis and inflammatory bowel disease in comparison to healthy controls.

    PubMed

    Piasecki, Bartosz; Stanisławska-Kubiak, Maia; Strzelecki, Wojciech; Mojs, Ewa

    2017-10-01

    The main aim of the study was to analyze and compare attention and memory performance in pediatric patients with cystic fibrosis (CF), inflammatory bowel disease (IBD) and in healthy controls. 28 patients with CF, 30 patients with IBD and 30 healthy subjects took part in the study (all in age range of 7-17). All subjects were in intellectual norm. To analyze the functioning of attention, the d2 Test of Attention by Brickenkamp (d2 test) was applied. Memory performance was assessed using the Benton Visual Retention Test (BVRT) and the Trial of 10 words. The CF and IBD groups committed significantly more errors in the d2 test than the healthy controls. The CF group also had significantly higher fluctuation rates and received significantly lower scores in overall concentration performance than the control group. Patients with CF made more mistakes and had fewer correct memory projections in BVRT than the healthy controls. Patients with IBD committed significantly more errors in BVRT than the control group. Patients with CF and IBD also got significantly lower scores in the Trial of 10 words than the control group. Pediatric patients with CF and IBD performed more poorly than the healthy controls on attention and memory tests. More distinct cognitive impairments were observed in the CF group. Further research is needed to find the underlying mechanisms and clinical and/or functional significance of observed cognitive deficits. © American Federation for Medical Research (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. Effects and limitations of an AED with audiovisual feedback for cardiopulmonary resuscitation: a randomized manikin study.

    PubMed

    Fischer, Henrik; Gruber, Julia; Neuhold, Stephanie; Frantal, Sophie; Hochbrugger, Eva; Herkner, Harald; Schöchl, Herbert; Steinlechner, Barbara; Greif, Robert

    2011-07-01

    Correctly performed basic life support (BLS) and early defibrillation are the most effective measures to treat sudden cardiac arrest. Audiovisual feedback improves BLS. Automated external defibrillators (AED) with feedback technology may play an important role in improving CPR quality. The aim of this simulation study was to investigate if an AED with audiovisual feedback improves CPR parameters during standard BLS performed by trained laypersons. With ethics committee approval and informed consent, 68 teams (2 flight attendants each) performed 12 min of standard CPR with the AED's audiovisual feedback mechanism enabled or disabled. We recorded CPR quality parameters during resuscitation on a manikin in this open, prospective, randomized controlled trial. Between the feedback and control-group we measured differences in compression depth and rate as main outcome parameters and effective compressions, correct hand position, and incomplete decompression as secondary outcome parameters. An effective compression was defined as a compression with correct depth, hand position, and decompression. The feedback-group delivered compression rates closest to the recommended guidelines (101 ± 9 vs. 109 ± 15/min, p=0.009), more effective compressions (20 ± 18 vs. 5 ± 6%, p<0.001), more compressions with correct hand position (96 ± 13 vs. 88 ± 16%, p<0.001), and less leaning (21 ± 31 vs. 77 ± 33%, p<0.001). However, only the control-group adhered to the recommended compression depth (44 ± 7 mm vs. 39 ± 6, p=0.003). Use of an AED's audiovisual feedback system improved some CPR-quality parameters, thus confirming findings of earlier studies with the notable exception of decreased compression depth, which is a key parameter that might be linked to reduced cardiac output. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. Acquisition and Retention of Esperanto: The Case for Error Correction and Immediate Feedback

    ERIC Educational Resources Information Center

    Brosvic, Gary M.; Epstein, Michael L.; Dihoff, Roberta E.; Cook, Michael J.

    2006-01-01

    Participants completed 5 laboratory examinations during which the number of responses permitted (1 response, up to 4 responses) and the timing of feedback (no feedback control: Scantron form; delayed feedback: end-of-test, 24-hr delay; immediate feedback: assistant, response form) were manipulated. Participants completed a 100-item cumulative…

  16. The Effects of Computer-Assisted Feedback Strategies in Technology Education: A Comparison of Learning Outcomes

    ERIC Educational Resources Information Center

    Adams, Ruifang Hope; Strickland, Jane

    2012-01-01

    This study investigated the effects of computer-assisted feedback strategies that have been utilized by university students in a technology education curriculum. Specifically, the study examined the effectiveness of the computer-assisted feedback strategy "Knowledge of Response feedback" (KOR), and the "Knowledge of Correct Responses feedback"…

  17. Effective silencing of ENaC by siRNA delivered with epithelial-targeted nanocomplexes in human cystic fibrosis cells and in mouse lung.

    PubMed

    Tagalakis, Aristides D; Munye, Mustafa M; Ivanova, Rositsa; Chen, Hanpeng; Smith, Claire M; Aldossary, Ahmad M; Rosa, Luca Z; Moulding, Dale; Barnes, Josephine L; Kafetzis, Konstantinos N; Jones, Stuart A; Baines, Deborah L; Moss, Guy W J; O'Callaghan, Christopher; McAnulty, Robin J; Hart, Stephen L

    2018-05-10

    Loss of the cystic fibrosis transmembrane conductance regulator in cystic fibrosis (CF) leads to hyperabsorption of sodium and fluid from the airway due to upregulation of the epithelial sodium channel (ENaC). Thickened mucus and depleted airway surface liquid (ASL) then lead to impaired mucociliary clearance. ENaC regulation is thus a promising target for CF therapy. Our aim was to develop siRNA nanocomplexes that mediate effective silencing of airway epithelial ENaC in vitro and in vivo with functional correction of epithelial ion and fluid transport. We investigated translocation of nanocomplexes through mucus and their transfection efficiency in primary CF epithelial cells grown at air-liquid interface (ALI).Short interfering RNA (SiRNA)-mediated silencing was examined by quantitative RT-PCR and western analysis of ENaC. Transepithelial potential (V t ), short circuit current (I sc ), ASL depth and ciliary beat frequency (CBF) were measured for functional analysis. Inflammation was analysed by histological analysis of normal mouse lung tissue sections. Nanocomplexes translocated more rapidly than siRNA alone through mucus. Transfections of primary CF epithelial cells with nanocomplexes targeting αENaC siRNA, reduced αENaC and βENaC mRNA by 30%. Transfections reduced V t , the amiloride-sensitive I sc and mucus protein concentration while increasing ASL depth and CBF to normal levels. A single dose of siRNA in mouse lung silenced ENaC by approximately 30%, which persisted for at least 7 days. Three doses of siRNA increased silencing to approximately 50%. Nanoparticle-mediated delivery of ENaCsiRNA to ALI cultures corrected aspects of the mucociliary defect in human CF cells and offers effective delivery and silencing in vivo. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. Pharmacological treatment of the ion transport defect in cystic fibrosis.

    PubMed

    Roomans, G M

    2001-01-01

    Cystic fibrosis (CF) is a lethal monogenetic disease characterised by impaired water and ion transport over epithelia. The lung pathology is fatal and causes death in 95% of CF patients. The genetic basis of the disease is a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-regulated chloride channel. The most common mutation, DeltaF508, results in a protein that cannot properly be folded in the endoplasmic reticulum, is destroyed and hence does not reach the apical cell membrane. This paper will discuss those pharmacological approaches that are directed at correcting the defect in ion transport. At present, no clinically effective drug is available, although research has defined areas in which progress might be made. These are the following: (1) the drug 4-phenylbutyrate (4PBA) increases the expression of DeltaF508-CFTR in the cell membrane, probably by breaking the association between DeltaF508-CFTR and a chaperone; (2) a number of xanthines, in particular 8-cyclopentyl-1, 3-dipropylxanthine (CPX), are effective in activating CFTR, presumably by direct binding and also possibly by correcting the trafficking defect; (3) the isoflavone genistein can activate both wild-type and mutant CFTR, probably through direct binding to the channel; (4) purinergic agonists (ATP and UTP) can stimulate chloride secretion via a Ca(2+)-dependent chloride channel and in this way compensate for the defect in CFTR, but stable analogues will be required before this type of treatment has clinical significance; (5) treatment with inhaled amiloride may correct the excessive absorption of Na(+) ions and water by airway epithelial cells that appears connected to the defect in CFTR; although clinical tests have not been very successful so far, amiloride analogues with a longer half-life may give better results. The role of CFTR in bicarbonate secretion has not yet been established with certainty, but correction of the defect in bicarbonate secretion may be important in clinical treatment of the disease. Currently, major efforts are directed at developing a pharmacological treatment of the ion transport defect in CF, but much basic research remains to be done, in particular, with regard to the mechanism by which defective CFTR is removed in the endoplasmic reticulum by the ubiquitin-proteasome pathway, which is a central pathway in protein production and of significance for several other diseases apart from CF.

  19. Effects of postidentification feedback on eyewitness identification and nonidentification confidence.

    PubMed

    Semmler, Carolyn; Brewer, Neil; Wells, Gary L

    2004-04-01

    Two experiments investigated new dimensions of the effect of confirming feedback on eyewitness identification confidence using target-absent and target-present lineups and (previously unused) unbiased witness instructions (i.e., "offender not present" option highlighted). In Experiment 1, participants viewed a crime video and were later asked to try to identify the thief from an 8-person target-absent photo array. Feedback inflated witness confidence for both mistaken identifications and correct lineup rejections. With target-present lineups in Experiment 2, feedback inflated confidence for correct and mistaken identifications and lineup rejections. Although feedback had no influence on the confidence-accuracy correlation, it produced clear overconfidence. Confidence inflation varied with the confidence measure reference point (i.e., retrospective vs. current confidence) and identification response latency.

  20. Comparison of Nasal Potential Difference and Intestinal Current Measurements as Surrogate Markers for CFTR Function.

    PubMed

    Wilschanski, Michael; Yaakov, Yasmin; Omari, Ibrahim; Zaman, Munir; Martin, Camilia R; Cohen-Cymberknoh, Malena; Shoseyov, David; Kerem, Eitan; Dasilva, Deborah; Sheth, Sunil; Uluer, Ahmet; OʼSullivan, Brian P; Freedman, Steven

    2016-11-01

    Nasal potential difference (NPD) measurement is part of the diagnostic criteria for cystic fibrosis (CF) and now used routinely as an endpoint in clinical trials of correcting the basic defect in CF. Intestinal current measurement (ICM), measured ex vivo on a rectal biopsy, has been used to study cystic fibrosis transmembrane conductance regulator (CFTR) function but has not been compared to NPD in the same subject in adults and children. The aim of the study is to evaluate the potential usefulness of ICM as a marker of CFTR function for treatment studies compared NPD in patients with CF and in healthy control subjects. ICM and NPD were performed on healthy controls and patients with CF. The healthy adults were individuals undergoing routine screening colonoscopy at the Beth Israel Deaconess Medical Center. The healthy children were undergoing colonoscopy for suspicion of inflammation in Hadassah Hebrew University Medical Center. The CF adults were recruited from Boston Children's Hospital CF Center and CF Center Worcester Mass, the children with CF from Hadassah CF Center. ICM measurements in healthy control subjects (n = 16) demonstrated a mean (±SE) carbachol response of 16.0 (2.2) μA/cm, histamine response of 13.2 (2.1) μA/cm and a forskolin response of 6.3 (2.0) μA/cm. Basal NPD of -15.9 (1.9) and response to Cl free + isoproterenol of -13.8 (2.0). These responses were inverted in CF subjects (n = 12) for ICM parameters with carbachol response of -3.0 (0.5) μA/cm, histamine -1.0 (0.8) μA/cm and a forskolin response of 0.5 (0.3) and also for NPD parameters; basal NPD of -42.2 (4.3) and response to Cl free + isoproterenol of 4.3 (0.7). Pearson correlation test showed the comparability of ICM and NPD in assessing CFTR function. ICM is equivalent to NPD in the ability to distinguish patients with CF from controls and could be used as surrogate markers of CFTR activity in treatment protocols.

  1. Efficacy of an ICALL Tutoring System and Process-Oriented Corrective Feedback

    ERIC Educational Resources Information Center

    Choi, Inn-Chull

    2016-01-01

    A Web-based form-focused intelligent computer-assisted language learning (ICALL) tutoring system equipped with a process-oriented corrective feedback function was developed to investigate the extent to which such a program may serve as a viable method of teaching grammar to Korean secondary and elementary students. The present study was also…

  2. Evidence in Support of Written Corrective Feedback

    ERIC Educational Resources Information Center

    Bitchener, John

    2008-01-01

    The extent to which ESL learners benefit from written corrective feedback has been debated at length since Truscott (1996) mounted a case for its abolition. Ten years later, the debate continues, not only because little attention has been given to testing its efficacy over time but also because studies that have investigated the issue have not…

  3. Individual Differences in Written Corrective Feedback: A Multi-Case Study

    ERIC Educational Resources Information Center

    Li, Su; Li, Pengjing

    2012-01-01

    Written corrective feedback (WCF) has been a long time practice in L2 writing instruction. However, in many cases, the effects are not satisfactory. There have been controversies about it both theoretically and empirically. This paper reports a multi-case study exploring individual differences that impact learners' responses to WCF. Four students'…

  4. Written Corrective Feedback: Practitioners' Perspectives

    ERIC Educational Resources Information Center

    Evans, Norman W.; Hartshorn, K. James; Tuioti, Emily Allen

    2010-01-01

    Considerable attention has been given to written corrective feedback (WCF) in second language writing (L2) over the past several decades. One of the central questions has focused on the appropriateness of its use in L2 writing. In these academic discussions, scholars frequently describe how WCF is utilized in the classroom. However, many of these…

  5. Types and Timing of Oral Corrective Feedback in EFL Classrooms: Voices from Students

    ERIC Educational Resources Information Center

    Ölmezer-Öztürk, Elçin; Öztürk, Gökhan

    2016-01-01

    Oral corrective feedback in language classrooms has received considerable attention for the last few decades. However, most of the studies focus on teachers' practices, and how learners perceive these practices still needs investigation. Based on this, the current study examined the perceptions and preferences of EFL learners regarding the types…

  6. Asynchronous Computer-Mediated Corrective Feedback and the Correct Use of Prepositions: Is It Really Effective?

    ERIC Educational Resources Information Center

    Hosseini, Seyyed Behrooz

    2012-01-01

    An area that has recently attracted increasing attention is providing feedback on learners' writing accuracy through the Internet. However, research in this area has largely focused on synchronous communication, i.e., chatting, with fewer studies assessing asynchronous technologies, i.e., e-mailing. Therefore, this study investigates the…

  7. Corrective Feedback via Instant Messenger Learning Activities in NS-NNS and NNS-NNS Dyads

    ERIC Educational Resources Information Center

    Sotillo, Susana

    2005-01-01

    This exploratory study examines corrective feedback in native speaker-nonnative speaker (NS-NNS) and NNS-NNS dyads while participants were engaged in communicative and problem-solving activities via "Yahoo! Instant Messenger" (YIM). As "negotiation of meaning" studies of the 1990s have shown, linguistic items which learners negotiate in…

  8. Smartwatch feedback device for high-quality chest compressions by a single rescuer during infant cardiac arrest: a randomized, controlled simulation study.

    PubMed

    Lee, Juncheol; Song, Yeongtak; Oh, Jaehoon; Chee, Youngjoon; Ahn, Chiwon; Shin, Hyungoo; Kang, Hyunggoo; Lim, Tae Ho

    2018-02-12

    According to the guidelines, rescuers should provide chest compressions (CC) ∼1.5 inches (40 mm) for infants. Feedback devices could help rescuers perform CC with adequate rates (CCR) and depths (CCD). However, there is no CC feedback device for infant cardiopulmonary resuscitation (CPR). We suggest a smartwatch-based CC feedback application for infant CPR. We created a smartwatch-based CC feedback application. This application provides feedback on CCD and CCR by colour and text for infant CPR. To evaluate the application, 30 participants were divided randomly into two groups on the basis of whether CC was performed with or without the assistance of the smartwatch application. Both groups performed continuous CC-only CPR for 2 min on an infant mannequin placed on a firm table. We collected CC parameters from the mannequin, including the proportion of correct depth, CCR, CCD and the proportion of correct decompression depth. Demographics between the two groups were not significantly different. The median (interquartile range) proportion of correct depth was 99 (97-100) with feedback compared with 83 (58-97) without feedback (P=0.002). The CCR and proportion of correct decompression depth were not significantly different between the two groups (P=0.482 and 0.089). The CCD of the feedback group was significantly deeper than that of the control group [feedback vs. 41.2 (39.8-41.7) mm vs. 38.6 (36.1-39.6) mm; P=0.004]. Rescuers who receive feedback of CC parameters from a smartwatch could perform adequate CC during infant CPR.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

  9. Phase-amplitude coupling within the anterior thalamic nuclei during seizures.

    PubMed

    Ibrahim, George M; Wong, Simeon; Morgan, Benjamin R; Lipsman, Nir; Fallah, Aria; Weil, Alexander G; Krishna, Vibhor; Wennberg, Richard A; Lozano, Andres A

    2018-04-01

    Cross-frequency phase-amplitude coupling (cfPAC) subserves an integral role in the hierarchical organization of interregional neuronal communication and is also expressed by epileptogenic cortex during seizures. Here, we sought to characterize patterns of cfPAC expression in the anterior thalamic nuclei during seizures by studying extra-operative recordings in patients implanted with deep brain stimulation electrodes for intractable epilepsy. Nine seizures from two patients were analyzed in the peri-ictal period. CfPAC was calculated using the modulation index and interregional functional connectivity was indexed using the phase-locking value. Statistical analysis was performed within subjects on the basis of nonparametric permutation and corrected with Gaussian field theory. Five of the nine analyzed seizures demonstrated significant cfPAC. Significant cfPAC occurred during the pre-ictal and ictal periods in three seizures, as well as the postictal windows in four seizures. The preferred phase at which cfPAC occurred differed 1) in space, between the thalami of the epileptogenic and nonepileptogenic hemispheres; and 2) in time, at seizure termination. The anterior thalamic nucleus of the epileptogenic hemisphere also exhibited altered interregional phase-locking synchrony concurrent with the expression of cfPAC. By analyzing extraoperative recordings from the anterior thalamic nuclei, we show that cfPAC associated with altered interregional phase synchrony is lateralized to the thalamus of the epileptogenic hemisphere during seizures. Electrophysiological differences in cfPAC, including preferred phase of oscillatory interactions may be further investigated as putative targets for individualized neuromodulation paradigms in patients with drug-resistant epilepsy. NEW & NOTEWORTHY The association between fast brain activity and slower oscillations is an integral mechanism for hierarchical neuronal communication, which is also manifested in epileptogenic cortex. Our data suggest that the same phenomenon occurs in the anterior thalamic nuclei during seizures. Further, the preferred phase of modulation shows differences in space, between the epileptogenic and nonepileptogenic hemispheres and time, as seizures terminate. Our data encourage the study of cross-frequency coupling for targeted, individualized closed-loop stimulation paradigms.

  10. A membrane lipid imbalance plays a role in the phenotypic expression of cystic fibrosis in cftr−/− mice

    PubMed Central

    Freedman, Steven D.; Katz, Mark H.; Parker, Eliza M.; Laposata, Michael; Urman, Mark Y.; Alvarez, Juan G.

    1999-01-01

    A deficiency in essential fatty acid metabolism has been reported in plasma from patients with cystic fibrosis (CF). However, its etiology and role in the expression of disease is unknown. The objective of this study was to determine whether alterations in fatty acid metabolism are specific to CF-regulated organs and whether they play a role in the expression of disease. A membrane lipid imbalance was found in ileum, pancreas, and lung from cftr−/− mice characterized by an increase in phospholipid-bound arachidonic acid and a decrease in phospholipid-bound docosahexaenoic acid (DHA). This lipid imbalance was observed in organs pathologically affected by CF including lung, pancreas, and ileum and was not secondary to impaired intestinal absorption or hepatic biosynthesis of DHA. As proof of concept, oral administration of DHA to cftr−/− mice corrected this lipid imbalance and reversed the observed pathological manifestations. These results strongly suggest that certain phenotypic manifestations of CF may result from remediable alterations in phospholipid-bound arachidonic acid and DHA levels. PMID:10570187

  11. [Energy corrective and antioxidative actions of cytoflavin during postischemic period of human dermal fibroblasts in vitro].

    PubMed

    Tiuriaeva, I I; Kuranova, M L; Gonchar, I V; Rozanov, Iu M

    2012-01-01

    The influence of metabolic drug Cytoflavin (CF) with antihypoxic and antioxidative properties on human dermal fibroblasts in a model of ischemia-reoxygenation in vitro was studied. It was revealed that the restoration of ATP synthesis in fibroblasts in the postischemic period was considerably accelerated (in 2.1 times) by the addition of CF to the culture medium. The drug had a cell protective effect of reducing cell mortality during the reoxygenation after ischemia by 2-2.7 times. CF effectively reduced the level of reactive oxygen species (ROS) in fibroblasts after H2O2 treatment which allowed maintaining their survival at the level of control cells. Pretreatment of the cells with CF for one day ensured the maintenance of normal levels of ROS during the investigated time period in the fibroblasts subjected to H2O2 treatment, and reduced H2O2-induced cell death by almost a third compared to control cells. The introduction of CF in culture medium after ischemia showed no influence on Hsp70 synthesis, but led to decrease in GRP78 synthesis, raised after ischemia, to the control level, indicating a resolve of the endoplasmic reticulum (ER) stress and functional normalization of ER.

  12. Is there evidence for correct diagnosis in cystic fibrosis registries?

    PubMed

    Thomas, Muriel; Lemonnier, Lydie; Gulmans, Vincent; Naehrlich, Lutz; Vermeulen, François; Cuppens, Harry; Castellani, Carlo; Norek, Aleksandra; De Boeck, Kris

    2014-05-01

    Cystic fibrosis (CF) spans a wide spectrum. Therefore, benchmarking between registries implies comparing similar cohorts. Explore patient characteristics in Belgian (B), French (F), German (G) and Dutch (NL) registries (total N=13,122) and determine whether they fulfill predefined diagnostic criteria. Using as case definition sweat chloride >60mmol/L or 2 CFTR mutations identified, CF diagnosis was not documented in 2.8, 5.7, 6.5 and 21.6% of subjects in the F, B, NL, and G registries. Restricting CFTR mutation interpretation to 124 CF causing mutations in CFTR2, these numbers rose to 10.5, 10.4, 14.5 and 24.3% respectively. Excluding these subjects impacted on outcomes. The impact differed between countries; the largest changes seen were a decrease in % adults from 51.9 to 47.8% in G, a decrease in % pancreas sufficiency from 17.0 to 13.0 in F, an increase in % homozygous for F508del from 55.3 to 63.7 in NL and a decrease of % with sweat chloride ≤60mmol/L from 8.4 to 1.1 in B. CF diagnosis is not documented in 10 to 24% of patients included in CF registries. Excluding these patients for analyses leads to significant changes in outcomes. © 2013.

  13. Learner Perceptions of Online Peer Pronunciation Feedback through P-Check

    ERIC Educational Resources Information Center

    Yonesaka, Suzanne M.

    2017-01-01

    Receiving adequate pronunciation feedback is an ongoing challenge for L2 learners. Although instructors are the most important source of corrective pronunciation feedback (Szpyra, 2014; Timson, 2007), L2 learners can also benefit from peer pronunciation feedback (Lord, 2008; Kim & Yoon, 2014; Roccamo, 2015). This paper examines Japanese…

  14. Impact of web searching and social feedback on consumer decision making: a prospective online experiment.

    PubMed

    Lau, Annie Y S; Coiera, Enrico W

    2008-01-22

    The World Wide Web has increasingly become an important source of information in health care consumer decision making. However, little is known about whether searching online resources actually improves consumers' understanding of health issues. The aim was to study whether searching on the World Wide Web improves consumers' accuracy in answering health questions and whether consumers' understanding of health issues is subject to further change under social feedback. This was a pre/post prospective online study. A convenience sample of 227 undergraduate students was recruited from the population of the University of New South Wales. Subjects used a search engine that retrieved online documents from PubMed, MedlinePlus, and HealthInsite and answered a set of six questions (before and after use of the search engine) designed for health care consumers. They were then presented with feedback consisting of a summary of the post-search answers provided by previous subjects for the same questions and were asked to answer the questions again. There was an improvement in the percentage of correct answers after searching (pre-search 61.2% vs post-search 82.0%, P <.001) and after feedback with other subjects' answers (pre-feedback 82.0% vs post-feedback 85.3%, P =.051). The proportion of subjects with highly confident correct answers (ie, confident or very confident) and the proportion with highly confident incorrect answers significantly increased after searching (correct pre-search 61.6% vs correct post-search 95.5%, P <.001; incorrect pre-search 55.3% vs incorrect post-search 82.0%, P <.001). Subjects who were not as confident in their post-search answers were 28.5% more likely than those who were confident or very confident to change their answer after feedback with other subjects' post-search answers (chi(2) (1)= 66.65, P <.001). Searching across quality health information sources on the Web can improve consumers' accuracy in answering health questions. However, a consumer's confidence in an answer is not a good indicator of the answer being correct. Consumers who are not confident in their answers after searching are more likely to be influenced to change their views when provided with feedback from other consumers.

  15. The Impact of Public Feedback on Three Recycling-Related Behaviors in South Korea

    ERIC Educational Resources Information Center

    Kim, Sungbum; Oah, Shezeen; Dickinson, Alyce M.

    2005-01-01

    The effectiveness of posted feedback on recycling in a lounge area at a South Korean university was studied. Participants were college students, professors, and staff members. The dependent variables were the percentage and number of correctly separated aluminum cans, the percentage and number of correctly separated paper cups, and the weight of…

  16. Retesting the Limits of Data-Driven Learning: Feedback and Error Correction

    ERIC Educational Resources Information Center

    Crosthwaite, Peter

    2017-01-01

    An increasing number of studies have looked at the value of corpus-based data-driven learning (DDL) for second language (L2) written error correction, with generally positive results. However, a potential conundrum for language teachers involved in the process is how to provide feedback on students' written production for DDL. The study looks at…

  17. The Effect of Teachers' Written Corrective Feedback (WCF) Types on Intermediate EFL Learners' Writing Performance

    ERIC Educational Resources Information Center

    Aghajanloo, Khadijeh; Mobini, Fariba; Khosravi, Robab

    2016-01-01

    Written Corrective Feedback (WCF) is a controversial topic among theorists and researchers in L2 studies. Ellis, Sheen, Murakami, and Takashima (2008) identify two dominant dichotomies in this regard, that is focused vs. unfocused WCF and direct vs. indirect WCF. This study considered both dichotomies in a matrix format, resulted in the…

  18. An Explanation of the Effectiveness of Written Corrective Feedback in Second-Language Acquisition

    ERIC Educational Resources Information Center

    Wagner, Jason

    2016-01-01

    The purpose of this study is to provide a theoretical explanation for the effectiveness of Written Corrective Feedback (WCF) in increasing second-language (L2) students' grammatical accuracy. WCF is examined via Skill Acquisition Theory (SAT) in order to account for uneven patterns of its effectiveness. As the study demonstrates, WCF is effective…

  19. Written Corrective Feedback from Sociocultural Theoretical Perspectives: A Research Agenda

    ERIC Educational Resources Information Center

    Storch, Neomy

    2018-01-01

    Using key constructs from sociocultural theory and activity theory, this paper outlines three broad areas of future research on written corrective feedback (WCF) that may be of interest to second language (L2) researchers and practitioners. The first area uses the constructs of the Zone of Proximal Development (ZPD) and scaffolding to assess the…

  20. Chinese EFL Learners' Noticing of Recasts: Its Relation to Target Structures, Uptake, and Working Memory Capacity

    ERIC Educational Resources Information Center

    Chen, Xiaoqing

    2013-01-01

    Recasts are one type of corrective feedback that reformulates all or part of a learner's erroneous utterance during communicative interaction without changing the meaning. Categorized as implicit and input-providing corrective feedback, recasts have become the focus of debate in the area of interaction research in recent years. The debate…

  1. The Relative Effectiveness of Different Types of Direct Written Corrective Feedback

    ERIC Educational Resources Information Center

    Bitchener, John; Knoch, Ute

    2009-01-01

    The effectiveness of different types of written corrective feedback has been investigated over the last twenty years but it is still not possible to make firm conclusions about which options are the most beneficial to ESL learners. This article first provides an overview of the currently available research findings and then presents the results of…

  2. Instructed Vision: Navigating Grammatical Rules by Using Landmarks for Linguistic Structures in Corrective Feedback Sequences

    ERIC Educational Resources Information Center

    Majlesi, Ali Reza

    2018-01-01

    This study aims to show how multimodality, that is, the mobilization of various communicative resources in social actions (Mondada, 2016), can be used to teach grammar. Drawing on ethnomethodological conversation analysis (Sacks, 1992), the article provides a detailed analysis of 2 corrective feedback sequences in a Swedish-as-a-second-language…

  3. The Contribution of Written Corrective Feedback to Language Development: A Ten Month Investigation

    ERIC Educational Resources Information Center

    Bitchener, John; Knoch, Ute

    2010-01-01

    The call for longitudinal evidence on the efficacy of written corrective feedback (WCF) for ESL (English as a second language) writers has been made repeatedly since Truscott (1996) claimed that it is ineffective, harmful, and should therefore be abandoned. This article discusses some of the theoretical issues raised against the practice, outlines…

  4. The Effects of Virtual Coaching on Teacher Candidates' Perceptions and Concerns Regarding On-Demand Corrective Feedback

    ERIC Educational Resources Information Center

    Wake, Donna; Dailey, Debbie; Cotabish, Alicia; Benson, Tammy

    2017-01-01

    A virtual coaching intervention utilizing Skype and Bluetooth (Bug-in-the-Ear) technology provided immediate corrective feedback to non-traditional teacher candidates during a semester-long internship experience. Participants completed their student teaching internship as a requirement of a teacher preparation program at a mid-size Southeastern…

  5. Nonverbal Behavior and Corrective Feedback in Nine ESL University-Level Classrooms

    ERIC Educational Resources Information Center

    Wang, Weiqing; Loewen, Shawn

    2016-01-01

    Nonverbal behavior is an area of recent interest in second language acquisition (SLA). Some researchers have found that teachers' nonverbal behavior plays a role in second language (L2) learners' learning. Furthermore, corrective feedback during L2 interaction can also be facilitative of L2 development; however, little is known about how nonverbal…

  6. Teaching Email Requests in the Academic Context: A Focus on the Role of Corrective Feedback

    ERIC Educational Resources Information Center

    Nguyen, Thi Thuy Minh; Do, Thi Thanh Ha; Nguyen, Anh Tuan; Pham, Thi Thanh Thuy

    2015-01-01

    As email requests from students to professors have become increasingly common in academic settings, research has also shown second-language (L2) students' unfamiliarity with email etiquette in L2 has adversely affected their communication with their professors. The present study examines whether giving corrective feedback on students' performance…

  7. Conditions Fostering the Use of Informative Feedback by Young Children.

    ERIC Educational Resources Information Center

    Teager, Joyce; Stern, Carolyn

    In order to investigate the effect of reinforcement on learning, 21 disadvantaged black children, 4 to 5 years of age, were divided among three treatment groups. Group I children received only feedback (information) as to the correctness or incorrectness of their responses. Group II children received a raisin for each correct response, and group…

  8. Counterintuitive Effects of Online Feedback in Middle School Math: Results from a Randomized Controlled Trial in ASSISTments

    ERIC Educational Resources Information Center

    McGuire, Patrick; Tu, Shihfen; Logue, Mary Ellin; Mason, Craig A.; Ostrow, Korinn

    2017-01-01

    This study compared the effects of three different feedback formats provided to sixth grade mathematics students within a web-based online learning platform, ASSISTments. A sample of 196 students were randomly assigned to one of three conditions: (1) text-based feedback; (2) image-based feedback; and (3) correctness only feedback. Regardless of…

  9. Symptoms and treatment of mental illness among prisoners: a study of Michigan state prisons.

    PubMed

    Fries, Brant E; Schmorrow, Angela; Lang, Sylvia W; Margolis, Philip M; Heany, Julia; Brown, Greg P; Barbaree, Howard E; Hirdes, John P

    2013-01-01

    This study reports on a representative sample of prisoners in Michigan correctional facilities to determine the prevalence of psychiatric illness and the delivery of mental health (MH) services. Mental health assessments were conducted with 618 incarcerated subjects using the interRAI Correctional Facilities (interRAI CF). Subjects were randomly sampled based on four strata: males in the general population, males in administrative segregation, males in special units, and females. The interRAI CF assessments were merged with secondary data provided by the Michigan Department of Corrections (MDOC) containing information on MH diagnoses or services that the subjects were receiving within the facilities, demographics, and sentencing. Study results show that 20.1% of men and 24.8% of women in Michigan prisons have a substantial level of MH symptoms and that 16.5% and 28.9%, respectively, are receiving MH services. However, when compared with Michigan Department of Corrections MH care records, 65.0% of prisoners who are experiencing symptoms of mental illness are not currently receiving any psychiatric services. The mis-match between symptoms and service delivery suggests the need for improved procedures for identifying and measuring psychiatric symptoms within Michigan correctional facilities to ensure that appropriate individuals receive needed care. It is recommended that a standardized assessment process be implemented and conducted at regular intervals for targeting and improving psychiatric care in the prison system. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Time Scales in the JPL and CfA Ephemerides

    NASA Technical Reports Server (NTRS)

    Standish, E. M.

    1998-01-01

    Over the past decades, the IAU has repeatedly attempted to correct its definition of the basic fundamental argument used in the emphemerides. Finally, they have defined a time system which is physically possible, according to the accepted standard theory of gravitation.

  11. The role of automated feedback in training and retaining biological recorders for citizen science.

    PubMed

    van der Wal, René; Sharma, Nirwan; Mellish, Chris; Robinson, Annie; Siddharthan, Advaith

    2016-06-01

    The rapid rise of citizen science, with lay people forming often extensive biodiversity sensor networks, is seen as a solution to the mismatch between data demand and supply while simultaneously engaging citizens with environmental topics. However, citizen science recording schemes require careful consideration of how to motivate, train, and retain volunteers. We evaluated a novel computing science framework that allowed for the automated generation of feedback to citizen scientists using natural language generation (NLG) technology. We worked with a photo-based citizen science program in which users also volunteer species identification aided by an online key. Feedback is provided after photo (and identification) submission and is aimed to improve volunteer species identification skills and to enhance volunteer experience and retention. To assess the utility of NLG feedback, we conducted two experiments with novices to assess short-term (single session) and longer-term (5 sessions in 2 months) learning, respectively. Participants identified a specimen in a series of photos. One group received only the correct answer after each identification, and the other group received the correct answer and NLG feedback explaining reasons for misidentification and highlighting key features that facilitate correct identification. We then developed an identification training tool with NLG feedback as part of the citizen science program BeeWatch and analyzed learning by users. Finally, we implemented NLG feedback in the live program and evaluated this by randomly allocating all BeeWatch users to treatment groups that received different types of feedback upon identification submission. After 6 months separate surveys were sent out to assess whether views on the citizen science program and its feedback differed among the groups. Identification accuracy and retention of novices were higher for those who received automated feedback than for those who received only confirmation of the correct identification without explanation. The value of NLG feedback in the live program, captured through questionnaires and evaluation of the online photo-based training tool, likewise showed that the automated generation of informative feedback fostered learning and volunteer engagement and thus paves the way for productive and long-lived citizen science projects. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  12. An improved car-following model with multiple preceding cars' velocity fluctuation feedback

    NASA Astrophysics Data System (ADS)

    Guo, Lantian; Zhao, Xiangmo; Yu, Shaowei; Li, Xiuhai; Shi, Zhongke

    2017-04-01

    In order to explore and evaluate the effects of velocity variation trend of multiple preceding cars used in the Cooperative Adaptive Cruise Control (CACC) strategy on the dynamic characteristic, fuel economy and emission of the corresponding traffic flow, we conduct a study as follows: firstly, with the real-time car-following (CF) data, the close relationship between multiple preceding cars' velocity fluctuation feedback and the host car's behaviors is explored, the evaluation results clearly show that multiple preceding cars' velocity fluctuation with different time window-width are highly correlated to the host car's acceleration/deceleration. Then, a microscopic traffic flow model is proposed to evaluate the effects of multiple preceding cars' velocity fluctuation feedback in the CACC strategy on the traffic flow evolution process. Finally, numerical simulations on fuel economy and exhaust emission of the traffic flow are also implemented by utilizing VT-micro model. Simulation results prove that considering multiple preceding cars' velocity fluctuation feedback in the control strategy of the CACC system can improve roadway traffic mobility, fuel economy and exhaust emission performance.

  13. Potentiator Ivacaftor Abrogates Pharmacological Correction of ΔF508 CFTR in Cystic Fibrosis

    PubMed Central

    Cholon, Deborah M.; Quinney, Nancy L.; Fulcher, M. Leslie; Esther, Charles R.; Das, Jhuma; Dokholyan, Nikolay V.; Randell, Scott H.; Boucher, Richard C.; Gentzsch, Martina

    2014-01-01

    Cystic Fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR). Newly developed “correctors” such as lumacaftor (VX-809) that improve CFTR maturation and trafficking and “potentiators” such as ivacaftor (VX-770) that enhance channel activity may provide important advances in CF therapy. Although VX-770 has demonstrated substantial clinical efficacy in the small subset of patients with a mutation (G551D) that affects only channel activity, a single compound is not sufficient to treat patients with the more common CFTR mutation, ΔF508. Thus, patients with ΔF508 will likely require treatment with both correctors and potentiators to achieve clinical benefit. However, whereas the effectiveness of acute treatment with this drug combination has been demonstrated in vitro, the impact of chronic therapy has not been established. In studies of human primary airway epithelial cells, we found that both acute and chronic treatment with VX-770 improved CFTR function in cells with the G551D mutation, consistent with clinical studies. In contrast, chronic VX-770 administration caused a dose-dependent reversal of VX-809-mediated CFTR correction in ΔF508 homozygous cultures. This result reflected the destabilization of corrected ΔF508 CFTR by VX-770, dramatically increasing its turnover rate. Chronic VX-770 treatment also reduced mature wild-type CFTR levels and function. These findings demonstrate that chronic treatment with CFTR potentiators and correctors may have unexpected effects that cannot be predicted from short-term studies. Combining of these drugs to maximize rescue of ΔF508 CFTR may require changes in dosing and/or development of new potentiator compounds that do not interfere with CFTR stability. PMID:25101886

  14. Developmental and Gender Related Differences in Response Switches after Nonrepresentative Negative Feedback

    ERIC Educational Resources Information Center

    Jansen, Brenda R. J.; van Duijvenvoorde, Anna C. K.; Huizenga, Hilde M.

    2014-01-01

    In many decision making tasks negative feedback is probabilistic and, as a consequence, may be given when the decision is actually correct. This feedback can be referred to as nonrepresentative negative feedback. In the current study, we investigated developmental and gender related differences in such switching after nonrepresentative negative…

  15. Inhibition of Protease-Epithelial Sodium Channel Signaling Improves Mucociliary Function in Cystic Fibrosis Airways.

    PubMed

    Reihill, James A; Walker, Brian; Hamilton, Robert A; Ferguson, Timothy E G; Elborn, J Stuart; Stutts, M Jackson; Harvey, Brian J; Saint-Criq, Vinciane; Hendrick, Siobhan M; Martin, S Lorraine

    2016-09-15

    In cystic fibrosis (CF) a reduction in airway surface liquid (ASL) height compromises mucociliary clearance, favoring mucus plugging and chronic bacterial infection. Inhibitors of the epithelial sodium channel (ENaC) have therapeutic potential in CF airways to reduce hyperstimulated sodium and fluid absorption to levels that can restore airway hydration. To determine whether a novel compound (QUB-TL1) designed to inhibit protease/ENaC signaling in CF airways restores ASL volume and mucociliary function. Protease activity was measured using fluorogenic activity assays. Differentiated primary airway epithelial cell cultures (F508del homozygotes) were used to determined ENaC activity (Ussing chamber recordings), ASL height (confocal microscopy), and mucociliary function (by tracking the surface flow of apically applied microbeads). Cell toxicity was measured using a lactate dehydrogenase assay. QUB-TL1 inhibits extracellularly located channel activating proteases (CAPs), including prostasin, matriptase, and furin, the activities of which are observed at excessive levels at the apical surface of CF airway epithelial cells. QUB-TL1-mediated CAP inhibition results in diminished ENaC-mediated Na(+) absorption in CF airway epithelial cells caused by internalization of a prominent pool of cleaved (active) ENaCγ from the cell surface. Importantly, diminished ENaC activity correlates with improved airway hydration status and mucociliary clearance. We further demonstrate QUB-TL1-mediated furin inhibition, which is in contrast to other serine protease inhibitors (camostat mesylate and aprotinin), affords protection against neutrophil elastase-mediated ENaC activation and Pseudomonas aeruginosa exotoxin A-induced cell death. QUB-TL1 corrects aberrant CAP activities, providing a mechanism to delay or prevent the development of CF lung disease in a manner independent of CF transmembrane conductance regulator mutation.

  16. Immediate detailed feedback to test-enhanced learning: an effective online educational tool.

    PubMed

    Wojcikowski, Ken; Kirk, Leslie

    2013-11-01

    Test-enhanced learning has gained popularity because it is an effective way to increase retention of knowledge; provided the student receives the correct answer soon after the test is taken. To determine whether detailed feedback provided to test-enhanced learning questions is an effective online educational tool for improving performance on complex biomedical information exams. A series of online multiple choice tests were developed to test knowledge of biomedical information that students were expected to know after each patient-case. Following submission of the student answers, one cohort (n = 52) received answers only while the following year, a second cohort (n = 51) received the answers with detailed feedback explaining why each answer was correct or incorrect. Students in both groups progressed through the series of online tests with little assessor intervention. Students receiving the answers along with the explanations within their feedback performed significantly better in the final biomedical information exam than those students receiving correct answers only. This pilot study found that the detailed feedback to test-enhanced learning questions is an important online learning tool. The increase in student performance in the complex biomedical information exam in this study suggests that detailed feedback should be investigated not only for increasing knowledge, but also be investigated for its effect on retention and application of knowledge.

  17. The Effects of Standardized Feedback on Orthopedic Patient Evaluation Skills.

    ERIC Educational Resources Information Center

    DaRosa, Debra A.; And Others

    1984-01-01

    A study examined whether there are performance differences between surgery clerks provided corrective reinforcement on orthopedic history and physical examination write-ups and those assessed by traditional feedback means when both groups are exposed to the feedback instrument. (MLW)

  18. Student Beliefs towards Written Corrective Feedback: The Case of Filipino High School Students

    ERIC Educational Resources Information Center

    Balanga, Roselle A.; Fidel, Irish Van B.; Gumapac, Mone Virma Ginry P.; Ho, Howell T.; Tullo, Riza Mae C.; Villaraza, Patricia Monette L.; Vizconde, Camilla J.

    2016-01-01

    The study identified the beliefs of high school students toward Written Corrective Feedback (WCF), based on the framework of Anderson (2010). It also investigated the most common errors that students commit in writing stories and the type of WCF students receive from teachers. Data in the form of stories which were checked by teachers were…

  19. The Value of Written Corrective Feedback for Migrant and International Students

    ERIC Educational Resources Information Center

    Bitchener, John; Knoch, Ute

    2008-01-01

    This article provides an overview of research that has investigated the effectiveness of written corrective feedback (WCF) on ESL student writing. In doing so, it highlights a number of shortcomings in the design of some studies and explains what needs to be done in future research so that answers to the issues that have been raised can be…

  20. Direct Written Corrective Feedback, Learner Differences, and the Acquisition of Second Language Article Use for Generic and Specific Plural Reference

    ERIC Educational Resources Information Center

    Stefanou, Charis; Revesz, Andrea

    2015-01-01

    This article reports on a classroom-based study that investigated the effectiveness of direct written corrective feedback in relation to learner differences in grammatical sensitivity and knowledge of metalanguage. The study employed a pretest-posttest-delayed posttest design with two treatment sessions. Eighty-nine Greek English as a foreign…

  1. Repair with Confianza: Rethinking the Context of Corrective Feedback for English Learners (ELS)

    ERIC Educational Resources Information Center

    Razfar, Aria

    2010-01-01

    In this paper, I focus on a prevalent and controversial practice in English instruction, namely corrective feedback or repair. While the pros and cons of this practice have been rigorously debated by language scholars for many years, the issue is mostly approached from a cognitive point of view with the focus being on the individual learner and…

  2. Detecting and Correcting Errors in Rapid Aiming Movements: Effects of Movement Time, Distance, and Velocity

    ERIC Educational Resources Information Center

    Sherwood, David E.

    2010-01-01

    According to closed-loop accounts of motor control, movement errors are detected by comparing sensory feedback to an acquired reference state. Differences between the reference state and the movement-produced feedback results in an error signal that serves as a basis for a correction. The main question addressed in the current study was how…

  3. The Comparative Effects of Comprehensible Input, Output and Corrective Feedback on the Receptive Acquisition of L2 Vocabulary Items

    ERIC Educational Resources Information Center

    Nowbakht, Mohammad; Shahnazari, Mohammadtaghi

    2015-01-01

    In the present study, the comparative effects of comprehensible input, output and corrective feedback on the receptive acquisition of L2 vocabulary items were investigated. Two groups of beginning EFL learners participated in the study. The control group received comprehensible input only, while the experimental group received input and was…

  4. The Effect of Two Types of Corrective Feedback on EFL Learners' Writing Skill

    ERIC Educational Resources Information Center

    Farshi, Sina Soltanabadi; Safa, Saeedeh Khalili

    2015-01-01

    The purpose of this study was to compare the effects of two types of corrective feedback on EFL learners' writing skill. Thirty five advanced learners in three groups participated in this study. Structures of written texts were taught in all three classes during fourteen sessions of treatment; and each session, a related topic was given and the…

  5. Feedback Codes and Action Plans: Building the Capacity of First-Year Students to Apply Feedback to a Scientific Report

    ERIC Educational Resources Information Center

    Bird, Fiona L.; Yucel, Robyn

    2015-01-01

    Effective feedback can build self-assessment skills in students so that they become more competent and confident to identify and self-correct weaknesses in their work. In this study, we trialled a feedback code as part of an integrated programme of formative and summative assessment tasks, which provided feedback to first-year students on their…

  6. The Effect of Concomitant Fields in Fast Spin Echo Acquisition on Asymmetric MRI Gradient Systems

    PubMed Central

    Tao, Shengzhen; Weavers, Paul T.; Trzasko, Joshua D.; Huston, John; Shu, Yunhong; Gray, Erin M.; Foo, Thomas K.F.; Bernstein, Matt A.

    2017-01-01

    Purpose To investigate the effect of the asymmetric gradient concomitant fields (CF) with zeroth and first-order spatial dependence on fast/turbo spin-echo acquisitions, and to demonstrate the effectiveness of their real-time compensation. Methods After briefly reviewing the CF produced by asymmetric gradients, the effects of the additional zeroth and first-order CFs on these systems are investigated using extended-phase graph simulations. Phantom and in vivo experiments are performed to corroborate the simulation. Experiments are performed before and after the real-time compensations using frequency tracking and gradient pre-emphasis to demonstrate their effectiveness in correcting the additional CFs. The interaction between the CFs and prescan-based correction to compensate for eddy currents is also investigated. Results It is demonstrated that, unlike the second-order CFs on conventional gradients, the additional zeroth/first-order CFs on asymmetric gradients cause substantial signal loss and dark banding in fast spin-echo acquisitions within a typical brain-scan field of view. They can confound the prescan correction for eddy currents and degrade image quality. Performing real-time compensation successfully eliminates the artifacts. Conclusions We demonstrate that the zeroth/first-order CFs specific to asymmetric gradients can cause substantial artifacts, including signal loss and dark bands for brain imaging. These effects can be corrected using real-time compensation. PMID:28643408

  7. Terrestrial Gamma Radiation Dose Rate of West Sarawak

    NASA Astrophysics Data System (ADS)

    Izham, A.; Ramli, A. T.; Saridan Wan Hassan, W. M.; Idris, H. N.; Basri, N. A.

    2017-10-01

    A study of terrestrial gamma radiation (TGR) dose rate was conducted in west of Sarawak, covering Kuching, Samarahan, Serian, Sri Aman, and Betong divisions to construct a baseline TGR dose rate level data of the areas. The total area covered was 20,259.2 km2, where in-situ measurements of TGR dose rate were taken using NaI(Tl) scintillation detector Ludlum 19 micro R meter NaI(Tl) approximately 1 meter above ground level. Twenty-nine soil samples were taken across the 5 divisions covering 26 pairings of 9 geological formations and 7 soil types. A hyperpure Germanium detector was then used to find the samples' 238U, 232Th, and 40K radionuclides concentrations producing a correction factor Cf = 0.544. A total of239 measured data were corrected with Cf resulting in a mean Dm of 47 ± 1 nGy h-1, with a range between 5 nGy h-1 - 103 nGy h-1. A multiple regression analysis was conducted between geological means and soil types means against the corrected TGR dose rate Dm, generating Dg,s= 0.847Dg+ 0.637Ds- 22.313 prediction model with a normalized Beta equation of Dg,s= 0.605Dg+ 0.395Ds. The model has an 84.6% acceptance of Whitney- Mann test null hypothesis when tested against the corrected TGR dose rates.

  8. Detection of nuclear resonance signals: modification of the receiver operating characteristics using feedback.

    PubMed

    Blauch, A J; Schiano, J L; Ginsberg, M D

    2000-06-01

    The performance of a nuclear resonance detection system can be quantified using binary detection theory. Within this framework, signal averaging increases the probability of a correct detection and decreases the probability of a false alarm by reducing the variance of the noise in the average signal. In conjunction with signal averaging, we propose another method based on feedback control concepts that further improves detection performance. By maximizing the nuclear resonance signal amplitude, feedback raises the probability of correct detection. Furthermore, information generated by the feedback algorithm can be used to reduce the probability of false alarm. We discuss the advantages afforded by feedback that cannot be obtained using signal averaging. As an example, we show how this method is applicable to the detection of explosives using nuclear quadrupole resonance. Copyright 2000 Academic Press.

  9. Adaptive control for accelerators

    DOEpatents

    Eaton, Lawrie E.; Jachim, Stephen P.; Natter, Eckard F.

    1991-01-01

    An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

  10. Independent voluntary correction and savings in locomotor learning.

    PubMed

    Leech, Kristan A; Roemmich, Ryan T

    2018-06-14

    People can acquire new walking patterns in many different ways. For example, we can change our gait voluntarily in response to instruction or adapt by sensing our movement errors. Here we investigated how acquisition of a new walking pattern through simultaneous voluntary correction and adaptive learning affected the resulting motor memory of the learned pattern. We studied adaptation to split-belt treadmill walking with and without visual feedback of stepping patterns. As expected, visual feedback enabled faster acquisition of the new walking pattern. However, upon later re-exposure to the same split-belt perturbation, participants exhibited similar motor memories whether they had learned with or without visual feedback. Participants who received feedback did not re-engage the mechanism used to accelerate initial acquisition of the new walking pattern to similarly accelerate subsequent relearning. These findings reveal that voluntary correction neither benefits nor interferes with the ability to save a new walking pattern over time. © 2018. Published by The Company of Biologists Ltd.

  11. Carbon footprint and land requirement for dairy herd rations: impacts of feed production practices and regional climate variations.

    PubMed

    Henriksson, M; Cederberg, C; Swensson, C

    2014-08-01

    Feed production is a significant source of greenhouse gas (GHG) emissions from dairy production and demands large arable and pasture acreage. This study analysed how regional conditions influence GHG emissions of dairy feed rations in a life cycle perspective, that is the carbon footprint (CF) and the land area required. Factors assessed included regional climate variations, grass/clover silage nutrient quality, feedstuff availability, crop yield and feed losses. Using the Nordic feed evaluation model NorFor, rations were optimised for different phases of lactation, dry and growing periods for older cows, first calvers and heifers by regional feed advisors and combined to annual herd rations. Feed production data at farm level were based on national statistics and studies. CF estimates followed standards for life cycle assessment and used emissions factors provided by IPCC. The functional unit was 'feed consumption to produce 1 kg energy corrected milk (ECM) from a cow with annual milk yield of 9 900 kg ECM including replacement animals and feed losses'. Feed ration CF varied from 417 to 531 g CO2 e/kg ECM. Grass/clover silage contributed more than 50% of total GHG emissions. Use of higher quality silage increased ration CF by up to 5% as a result of an additional cut and increased rates of synthetic N-fertiliser. Domestically produced horse bean (Vicia faba), by-products from the sugar industry and maize silage were included in the rations with the lowest CF, but horse bean significantly increased ration land requirement. Rations required between 1.4 to 2 m2 cropland and 0.1 to 0.2 m2/kg semi-natural grassland per kg ECM and year. Higher yield levels reduced ration total CF. Inclusion of GHG emissions from land use change associated with Brazilian soya feed significantly increased ration CF. Ration CF and land use depended on ration composition, which was highly influenced by the regional availability and production of feedstuffs. The impact of individual feedstuffs on ration CF varies due to, for example, cultivation practices and climate conditions and feedstuffs should therefore be assessed in a ration and regional perspective before being used to decrease milk CF. Land use efficiency should be considered together with ration CF, as these can generate goal conflicts.

  12. Levofloxacin Pharmacokinetics in Adult Cystic Fibrosis

    PubMed Central

    Lee, Carlton K. K.; Boyle, Michael P.; Diener-West, Marie; Brass-Ernst, Lois; Noschese, Michelle; Zeitlin, Pamela L.

    2007-01-01

    Background Cystic fibrosis (CF) patients have enhanced renal clearance of aminoglycosides and several β-lactams and require higher dosages. Levofloxacin is a fluoroquinolone with extensive renal elimination and enhanced penetration into lungs and Pseudomonas aeruginosa (PA) biofilms. We studied the preliminary pharmacokinetic and pharmacodynamic (PK/PD) relationship of levofloxacin in CF. Methods Twelve patients at least 18 years old with a mild-to-moderate pulmonary exacerbation and fluoroquinolone-sensitive PA colonization received oral levofloxacin, 500 mg qd, for 14 days. Steady-state serum concentrations were collected after 3 to 7 days, and sputum samples for PA densities were collected before and after levofloxacin. PK/PD relationships for reducing PA sputum densities were evaluated. Results When compared to published data on non-CF patients, CF patients had similar area under the curve for 24 h (AUC24), total clearance, volume of distribution, maximum serum concentration (Cpmax), and elimination half-life: mean, 7.33 μg × h/mL/kg (SD, 1.70); 2.43 mL/min/kg (SD, 0.74); 1.33 L/kg (SD, 0.37); 7.06 μg/mL (SD, 2.35); and 6.44 h (SD, 1.1), respectively. Time to reach maximum serum concentration (Tmax) in CF was longer: mean, 2.20 h (SD, 0.99) vs 1.1 h (SD, 0.4) [p < 0.01]. Preliminary PK/PD analysis failed to demonstrate trends for decreasing PA sputum densities with increasing Cpmax/minimum inhibitory concentration (MIC) ratio and AUC24/MIC ratio. Conclusion CF levofloxacin pharmacokinetics corrected for body weight are similar to non-CF, except for Tmax. Standard levofloxacin dosing (especially monotherapy) is unlikely to produce maximum therapeutic effectiveness. Additional levofloxacin studies in CF are necessary to evaluate its sputum concentrations; the benefits of higher daily dosages (≥ 750 mg); and establish PK/PD targets for managing PA pulmonary infections. PMID:17356095

  13. Life cycle assessment of milk production from commercial dairy farms: the influence of management tactics.

    PubMed

    Yan, M-J; Humphreys, J; Holden, N M

    2013-07-01

    Little consideration has been given to how farm management, specifically tactics used to implement the management strategy, may influence the carbon footprint (CF) and land use for milk produced on commercial farms. In this study, the CF and land use of milk production from 18 Irish commercial dairy farms were analyzed based on foreground data from a 12-mo survey capturing management tactics and background data from the literature. Large variation was found in farm attributes and management tactics; for example, up to a 1.5-fold difference in fertilizer nitrogen input was used to support the same stocking density, and up to a 3.5-fold difference in concentrate fed for similar milk output per cow. However, the coefficient of variation for milk CF between farms only varied by 13% and for land use by 18%. The overall CF and overall land use of the milk production from the 18 dairy farms was 1.23±0.04kg of CO2 Eq and 1.22±0.05 m(2) per kilogram of energy-corrected milk. Milk output per cow, economic allocation between exports of milk and liveweight, and on-farm diesel use per ha were found to be influential factors on milk CF, whereas the fertilizer N rate, milk output per cow, and economic allocation between exports of milk and liveweight were influential on land use. Effective sward management of white clover within a few farms appeared to lower the CF but increased on-farm land use. It was concluded that a combination of multiple tactics determines CF and land use for milk production on commercial dairy farms and, although these 2 measures of environmental impact are correlated, a farm with a low CF did not always have low land use and vice versa. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. The Use of Video Feedback in Teaching Process-Approach EFL Writing

    ERIC Educational Resources Information Center

    Özkul, Sertaç; Ortaçtepe, Deniz

    2017-01-01

    This experimental study investigated the use of video feedback as an alternative to feedback with correction codes at an institution where the latter was commonly used for teaching process-approach English as a foreign language (EFL) writing. Over a 5-week period, the control and the experimental groups were provided with feedback based on…

  15. Exploring Learner Perception and Use of Task-Based Interactional Feedback in FTF and CMC Modes

    ERIC Educational Resources Information Center

    Gurzynski-Weiss, Laura; Baralt, Melissa

    2014-01-01

    Theoretical claims about the benefits of corrective feedback have been largely premised on learners' noticing of feedback (e.g., Gass & Mackey, 2006; Long, 1996; Schmidt, 1990, 1995; Swain, 1995), and findings have demonstrated that both the feedback target (Mackey, Gass, & McDonough, 2000) and the mode of provision (Lai & Zhao,…

  16. Effects of Feedback on the Vigilance Task Performance of Hyperactive and Hypoactive Children.

    ERIC Educational Resources Information Center

    Ozolins, Delmar A.; Anderson, Robert P.

    1980-01-01

    The effects of feedback on the approaches of 20 hyperactive and 20 hypoactive children (ages 6 to 10) to a vigilance task were studied. Results showed that hyperactive Ss had more errors than hypoactive Ss under the feedback for correct responses condition and fewer errors under the feedback for false alarms condition. (PHR)

  17. Vibrotactile grasping force and hand aperture feedback for myoelectric forearm prosthesis users.

    PubMed

    Witteveen, Heidi J B; Rietman, Hans S; Veltink, Peter H

    2015-06-01

    User feedback about grasping force and hand aperture is very important in object handling with myoelectric forearm prostheses but is lacking in current prostheses. Vibrotactile feedback increases the performance of healthy subjects in virtual grasping tasks, but no extensive validation on potential users has been performed. Investigate the performance of upper-limb loss subjects in grasping tasks with vibrotactile stimulation, providing hand aperture, and grasping force feedback. Cross-over trial. A total of 10 subjects with upper-limb loss performed virtual grasping tasks while perceiving vibrotactile feedback. Hand aperture feedback was provided through an array of coin motors and grasping force feedback through a single miniature stimulator or an array of coin motors. Objects with varying sizes and weights had to be grasped by a virtual hand. Percentages correctly applied hand apertures and correct grasping force levels were all higher for the vibrotactile feedback condition compared to the no-feedback condition. With visual feedback, the results were always better compared to the vibrotactile feedback condition. Task durations were comparable for all feedback conditions. Vibrotactile grasping force and hand aperture feedback improves grasping performance of subjects with upper-limb loss. However, it should be investigated whether this is of additional value in daily-life tasks. This study is a first step toward the implementation of sensory vibrotactile feedback for users of myoelectric forearm prostheses. Grasping force feedback is crucial for optimal object handling, and hand aperture feedback is essential for reduction of required visual attention. Grasping performance with feedback is evaluated for the potential users. © The International Society for Prosthetics and Orthotics 2014.

  18. Airway surface liquid homeostasis in cystic fibrosis: pathophysiology and therapeutic targets.

    PubMed

    Haq, Iram J; Gray, Michael A; Garnett, James P; Ward, Christopher; Brodlie, Malcolm

    2016-03-01

    Cystic fibrosis (CF) is a life-limiting disease characterised by recurrent respiratory infections, inflammation and lung damage. The volume and composition of the airway surface liquid (ASL) are important in maintaining ciliary function, mucociliary clearance and antimicrobial properties of the airway. In CF, these homeostatic mechanisms are impaired, leading to a dehydrated and acidic ASL. ASL volume depletion in CF is secondary to defective anion transport by the abnormal cystic fibrosis transmembrane conductance regulator protein (CFTR). Abnormal CFTR mediated bicarbonate transport creates an unfavourable, acidic environment, which impairs antimicrobial function and alters mucus properties and clearance. These disease mechanisms create a disordered airway milieu, consisting of thick mucopurulent secretions and chronic bacterial infection. In addition to CFTR, there are additional ion channels and transporters in the apical airway epithelium that play a role in maintaining ASL homeostasis. These include the epithelial sodium channel (ENaC), the solute carrier 26A (SLC26A) family of anion exchangers, and calcium-activated chloride channels. In this review we discuss how the ASL is abnormal in CF and how targeting these alternative channels and transporters could provide an attractive therapeutic strategy to correct the underlying ASL abnormalities evident in CF. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  19. Does Grading Undermine Feedback? the Influence of Grades on the Effectiveness of Corrective Feedback on L2 Writing

    ERIC Educational Resources Information Center

    Dlaska, Andrea; Krekeler, Christian

    2017-01-01

    It has been questioned whether students notice, act upon and, ultimately, learn from feedback if feedback about a task is received in conjunction with grades. If grades undermine feedback, it could be argued that it is a waste of teachers' time to add comments to students' written work if the students also receive grades. With reference to SLA…

  20. The Effect of Written Corrective Feedback on Grammatical Accuracy of EFL Students: An Improvement over Previous Unfocused Designs

    ERIC Educational Resources Information Center

    Khanlarzadeh, Mobin; Nemati, Majid

    2016-01-01

    The effectiveness of written corrective feedback (WCF) in the improvement of language learners' grammatical accuracy has been a topic of interest in SLA studies for the past couple of decades. The present study reports the findings of a three-month study investigating the effect of direct unfocused WCF on the grammatical accuracy of elementary…

  1. A Study of the Design and Implementation of the ASR-Based iCASL System with Corrective Feedback to Facilitate English Learning

    ERIC Educational Resources Information Center

    Wang, Yi-Hsuan; Young, Shelley Shwu-Ching

    2014-01-01

    The purpose of the study is to explore and describe how to implement a pedagogical ASR-based intelligent computer-assisted speaking learning (iCASL) system to support adult learners with a private, flexible and individual learning environment to practice English pronunciation. The iCASL system integrates multiple levels of corrective feedback and…

  2. Evaluating the Effects of Formal Corrective Feedback on Off-Task/On-Task Behavior of Mild Intellectually Disabled Students: An Action Research Study

    ERIC Educational Resources Information Center

    George, Kevin

    2016-01-01

    The off-task behavior demonstrated by the study participants appears to interfere with classroom instruction, contribute to poor academic performance and in many instances lead to disciplinary actions such as suspension. The purpose of the study entailed determining if formal corrective feedback has an effect on the off-task/on-task behavior of…

  3. Robot-Arm Dynamic Control by Computer

    NASA Technical Reports Server (NTRS)

    Bejczy, Antal K.; Tarn, Tzyh J.; Chen, Yilong J.

    1987-01-01

    Feedforward and feedback schemes linearize responses to control inputs. Method for control of robot arm based on computed nonlinear feedback and state tranformations to linearize system and decouple robot end-effector motions along each of cartesian axes augmented with optimal scheme for correction of errors in workspace. Major new feature of control method is: optimal error-correction loop directly operates on task level and not on joint-servocontrol level.

  4. Rotational relaxation of CF+(X1Σ) in collision with He(1S)

    NASA Astrophysics Data System (ADS)

    Denis-Alpizar, O.; Inostroza, N.; Castro Palacio, J. C.

    2018-01-01

    The carbon monofluoride cation (CF+) has been detected recently in Galactic and extragalactic regions. Therefore, excitation rate coefficients of this molecule in collision with He and H2 are necessary for a correct interpretation of the astronomical observations. The main goal of this work is to study the collision of CF+ with He in full dimensionality at the close-coupling level and to report a large set of rotational rate coefficients. New ab initio interaction energies at the CCSD(T)/aug-cc-pv5z level of theory were computed, and a three-dimensional potential energy surface was represented using a reproducing kernel Hilbert space. Close-coupling scattering calculations were performed at collisional energies up to 1600 cm-1 in the ground vibrational state. The vibrational quenching cross-sections were found to be at least three orders of magnitude lower than the pure rotational cross-sections. Also, the collisional rate coefficients were reported for the lowest 20 rotational states of CF+ and an even propensity rule was found to be in action only for j > 4. Finally, the hyperfine rate coefficients were explored. These data can be useful for the determination of the interstellar conditions where this molecule has been detected.

  5. Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves

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

    Hicken, Malcolm; /Harvard-Smithsonian Ctr. Astrophys. /Harvard U.; Wood-Vasey, W.Michael

    2012-04-06

    We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski et al. to form the Constitution set and, combined with a BAO prior, produces 1 + w = 0.013{sub -0.068}{sup +0.066} (0.11 syst), consistent with the cosmological constant. The CfA3 addition makes the cosmologically useful sample of nearby SN Ia between 2.6 and 2.9 times larger than before, reducing the statistical uncertainty to the point where systematics play the largest role.more » We use four light-curve fitters to test for systematic differences: SALT, SALT2, MLCS2k2 (R{sub V} = 3.1), and MLCS2k2 (R{sub V} = 1.7). SALT produces high-redshift Hubble residuals with systematic trends versus color and larger scatter than MLCS2k2. MLCS2k2 overestimates the intrinsic luminosity of SN Ia with 0.7 < {Delta} < 1.2. MLCS2k2 with R{sub V} = 3.1 overestimates host-galaxy extinction while R{sub V} {approx} 1.7 does not. Our investigation is consistent with no Hubble bubble. We also find that, after light-curve correction, SN Ia in Scd/Sd/Irr hosts are intrinsically fainter than those in E/S0 hosts by 2{sigma}, suggesting that they may come from different populations. We also find that SN Ia in Scd/Sd/Irr hosts have low scatter (0.1 mag) and reddening. Current systematic errors can be reduced by improving SN Ia photometric accuracy, by including the CfA3 sample to retrain light-curve fitters, by combining optical SN Ia photometry with near-infrared photometry to understand host-galaxy extinction, and by determining if different environments give rise to different intrinsic SN Ia luminosity after correction for light-curve shape and color.« less

  6. IMPROVED DARK ENERGY CONSTRAINTS FROM {approx}100 NEW CfA SUPERNOVA TYPE Ia LIGHT CURVES

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

    Hicken, Malcolm; Challis, Peter; Kirshner, Robert P.

    2009-08-01

    We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski et al. to form the Constitution set and, combined with a BAO prior, produces 1 + w = 0.013{sup +0.066} {sub -0.068} (0.11 syst), consistent with the cosmological constant. The CfA3 addition makes the cosmologically useful sample of nearby SN Ia between 2.6 and 2.9 times larger than before, reducing the statistical uncertainty to the point where systematics play the largestmore » role. We use four light-curve fitters to test for systematic differences: SALT, SALT2, MLCS2k2 (R{sub V} = 3.1), and MLCS2k2 (R{sub V} = 1.7). SALT produces high-redshift Hubble residuals with systematic trends versus color and larger scatter than MLCS2k2. MLCS2k2 overestimates the intrinsic luminosity of SN Ia with 0.7 < {delta} < 1.2. MLCS2k2 with R{sub V} = 3.1 overestimates host-galaxy extinction while R{sub V} {approx} 1.7 does not. Our investigation is consistent with no Hubble bubble. We also find that, after light-curve correction, SN Ia in Scd/Sd/Irr hosts are intrinsically fainter than those in E/S0 hosts by 2{sigma}, suggesting that they may come from different populations. We also find that SN Ia in Scd/Sd/Irr hosts have low scatter (0.1 mag) and reddening. Current systematic errors can be reduced by improving SN Ia photometric accuracy, by including the CfA3 sample to retrain light-curve fitters, by combining optical SN Ia photometry with near-infrared photometry to understand host-galaxy extinction, and by determining if different environments give rise to different intrinsic SN Ia luminosity after correction for light-curve shape and color.« less

  7. Secondary adaptation of memory-guided saccades

    PubMed Central

    Srimal, Riju; Curtis, Clayton E.

    2011-01-01

    Adaptation of saccade gains in response to errors keeps vision and action co-registered in the absence of awareness or effort. Timing is key, as the visual error must be available shortly after the saccade is generated or adaptation does not occur. Here, we tested the hypothesis that when feedback is delayed, learning still occurs, but does so through small secondary corrective saccades. Using a memory-guided saccade task, we gave feedback about the accuracy of saccades that was falsely displaced by a consistent amount, but only after long delays. Despite the delayed feedback, over time subjects improved in accuracy toward the false feedback. They did so not by adjusting their primary saccades, but via directed corrective saccades made before feedback was given. We propose that saccade learning may be driven by different types of feedback teaching signals. One teaching signal relies upon a tight temporal relation with the saccade and contributes to obligatory learning independent of awareness. When this signal is ineffective due to delayed error feedback, a second compensatory teaching signal enables flexible adjustments to the spatial goal of saccades and helps maintain sensorimotor accuracy. PMID:20803135

  8. Examining recognition criterion rigidity during testing using a biased feedback technique: Evidence for adaptive criterion learning

    PubMed Central

    Han, Sanghoon; Dobbins, Ian G.

    2009-01-01

    Recognition models often assume that subjects use specific evidence values (decision criteria) to adaptively parse continuous memory evidence into response categories (e.g., “old” or “new”). Although explicit pre-test instructions influence criterion placement, these criteria appear extremely resistant to change once testing begins. We tested criterion sensitivity to local feedback using a novel, biased feedback technique designed to tacitly encourage certain errors by indicating they were correct choices. Experiment 1 demonstrated that fully correct feedback had little effect on criterion placement, whereas biased feedback during Experiments 2 and 3 yielded prominent, durable, and adaptive criterion shifts, with observers reporting they were unaware of the manipulation in Experiment 3. These data suggest recognition criteria can be easily modified during testing through a form of feedback learning that operates independent of stimulus characteristics and observer awareness of the nature of the manipulation. This mechanism may be fundamentally different than criterion shifts following explicit instructions and warnings, or shifts linked to manipulations of stimulus characteristics combined with feedback highlighting those manipulations. PMID:18604954

  9. [On efficiency of biomanagement with negative feedback from patient's EEG in correction of functional disorders, caused by stress].

    PubMed

    Fedotchev, A I

    2010-01-01

    The perspective approach to non-pharmacological correction of the stress induced functional disorders in humans, based on the double negative feedback from patient's EEG was validated and experimentally tested. The approach implies a simultaneous use of narrow frequency EEG-oscillators, characteristic for each patient and recorded in real time span, in two independent contours of negative feedback--traditional contour of adaptive biomanagement and additional contour of resonance stimulation. In the last the signals of negative feedback from individual narrow frequency EEG oscillators are not recognized by the subject, but serve for an automatic modulation of the parameters of the sensory impact. Was shown that due to combination of active (conscious perception) and passive (automatic modulation) use of signals of negative feedback from narrow frequency EEG components of the patient, opens a possibility of considerable increase of efficiency of the procedures of EEG biomanagement.

  10. Examining action effects in the execution of a skilled soccer kick by using erroneous feedback.

    PubMed

    Ford, Paul; Hodges, Nicola J; Williams, A Mark

    2007-11-01

    The authors examined the role of action effects (i.e., ball trajectory) during the performance of a soccer kick. Participants were 20 expert players who kicked a ball over a height barrier toward a ground-level target. The authors occluded participants' vision of the ball trajectory after foot-to-ball contact. Participants in a 1st group received erroneous feedback from a video that showed a ball-trajectory apex approximately 75 cm lower than that of their actual kick, although the ball's landing position was unaltered. Participants in a 2nd group received correct video feedback of both the ball trajectory and the landing position. The erroneous-feedback group showed a significant bias toward higher ball trajectories than did the correct-feedback group. The authors conclude that performers at high levels of skill use the visual consequences of the action to plan and execute an action.

  11. Mitigation of Cognitive Bias with a Serious Game: Two Experiments Testing Feedback Timing and Source

    ERIC Educational Resources Information Center

    Dunbar, Norah E.; Jensen, Matthew L.; Miller, Claude H.; Bessarabova, Elena; Lee, Yu-Hao; Wilson, Scott N.; Elizondo, Javier; Adame, Bradley J.; Valacich, Joseph; Straub, Sara; Burgoon, Judee K.; Lane, Brianna; Piercy, Cameron W.; Wilson, David; King, Shawn; Vincent, Cindy; Schuetzler, Ryan M.

    2017-01-01

    One of the benefits of using digital games for education is that games can provide feedback for learners to assess their situation and correct their mistakes. We conducted two studies to examine the effectiveness of different feedback design (timing, duration, repeats, and feedback source) in a serious game designed to teach learners about…

  12. Correction algorithm for online continuous flow δ13C and δ18O carbonate and cellulose stable isotope analyses

    NASA Astrophysics Data System (ADS)

    Evans, M. N.; Selmer, K. J.; Breeden, B. T.; Lopatka, A. S.; Plummer, R. E.

    2016-09-01

    We describe an algorithm to correct for scale compression, runtime drift, and amplitude effects in carbonate and cellulose oxygen and carbon isotopic analyses made on two online continuous flow isotope ratio mass spectrometry (CF-IRMS) systems using gas chromatographic (GC) separation. We validate the algorithm by correcting measurements of samples of known isotopic composition which are not used to estimate the corrections. For carbonate δ13C (δ18O) data, median precision of validation estimates for two reference materials and two calibrated working standards is 0.05‰ (0.07‰); median bias is 0.04‰ (0.02‰) over a range of 49.2‰ (24.3‰). For α-cellulose δ13C (δ18O) data, median precision of validation estimates for one reference material and five working standards is 0.11‰ (0.27‰); median bias is 0.13‰ (-0.10‰) over a range of 16.1‰ (19.1‰). These results are within the 5th-95th percentile range of subsequent routine runtime validation exercises in which one working standard is used to calibrate the other. Analysis of the relative importance of correction steps suggests that drift and scale-compression corrections are most reliable and valuable. If validation precisions are not already small, routine cross-validated precision estimates are improved by up to 50% (80%). The results suggest that correction for systematic error may enable these particular CF-IRMS systems to produce δ13C and δ18O carbonate and cellulose isotopic analyses with higher validated precision, accuracy, and throughput than is typically reported for these systems. The correction scheme may be used in support of replication-intensive research projects in paleoclimatology and other data-intensive applications within the geosciences.

  13. Role of Focus-on-Form Instruction, Corrective Feedback and Uptake in Second Language Classrooms: Some Insights from Recent Second Language Acquisition Research

    ERIC Educational Resources Information Center

    Afitska, Oksana

    2015-01-01

    A considerable number of studies on focus-on-form instruction, corrective feedback and uptake have been carried out in the field of second language acquisition (SLA) research over the last two decades. These studies have investigated the above-mentioned concepts from different perspectives, in a number of different contexts and in a number of…

  14. Earning Influence by Communicating Respect: Facework's Contributions to Effective Instructional Feedback

    ERIC Educational Resources Information Center

    Trees, April R.; Kerssen-Griep, Jeff; Hess, Jon A.

    2009-01-01

    Successfully evaluating students' work challenges teachers to achieve both corrective task and identity-protection goals in interaction. This study investigated how face-threat mitigation that students received from their teachers during feedback influenced students' judgments about the quality and usefulness of the feedback their instructors…

  15. Sequence Learning Under Uncertainty in Children: Self-Reflection vs. Self-Assertion

    PubMed Central

    Lange-Küttner, Christiane; Averbeck, Bruno B.; Hirsch, Silvia V.; Wießner, Isabel; Lamba, Nishtha

    2012-01-01

    We know that stochastic feedback impairs children’s associative stimulus–response (S–R) learning (Crone et al., 2004a; Eppinger et al., 2009), but the impact of stochastic feedback on sequence learning that involves deductive reasoning has not been not tested so far. In the current study, 8- to 11-year-old children (N = 171) learned a sequence of four left and right button presses, LLRR, RRLL, LRLR, RLRL, LRRL, and RLLR, which needed to be deduced from feedback because no directional cues were given. One group of children experienced consistent feedback only (deterministic feedback, 100% correct). In this condition, green feedback on the screen indicated that the children had been right when they were right, and red feedback indicated that the children had been wrong when they were wrong. Another group of children experienced inconsistent feedback (stochastic feedback, 85% correct, 15% false), where in some trials, green feedback on the screen could signal that children were right when in fact they were wrong, and red feedback could indicate that they were wrong when in fact they had been right. Independently of age, children’s sequence learning in the stochastic condition was initially much lower than in the deterministic condition, but increased gradually and improved with practice. Responses toward positive vs. negative feedback varied with age. Children were increasingly able to understand that they could have been wrong when feedback indicated they were right (self-reflection), but they remained unable to understand that they could have been right when feedback indicated they were wrong (self-assertion). PMID:22563324

  16. Sequence Learning Under Uncertainty in Children: Self-Reflection vs. Self-Assertion.

    PubMed

    Lange-Küttner, Christiane; Averbeck, Bruno B; Hirsch, Silvia V; Wießner, Isabel; Lamba, Nishtha

    2012-01-01

    We know that stochastic feedback impairs children's associative stimulus-response (S-R) learning (Crone et al., 2004a; Eppinger et al., 2009), but the impact of stochastic feedback on sequence learning that involves deductive reasoning has not been not tested so far. In the current study, 8- to 11-year-old children (N = 171) learned a sequence of four left and right button presses, LLRR, RRLL, LRLR, RLRL, LRRL, and RLLR, which needed to be deduced from feedback because no directional cues were given. One group of children experienced consistent feedback only (deterministic feedback, 100% correct). In this condition, green feedback on the screen indicated that the children had been right when they were right, and red feedback indicated that the children had been wrong when they were wrong. Another group of children experienced inconsistent feedback (stochastic feedback, 85% correct, 15% false), where in some trials, green feedback on the screen could signal that children were right when in fact they were wrong, and red feedback could indicate that they were wrong when in fact they had been right. Independently of age, children's sequence learning in the stochastic condition was initially much lower than in the deterministic condition, but increased gradually and improved with practice. Responses toward positive vs. negative feedback varied with age. Children were increasingly able to understand that they could have been wrong when feedback indicated they were right (self-reflection), but they remained unable to understand that they could have been right when feedback indicated they were wrong (self-assertion).

  17. Seeing the hand while reaching speeds up on-line responses to a sudden change in target position

    PubMed Central

    Reichenbach, Alexandra; Thielscher, Axel; Peer, Angelika; Bülthoff, Heinrich H; Bresciani, Jean-Pierre

    2009-01-01

    Goal-directed movements are executed under the permanent supervision of the central nervous system, which continuously processes sensory afferents and triggers on-line corrections if movement accuracy seems to be compromised. For arm reaching movements, visual information about the hand plays an important role in this supervision, notably improving reaching accuracy. Here, we tested whether visual feedback of the hand affects the latency of on-line responses to an external perturbation when reaching for a visual target. Two types of perturbation were used: visual perturbation consisted in changing the spatial location of the target and kinesthetic perturbation in applying a force step to the reaching arm. For both types of perturbation, the hand trajectory and the electromyographic (EMG) activity of shoulder muscles were analysed to assess whether visual feedback of the hand speeds up on-line corrections. Without visual feedback of the hand, on-line responses to visual perturbation exhibited the longest latency. This latency was reduced by about 10% when visual feedback of the hand was provided. On the other hand, the latency of on-line responses to kinesthetic perturbation was independent of the availability of visual feedback of the hand. In a control experiment, we tested the effect of visual feedback of the hand on visual and kinesthetic two-choice reaction times – for which coordinate transformation is not critical. Two-choice reaction times were never facilitated by visual feedback of the hand. Taken together, our results suggest that visual feedback of the hand speeds up on-line corrections when the position of the visual target with respect to the body must be re-computed during movement execution. This facilitation probably results from the possibility to map hand- and target-related information in a common visual reference frame. PMID:19675067

  18. Multidimensional student skills with collaborative filtering

    NASA Astrophysics Data System (ADS)

    Bergner, Yoav; Rayyan, Saif; Seaton, Daniel; Pritchard, David E.

    2013-01-01

    Despite the fact that a physics course typically culminates in one final grade for the student, many instructors and researchers believe that there are multiple skills that students acquire to achieve mastery. Assessment validation and data analysis in general may thus benefit from extension to multidimensional ability. This paper introduces an approach for model determination and dimensionality analysis using collaborative filtering (CF), which is related to factor analysis and item response theory (IRT). Model selection is guided by machine learning perspectives, seeking to maximize the accuracy in predicting which students will answer which items correctly. We apply the CF to response data for the Mechanics Baseline Test and combine the results with prior analysis using unidimensional IRT.

  19. Practical scheme for error control using feedback

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

    Sarovar, Mohan; Milburn, Gerard J.; Ahn, Charlene

    2004-05-01

    We describe a scheme for quantum-error correction that employs feedback and weak measurement rather than the standard tools of projective measurement and fast controlled unitary gates. The advantage of this scheme over previous protocols [for example, Ahn et al. Phys. Rev. A 65, 042301 (2001)], is that it requires little side processing while remaining robust to measurement inefficiency, and is therefore considerably more practical. We evaluate the performance of our scheme by simulating the correction of bit flips. We also consider implementation in a solid-state quantum-computation architecture and estimate the maximal error rate that could be corrected with current technology.

  20. Active vibration control with model correction on a flexible laboratory grid structure

    NASA Technical Reports Server (NTRS)

    Schamel, George C., II; Haftka, Raphael T.

    1991-01-01

    This paper presents experimental and computational comparisons of three active damping control laws applied to a complex laboratory structure. Two reduced structural models were used with one model being corrected on the basis of measured mode shapes and frequencies. Three control laws were investigated, a time-invariant linear quadratic regulator with state estimation and two direct rate feedback control laws. Experimental results for all designs were obtained with digital implementation. It was found that model correction improved the agreement between analytical and experimental results. The best agreement was obtained with the simplest direct rate feedback control.

  1. Measurement of the 23Na(n,2n) cross section in 235U and 252Cf fission neutron spectra

    NASA Astrophysics Data System (ADS)

    Košťál, Michal; Schulc, Martin; Rypar, Vojtěch; Losa, Evžen; Švadlenková, Marie; Baroň, Petr; Jánský, Bohumil; Novák, Evžen; Mareček, Martin; Uhlíř, Jan

    2017-09-01

    The presented paper aims to compare the calculated and experimental reaction rates of 23Na(n,2n)22Na in a well-defined reactor spectra and in the spontaneous fission spectrum of 252Cf. The experimentally determined reaction rate, derived using gamma spectroscopy of irradiated NaF sample, is used for average cross section determination.Estimation of this cross-section is important as it is included in International Reactor Dosimetry and Fusion File and is also relevant to the correct estimation of long-term activity of Na coolant in Sodium Fast Reactors. The calculations were performed with the MCNP6 code using ENDF/B-VII.0, JEFF-3.1, JEFF-3.2, JENDL-3.3, JENDL-4, ROSFOND-2010, CENDL-3.1 and IRDFF nuclear data libraries. In the case of reactor spectrum, reasonable agreement was not achieved with any library. However, in the case of 252Cf spectrum agreement was achieved with IRDFF, JEFF-3.1 and JENDL libraries.

  2. The Role of Written Corrective Feedback in Enhancing the Linguistic Accuracy of Iranian Japanese Learners' Writing

    ERIC Educational Resources Information Center

    Shirazi, Masoumeh Ahmadi; Shekarabi, Zeinab

    2014-01-01

    This study is an attempt to investigate the effect of direct and indirect feedback on the writing performance of Iranian learners of Japanese as a foreign language. During one academic semester, three indirect feedback types including underlining, coding and translation were used as well as direct type of feedback in order to see which one makes a…

  3. Rescuing mutant CFTR: a multi-task approach to a better outcome in treating cystic fibrosis.

    PubMed

    Amaral, Margarida D; Farinha, Carlos M

    2013-01-01

    Correcting multiple defects of mutant CFTR with small molecule compounds has been the goal of an increasing number of recent Cystic Fibrosis (CF) drug discovery programmes. However, the mechanism of action (MoA) by which these molecules restore mutant CFTR is still poorly understood, in particular of CFTR correctors, i.e., compounds rescuing to the cells surface the most prevalent mutant in CF patients--F508del-CFTR. However, there is increasing evidence that to fully restore the multiple defects associated with F508del-CFTR, different small molecules with distinct corrective properties may be required. Towards this goal, a better insight into MoA of correctors is needed and several constraints should be addressed. The methodological approaches to achieve this include: 1) testing the combined effect of compounds with that of other (non-pharmacological) rescuing strategies (e.g., revertants or low temperature); 2) assessing effects in multiple cellular models (non-epithelial vs epithelial, non-human vs human, immortalized vs primary cultures, polarized vs non polarized, cells vs tissues); 3) assessing compound effects on isolated CFTR domains (e.g., compound binding by surface plasmon resonance, assessing effects on domain folding and aggregation); and finally 4) assessing compounds specificity in rescuing different CFTR mutants and other mutant proteins. These topics are reviewed and discussed here so as to provide a state-of-the art review on how to combine multiple ways of rescuing mutant CFTR to the ultimate benefit of CF patients.

  4. Visuomotor Map Determines How Visually Guided Reaching Movements are Corrected Within and Across Trials123

    PubMed Central

    Hirashima, Masaya

    2016-01-01

    Abstract When a visually guided reaching movement is unexpectedly perturbed, it is implicitly corrected in two ways: immediately after the perturbation by feedback control (online correction) and in the next movement by adjusting feedforward motor commands (offline correction or motor adaptation). Although recent studies have revealed a close relationship between feedback and feedforward controls, the nature of this relationship is not yet fully understood. Here, we show that both implicit online and offline movement corrections utilize the same visuomotor map for feedforward movement control that transforms the spatial location of visual objects into appropriate motor commands. First, we artificially distorted the visuomotor map by applying opposite visual rotations to the cursor representing the hand position while human participants reached for two different targets. This procedure implicitly altered the visuomotor map so that changes in the movement direction to the target location were more insensitive or more sensitive. Then, we examined how such visuomotor map distortion influenced online movement correction by suddenly changing the target location. The magnitude of online movement correction was altered according to the shape of the visuomotor map. We also examined offline movement correction; the aftereffect induced by visual rotation in the previous trial was modulated according to the shape of the visuomotor map. These results highlighted the importance of the visuomotor map as a foundation for implicit motor control mechanisms and the intimate relationship between feedforward control, feedback control, and motor adaptation. PMID:27275006

  5. Visuomotor Map Determines How Visually Guided Reaching Movements are Corrected Within and Across Trials.

    PubMed

    Hayashi, Takuji; Yokoi, Atsushi; Hirashima, Masaya; Nozaki, Daichi

    2016-01-01

    When a visually guided reaching movement is unexpectedly perturbed, it is implicitly corrected in two ways: immediately after the perturbation by feedback control (online correction) and in the next movement by adjusting feedforward motor commands (offline correction or motor adaptation). Although recent studies have revealed a close relationship between feedback and feedforward controls, the nature of this relationship is not yet fully understood. Here, we show that both implicit online and offline movement corrections utilize the same visuomotor map for feedforward movement control that transforms the spatial location of visual objects into appropriate motor commands. First, we artificially distorted the visuomotor map by applying opposite visual rotations to the cursor representing the hand position while human participants reached for two different targets. This procedure implicitly altered the visuomotor map so that changes in the movement direction to the target location were more insensitive or more sensitive. Then, we examined how such visuomotor map distortion influenced online movement correction by suddenly changing the target location. The magnitude of online movement correction was altered according to the shape of the visuomotor map. We also examined offline movement correction; the aftereffect induced by visual rotation in the previous trial was modulated according to the shape of the visuomotor map. These results highlighted the importance of the visuomotor map as a foundation for implicit motor control mechanisms and the intimate relationship between feedforward control, feedback control, and motor adaptation.

  6. Correction of a Cystic Fibrosis Splicing Mutation by Antisense Oligonucleotides.

    PubMed

    Igreja, Susana; Clarke, Luka A; Botelho, Hugo M; Marques, Luís; Amaral, Margarida D

    2016-02-01

    Cystic fibrosis (CF), the most common life-threatening genetic disease in Caucasians, is caused by ∼2,000 different mutations in the CF transmembrane conductance regulator (CFTR) gene. A significant fraction of these (∼13%) affect pre-mRNA splicing for which novel therapies have been somewhat neglected. We have previously described the effect of the CFTR splicing mutation c.2657+5G>A in IVS16, showing that it originates transcripts lacking exon 16 as well as wild-type transcripts. Here, we tested an RNA-based antisense oligonucleotide (AON) strategy to correct the aberrant splicing caused by this mutation. Two AONs (AON1/2) complementary to the pre-mRNA IVS16 mutant region were designed and their effect on splicing was assessed at the RNA and protein levels, on intracellular protein localization and function. To this end, we used the 2657+5G>A mutant CFTR minigene stably expressed in HEK293 Flp-In cells that express a single copy of the transgene. RNA data from AON1-treated mutant cells show that exon 16 inclusion was almost completely restored (to 95%), also resulting in increased levels of correctly localized CFTR protein at the plasma membrane (PM) and with increased function. A novel two-color CFTR splicing reporter minigene developed here allowed the quantitative monitoring of splicing by automated microscopy localization of CFTR at the PM. The AON strategy is thus a promising therapeutic approach for the specific correction of alternative splicing. © 2015 WILEY PERIODICALS, INC.

  7. Reducing failures of working memory with performance feedback.

    PubMed

    Adam, Kirsten C S; Vogel, Edward K

    2016-10-01

    Fluctuations in attentional control can lead to failures of working memory (WM), in which the subject is no better than chance at reporting items from a recent display. In three experiments, we used a whole-report measure of visual WM to examine the impact of feedback on the rate of failures. In each experiment, subjects remembered an array of colored items across a blank delay, and then reported the identity of items using a whole-report procedure. In Experiment 1, we gave subjects simple feedback about the number of items they correctly identified at the end of each trial. In Experiment 2, we gave subjects additional information about the cumulative number of items correctly identified within each block. Finally, in Experiment 3, we gave subjects weighted feedback in which poor trials resulted in lost points and consistent successful performance received "streak" points. Surprisingly, simple feedback (Exp. 1) was ineffective at improving average performance or decreasing the rate of poor-performance trials. Simple cumulative feedback (Exp. 2) modestly decreased poor-performance trials (by 7 %). Weighted feedback produced the greatest benefits, decreasing the frequency of poor-performance trials by 28 % relative to baseline performance. This set of results demonstrates the usefulness of whole-report WM measures for investigating the effects of feedback on WM performance. Further, we showed that only a feedback structure that specifically discouraged lapses using negative feedback led to large reductions in WM failures.

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

    Sawada, Y.; Kawai, R.; McManaway, M.

    (3H)Cyclofoxy (CF: 17-cyclopropylmethyl-3,14-dihydroxy-4,5-alpha-epoxy-6-beta-fluoromorp hinan) is an opioid antagonist with affinity to both mu and kappa subtypes that was synthesized for quantitative evaluation of opioid receptor binding in vivo. Two sets of experiments in rats were analyzed. The first involved determining the metabolite-corrected blood concentration and tissue distribution of CF in brain 1 to 60 min after i.v. bolus injection. The second involved measuring brain washout for 15 to 120 s following intracarotid artery injection of CF. A physiologically based model and a classical compartmental pharmacokinetic model were compared. The models included different assumptions for transport across the blood-brain barrier (BBB);more » estimates of nonspecific tissue binding and specific binding to a single opiate receptor site were found to be essentially the same with both models. The nonspecific binding equilibrium constant varied modestly in different brain structures (Keq = 3-9), whereas the binding potential (BP) varied over a much broader range (BP = 0.6-32). In vivo estimates of the opioid receptor dissociation constant were similar for different brain structures (KD = 2.1-5.2 nM), whereas the apparent receptor density (Bmax) varied between 1 (cerebellum) and 78 (thalamus) pmol/g of brain. The receptor dissociation rate constants in cerebrum (k4 = 0.08-0.16 min-1; koff = 0.16-0.23 min-1) and brain vascular permeability (PS = 1.3-3.4 ml/min/g) are sufficiently high to achieve equilibrium conditions within a reasonable period of time. Graphical analysis of the data is inappropriate due to the high tissue-loss rate constant for CF in brain. From these findings, CF should be a very useful opioid receptor ligand for the estimation of the receptor binding parameters in human subjects using (18F)CF and positron emission tomography.« less

  9. A novel method for blood volume estimation using trivalent chromium in rabbit models.

    PubMed

    Baby, Prathap Moothamadathil; Kumar, Pramod; Kumar, Rajesh; Jacob, Sanu S; Rawat, Dinesh; Binu, V S; Karun, Kalesh M

    2014-05-01

    Blood volume measurement though important in management of critically ill-patients is not routinely estimated in clinical practice owing to labour intensive, intricate and time consuming nature of existing methods. The aim was to compare blood volume estimations using trivalent chromium [(51)Cr(III)] and standard Evans blue dye (EBD) method in New Zealand white rabbit models and establish correction-factor (CF). Blood volume estimation in 33 rabbits was carried out using EBD method and concentration determined using spectrophotometric assay followed by blood volume estimation using direct injection of (51)Cr(III). Twenty out of 33 rabbits were used to find CF by dividing blood volume estimation using EBD with blood volume estimation using (51)Cr(III). CF is validated in 13 rabbits by multiplying it with blood volume estimation values obtained using (51)Cr(III). The mean circulating blood volume of 33 rabbits using EBD was 142.02 ± 22.77 ml or 65.76 ± 9.31 ml/kg and using (51)Cr(III) was estimated to be 195.66 ± 47.30 ml or 89.81 ± 17.88 ml/kg. The CF was found to be 0.77. The mean blood volume of 13 rabbits measured using EBD was 139.54 ± 27.19 ml or 66.33 ± 8.26 ml/kg and using (51)Cr(III) with CF was 152.73 ± 46.25 ml or 71.87 ± 13.81 ml/kg (P = 0.11). The estimation of blood volume using (51)Cr(III) was comparable to standard EBD method using CF. With further research in this direction, we envisage human blood volume estimation using (51)Cr(III) to find its application in acute clinical settings.

  10. Development of the Nasopharyngeal Microbiota in Infants with Cystic Fibrosis.

    PubMed

    Prevaes, Sabine M P J; de Winter-de Groot, Karin M; Janssens, Hettie M; de Steenhuijsen Piters, Wouter A A; Tramper-Stranders, Gerdien A; Wyllie, Anne L; Hasrat, Raiza; Tiddens, Harm A; van Westreenen, Mireille; van der Ent, Cornelis K; Sanders, Elisabeth A M; Bogaert, Debby

    2016-03-01

    Cystic fibrosis (CF) is characterized by early structural lung disease caused by pulmonary infections. The nasopharynx of infants is a major ecological reservoir of potential respiratory pathogens. To investigate the development of nasopharyngeal microbiota profiles in infants with CF compared with those of healthy control subjects during the first 6 months of life. We conducted a prospective cohort study, from the time of diagnosis onward, in which we collected questionnaires and 324 nasopharynx samples from 20 infants with CF and 45 age-matched healthy control subjects. Microbiota profiles were characterized by 16S ribosomal RNA-based sequencing. We observed significant differences in microbial community composition (P < 0.0002 by permutational multivariate analysis of variance) and development between groups. In infants with CF, early Staphylococcus aureus and, to a lesser extent, Corynebacterium spp. and Moraxella spp. dominance were followed by a switch to Streptococcus mitis predominance after 3 months of age. In control subjects, Moraxella spp. enrichment occurred throughout the first 6 months of life. In a multivariate analysis, S. aureus, S. mitis, Corynebacterium accolens, and bacilli were significantly more abundant in infants with CF, whereas Moraxella spp., Corynebacterium pseudodiphtericum and Corynebacterium propinquum and Haemophilus influenzae were significantly more abundant in control subjects, after correction for age, antibiotic use, and respiratory symptoms. Antibiotic use was independently associated with increased colonization of gram-negative bacteria such as Burkholderia spp. and members of the Enterobacteriaceae bacteria family and reduced colonization of potential beneficial commensals. From diagnosis onward, we observed distinct patterns of nasopharyngeal microbiota development in infants with CF under 6 months of age compared with control subjects and a marked effect of antibiotic therapy leading toward a gram-negative microbial composition.

  11. Epidemic Achromobacter xylosoxidans strain among Belgian cystic fibrosis patients and review of literature.

    PubMed

    Cools, Piet; Ho, Erwin; Vranckx, Katleen; Schelstraete, Petra; Wurth, Bettina; Franckx, Hilde; Ieven, Greet; Van Simaey, Leen; Van Daele, Sabine; Verhulst, Stijn; De Baets, Frans; Vaneechoutte, Mario

    2016-06-24

    Achromobacter xylosoxidans is increasingly being recognized as an emerging pathogen in cystic fibrosis. Recent severe infections with A. xylosoxidans in some of our cystic fibrosis (CF) patients led to a re-evaluation of the epidemiology of CF-associated A. xylosoxidans infections in two Belgian reference centres (Antwerp and Ghent). Several of these patients also stayed at the Rehabilitation Centre De Haan (RHC). In total, 59 A. xylosoxidans isolates from 31 patients (including 26 CF patients), collected between 2001 and 2014, were studied. We evaluated Matrix Assisted Laser Desorption Ionisation -Time of Flight mass spectrometry (MALDI-TOF) as an alternative for McRAPD typing. Both typing approaches established the presence of a major cluster, comprising isolates, all from 21 CF patients, including from two patients sampled when staying at the RHC a decade ago. This major cluster was the same as the cluster established already a decade ago at the RHC. A minor cluster consisted of 13 isolates from miscellaneous origin. A further seven isolates, including one from a non-CF patient who had stayed recently at the RHC, were singletons. Typing results of both methods were similar, indicating transmission of a single clone of A. xylosoxidans among several CF patients from at least two reference centres. Isolates of the same clone were already observed at the RHC, a decade ago. It is difficult to establish to what extent the RHC is the source of transmission, because the epidemic strain was already present when the first epidemiological study in the RHC was carried out. This study also documents the applicability of MALDI-TOF for typing of strains within the species A. xylosoxidans and the need to use the dynamic cutoff algorithm of the BioNumerics® software for correct clustering of the fingerprints.

  12. Parent knowledge of disease management in cystic fibrosis: Assessing behavioral treatment management.

    PubMed

    Nicolais, Christina J; Bernstein, Ruth; Riekert, Kristin A; Quittner, Alexandra L

    2018-02-01

    Cystic fibrosis (CF) is a life-shortening, burdensome disease requiring complex knowledge to manage the disease. Significant gaps in knowledge have been documented for parents, which may lead to unintentionally poor adherence and insufficient transfer of treatment responsibility from parents to adolescents. There are no current, validated measures of parent knowledge for this population and there are no measures that assess the knowledge required for day-to-day behavioral management of CF. We assessed the psychometric properties of the parent version of the Knowledge of Disease Management-Cystic Fibrosis measure (KDM-CF-P) using data from iCARE (I Change Adherence and Raise Expectations), a randomized control adherence intervention trial. A total of 196 parents in the iCARE standard care/control arm completed 35 items assessing their knowledge of disease management at their 12-month study visit, prior to beginning the intervention. Items were eliminated from the measure if they met the threshold for ceiling effects, were deemed clinically irrelevant, or did not correlate well with their intended scale. Item-to-total correlations, confirmatory factor analysis, discriminant function, reliability, and convergent validity were calculated. The KDM-CF-P (19 items) demonstrated internal consistency of KR20 = 0.60 on each scale and a two-scale structure. Convergent validity for knowledge scores was found with maternal education, family income, and type of medical insurance. Parents correctly answered approximately 85% of items on the KDM-CF-P. The KDM-CF-P psychometrics support a two-scale measure with clinical utility. It is useful for assessing gaps in knowledge that can be remediated through individualized, tailored interventions. © 2017 Wiley Periodicals, Inc.

  13. Liver Disease in Cystic Fibrosis: an Update

    PubMed Central

    Parisi, Giuseppe Fabio; Di Dio, Giovanna; Franzonello, Chiara; Gennaro, Alessia; Rotolo, Novella; Lionetti, Elena; Leonardi, Salvatore

    2013-01-01

    Context Cystic fibrosis (CF) is the most widespread autosomal recessive genetic disorder that limits life expectation amongst the Caucasian population. As the median survival has increased related to early multidisciplinary intervention, other manifestations of CF have emergedespecially for the broad spectrum of hepatobiliary involvement. The present study reviews the existing literature on liver disease in cystic fibrosis and describes the key issues for an adequate clinical evaluation and management of patients, with a focus on the pathogenetic, clinical and diagnostic-therapeutic aspects of liver disease in CF. Evidence Acquisition A literature search of electronic databases was undertaken for relevant studies published from 1990 about liver disease in cystic fibrosis. The databases searched were: EMBASE, PubMed and Cochrane Library. Results CF is due to mutations in the gene on chromosome 7 that encodes an amino acidic polypeptide named CFTR (cystic fibrosis transmembrane regulator). The hepatic manifestations include particular changes referring to the basic CFTR defect, iatrogenic lesions or consequences of the multisystem disease. Even though hepatobiliary disease is the most common non-pulmonary cause ofmortalityin CF (the third after pulmonary disease and transplant complications), only about the 33%ofCF patients presents clinically significant hepatobiliary disease. Conclusions Liver disease will have a growing impact on survival and quality of life of cystic fibrosis patients because a longer life expectancy and for this it is important its early recognition and a correct clinical management aimed atdelaying the onset of complications. This review could represent an opportunity to encourage researchers to better investigate genotype-phenotype correlation associated with the development of cystic fibrosis liver disease, especially for non-CFTR genetic polymorphisms, and detect predisposed individuals. Therapeutic trials are needed to find strategies of fibrosis prevention and to avoid its progression prior to development its related complications. PMID:24171010

  14. Screening for ADHD in adults with cystic fibrosis: Prevalence, health-related quality of life, and adherence.

    PubMed

    Georgiopoulos, Anna M; Friedman, Deborah; Porter, Elizabeth A; Krasner, Amy; Kakarala, Sheetal P; Glaeser, Breanna K; Napoleon, Siena C; Wozniak, Janet

    2018-03-01

    International guidelines recommend depression and anxiety screening in individuals with cystic fibrosis (CF), but Attention-Deficit Hyperactivity Disorder (ADHD) remains understudied. Adults with CF (n=53) were screened using the Adult ADHD Self-Report Scale-v1.1 Symptom Checklist (ASRS-v1.1), Cystic Fibrosis Questionnaire-Revised (CFQ-R), and a self-report measure of treatment adherence. Elevated ADHD symptoms on the ASRS-v1.1 screener were reported by 15% of participants. Self-reported adherence, Body Mass Index in kg/m 2 (BMI), and Forced Expiratory Volume in 1 Second, Percent Predicted (FEV1%pred) did not differ between participants with vs. without elevated ADHD scores. Three CFQ-R scales, Physical Functioning, Role Functioning, and Respiratory Symptoms, were significantly lower in participants with elevated ADHD screens (unadjusted p<0.05). This difference remained statistically significant for the Role Functioning and Respiratory Symptoms scales following correction for multiple comparisons. The highly specific screening tool ASRS-v1.1 can ascertain previously undetected ADHD symptoms in adults with CF. ADHD was substantially more prevalent than expected in this population. Elevated ASRS-v1.1 screens correlated with poorer Health-Related Quality of Life (HRQoL) in some domains, but not with BMI, FEV1%pred, or self-reported CF treatment adherence. Additional research will elucidate the impact of ADHD and its treatment on HRQoL, CF self-care and health outcomes. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  15. Self-Monitoring and Verbal Feedback to Reduce Stereotypic Body Rocking in a Congenitally Blind Adult.

    ERIC Educational Resources Information Center

    McAdam, David B.; And Others

    1993-01-01

    A self-management approach (utilizing self-counting of behaviors, corrective verbal feedback, and contingent verbal praise) was effectively used to reduce stereotypical body rocking in a congenitally blind young adult. Positive results were maintained, with replacement of overt counting with covert counting and immediate with delayed feedback as…

  16. Type and Amount of Input-Based Practice in CALI: The Revelations of a Triangulated Research Design

    ERIC Educational Resources Information Center

    Cerezo, Luis

    2016-01-01

    Research shows that computer-generated corrective feedback can promote second language development, but there is no consensus about which type is the most effective. The scale is tipped in favor of more explicit feedback that provides metalinguistic explanations, but counterevidence indicates that minimally explicit feedback of the…

  17. Recasts, Metalinguistic Feedback, and Learners' Perceptions: A Case of Persian EFL Learners

    ERIC Educational Resources Information Center

    Rassaei, Ehsan; Moinzadeh, Ahmad

    2014-01-01

    In the current study, we present the results of an experiment with 30 Persian EFL learners in which we explored the learners' perceptions of recasts and metalinguistic corrective feedback. The participant learners received either recasts or metalinguistic feedback for their errors during task-based interactions with their interlocutors and then…

  18. Mathematics Practice without Feedback: A Desirable Difficulty in a Classroom Setting

    ERIC Educational Resources Information Center

    Fyfe, Emily R.; Rittle-Johnson, Bethany

    2017-01-01

    Recent research highlights the potential benefits of practice without feedback on learner's strategy knowledge. However, most prior work has been conducted in one-on-one settings with short retention intervals. We compared the effects of mathematics practice with and without correct-answer feedback on immediate and 1-week delayed performance in a…

  19. Detrimental Effects of Immediate Explanation Feedback

    ERIC Educational Resources Information Center

    Roelle, Julian; Rahimkhani-Sagvand, Natalie; Berthold, Kirsten

    2017-01-01

    Adjunct questions are a common means to foster learning from instructional explanations. As the benefit of adjunct questions is mitigated if learner performance on them is low, it is also common to provide feedback as an add-on if learners fail to correctly respond to them. However, if adjunct questions are highly demanding, feedback might not…

  20. Restoration of R117H CFTR folding and function in human airway cells through combination treatment with VX-809 and VX-770

    PubMed Central

    Gentzsch, Martina; Ren, Hong Y.; Houck, Scott A.; Quinney, Nancy L.; Cholon, Deborah M.; Sopha, Pattarawut; Chaudhry, Imron G.; Das, Jhuma; Dokholyan, Nikolay V.; Randell, Scott H.

    2016-01-01

    Cystic fibrosis (CF) is a lethal recessive genetic disease caused primarily by the F508del mutation in the CF transmembrane conductance regulator (CFTR). The potentiator VX-770 was the first CFTR modulator approved by the FDA for treatment of CF patients with the gating mutation G551D. Orkambi is a drug containing VX-770 and corrector VX809 and is approved for treatment of CF patients homozygous for F508del, which has folding and gating defects. At least 30% of CF patients are heterozygous for the F508del mutation with the other allele encoding for one of many different rare CFTR mutations. Treatment of heterozygous F508del patients with VX-809 and VX-770 has had limited success, so it is important to identify heterozygous patients that respond to CFTR modulator therapy. R117H is a more prevalent rare mutation found in over 2,000 CF patients. In this study we investigated the effectiveness of VX-809/VX-770 therapy on restoring CFTR function in human bronchial epithelial (HBE) cells from R117H/F508del CF patients. We found that VX-809 stimulated more CFTR activity in R117H/F508del HBEs than in F508del/F508del HBEs. R117H expressed exclusively in immortalized HBEs exhibited a folding defect, was retained in the ER, and degraded prematurely. VX-809 corrected the R117H folding defect and restored channel function. Because R117 is involved in ion conductance, VX-770 acted additively with VX-809 to restore CFTR function in chronically treated R117H/F508del cells. Although treatment of R117H patients with VX-770 has been approved, our studies indicate that Orkambi may be more beneficial for rescue of CFTR function in these patients. PMID:27402691

  1. Restoration of R117H CFTR folding and function in human airway cells through combination treatment with VX-809 and VX-770.

    PubMed

    Gentzsch, Martina; Ren, Hong Y; Houck, Scott A; Quinney, Nancy L; Cholon, Deborah M; Sopha, Pattarawut; Chaudhry, Imron G; Das, Jhuma; Dokholyan, Nikolay V; Randell, Scott H; Cyr, Douglas M

    2016-09-01

    Cystic fibrosis (CF) is a lethal recessive genetic disease caused primarily by the F508del mutation in the CF transmembrane conductance regulator (CFTR). The potentiator VX-770 was the first CFTR modulator approved by the FDA for treatment of CF patients with the gating mutation G551D. Orkambi is a drug containing VX-770 and corrector VX809 and is approved for treatment of CF patients homozygous for F508del, which has folding and gating defects. At least 30% of CF patients are heterozygous for the F508del mutation with the other allele encoding for one of many different rare CFTR mutations. Treatment of heterozygous F508del patients with VX-809 and VX-770 has had limited success, so it is important to identify heterozygous patients that respond to CFTR modulator therapy. R117H is a more prevalent rare mutation found in over 2,000 CF patients. In this study we investigated the effectiveness of VX-809/VX-770 therapy on restoring CFTR function in human bronchial epithelial (HBE) cells from R117H/F508del CF patients. We found that VX-809 stimulated more CFTR activity in R117H/F508del HBEs than in F508del/F508del HBEs. R117H expressed exclusively in immortalized HBEs exhibited a folding defect, was retained in the ER, and degraded prematurely. VX-809 corrected the R117H folding defect and restored channel function. Because R117 is involved in ion conductance, VX-770 acted additively with VX-809 to restore CFTR function in chronically treated R117H/F508del cells. Although treatment of R117H patients with VX-770 has been approved, our studies indicate that Orkambi may be more beneficial for rescue of CFTR function in these patients. Copyright © 2016 the American Physiological Society.

  2. Application of real-time PCR of sex-independent insertion-deletion polymorphisms to determine fetal sex using cell-free fetal DNA from maternal plasma.

    PubMed

    Ho, Sherry Sze Yee; Barrett, Angela; Thadani, Henna; Asibal, Cecille Laureano; Koay, Evelyn Siew-Chuan; Choolani, Mahesh

    2015-07-01

    Prenatal diagnosis of sex-linked disorders requires invasive procedures, carrying a risk of miscarriage of up to 1%. Cell-free fetal DNA (cffDNA) present in cell-free DNA (cfDNA) from maternal plasma offers a non-invasive source of fetal genetic material for analysis. Detection of Y-chromosome sequences in cfDNA indicates presence of a male fetus; in the absence of a Y-chromosome signal a female fetus is inferred. We aimed to validate the clinical utility of insertion-deletion polymorphisms (INDELs) to confirm presence of a female fetus using cffDNA. Quantitative real-time PCR (qPCR) for the Y-chromosome-specific sequence, SRY, was performed on cfDNA from 82 samples at 6-39 gestational weeks. In samples without detectable SRY, qPCRs for eight INDELs were performed on maternal genomic DNA and cfDNA. Detection of paternally inherited fetal alleles in cfDNA negative for SRY confirmed a female fetus. Fetal sex was correctly determined in 77/82 (93.9%) cfDNA samples. SRY was detected in all 39 samples from male-bearing pregnancies, and none of the 43 female-bearing pregnancies (sensitivity and specificity of SRY qPCR is therefore 100%; 95% CI 91%-100%). Paternally inherited fetal alleles were detected in 38/43 samples with no SRY signal, confirming the presence of a female fetus (INDEL assay sensitivity is therefore 88.4%; 95% CI 74.1%-95.6%). Since paternally inherited fetal INDELs were not used in women bearing male fetuses, the specificity of INDELs cannot be calculated. Five cfDNA samples were negative for both SRY and INDELS. We have validated a non-invasive prenatal test to confirm fetal sex as early as 6 gestational weeks using cffDNA from maternal plasma.

  3. A high level computational study of the CH4/CF4 dimer: how does it compare with the CH4/CH4 and CF4/CF4 dimers?

    NASA Astrophysics Data System (ADS)

    Biller, Matthew J.; Mecozzi, Sandro

    2012-04-01

    The interaction within the methane-methane (CH4/CH4), perfluoromethane-perfluoromethane (CF4/CF4) methane-perfluoromethane dimers (CH4/CF4) was calculated using the Hartree-Fock (HF) method, multiple orders of Møller-Plesset perturbation theory [MP2, MP3, MP4(DQ), MP4(SDQ), MP4(SDTQ)], and coupled cluster theory [CCSD, CCSD(T)], as well as the PW91, B97D, and M06-2X density functional theory (DFT) functionals. The basis sets of Dunning and coworkers (aug-cc-pVxZ, x = D, T, Q), Krishnan and coworkers [6-311++G(d,p), 6-311++G(2d,2p)], and Tsuzuki and coworkers [aug(df, pd)-6-311G(d,p)] were used. Basis set superposition error (BSSE) was corrected via the counterpoise method in all cases. Interaction energies obtained with the MP2 method do not fit with the experimental finding that the methane-perfluoromethane system phase separates at 94.5 K. It was not until the CCSD(T) method was considered that the interaction energy of the methane-perfluoromethane dimer (-0.69 kcal mol-1) was found to be intermediate between the methane (-0.51 kcal mol-1) and perfluoromethane (-0.78 kcal mol-1) dimers. This suggests that a perfluoromethane molecule interacts preferentially with another perfluoromethane (by about 0.09 kcal mol-1) than with a methane molecule. At temperatures much lower than the CH4/CF4 critical solution temperature of 94.5 K, this energy difference becomes significant and leads perfluoromethane molecules to associate with themselves, forming a phase separation. The DFT functionals yielded erratic results for the three dimers. Further development of DFT is needed in order to model dispersion interactions in hydrocarbon/perfluorocarbon systems.

  4. Autonomous Quantum Error Correction with Application to Quantum Metrology

    NASA Astrophysics Data System (ADS)

    Reiter, Florentin; Sorensen, Anders S.; Zoller, Peter; Muschik, Christine A.

    2017-04-01

    We present a quantum error correction scheme that stabilizes a qubit by coupling it to an engineered environment which protects it against spin- or phase flips. Our scheme uses always-on couplings that run continuously in time and operates in a fully autonomous fashion without the need to perform measurements or feedback operations on the system. The correction of errors takes place entirely at the microscopic level through a build-in feedback mechanism. Our dissipative error correction scheme can be implemented in a system of trapped ions and can be used for improving high precision sensing. We show that the enhanced coherence time that results from the coupling to the engineered environment translates into a significantly enhanced precision for measuring weak fields. In a broader context, this work constitutes a stepping stone towards the paradigm of self-correcting quantum information processing.

  5. Grammatical Accuracy and Learner Autonomy in Advanced Writing

    ERIC Educational Resources Information Center

    Vickers, Caroline H.; Ene, Estela

    2006-01-01

    This paper aims to explore advanced ESL learners' ability to make improvements in grammatical accuracy by autonomously noticing and correcting their own grammatical errors. In the recent literature in SLA, it is suggested that classroom tasks can be used to foster autonomous language learning habits (cf. Dam 2001). Therefore, it is important to…

  6. 19 CFR Appendix to Part 163 - Interim (a)(1)(A) List

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... for commercial samples, tools, theatrical effects §§ 10.70, 10.71Purebred breeding certificate § 10..., merchandise (commercial product) description, quantities, values, unit price, trade terms, part, model, style... Access Program (9802/GSP/CBI) § 141.89CF 5523 Part 141Corrected Commercial Invoice 141.86 (e)Packing List...

  7. 19 CFR Appendix to Part 163 - Interim (a)(1)(A) List

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... for commercial samples, tools, theatrical effects §§ 10.70, 10.71Purebred breeding certificate § 10..., merchandise (commercial product) description, quantities, values, unit price, trade terms, part, model, style... Access Program (9802/GSP/CBI) § 141.89CF 5523 Part 141Corrected Commercial Invoice 141.86 (e)Packing List...

  8. 19 CFR Appendix to Part 163 - Interim (a)(1)(A) List

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... for commercial samples, tools, theatrical effects §§ 10.70, 10.71Purebred breeding certificate § 10..., merchandise (commercial product) description, quantities, values, unit price, trade terms, part, model, style... Access Program (9802/GSP/CBI) § 141.89CF 5523 Part 141Corrected Commercial Invoice 141.86 (e)Packing List...

  9. 19 CFR Appendix to Part 163 - Interim (a)(1)(A) List

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... for commercial samples, tools, theatrical effects §§ 10.70, 10.71Purebred breeding certificate § 10..., merchandise (commercial product) description, quantities, values, unit price, trade terms, part, model, style... Access Program (9802/GSP/CBI) § 141.89CF 5523 Part 141Corrected Commercial Invoice 141.86 (e)Packing List...

  10. 19 CFR Appendix to Part 163 - Interim (a)(1)(A) List

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... for commercial samples, tools, theatrical effects §§ 10.70, 10.71Purebred breeding certificate § 10..., merchandise (commercial product) description, quantities, values, unit price, trade terms, part, model, style... Access Program (9802/GSP/CBI) § 141.89CF 5523 Part 141Corrected Commercial Invoice 141.86 (e)Packing List...

  11. Simple image-based no-wash method for quantitative detection of surface expressed CFTR

    PubMed Central

    Larsen, Mads Breum; Hu, Jennifer; Frizzell, Raymond A.; Watkins, Simon C.

    2016-01-01

    Cystic fibrosis (CF) is the most common lethal genetic disease among Caucasians. It is caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, which encodes an apical membrane anion channel that is required for regulating the volume and composition of epithelial secretions. The most common CFTR mutation, present on at least one allele in >90% of CF patients, deletes phenylalanine at position 508 (F508del), which causes the protein to misfold. Endoplasmic reticulum (ER) quality control elicits the degradation of mutant CFTR, compromising its trafficking to the epithelial cell apical membrane. The absence of functional CFTR leads to depletion of airway surface liquid, impaired clearance of mucus and bacteria from the lung, and predisposes to recurrent infections. Ultimately, respiratory failure results from inflammation and bronchiectasis. Although high throughput screening has identified small molecules that can restore the anion transport function of F508del CFTR, they correct less than 15% of WT CFTR activity, yielding insufficient clinical benefit. To date, most primary CF drug discovery assays have employed measurements of CFTR’s anion transport function, a method that depends on the recruitment of a functional CFTR to the cell surface, involves multiple wash steps, and relies on a signal that saturates rapidly. Screening efforts have also included assays for detection of extracellularly HA-tagged or HRP-tagged CFTR, which require multiple washing steps. We have recently developed tools and cell lines that report the correction of mutant CFTR trafficking by currently available small molecules, and have extended this assay to the 96-well format. This new and simple no-wash assay of F508del CFTR at the cell surface may permit the discovery of more efficacious drugs, and hopefully thereby prevent the catastrophic effects of this disease. In addition, the modular design of this platform should make it useful for other diseases where loss-of-function results from folding and/or trafficking defects in membrane proteins. PMID:26361332

  12. New treatments targeting the basic defects in cystic fibrosis.

    PubMed

    Fajac, Isabelle; Wainwright, Claire E

    2017-06-01

    Cystic fibrosis (CF) is a monogenic autosomal recessive disorder affecting around 75,000 individuals worldwide. It is a multi-system disease but the main morbidity and mortality is caused by chronic lung disease. Due to newborn screening, a multidisciplinary approach to care and intensive symptomatic treatment, the prognosis has dramatically improved over the last decades and there are currently more adults than children in many countries. However, CF is still a very severe disease with a current median age of life expectancy in the fourth decade of life. The disease is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which encodes the CFTR protein, a protein kinase A-activated ATP-gated anion channel that regulates the transport of electrolytes such as chloride and bicarbonate. More than 2000 mutations have been reported, although not all of these have functional consequences. An enormous research effort and progress has been made in understanding the consequences of these mutations on the CFTR protein structure and function, and this has led to the approval of two new drug therapies that are able to bind to defective CFTR proteins and partially restore their function. They are mutation-specific therapies and available at present for specific mutations only. They are the first personalized medicine for CF with a possible disease-modifying effect. A pipeline of other compounds is under development with different mechanisms of action. It is foreseeable that new combinations of compounds will further improve the correction of CFTR function. Other strategies including premature stop codon read-through drugs, antisense oligonucleotides that correct the basic defect at the mRNA level or gene editing to restore the defective gene as well as gene therapy approaches are all in the pipeline. All these strategies are needed to develop disease-modifying therapies for all patients with CF. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Directional errors of movements and their correction in a discrete tracking task. [pilot reaction time and sensorimotor performance

    NASA Technical Reports Server (NTRS)

    Jaeger, R. J.; Agarwal, G. C.; Gottlieb, G. L.

    1978-01-01

    Subjects can correct their own errors of movement more quickly than they can react to external stimuli by using three general categories of feedback: (1) knowledge of results, primarily visually mediated; (2) proprioceptive or kinaesthetic such as from muscle spindles and joint receptors, and (3) corollary discharge or efference copy within the central nervous system. The effects of these feedbacks on simple reaction time, choice reaction time, and error correction time were studied in four normal human subjects. The movement used was plantarflexion and dorsiflexion of the ankle joint. The feedback loops were modified, by changing the sign of the visual display to alter the subject's perception of results, and by applying vibration at 100 Hz simultaneously to both the agonist and antagonist muscles of the ankle joint. The central processing was interfered with when the subjects were given moderate doses of alcohol (blood alcohol concentration levels of up to 0.07%). Vibration and alcohol increase both the simple and choice reaction times but not the error correction time.

  14. Electrophysiological Correlates of Error Monitoring and Feedback Processing in Second Language Learning.

    PubMed

    Bultena, Sybrine; Danielmeier, Claudia; Bekkering, Harold; Lemhöfer, Kristin

    2017-01-01

    Humans monitor their behavior to optimize performance, which presumably relies on stable representations of correct responses. During second language (L2) learning, however, stable representations have yet to be formed while knowledge of the first language (L1) can interfere with learning, which in some cases results in persistent errors. In order to examine how correct L2 representations are stabilized, this study examined performance monitoring in the learning process of second language learners for a feature that conflicts with their first language. Using EEG, we investigated if L2 learners in a feedback-guided word gender assignment task showed signs of error detection in the form of an error-related negativity (ERN) before and after receiving feedback, and how feedback is processed. The results indicated that initially, response-locked negativities for correct (CRN) and incorrect (ERN) responses were of similar size, showing a lack of internal error detection when L2 representations are unstable. As behavioral performance improved following feedback, the ERN became larger than the CRN, pointing to the first signs of successful error detection. Additionally, we observed a second negativity following the ERN/CRN components, the amplitude of which followed a similar pattern as the previous negativities. Feedback-locked data indicated robust FRN and P300 effects in response to negative feedback across different rounds, demonstrating that feedback remained important in order to update memory representations during learning. We thus show that initially, L2 representations may often not be stable enough to warrant successful error monitoring, but can be stabilized through repeated feedback, which means that the brain is able to overcome L1 interference, and can learn to detect errors internally after a short training session. The results contribute a different perspective to the discussion on changes in ERN and FRN components in relation to learning, by extending the investigation of these effects to the language learning domain. Furthermore, these findings provide a further characterization of the online learning process of L2 learners.

  15. Improving newborn screening for cystic fibrosis using next-generation sequencing technology: a technical feasibility study.

    PubMed

    Baker, Mei W; Atkins, Anne E; Cordovado, Suzanne K; Hendrix, Miyono; Earley, Marie C; Farrell, Philip M

    2016-03-01

    Many regions have implemented newborn screening (NBS) for cystic fibrosis (CF) using a limited panel of cystic fibrosis transmembrane regulator (CFTR) mutations after immunoreactive trypsinogen (IRT) analysis. We sought to assess the feasibility of further improving the screening using next-generation sequencing (NGS) technology. An NGS assay was used to detect 162 CFTR mutations/variants characterized by the CFTR2 project. We used 67 dried blood spots (DBSs) containing 48 distinct CFTR mutations to validate the assay. NGS assay was retrospectively performed on 165 CF screen-positive samples with one CFTR mutation. The NGS assay was successfully performed using DNA isolated from DBSs, and it correctly detected all CFTR mutations in the validation. Among 165 screen-positive infants with one CFTR mutation, no additional disease-causing mutation was identified in 151 samples consistent with normal sweat tests. Five infants had a CF-causing mutation that was not included in this panel, and nine with two CF-causing mutations were identified. The NGS assay was 100% concordant with traditional methods. Retrospective analysis results indicate an IRT/NGS screening algorithm would enable high sensitivity, better specificity and positive predictive value (PPV). This study lays the foundation for prospective studies and for introducing NGS in NBS laboratories.

  16. Development of an airway mucus defect in the cystic fibrosis rat

    PubMed Central

    Birket, Susan E.; Davis, Joy M.; Fernandez, Courtney M.; Tuggle, Katherine L.; Oden, Ashley M.; Chu, Kengyeh K.; Tearney, Guillermo J.; Fanucchi, Michelle V.; Sorscher, Eric J.

    2018-01-01

    The mechanisms underlying the development and natural progression of the airway mucus defect in cystic fibrosis (CF) remain largely unclear. New animal models of CF, coupled with imaging using micro-optical coherence tomography, can lead to insights regarding these questions. The Cftr–/– (KO) rat allows for longitudinal examination of the development and progression of airway mucus abnormalities. The KO rat exhibits decreased periciliary depth, hyperacidic pH, and increased mucus solid content percentage; however, the transport rates and viscoelastic properties of the mucus are unaffected until the KO rat ages. Airway submucosal gland hypertrophy develops in the KO rat by 6 months of age. Only then does it induce increased mucus viscosity, collapse of the periciliary layer, and delayed mucociliary transport; stimulation of gland secretion potentiates this evolution. These findings could be reversed by bicarbonate repletion but not pH correction without counterion donation. These studies demonstrate that abnormal surface epithelium in CF does not cause delayed mucus transport in the absence of functional gland secretions. Furthermore, abnormal bicarbonate transport represents a specific target for restoring mucus clearance, independent of effects on periciliary collapse. Thus, mature airway secretions are required to manifest the CF defect primed by airway dehydration and bicarbonate deficiency. PMID:29321377

  17. Failure to learn from feedback underlies word learning difficulties in toddlers at risk for autism.

    PubMed

    Bedford, R; Gliga, T; Frame, K; Hudry, K; Chandler, S; Johnson, M H; Charman, T

    2013-01-01

    Children's assignment of novel words to nameless objects, over objects whose names they know (mutual exclusivity; ME) has been described as a driving force for vocabulary acquisition. Despite their ability to use ME to fast-map words (Preissler & Carey, 2005), children with autism show impaired language acquisition. We aimed to address this puzzle by building on studies showing that correct referent selection using ME does not lead to word learning unless ostensive feedback is provided on the child's object choice (Horst & Samuelson, 2008). We found that although toddlers aged 2;0 at risk for autism can use ME to choose the correct referent of a word, they do not benefit from feedback for long-term retention of the word-object mapping. Further, their difficulty using feedback is associated with their smaller receptive vocabularies. We propose that difficulties learning from social feedback, not lexical principles, limits vocabulary building during development in children at risk for autism.

  18. Modulation of ventral striatal activity by cognitive effort

    PubMed Central

    Dobryakova, Ekaterina; Jessup, Ryan K; Tricomi, Elizabeth

    2016-01-01

    Effort discounting theory suggests that the value of a reward should be lower if it was effortful to obtain, whereas contrast theory suggests that the contrast between the costly effort and the reward makes the reward seem more valuable. To test these alternative hypotheses, we used functional magnetic resonance imaging (fMRI) as participants engaged in feedback-based learning that required low or high cognitive effort to obtain positive feedback, while the objective amount of information provided by feedback remained constant. In the low effort condition, a single image was presented with four response options. In the high effort condition, two images were presented, each with two response options, and correct feedback was presented only when participants responded correctly to both of the images. Accuracy was significantly lower for the high effort condition, and all participants reported that the high effort condition was more difficult. A region of the ventral striatum selected for sensitivity to feedback value also showed increased activation to feedback presentation associated with the high effort condition relative to the low effort condition, when controlling for activation from corresponding control conditions where feedback was random. These results suggest that increased cognitive effort produces corresponding increases in positive feedback-related ventral striatum activity, in line with the predictions made by contrast theory. The accomplishment of obtaining a hard-earned intrinsic reward, such as positive feedback, may be particularly likely to promote reward-related brain activity. PMID:27989778

  19. Modeling the time-varying and level-dependent effects of the medial olivocochlear reflex in auditory nerve responses.

    PubMed

    Smalt, Christopher J; Heinz, Michael G; Strickland, Elizabeth A

    2014-04-01

    The medial olivocochlear reflex (MOCR) has been hypothesized to provide benefit for listening in noisy environments. This advantage can be attributed to a feedback mechanism that suppresses auditory nerve (AN) firing in continuous background noise, resulting in increased sensitivity to a tone or speech. MOC neurons synapse on outer hair cells (OHCs), and their activity effectively reduces cochlear gain. The computational model developed in this study implements the time-varying, characteristic frequency (CF) and level-dependent effects of the MOCR within the framework of a well-established model for normal and hearing-impaired AN responses. A second-order linear system was used to model the time-course of the MOCR using physiological data in humans. The stimulus-level-dependent parameters of the efferent pathway were estimated by fitting AN sensitivity derived from responses in decerebrate cats using a tone-in-noise paradigm. The resulting model uses a binaural, time-varying, CF-dependent, level-dependent OHC gain reduction for both ipsilateral and contralateral stimuli that improves detection of a tone in noise, similarly to recorded AN responses. The MOCR may be important for speech recognition in continuous background noise as well as for protection from acoustic trauma. Further study of this model and its efferent feedback loop may improve our understanding of the effects of sensorineural hearing loss in noisy situations, a condition in which hearing aids currently struggle to restore normal speech perception.

  20. Outcomes of a Peer Assessment/Feedback Training Program in an Undergraduate Sports Medicine Course

    ERIC Educational Resources Information Center

    Marty, Melissa Catherine

    2010-01-01

    Peer assessment/feedback is clearly occurring in athletic training education programs. However, it remains unclear whether students would improve their ability to assess their peers and provide corrective feedback if they received formal training in how to do so. The purpose of this study was to determine the following: (1) if a peer…

  1. Corrective Feedback and Working Memory Capacity in Interaction-Driven L2 Learning

    ERIC Educational Resources Information Center

    Goo, Jaemyung

    2012-01-01

    The present study explores the relative efficacy of recasts over metalinguistic feedback on the learning of the English "that"-trace filter and how working memory capacity (WMC) is related to the extent to which learners can benefit from recasts and metalinguistic feedback. Fifty-four Korean English as a foreign language (EFL) learners…

  2. Comparison of Meaning and Graphophonemic Feedback Strategies for Guided Reading Instruction of Children with Language Delays

    ERIC Educational Resources Information Center

    Kouri, Theresa A.; Selle, Carrie A.; Riley, Sarah A.

    2006-01-01

    Purpose: Guided reading is a common practice recommended for children in the early stages of literacy development. While experts agree that oral reading facilitates literacy skills, controversy exists concerning which corrective feedback strategies are most effective. The purpose of this study was to compare feedback procedures stemming from 2…

  3. Structure of corrective feedback for selection of ineffective vegetable parenting practices for use in a simulation videogame

    USDA-ARS?s Scientific Manuscript database

    A serious videogame is being developed to train parents of preschool children in selecting and using parenting practices that are likely to encourage their child to eat more vegetables. The structure of feedback to the parents on their selection may influence what they learn from the game. Feedback ...

  4. Levels of Questioning and Forms of Feedback: Instructional Factors in Courseware Design.

    ERIC Educational Resources Information Center

    Merrill, John

    High and low level questions as determined by a panel of evaluators were combined with corrective feedback and attribute isolation feedback to form four versions of a computer-based science lesson. The sample consisted of 154 high school chemistry students in a suburban high school. The primary hypothesis was that students who received high level…

  5. Luck and Learning: Feedback Contingencies and Initial Success in Verbal Discrimination Learning.

    ERIC Educational Resources Information Center

    Schneider, H. G.; Ferrante, A. P.

    1983-01-01

    A total of 90 undergraduate volunteers learned a 12-pair, low-frequency verbal discrimination list. Independent variables were feedback (positive only, negative only, or both) and initial success (17, 50, or 83 percent correct on the first trial). While the main effect of feedback was not significant, that of initial success was. (Author/RH)

  6. The Benefits of Computer-Generated Feedback for Mathematics Problem Solving

    ERIC Educational Resources Information Center

    Fyfe, Emily R.; Rittle-Johnson, Bethany

    2016-01-01

    The goal of the current research was to better understand when and why feedback has positive effects on learning and to identify features of feedback that may improve its efficacy. In a randomized experiment, second-grade children (N = 75) received instruction on a correct problem-solving strategy and then solved a set of relevant problems.…

  7. Structured feedback on students' concept maps: the proverbial path to learning?

    PubMed

    Joseph, Conran; Conradsson, David; Nilsson Wikmar, Lena; Rowe, Michael

    2017-05-25

    Good conceptual knowledge is an essential requirement for health professions students, in that they are required to apply concepts learned in the classroom to a variety of different contexts. However, the use of traditional methods of assessment limits the educator's ability to correct students' conceptual knowledge prior to altering the educational context. Concept mapping (CM) is an educational tool for evaluating conceptual knowledge, but little is known about its use in facilitating the development of richer knowledge frameworks. In addition, structured feedback has the potential to develop good conceptual knowledge. The purpose of this study was to use Kinchin's criteria to assess the impact of structured feedback on the graphical complexity of CM's by observing the development of richer knowledge frameworks. Fifty-eight physiotherapy students created CM's targeting the integration of two knowledge domains within a case-based teaching paradigm. Each student received one round of structured feedback that addressed correction, reinforcement, forensic diagnosis, benchmarking, and longitudinal development on their CM's prior to the final submission. The concept maps were categorized according to Kinchin's criteria as either Spoke, Chain or Net representations, and then evaluated against defined traits of meaningful learning. The inter-rater reliability of categorizing CM's was good. Pre-feedback CM's were predominantly Chain structures (57%), with Net structures appearing least often. There was a significant reduction of the basic Spoke- structured CMs (P = 0.002) and a significant increase of Net-structured maps (P < 0.001) at the final evaluation (post-feedback). Changes in structural complexity of CMs appeared to be indicative of broader knowledge frameworks as assessed against the meaningful learning traits. Feedback on CM's seemed to have contributed towards improving conceptual knowledge and correcting naive conceptions of related knowledge. Educators in medical education could therefore consider using CM's to target individual student development.

  8. CPR feedback/prompt device improves the quality of hands-only CPR performed in manikin by laypersons following the 2015 AHA guidelines.

    PubMed

    Liu, Yuanshan; Huang, Zitong; Li, Heng; Zheng, Guanghui; Ling, Qin; Tang, Wanchun; Yang, Zhengfei

    2018-03-06

    We investigated the effects of a cardiopulmonary resuscitation (CPR) feedback/prompt device on the quality of chest compression (CC) during hands-only CPR following the 2015 AHA guidelines. A total of 124 laypersons were randomly assigned into three groups. The first (n=42) followed the 2010 guidelines, the second (n=42) followed the 2015 guidelines with no feedback/prompt device, the third (n=40) followed the 2015 guidelines with a feedback/prompt device (2015F). Participants underwent manual CPR training and took a written basic life support examination, then required to perform 2min of hands-only CPR monitored by a CPR feedback/prompt device. The quality of CPR was quantified as the percentage of correct CCs (mean CC depth and rate, complete recoil and chest compression fraction (CCF)) per 20s, as recorded by the CPR feedback/prompt device. Significantly higher correct ratios of CC, CC depth, and rate were achieved in the 2010 group in each minute vs the 2015 group. The greater mean CC depth and rate were observed in the 2015F group vs the 2015 group. The correct ratio of CC was significantly higher in the 2015F group vs the 2015 group. CCF was also significantly higher in the 2015F group vs the 2015 group in the last 20s of CPR. It is difficult for a large percentage of laypersons to achieve the targets of CC depth and rate following the 2015 AHA guidelines. CPR feedback/prompt devices significantly improve the quality of hands-only CPR performance by laypersons following the standards of the 2015 AHA guidelines. Copyright © 2017. Published by Elsevier Inc.

  9. The Role of Teacher's Corrective Feedback in Improving Iranian EFL Learners' Writing Accuracy over Time: Is Learner's Mother Tongue Relevant?

    ERIC Educational Resources Information Center

    Rahimi, Mohammad

    2009-01-01

    The purpose of the present study was to investigate the impact of feedback on writing accuracy over time and examine the relevance of the students' mother tongue to the feedback effect. To this end, the study compared two groups of Iranian English majors (N = 56) over a period of four months: one with indirect grammar feedback and the other with…

  10. Surprising feedback improves later memory.

    PubMed

    Fazio, Lisa K; Marsh, Elizabeth J

    2009-02-01

    The hypercorrection effect is the finding that high-confidence errors are more likely to be corrected after feedback than are low-confidence errors (Butterfield & Metcalfe, 2001). In two experiments, we explored the idea that the hypercorrection effect results from increased attention to surprising feedback. In Experiment 1, participants were more likely to remember the appearance of the presented feedback when the feedback did not match expectations. In Experiment 2, we replicated this effect using more distinctive sources and also demonstrated the hypercorrection effect in this modified paradigm. Overall, participants better remembered both the surface features and the content of surprising feedback.

  11. Automated Error Detection in Physiotherapy Training.

    PubMed

    Jovanović, Marko; Seiffarth, Johannes; Kutafina, Ekaterina; Jonas, Stephan M

    2018-01-01

    Manual skills teaching, such as physiotherapy education, requires immediate teacher feedback for the students during the learning process, which to date can only be performed by expert trainers. A machine-learning system trained only on correct performances to classify and score performed movements, to identify sources of errors in the movement and give feedback to the learner. We acquire IMU and sEMG sensor data from a commercial-grade wearable device and construct an HMM-based model for gesture classification, scoring and feedback giving. We evaluate the model on publicly available and self-generated data of an exemplary movement pattern executions. The model achieves an overall accuracy of 90.71% on the public dataset and 98.9% on our dataset. An AUC of 0.99 for the ROC of the scoring method could be achieved to discriminate between correct and untrained incorrect executions. The proposed system demonstrated its suitability for scoring and feedback in manual skills training.

  12. Self-controlled video feedback on tactical skills for soccer teams results in more active involvement of players.

    PubMed

    van Maarseveen, Mariëtte J J; Oudejans, Raôul R D; Savelsbergh, Geert J P

    2018-02-01

    Many studies have shown that self-controlled feedback is beneficial for learning motor tasks, and that learners prefer to receive feedback after supposedly good trials. However, to date all studies conducted on self-controlled learning have used individual tasks and mainly relatively simple skills. Therefore, the aim of this study was to examine self-controlled feedback on tactical skills in small-sided soccer games. Highly talented youth soccer players were assigned to a self-control or yoked group and received video feedback on their offensive performance in 3 vs. 2 small-sided games. The results showed that the self-control group requested feedback mostly after good trials, that is, after they scored a goal. In addition, the perceived performance of the self-control group was higher on feedback than on no-feedback trials. Analyses of the conversations around the video feedback revealed that the players and coach discussed good and poor elements of performance and how to improve it. Although the coach had a major role in these conversations, the players of the self-control group spoke more and showed more initiative compared to the yoked group. The results revealed no significant beneficial effect of self-controlled feedback on performance as judged by the coach. Overall, the findings suggest that in such a complex situation as small-sided soccer games, self-controlled feedback is used both to confirm correct performance elements and to determine and correct errors, and that self-controlled learning stimulates the involvement of the learner in the learning process. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Control of the proinflammatory state in cystic fibrosis lung epithelial cells by genes from the TNF-alphaR/NFkappaB pathway.

    PubMed Central

    Eidelman, O.; Srivastava, M.; Zhang, J.; Leighton, X.; Murtie, J.; Jozwik, C.; Jacobson, K.; Weinstein, D. L.; Metcalf, E. L.; Pollard, H. B.

    2001-01-01

    BACKGROUND: Cystic fibrosis (CF) is the most common, lethal autosomal recessive disease affecting children in the United States and Europe. Extensive work is being performed to develop both gene and drug therapies. The principal mutation causing CF is in the CFTR gene ([Delta F508]CFTR). This mutation causes the mutant protein to traffic poorly to the plasma membrane, and degrades CFTR chloride channel activity. CPX, a candidate drug for CF, binds to mutant CFTR and corrects the trafficking deficit. CPX also activates mutant CFTR chloride channel activity. CF airways are phenotypically inundated by inflammatory signals, primarily contributed by sustained secretion of the proinflammatory cytokine interleukin 8 (IL-8) from mutant CFTR airway epithelial cells. IL-8 production is controlled by genes from the TNF-alphaR/NFkappaB pathway, and it is possible that the CF phenotype is due to dysfunction of genes from this pathway. In addition, because drug therapy with CPX and gene therapy with CFTR have the same common endpoint of raising the levels of CFTR, we have hypothesized that either approach should have a common genomic endpoint. MATERIALS AND METHODS: To test this hypothesis, we studied IL-8 secretion and global gene expression in IB-3 CF lung epithelial cells. The cells were treated by either gene therapy with wild-type CFTR, or by pharmacotherapy with the CFTR-surrogate drug CPX. CF cells, treated with either CFTR or CPX, were also exposed to Pseudomonas aeruginosa, a common chronic pathogen in CF patients. cDNA microarrays were used to assess global gene expression under the different conditions. A novel bioinformatic algorithm (GENESAVER) was developed to identify genes whose expression paralleled secretion of IL-8. RESULTS: We report here that IB3 CF cells secrete massive levels of IL-8. However, both gene therapy with CFTR and drug therapy with CPX substantially suppress IL-8 secretion. Nonetheless, both gene and drug therapy allow the CF cells to respond with physiologic secretion of IL-8 when the cells are exposed to P. aeruginosa. Thus, neither CFTR nor CPX acts as a nonspecific suppressor of IL-8 secretion from CF cells. Consistently, pharmacogenomic analysis indicates that CF cells treated with CPX greatly resemble CF cells treated with CFTR by gene therapy. Additionally, the same result obtains in the presence of P. aeruginosa. Classical hierarchical cluster analysis, based on similarity of global gene expression, also supports this conclusion. The GENESAVER algorithm, using the IL-8 secretion level as a physiologic variable, identifies a subset of genes from the TNF-alphaR/NFkappaB pathway that is expressed in phase with IL-8 secretion from CF epithelial cells. Certain other genes, previously known to be positively associated with CF, also fall into this category. Identified genes known to code for known inhibitors are expressed inversely, out of phase with IL-8 secretion. CONCLUSIONS: Wild-type CFTR and CPX both suppress proinflammatory IL-8 secretion from CF epithelial cells. The mechanism, as defined by pharmacogenomic analysis, involves identified genes from the TNF-alphaR/NFkappaB pathway. The close relationship between IL-8 secretion and genes from the TNF-alphaR/NFkappaB pathway suggests that molecular or pharmaceutical targeting of these novel genes may have strategic use in the development of new therapies for CF. From the perspective of global gene expression, both gene and drug therapy have similar genomic consequences. This is the first example showing equivalence of gene and drug therapy in CF, and suggests that a gene therapy-defined endpoint may prove to be a powerful paradigm for CF drug discovery. Finally, because the GENESAVER algorithm is capable of isolating disease-relevant genes in a hypothesis-driven manner without recourse to any a priori knowledge about the system, this new algorithm may also prove useful in applications to other genetic diseases. PMID:11591888

  14. Predictive error detection in pianists: a combined ERP and motion capture study

    PubMed Central

    Maidhof, Clemens; Pitkäniemi, Anni; Tervaniemi, Mari

    2013-01-01

    Performing a piece of music involves the interplay of several cognitive and motor processes and requires extensive training to achieve a high skill level. However, even professional musicians commit errors occasionally. Previous event-related potential (ERP) studies have investigated the neurophysiological correlates of pitch errors during piano performance, and reported pre-error negativity already occurring approximately 70–100 ms before the error had been committed and audible. It was assumed that this pre-error negativity reflects predictive control processes that compare predicted consequences with actual consequences of one's own actions. However, in previous investigations, correct and incorrect pitch events were confounded by their different tempi. In addition, no data about the underlying movements were available. In the present study, we exploratively recorded the ERPs and 3D movement data of pianists' fingers simultaneously while they performed fingering exercises from memory. Results showed a pre-error negativity for incorrect keystrokes when both correct and incorrect keystrokes were performed with comparable tempi. Interestingly, even correct notes immediately preceding erroneous keystrokes elicited a very similar negativity. In addition, we explored the possibility of computing ERPs time-locked to a kinematic landmark in the finger motion trajectories defined by when a finger makes initial contact with the key surface, that is, at the onset of tactile feedback. Results suggest that incorrect notes elicited a small difference after the onset of tactile feedback, whereas correct notes preceding incorrect ones elicited negativity before the onset of tactile feedback. The results tentatively suggest that tactile feedback plays an important role in error-monitoring during piano performance, because the comparison between predicted and actual sensory (tactile) feedback may provide the information necessary for the detection of an upcoming error. PMID:24133428

  15. Effects of reward and punishment on learning from errors in smokers.

    PubMed

    Duehlmeyer, Leonie; Levis, Bianca; Hester, Robert

    2018-04-30

    Punishing errors facilitates adaptation in healthy individuals, while aberrant reward and punishment sensitivity in drug-dependent individuals may change this impact. Many societies have institutions that use the concept of punishing drug use behavior, making it important to understand how drug dependency mediates the effects of negative feedback for influencing adaptive behavior. Using an associative learning task, we investigated differences in error correction rates of dependent smokers, compared with controls. Two versions of the task were administered to different participant samples: One assessed the effect of varying monetary contingencies to task performance, the other, the presence of reward as compared to avoidance of punishment for correct performance. While smokers recalled associations that were rewarded with a higher value 11% more often than lower rewarded locations, they did not correct higher punished locations more often. Controls exhibited the opposite pattern. The three-way interaction between magnitude, feedback type and group was significant, F(1,48) = 5.288, p =0.026, ɳ 2 p =0.099. Neither participant group corrected locations offering reward more often than those offering avoidances of punishment. The interaction between group and feedback condition was not significant, F(1,58) = 0.0, p =0.99, ɳ 2 p =0.001. The present results suggest that smokers have poorer learning from errors when receiving negative feedback. Moreover, larger rewards reinforce smokers' behavior stronger than smaller rewards, whereas controls made no distinction. These findings support the hypothesis that dependent smokers may respond to positively framed and rewarded anti-smoking programs when compared to those relying on negative feedback or punishment. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. 78 FR 34280 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ... this proposal in light of the comments we receive. Discussion Transport Canada (TC), which is the aviation authority for Canada, has issued TC AD No. CF-2007-13R2, dated November 10, 2009, to correct an.... TC advises of several failures of third stage turbine wheels used in Rolls Royce 250-C20 engines...

  17. 78 FR 34286 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ... in light of the comments we receive. Discussion Transport Canada (TC), which is the aviation authority for Canada, has issued TC AD No. CF-2004-09R1, dated July 4, 2005, to correct an unsafe condition for Model 407 helicopters. TC advises of several failures of third stage turbine wheels used in Rolls...

  18. 78 FR 34279 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    .... Discussion Transport Canada (TC), which is the aviation authority for Canada, has issued TC AD No. CF-2005-24, dated July 4, 2005, to correct an unsafe condition for Model 230 helicopters. TC advises of several... these failures have occurred on the same engine used by Bell on Model 230 helicopters. According to TC...

  19. Augmented Hebbian reweighting accounts for accuracy and induced bias in perceptual learning with reverse feedback

    PubMed Central

    Liu, Jiajuan; Dosher, Barbara Anne; Lu, Zhong-Lin

    2015-01-01

    Using an asymmetrical set of vernier stimuli (−15″, −10″, −5″, +10″, +15″) together with reverse feedback on the small subthreshold offset stimulus (−5″) induces response bias in performance (Aberg & Herzog, 2012; Herzog, Eward, Hermens, & Fahle, 2006; Herzog & Fahle, 1999). These conditions are of interest for testing models of perceptual learning because the world does not always present balanced stimulus frequencies or accurate feedback. Here we provide a comprehensive model for the complex set of asymmetric training results using the augmented Hebbian reweighting model (Liu, Dosher, & Lu, 2014; Petrov, Dosher, & Lu, 2005, 2006) and the multilocation integrated reweighting theory (Dosher, Jeter, Liu, & Lu, 2013). The augmented Hebbian learning algorithm incorporates trial-by-trial feedback, when present, as another input to the decision unit and uses the observer's internal response to update the weights otherwise; block feedback alters the weights on bias correction (Liu et al., 2014). Asymmetric training with reversed feedback incorporates biases into the weights between representation and decision. The model correctly predicts the basic induction effect, its dependence on trial-by-trial feedback, and the specificity of bias to stimulus orientation and spatial location, extending the range of augmented Hebbian reweighting accounts of perceptual learning. PMID:26418382

  20. Augmented Hebbian reweighting accounts for accuracy and induced bias in perceptual learning with reverse feedback.

    PubMed

    Liu, Jiajuan; Dosher, Barbara Anne; Lu, Zhong-Lin

    2015-01-01

    Using an asymmetrical set of vernier stimuli (-15″, -10″, -5″, +10″, +15″) together with reverse feedback on the small subthreshold offset stimulus (-5″) induces response bias in performance (Aberg & Herzog, 2012; Herzog, Eward, Hermens, & Fahle, 2006; Herzog & Fahle, 1999). These conditions are of interest for testing models of perceptual learning because the world does not always present balanced stimulus frequencies or accurate feedback. Here we provide a comprehensive model for the complex set of asymmetric training results using the augmented Hebbian reweighting model (Liu, Dosher, & Lu, 2014; Petrov, Dosher, & Lu, 2005, 2006) and the multilocation integrated reweighting theory (Dosher, Jeter, Liu, & Lu, 2013). The augmented Hebbian learning algorithm incorporates trial-by-trial feedback, when present, as another input to the decision unit and uses the observer's internal response to update the weights otherwise; block feedback alters the weights on bias correction (Liu et al., 2014). Asymmetric training with reversed feedback incorporates biases into the weights between representation and decision. The model correctly predicts the basic induction effect, its dependence on trial-by-trial feedback, and the specificity of bias to stimulus orientation and spatial location, extending the range of augmented Hebbian reweighting accounts of perceptual learning.

  1. Debris of carbon-fibers originated from a CFRP (pEEK) wrist-plate triggered a destruent synovitis in human.

    PubMed

    Merolli, Antonio; Rocchi, Lorenzo; De Spirito, Marco; Federico, Francesco; Morini, Alessandro; Mingarelli, Luigi; Fanfani, Francesco

    2016-03-01

    Application of carbon-fiber-reinforced-polymer (CFRP) artifacts in humans has been promoted in Orthopedic and Trauma Surgery. Literature documents the biocompatibility of materials used, namely carbon fibers (CF) and poly-ether thermoplastics, like poly-ether-ether-ketone (PEEK). A properly designed and accurately implanted composite artifact should not expose its fibers during or after surgery: however this may happen. A white Caucasian woman came to our attention 11 months after surgery for a wrist fracture. She had a severe impairment, being unable to flex the thumb; index finger and distal phalanx of third finger. We retrieved a correctly positioned plate and documented an aggressive erosive flexor tendons synovitis with eroded stumps of flexor tendons. The plate and soft tissues were analyzed by Visible Light and Scanning Electron Microscopy. Histopathology showed granulomatous fibrogenic process with CF engulfed inside multinucleated giant cells. Fibers were unmasked and disrupted inside the holes where screws were tightened and corrugation of the polymer coating led to further unmasking. The mechanism of foreign-body reaction to CF has not been studied in depth yet, particularly at the ultrastructural level and in Humans. This case documents a damage occurred in a clinical application and which was theoretically possible. Our opinion is that a proper way to promote the use of CRFP in the Clinic in the short term is to direct Research towards finding a better way to prevent CF debris to be exposed and released. In the longer term, the biological response to CF deserves a deeper understanding.

  2. The Effect of Direct and Indirect Corrective Feedback on Students' Spelling Errors (El efecto de la retroalimentación directa e indirecta sobre los errores de ortografía de los estudiantes)

    ERIC Educational Resources Information Center

    Baleghizadeh, Sasan; Dadashi, Mehdi

    2011-01-01

    The study presented here is an attempt to examine the role of indirect feedback in promoting junior high school students' spelling accuracy in English. It compares the effect of direct feedback with indirect feedback on students' written work dictated by their teacher from their textbooks. Two classes were selected from the Zanjanrood District in…

  3. Case-Based Learning with Worked Examples in Complex Domains: Two Experimental Studies in Undergraduate Medical Education

    ERIC Educational Resources Information Center

    Stark, Robin; Kopp, Veronika; Fischer, Martin R.

    2011-01-01

    To investigate the effects of example format (erroneous examples vs. correct examples) and feedback format (elaborated feedback vs. knowledge of results feedback) on medical students' diagnostic competence in the context of a web-based learning environment containing case-based worked examples, two studies with a 2 x 2 design were conducted in the…

  4. Immediate vs. Delayed Feedback in a Computer-Managed Test: Effects on Long-Term Retention. Technical Report, March 1976-August 1976.

    ERIC Educational Resources Information Center

    Sturges, Persis T.

    This experiment was designed to test the effect of immediate and delayed feedback on retention of learning in an educational situation. Four groups of college undergraduates took a multiple-choice computer-managed test. Three of these groups received informative feedback (the entire item with the correct answer identified) either: (1) immediately…

  5. The Timing of Feedback on Mathematics Problem Solving in a Classroom Setting

    ERIC Educational Resources Information Center

    Fyfe, Emily R.; Rittle-Johnson, Bethany

    2015-01-01

    Feedback is a ubiquitous learning tool that is theorized to help learners detect and correct their errors. The goal of this study was to examine the effects of feedback in a classroom context for children solving math equivalence problems (problems with operations on both sides of the equal sign). The authors worked with children in 7 second-grade…

  6. The Effect of the Immediate Feedback by the Collaborative Education Tool ViLLE on Learning for Business Mathematics in Higher Education

    ERIC Educational Resources Information Center

    Kuikka, Matti; Laakso, Mikko-Jussi; Joshi, Marjo

    2016-01-01

    This article outlines the effect of the collaborative educational tool ViLLE when learning business mathematics in higher education. ViLLE validates students' answers during the assessment process and provides immediate feedback, enabling students to receive feedback and guidance about the correctness of their answers. The learning results in the…

  7. Program and Abstracts of the International Free Electron Laser Conference (10th) Held in Jerusalem, Israel on August 29-September 2, 1988

    DTIC Science & Technology

    1988-09-02

    J.P. De Brion, J. Frehaut, G. Haouat, A. Herscovici, D. Iracane, S. Joly, J.G. Marmouget and Y. Pranal. 6.7 Proposal for a Race - Track Microtron with...measurement capability of the rf phase stability of the SCA has Improved the operating stability of the FEL, and has allowed the beam bunch length to be...tapered wiggler with online feedback control. The status cf these developments will be presented. 6 6 PROPOSAL FOR A RACE - TRACK HICROTRON WITH HIGH

  8. Tumbling cartilage flap and free auricular composite tissue transplantation for correcting mild and moderate forms of constricted ear.

    PubMed

    Pan, Bo; Zhao, Yanyong; Zhuang, Hongxing; Lin, Lin; Liu, Lei; Jiang, Haiyue

    2010-01-01

    To report a new surgical approach that results in a natural size and contour of the external malformed constricted ear. A total of 62 consecutive patients with constricted ear underwent surgery between July 1, 2005, and December 31, 2007. Depending on the features and severity of the deformity, the methods of tumbling cartilage flap (CF), free auricular composite graft, or a combination of these 2 techniques were applied. A total of 45 patients were treated with the method of tumbling CF. Twelve were treated with an auricular composite graft from the contralateral ear, and in 5 patients a combination of the 2 methods was used. In all cases, there was an improvement in the size, shape, and symmetry of the ears, and most patients were satisfied with the outcome. Complications were rare, and there was no donor site deformity. The technique of tumbling CF and free auricular composite graft provides a simple and promising treatment for constricted ears. Furthermore, this technique is easy to apply with a predictable good outcome.

  9. Effects on auditory-nerve fibers of opening the otic capsule at the apex of the chinchilla cochlea

    NASA Astrophysics Data System (ADS)

    Recio-Spinoso, Alberto; Temchin, Andrei N.; Ruggero, Mario A.

    2015-12-01

    Vibration responses to clicks measured at the apex of chinchilla cochleae with open otic capsules have onsets much shorter than those of responses of auditory-nerve fibers (ANFs) corrected for synaptic and neural delays. Apical vibration responses to tones in open cochleae also differ in other respects from the responses to tones of ANFs with low characteristic frequency (CF) in normal chinchilla cochleae. To further specify the origin(s) of these differences, we recorded from chinchilla ANFs after delicately opening a small hole in the otic capsule overlying scala vestibuli in the cochlear apex. In those cochleae, the earliest ANF responses to clicks are often evoked by condensation (rather than rarefaction) clicks and responses to tones often exhibit level-dependent phase changes different from those in normal cochleae. These findings are largely consistent with, and seem to account for, apical vibration responses of cochleae with open otic capsules. An unexpected finding is that the tuning curves of ANFs with moderately high CF and normal CF thresholds often had hypersensitive tails.

  10. Linguistic Knowledge and Reasoning for Error Diagnosis and Feedback Generation.

    ERIC Educational Resources Information Center

    Delmonte, Rodolfo

    2003-01-01

    Presents four sets of natural language processing-based exercises for which error correction and feedback are produced by means of a rich database in which linguistic information is encoded either at the lexical or the grammatical level. (Author/VWL)

  11. Target Uncertainty Mediates Sensorimotor Error Correction

    PubMed Central

    Vijayakumar, Sethu; Wolpert, Daniel M.

    2017-01-01

    Human movements are prone to errors that arise from inaccuracies in both our perceptual processing and execution of motor commands. We can reduce such errors by both improving our estimates of the state of the world and through online error correction of the ongoing action. Two prominent frameworks that explain how humans solve these problems are Bayesian estimation and stochastic optimal feedback control. Here we examine the interaction between estimation and control by asking if uncertainty in estimates affects how subjects correct for errors that may arise during the movement. Unbeknownst to participants, we randomly shifted the visual feedback of their finger position as they reached to indicate the center of mass of an object. Even though participants were given ample time to compensate for this perturbation, they only fully corrected for the induced error on trials with low uncertainty about center of mass, with correction only partial in trials involving more uncertainty. The analysis of subjects’ scores revealed that participants corrected for errors just enough to avoid significant decrease in their overall scores, in agreement with the minimal intervention principle of optimal feedback control. We explain this behavior with a term in the loss function that accounts for the additional effort of adjusting one’s response. By suggesting that subjects’ decision uncertainty, as reflected in their posterior distribution, is a major factor in determining how their sensorimotor system responds to error, our findings support theoretical models in which the decision making and control processes are fully integrated. PMID:28129323

  12. Target Uncertainty Mediates Sensorimotor Error Correction.

    PubMed

    Acerbi, Luigi; Vijayakumar, Sethu; Wolpert, Daniel M

    2017-01-01

    Human movements are prone to errors that arise from inaccuracies in both our perceptual processing and execution of motor commands. We can reduce such errors by both improving our estimates of the state of the world and through online error correction of the ongoing action. Two prominent frameworks that explain how humans solve these problems are Bayesian estimation and stochastic optimal feedback control. Here we examine the interaction between estimation and control by asking if uncertainty in estimates affects how subjects correct for errors that may arise during the movement. Unbeknownst to participants, we randomly shifted the visual feedback of their finger position as they reached to indicate the center of mass of an object. Even though participants were given ample time to compensate for this perturbation, they only fully corrected for the induced error on trials with low uncertainty about center of mass, with correction only partial in trials involving more uncertainty. The analysis of subjects' scores revealed that participants corrected for errors just enough to avoid significant decrease in their overall scores, in agreement with the minimal intervention principle of optimal feedback control. We explain this behavior with a term in the loss function that accounts for the additional effort of adjusting one's response. By suggesting that subjects' decision uncertainty, as reflected in their posterior distribution, is a major factor in determining how their sensorimotor system responds to error, our findings support theoretical models in which the decision making and control processes are fully integrated.

  13. Improving ESL Writing Using an Online Formulaic Sequence Word-Combination Checker

    ERIC Educational Resources Information Center

    Grami, G. M. A.; Alkazemi, B. Y.

    2016-01-01

    Writing correct English sentences can be challenging. Furthermore, writing correct formulaic sequences can be especially difficult because accepted combinations do not follow clear rules governing which words appear together in a sequence. One solution is to provide examples of correct usage accompanied by statistical feedback from web-based…

  14. The benefits of computer-generated feedback for mathematics problem solving.

    PubMed

    Fyfe, Emily R; Rittle-Johnson, Bethany

    2016-07-01

    The goal of the current research was to better understand when and why feedback has positive effects on learning and to identify features of feedback that may improve its efficacy. In a randomized experiment, second-grade children received instruction on a correct problem-solving strategy and then solved a set of relevant problems. Children were assigned to receive no feedback, immediate feedback, or summative feedback from the computer. On a posttest the following day, feedback resulted in higher scores relative to no feedback for children who started with low prior knowledge. Immediate feedback was particularly effective, facilitating mastery of the material for children with both low and high prior knowledge. Results suggest that minimal computer-generated feedback can be a powerful form of guidance during problem solving. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. [Anesthetic complications in sequential bipulmonary transplantation in patients with cystic fibrosis. Apropos of 6 cases].

    PubMed

    López, L M; Vicente, R; Ramos, F; Palacios, L; Calvo, A; Hernández, S; Borro, J M; Morales, P; Montero, R

    1996-03-01

    Cystic fibrosis (CF) is a disease characterized mainly by altered exocrine gland function that eventually produces irreversible dysfunction of the pancreas and lungs. The respiratory insufficiency that develops in CF patients in the advanced stages of disease can only be corrected at this time by lung or heart-lung transplantation. We describe our experience with 6 terminal phase CF patients who underwent sequential double lung transplantation (SDLT). Anesthesia was intravenous, with exhaustive hemodynamic and respiratory monitoring. During surgery the most frequently encountered hemodynamic complications were low minute volume, arterial hypotension and irregular heart rate. The main respiratory complications were hypoxemia, hypercapnia and pulmonary edema of the implanted lung, which developed in all cases to varying degrees related to the organ's state of preservation and duration of ischemia. Other complications were the need for extracorporeal circulation in 1 case, oliguria and blood loss requiring multiple transfusions. The most critical moments were at the time of clamping the pulmonary artery, the period after revascularization of the donated lung, and at the start of patient ventilation through the first implanted lung so that the second could be implanted. Although our series is small, it is of interest given the limited Spanish experience with lung transplantation in CF patients, and the good early results obtained, which are similar to those reported for other diseases.

  16. [Mucoviscidosis: CFTR mutation-specific therapy: a ray of sunshine in a cloudy sky].

    PubMed

    Leonard, A; Leal, T; Lebecque, P

    2013-01-01

    There is a need to find a cure for pulmonary disease in cystic fibrosis (CF), though full benefit of this approach will be restricted to those patients with well-preserved lungs. The most promising route is currently that of a pharmacological mutation-specific approach aiming at correcting the mechanism by which mutations lead to impairment of chloride conductance across respiratory epithelial cells. In the past 14years, 7 candidate drugs (CPX, 4PBA, gentamicin, PTC124, VX-770 or Ivacaftor, VX-809 or Lumacaftor, and Miglustat) have been investigated in CF patients. A postulate of 14 out of the 15 published studies has been that an effective agent had to improve total chloride secretion as assessed in vivo by nasal potential difference measurements. The present review casts a critical look at these studies. Apparent inconsistencies are discussed as well as possible limitations of nasal potential difference measurements as outcome parameters in these trials. Primarily targeting a mutation carried by less than 2% of French CF patients, the 2 Ivacaftor studies could well be a milestone on the long road toward a cure for CF. However, further data on safety and long-term efficacy are obviously needed and the current price of this medication in the US would make it unaffordable for European patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Supine posture changes lung volumes and increases ventilation heterogeneity in cystic fibrosis.

    PubMed

    Smith, Laurie J; Macleod, Kenneth A; Collier, Guilhem J; Horn, Felix C; Sheridan, Helen; Aldag, Ina; Taylor, Chris J; Cunningham, Steve; Wild, Jim M; Horsley, Alex

    2017-01-01

    Lung Clearance Index (LCI) is recognised as an early marker of cystic fibrosis (CF) lung disease. The effect of posture on LCI however is important when considering longitudinal measurements from infancy and when comparing LCI to imaging studies. 35 children with CF and 28 healthy controls (HC) were assessed. Multiple breath washout (MBW) was performed both sitting and supine in triplicate and analysed for LCI, Scond, Sacin, and lung volumes. These values were also corrected for the Fowler dead-space to create 'alveolar' indices. From sitting to supine there was a significant increase in LCI and a significant decrease in FRC for both CF and HC (p<0.01). LCI, when adjusted to estimate 'alveolar' LCI (LCIalv), increased the magnitude of change with posture for both LCIalv and FRCalv in both groups, with a greater effect of change in lung volume in HC compared with children with CF. The % change in LCIalv for all subjects correlated significantly with lung volume % changes, most notably tidal volume/functional residual capacity (Vtalv/FRCalv (r = 0.54,p<0.001)). There is a significant increase in LCI from sitting to supine, which we believe to be in part due to changes in lung volume and also increasing ventilation heterogeneity related to posture. This may have implications in longitudinal measurements from infancy to older childhood and for studies comparing supine imaging methods to LCI.

  18. A further note on the scientific name of Bullocks’ Oriole

    USGS Publications Warehouse

    Chesser, R. Terry

    2015-01-01

    Chesser (2013) intended to introduce a justified emendation to Icterus bullockii under Article 32.5.1 of the Code (ICZN 1999), because the name honors both William Bullock, Sr., and William Bullock, Jr. However, the correction bullockorum is "incorrect" and therefore is an unjustified emendation (Article 33.2.3). Under the assumption that the name Bullock was latinized (cf. Article 31.1.1) to Bullockius (bullocki– + the nominative case ending –us) and therefore that the name bullockii comprises the stem bullocki– + the genitive case ending –i, the justified correction bullockiorum is required.

  19. Speaking out on Behalf of the Voiceless Learners: Written Corrective Feedback for English Language Learners in Iran

    ERIC Educational Resources Information Center

    Nemati, Majid; Alavi, Sayyed Mohammad; Mohebbi, Hassan; Masjedlou, Ali Panahi

    2017-01-01

    To date, L2 researchers have studied the effect of feedback on improving L2 learners' writing from different perspectives. However, there are a lot of aspects which are not comprehensively researched yet, such as L2 learners' and teachers' perceptions and practices about feedback. To close the gap, this study investigates language learners'…

  20. Factors Influencing Oral Corrective Feedback Provision in the Spanish Foreign Language Classroom: Investigating Instructor Native/Nonnative Speaker Status, SLA Education, & Teaching Experience

    ERIC Educational Resources Information Center

    Gurzynski-Weiss, Laura

    2010-01-01

    The role of interactional feedback has been a critical area of second language acquisition (SLA) research for decades and while findings suggest interactional feedback can facilitate SLA, the extent of its influence can vary depending on a number of factors, including the native language of those involved in communication. Although studies have…

  1. "Coded and Uncoded Error Feedback: Effects on Error Frequencies in Adult Colombian EFL Learners' Writing"

    ERIC Educational Resources Information Center

    Sampson, Andrew

    2012-01-01

    This paper reports on a small-scale study into the effects of uncoded correction (writing the correct forms above each error) and coded annotations (writing symbols that encourage learners to self-correct) on Colombian university-level EFL learners' written work. The study finds that while both coded annotations and uncoded correction appear to…

  2. Balanced Cortical Microcircuitry for Spatial Working Memory Based on Corrective Feedback Control

    PubMed Central

    2014-01-01

    A hallmark of working memory is the ability to maintain graded representations of both the spatial location and amplitude of a memorized stimulus. Previous work has identified a neural correlate of spatial working memory in the persistent maintenance of spatially specific patterns of neural activity. How such activity is maintained by neocortical circuits remains unknown. Traditional models of working memory maintain analog representations of either the spatial location or the amplitude of a stimulus, but not both. Furthermore, although most previous models require local excitation and lateral inhibition to maintain spatially localized persistent activity stably, the substrate for lateral inhibitory feedback pathways is unclear. Here, we suggest an alternative model for spatial working memory that is capable of maintaining analog representations of both the spatial location and amplitude of a stimulus, and that does not rely on long-range feedback inhibition. The model consists of a functionally columnar network of recurrently connected excitatory and inhibitory neural populations. When excitation and inhibition are balanced in strength but offset in time, drifts in activity trigger spatially specific negative feedback that corrects memory decay. The resulting networks can temporally integrate inputs at any spatial location, are robust against many commonly considered perturbations in network parameters, and, when implemented in a spiking model, generate irregular neural firing characteristic of that observed experimentally during persistent activity. This work suggests balanced excitatory–inhibitory memory circuits implementing corrective negative feedback as a substrate for spatial working memory. PMID:24828633

  3. Seeing the Errors You Feel Enhances Locomotor Performance but Not Learning.

    PubMed

    Roemmich, Ryan T; Long, Andrew W; Bastian, Amy J

    2016-10-24

    In human motor learning, it is thought that the more information we have about our errors, the faster we learn. Here, we show that additional error information can lead to improved motor performance without any concomitant improvement in learning. We studied split-belt treadmill walking that drives people to learn a new gait pattern using sensory prediction errors detected by proprioceptive feedback. When we also provided visual error feedback, participants acquired the new walking pattern far more rapidly and showed accelerated restoration of the normal walking pattern during washout. However, when the visual error feedback was removed during either learning or washout, errors reappeared with performance immediately returning to the level expected based on proprioceptive learning alone. These findings support a model with two mechanisms: a dual-rate adaptation process that learns invariantly from sensory prediction error detected by proprioception and a visual-feedback-dependent process that monitors learning and corrects residual errors but shows no learning itself. We show that our voluntary correction model accurately predicted behavior in multiple situations where visual feedback was used to change acquisition of new walking patterns while the underlying learning was unaffected. The computational and behavioral framework proposed here suggests that parallel learning and error correction systems allow us to rapidly satisfy task demands without necessarily committing to learning, as the relative permanence of learning may be inappropriate or inefficient when facing environments that are liable to change. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Evaluation of sea-surface photosynthetically available radiation algorithms under various sky conditions and solar elevations.

    PubMed

    Somayajula, Srikanth Ayyala; Devred, Emmanuel; Bélanger, Simon; Antoine, David; Vellucci, V; Babin, Marcel

    2018-04-20

    In this study, we report on the performance of satellite-based photosynthetically available radiation (PAR) algorithms used in published oceanic primary production models. The performance of these algorithms was evaluated using buoy observations under clear and cloudy skies, and for the particular case of low sun angles typically encountered at high latitudes or at moderate latitudes in winter. The PAR models consisted of (i) the standard one from the NASA-Ocean Biology Processing Group (OBPG), (ii) the Gregg and Carder (GC) semi-analytical clear-sky model, and (iii) look-up-tables based on the Santa Barbara DISORT atmospheric radiative transfer (SBDART) model. Various combinations of atmospheric inputs, empirical cloud corrections, and semi-analytical irradiance models yielded a total of 13 (11 + 2 developed in this study) different PAR products, which were compared with in situ measurements collected at high frequency (15 min) at a buoy site in the Mediterranean Sea (the "BOUée pour l'acquiSition d'une Série Optique à Long termE," or, "BOUSSOLE" site). An objective ranking method applied to the algorithm results indicated that seven PAR products out of 13 were well in agreement with the in situ measurements. Specifically, the OBPG method showed the best overall performance with a root mean square difference (RMSD) (bias) of 19.7% (6.6%) and 10% (6.3%) followed by the look-up-table method with a RMSD (bias) of 25.5% (6.8%) and 9.6% (2.6%) at daily and monthly scales, respectively. Among the four methods based on clear-sky PAR empirically corrected for cloud cover, the Dobson and Smith method consistently underestimated daily PAR while the Budyko formulation overestimated daily PAR. Empirically cloud-corrected methods using cloud fraction (CF) performed better under quasi-clear skies (CF<0.3) with an RMSD (bias) of 9.7%-14.8% (3.6%-11.3%) than under partially clear to cloudy skies (0.30.7), however, all methods showed larger RMSD differences (biases) ranging between 32% and 80.6% (-54.5%-8.7%). Finally, three methods tested for low sun elevations revealed systematic overestimation, and one method showed a systematic underestimation of daily PAR, with relative RMSDs as large as 50% under all sky conditions. Under partially clear to overcast conditions all the methods underestimated PAR. Model uncertainties predominantly depend on which cloud products were used.

  5. 77 FR 64543 - Notice of Availability of the Final Environmental Impact Statement for the Mount Hope Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLNVB01000 L51100000.GN0000.LVEMF12CF010 241A; NVN-082096; NVN-084632; NVN-091272; 12-08807; MO 4500039779; TAS: 14X5017] Notice of Availability of the Final Environmental Impact Statement for the Mount Hope Project, Eureka County, NV Correction...

  6. 78 FR 34282 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ... this proposal in light of the comments we receive. Discussion Transport Canada (TC), which is the aviation authority for Canada, has issued TC AD No. CF-2005-28R1, dated June 14, 2007, to correct an unsafe condition for certain Model 206L-3 and 206L-4 helicopters. TC advises of several failures of third stage...

  7. 78 FR 34290 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    .... Discussion Transport Canada (TC), which is the aviation authority for Canada, has issued TC AD No. CF-2005-25, dated July 5, 2005, to correct an unsafe condition for Model 430 helicopters. TC advises of several... turbine wheel is installed on the 250-C40B engine used by Bell on Model 430 helicopters. According to TC...

  8. Calibration of neutron detectors on the Joint European Torus.

    PubMed

    Batistoni, Paola; Popovichev, S; Conroy, S; Lengar, I; Čufar, A; Abhangi, M; Snoj, L; Horton, L

    2017-10-01

    The present paper describes the findings of the calibration of the neutron yield monitors on the Joint European Torus (JET) performed in 2013 using a 252 Cf source deployed inside the torus by the remote handling system, with particular regard to the calibration of fission chambers which provide the time resolved neutron yield from JET plasmas. The experimental data obtained in toroidal, radial, and vertical scans are presented. These data are first analysed following an analytical approach adopted in the previous neutron calibrations at JET. In this way, a calibration function for the volumetric plasma source is derived which allows us to understand the importance of the different plasma regions and of different spatial profiles of neutron emissivity on fission chamber response. Neutronics analyses have also been performed to calculate the correction factors needed to derive the plasma calibration factors taking into account the different energy spectrum and angular emission distribution of the calibrating (point) 252 Cf source, the discrete positions compared to the plasma volumetric source, and the calibration circumstances. All correction factors are presented and discussed. We discuss also the lessons learnt which are the basis for the on-going 14 MeV neutron calibration at JET and for ITER.

  9. Atmospheric Degradation Initiated by OH Radicals of the Potential Foam Expansion Agent, CF3(CF2)2CH═CH2 (HFC-1447fz): Kinetics and Formation of Gaseous Products and Secondary Organic Aerosols.

    PubMed

    Jiménez, Elena; González, Sergio; Cazaunau, Mathieu; Chen, Hui; Ballesteros, Bernabé; Daële, Véronique; Albaladejo, José; Mellouki, Abdelwahid

    2016-02-02

    The assessment of the atmospheric impact of the potential foam expansion agent, CF3(CF2)2CH═CH2 (HFC-1447fz), requires the knowledge of its degradation routes, oxidation products, and radiative properties. In this paper, the gas-phase reactivity of HFC-1447fz with OH radicals is presented as a function of temperature, obtaining kOH (T = 263-358 K) = (7.4 ± 0.4) × 10(-13)exp{(161 ± 16)/T} (cm(3)·molecule(-1)·s(-1)) (uncertainties: ±2σ). The formation of gaseous oxidation products and secondary organic aerosols (SOAs) from the OH + HFC-1447fz reaction was investigated in the presence of NOx at 298 K. CF3(CF2)2CHO was observed at low- and high-NOx conditions. Evidence of SOA formation (ultrafine particles in the range 10-100 nm) is reported with yields ranging from 0.12 to 1.79%. In addition, the absolute UV (190-368 nm) and IR (500-4000 cm(-1)) absorption cross-sections of HFC-1447fz were determined at room temperature. No appreciable absorption in the solar actinic region (λ > 290 nm) was observed, leaving the removal by OH radicals as the main atmospheric loss process for HFC-1447fz. The major contribution of the atmospheric loss of HFC-1447fz is due to OH reaction (84%), followed by ozone (10%) and chlorine atoms (6%). Correction of the instantaneous radiative efficiency (0.36 W m(-2)·ppbv(-1)) with the relatively short lifetime of HFC-1447fz (ca. 8 days) implies that its global warming potential at a time horizon of 100 year is negligible (0.19) compared to that of HCFC-141b (782) and to that of modern foam-expansion blowing agents (148, 882, and 804 for HFC-152a, HFC-245fa and HFC-365mfc, respectively).

  10. Genetic Correction of Induced Pluripotent Stem Cells From a Deaf Patient With MYO7A Mutation Results in Morphologic and Functional Recovery of the Derived Hair Cell-Like Cells.

    PubMed

    Tang, Zi-Hua; Chen, Jia-Rong; Zheng, Jing; Shi, Hao-Song; Ding, Jie; Qian, Xiao-Dan; Zhang, Cui; Chen, Jian-Ling; Wang, Cui-Cui; Li, Liang; Chen, Jun-Zhen; Yin, Shan-Kai; Huang, Tao-Sheng; Chen, Ping; Guan, Min-Xin; Wang, Jin-Fu

    2016-05-01

    The genetic correction of induced pluripotent stem cells (iPSCs) induced from somatic cells of patients with sensorineural hearing loss (caused by hereditary factors) is a promising method for its treatment. The correction of gene mutations in iPSCs could restore the normal function of cells and provide a rich source of cells for transplantation. In the present study, iPSCs were generated from a deaf patient with compound heterozygous MYO7A mutations (c.1184G>A and c.4118C>T; P-iPSCs), the asymptomatic father of the patient (MYO7A c.1184G>A mutation; CF-iPSCs), and a normal donor (MYO7A(WT/WT); C-iPSCs). One of MYO7A mutation sites (c.4118C>T) in the P-iPSCs was corrected using CRISPR/Cas9. The corrected iPSCs (CP-iPSCs) retained cell pluripotency and normal karyotypes. Hair cell-like cells induced from CP-iPSCs showed restored organization of stereocilia-like protrusions; moreover, the electrophysiological function of these cells was similar to that of cells induced from C-iPSCs and CF-iPSCs. These results might facilitate the development of iPSC-based gene therapy for genetic disorders. Induced pluripotent stem cells (iPSCs) were generated from a deaf patient with compound heterozygous MYO7A mutations (c.1184G>A and c.4118C>T). One of the MYO7A mutation sites (c.4118C>T) in the iPSCs was corrected using CRISPR/Cas9. The genetic correction of MYO7A mutation resulted in morphologic and functional recovery of hair cell-like cells derived from iPSCs. These findings confirm the hypothesis that MYO7A plays an important role in the assembly of stereocilia into stereociliary bundles. Thus, the present study might provide further insight into the pathogenesis of sensorineural hearing loss and facilitate the development of therapeutic strategies against monogenic disease through the genetic repair of patient-specific iPSCs. ©AlphaMed Press.

  11. Genetic Correction of Induced Pluripotent Stem Cells From a Deaf Patient With MYO7A Mutation Results in Morphologic and Functional Recovery of the Derived Hair Cell-Like Cells

    PubMed Central

    Tang, Zi-Hua; Chen, Jia-Rong; Zheng, Jing; Shi, Hao-Song; Ding, Jie; Qian, Xiao-Dan; Zhang, Cui; Chen, Jian-Ling; Wang, Cui-Cui; Li, Liang; Chen, Jun-Zhen; Yin, Shan-Kai; Huang, Tao-Sheng; Chen, Ping; Guan, Min-Xin

    2016-01-01

    The genetic correction of induced pluripotent stem cells (iPSCs) induced from somatic cells of patients with sensorineural hearing loss (caused by hereditary factors) is a promising method for its treatment. The correction of gene mutations in iPSCs could restore the normal function of cells and provide a rich source of cells for transplantation. In the present study, iPSCs were generated from a deaf patient with compound heterozygous MYO7A mutations (c.1184G>A and c.4118C>T; P-iPSCs), the asymptomatic father of the patient (MYO7A c.1184G>A mutation; CF-iPSCs), and a normal donor (MYO7AWT/WT; C-iPSCs). One of MYO7A mutation sites (c.4118C>T) in the P-iPSCs was corrected using CRISPR/Cas9. The corrected iPSCs (CP-iPSCs) retained cell pluripotency and normal karyotypes. Hair cell-like cells induced from CP-iPSCs showed restored organization of stereocilia-like protrusions; moreover, the electrophysiological function of these cells was similar to that of cells induced from C-iPSCs and CF-iPSCs. These results might facilitate the development of iPSC-based gene therapy for genetic disorders. Significance Induced pluripotent stem cells (iPSCs) were generated from a deaf patient with compound heterozygous MYO7A mutations (c.1184G>A and c.4118C>T). One of the MYO7A mutation sites (c.4118C>T) in the iPSCs was corrected using CRISPR/Cas9. The genetic correction of MYO7A mutation resulted in morphologic and functional recovery of hair cell-like cells derived from iPSCs. These findings confirm the hypothesis that MYO7A plays an important role in the assembly of stereocilia into stereociliary bundles. Thus, the present study might provide further insight into the pathogenesis of sensorineural hearing loss and facilitate the development of therapeutic strategies against monogenic disease through the genetic repair of patient-specific iPSCs. PMID:27013738

  12. Elaborated Corrective Feedback and the Acquisition of Reasoning Skills: A Study of Computer-Assisted Instruction.

    ERIC Educational Resources Information Center

    Collins, Maria; And Others

    1987-01-01

    Thirteen learning disabled and 15 remedial high school students were taught reasoning skills using computer-assisted instruction and were given basic or elaborated corrections. Criterion-referenced test scores were significantly higher for the elaborated-corrections treatment on the post- and maintenance tests and on a transfer test assessing…

  13. CFTR rescue with VX-809 and VX-770 favors the repair of primary airway epithelial cell cultures from patients with class II mutations in the presence of Pseudomonas aeruginosa exoproducts.

    PubMed

    Adam, Damien; Bilodeau, Claudia; Sognigbé, Laura; Maillé, Émilie; Ruffin, Manon; Brochiero, Emmanuelle

    2018-04-13

    Progressive airway damage due to bacterial infections, especially with Pseudomonas aeruginosa remains the first cause of morbidity and mortality in CF patients. Our previous work revealed a repair delay in CF airway epithelia compared to non-CF. This delay was partially prevented after CFTR correction (with VRT-325) in the absence of infection. Our goals were now to evaluate the effect of the Orkambi combination (CFTR VX-809 corrector + VX-770 potentiator) on the repair of CF primary airway epithelia, in infectious conditions. Primary airway epithelial cell cultures from patients with class II mutations were mechanically injured and wound healing rates and transepithelial resistances were monitored after CFTR rescue, in the absence and presence of P. aeruginosa exoproducts. Our data revealed that combined treatment with VX-809 and VX-770 elicited a greater beneficial impact on airway epithelial repair than VX-809 alone, in the absence of infection. The treatment with Orkambi was effective not only in airway epithelial cell cultures from patients homozygous for the F508del mutation but also from heterozygous patients carrying F508del and another class II mutation (N1303 K, I507del). The stimulatory effect of the Orkambi treatment was prevented by CFTR inhibition with GlyH101. Finally, Orkambi combination elicited a slight but significant improvement in airway epithelial repair and transepithelial resistance, despite the presence of P. aeruginosa exoproducts. Our findings indicate that Orkambi may favor airway epithelial integrity in CF patients with class II mutations. Complementary approaches would however be needed to further improve CFTR rescue and airway epithelial repair. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  14. In vitro pharmacologic restoration of CFTR-mediated chloride transport with sodium 4-phenylbutyrate in cystic fibrosis epithelial cells containing delta F508-CFTR.

    PubMed Central

    Rubenstein, R C; Egan, M E; Zeitlin, P L

    1997-01-01

    The most common cystic fibrosis transmembrane conductance regulator mutation, delta F508-CFTR, is a partially functional chloride channel that is retained in the endoplasmic reticulum and degraded. We hypothesize that a known transcriptional regulator, sodium 4-phenylbutyrate (4PBA), will enable a greater fraction of delta F508-CFTR to escape degradation and appear at the cell surface. Primary cultures of nasal polyp epithelia from CF patients (delta F508 homozygous or heterozygous), or the CF bronchial epithelial cell line IB3-1 (delta F508/W1282X) were exposed to 4PBA for up to 7 d in culture. 4PBA treatment at concentrations of 0.1 and 2 mM resulted in the restoration of forskolin-activated chloride secretion. Protein kinase A-activated, linear, 10 pS chloride channels appeared at the plasma membrane of IB3-1 cells at the tested concentration of 2.5 mM. Treatment of IB3-1 cells with 0.1-1 mM 4PBA and primary nasal epithelia with 5 mM 4PBA also resulted in the appearance of higher molecular mass forms of CFTR consistent with addition and modification of oligosaccharides in the Golgi apparatus, as detected by immunoblotting of whole cell lysates with anti-CFTR antisera. Immunocytochemistry in CF epithelial cells treated with 4PBA was consistent with increasing amounts of delta F508-CFTR. These data indicate that 4PBA is a promising pharmacologic agent for inducing correction of the CF phenotype in CF patients carrying the delta F508 mutation. PMID:9366560

  15. In vitro pharmacologic restoration of CFTR-mediated chloride transport with sodium 4-phenylbutyrate in cystic fibrosis epithelial cells containing delta F508-CFTR.

    PubMed

    Rubenstein, R C; Egan, M E; Zeitlin, P L

    1997-11-15

    The most common cystic fibrosis transmembrane conductance regulator mutation, delta F508-CFTR, is a partially functional chloride channel that is retained in the endoplasmic reticulum and degraded. We hypothesize that a known transcriptional regulator, sodium 4-phenylbutyrate (4PBA), will enable a greater fraction of delta F508-CFTR to escape degradation and appear at the cell surface. Primary cultures of nasal polyp epithelia from CF patients (delta F508 homozygous or heterozygous), or the CF bronchial epithelial cell line IB3-1 (delta F508/W1282X) were exposed to 4PBA for up to 7 d in culture. 4PBA treatment at concentrations of 0.1 and 2 mM resulted in the restoration of forskolin-activated chloride secretion. Protein kinase A-activated, linear, 10 pS chloride channels appeared at the plasma membrane of IB3-1 cells at the tested concentration of 2.5 mM. Treatment of IB3-1 cells with 0.1-1 mM 4PBA and primary nasal epithelia with 5 mM 4PBA also resulted in the appearance of higher molecular mass forms of CFTR consistent with addition and modification of oligosaccharides in the Golgi apparatus, as detected by immunoblotting of whole cell lysates with anti-CFTR antisera. Immunocytochemistry in CF epithelial cells treated with 4PBA was consistent with increasing amounts of delta F508-CFTR. These data indicate that 4PBA is a promising pharmacologic agent for inducing correction of the CF phenotype in CF patients carrying the delta F508 mutation.

  16. Comparison of digital color fundus imaging and fluorescein angiographic findings for the early detection of diabetic retinopathy in young type 1 diabetic patients.

    PubMed

    Kapsala, Z; Anastasakis, A; Mamoulakis, D; Maniadaki, I; Tsilimbaris, M

    2018-01-01

    To compare the findings from digital 7-field color fundus (CF) photography and fundus fluorescein angiography (FFA) in young patients with diabetes mellitus (DM) type 1 without known diabetic retinopathy. In this prospective, observational cohort study, 54 type 1 diabetic patients were recruited. Participants had been diagnosed with diabetes mellitus (DM) for at least 6 years, had Best Corrected Visual Acuity of 20/25 or better and did not have any known retinal pathology. One hundred and seven eyes were analyzed. All patients underwent a complete ophthalmic examination in the Retina Service of a University Eye Clinic including digital CF imaging and FFA. The mean age of the patients was 18.6 years. Mean duration of DM was 11.3 years, and mean haemoglobin A1c (HbA1c) level was 8.6%. Of the 107 eyes, 8 eyes (7.5%) showed microvascular abnormalities on CF images, while FFA images revealed changes in 26 eyes (24.3%). Hence, 18 of the 26 eyes showing abnormalities on FFA did not show any abnormalities on CF images. Mean DM duration in the patient group with detectable microvascular changes was found to be significantly higher compared to patients without changes, while no difference in HbA1c levels, serum lipid levels or blood pressure was observed. Comparison of digital CF and FFA findings for the detection of diabetic microvascular changes in type 1 diabetic patients showed that FFA reveals more information about retinal vascular pathology for early detection of diabetic retinopathy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Galectin-9 Signaling through TIM-3 Is Involved in Neutrophil-Mediated Gram-Negative Bacterial Killing: An Effect Abrogated within the Cystic Fibrosis Lung

    PubMed Central

    Vega-Carrascal, Isabel; Bergin, David A.; McElvaney, Oliver J.; McCarthy, Cormac; Banville, Nessa; Pohl, Kerstin; Hirashima, Mitsuomi; Kuchroo, Vijay K.; Reeves, Emer P.; McElvaney, Noel G.

    2016-01-01

    The T cell Ig and mucin domain–containing molecule (TIM) family of receptors have emerged as potential therapeutic targets to correct abnormal immune function in chronic inflammatory conditions. TIM-3 serves as a functional receptor in structural cells of the airways and via the ligand galectin-9 (Gal-9) can modulate the inflammatory response. The aim of this study was to investigate TIM-3 expression and function in neutrophils, focusing on its potential role in cystic fibrosis (CF) lung disease. Results revealed that TIM-3 mRNA and protein expression values of circulating neutrophils were equal between healthy controls (n = 20) and people with CF (n = 26). TIM-3 was detected on resting neutrophil membranes by FACS analysis, and expression levels significantly increased post IL-8 or TNF-α exposure (p < 0.05). Our data suggest a novel role for TIM-3/Gal-9 signaling involving modulation of cytosolic calcium levels. Via TIM-3 interaction, Gal-9 induced neutrophil degranulation and primed the cell for enhanced NADPH oxidase activity. Killing of Pseudomonas aeruginosa was significantly increased upon bacterial opsonization with Gal-9 (p < 0.05), an effect abrogated by blockade of TIM-3 receptors. This mechanism appeared to be Gram-negative bacteria specific and mediated via Gal-9/ LPS binding. Additionally, we have demonstrated that neutrophil TIM-3/Gal-9 signaling is perturbed in the CF airways due to proteolytic degradation of the receptor. In conclusion, results suggest a novel neutrophil defect potentially contributing to the defective bacterial clearance observed in the CF airways and suggest that manipulation of the TIM-3 signaling pathway may be of therapeutic value in CF, preferably in conjunction with antiprotease treatment. PMID:24477913

  18. Quorum Sensing Down-Regulation Counteracts the Negative Impact of Pseudomonas aeruginosa on CFTR Channel Expression, Function and Rescue in Human Airway Epithelial Cells

    PubMed Central

    Maillé, Émilie; Ruffin, Manon; Adam, Damien; Messaoud, Hatem; Lafayette, Shantelle L.; McKay, Geoffrey; Nguyen, Dao; Brochiero, Emmanuelle

    2017-01-01

    The function of cystic fibrosis transmembrane conductance regulator (CFTR) channels is crucial in human airways. However unfortunately, chronic Pseudomonas aeruginosa infection has been shown to impair CFTR proteins in non-CF airway epithelial cells (AEC) and to alter the efficiency of new treatments with CFTR modulators designed to correct the basic CFTR default in AEC from cystic fibrosis (CF) patients carrying the F508del mutation. Our aim was first to compare the effect of laboratory strains, clinical isolates, engineered and natural mutants to determine the role of the LasR quorum sensing system in CFTR impairment, and second, to test the efficiency of a quorum sensing inhibitor to counteract the deleterious impact of P. aeruginosa both on wt-CFTR and on the rescue of F508del-CFTR by correctors. We first report that exoproducts from either the laboratory PAO1 strain or a clinical ≪Early≫ isolate (from an early stage of infection) altered CFTR expression, localization and function in AEC expressing wt-CFTR. Genetic inactivation of the quorum-sensing LasR in PAO1 (PAO1ΔlasR) or in a natural clinical mutant (≪Late≫ CF-adapted clinical isolate) abolished wt-CFTR impairment. PAO1 exoproducts also dampened F508del-CFTR rescue by VRT-325 or Vx-809 correctors in CF cells, whereas PAO1ΔlasR had no impact. Importantly, treatment of P. aeruginosa cultures with a quorum sensing inhibitor (HDMF) prevented the negative effect of P. aeruginosa exoproducts on wt-CFTR and preserved CFTR rescue by correctors in CF AEC. These findings indicate that LasR-interfering strategies could be of benefits to counteract the deleterious effect of P. aeruginosa in infected patients. PMID:29177135

  19. Prevention of myopia by partial correction of hyperopia: a twins study.

    PubMed

    Medina, Antonio

    2018-04-01

    To confirm the prediction of emmetropization feedback theory that myopia can be prevented by correcting the hyperopia of a child at risk of becoming myopic. We conducted such myopia prevention treatment with twins at risk. Their hyperopia was partially corrected by one half at age 7 and in subsequent years until age 16. Hyperopia progressively decreased in all eyes as expected. None of the twins developed myopia. The spherical equivalent refractions of the followed eyes were +1 and +1.25 D at age 16. Feedback theory accurately predicted these values. The treatment of the twins with partial correction of their hyperopia was successful. Prevention of myopia with this technique is relatively simple and powerful. The use of this myopia prevention treatment has no adverse effects. This prevention treatment is indicated in children with a hyperopic reserve at risk of developing myopia.

  20. The effects of feedback on computer workstation posture habits.

    PubMed

    Epstein, Rhonda; Colford, Sean; Epstein, Ethan; Loye, Brandon; Walsh, Michael

    2012-01-01

    Repetitive stress injuries (RSI) and musculoskeletal disorders in the United States and worldwide are increasing at an alarming rate due to the advent of ubiquitous computer usage. Factors that lead to computer-related musculoskeletal disorders (MSD) include inadequately designed workstations, poor posture, and lack of knowledge about proper ergonomics and use habits. Studies have documented the negative impact of improper posture and the MSD seen in students and office workers due to frequent computer usage. Determine if the frequency (single vs. continuous reminder) and/or use of feedback affects posture at a computer workstation. Observations of posture habits were made in three local schools and one local company. Feedback effects were tested on the students (ages 10-15). Real time feedback was given in two studies. In one study, instructions and a verbal reminder were given to students and in a second study, a prototype 'Posture Pad' was developed to provide continuous feedback to the user. Verbal reminders to sit correctly led to transient improvement of posture. Use of the 'Posture Pad' resulted in significant improvement in posture with subjects exhibiting correct posture 98 ± 5% of the time. Real time feedback about how one is sitting is an effective mechanism for non-transient improvement of posture at computer workstations.

  1. Probabilistic Category Learning in Developmental Dyslexia: Evidence from Feedback and Paired-Associate Weather Prediction Tasks

    PubMed Central

    Gabay, Yafit; Vakil, Eli; Schiff, Rachel; Holt, Lori L.

    2015-01-01

    Objective Developmental dyslexia is presumed to arise from specific phonological impairments. However, an emerging theoretical framework suggests that phonological impairments may be symptoms stemming from an underlying dysfunction of procedural learning. Method We tested procedural learning in adults with dyslexia (n=15) and matched-controls (n=15) using two versions of the Weather Prediction Task: Feedback (FB) and Paired-associate (PA). In the FB-based task, participants learned associations between cues and outcomes initially by guessing and subsequently through feedback indicating the correctness of response. In the PA-based learning task, participants viewed the cue and its associated outcome simultaneously without overt response or feedback. In both versions, participants trained across 150 trials. Learning was assessed in a subsequent test without presentation of the outcome, or corrective feedback. Results The Dyslexia group exhibited impaired learning compared with the Control group on both the FB and PA versions of the weather prediction task. Conclusions The results indicate that the ability to learn by feedback is not selectively impaired in dyslexia. Rather it seems that the probabilistic nature of the task, shared by the FB and PA versions of the weather prediction task, hampers learning in those with dyslexia. Results are discussed in light of procedural learning impairments among participants with dyslexia. PMID:25730732

  2. Feedback-based probabilistic category learning is selectively impaired in attention/hyperactivity deficit disorder.

    PubMed

    Gabay, Yafit; Goldfarb, Liat

    2017-07-01

    Although Attention-Deficit Hyperactivity Disorder (ADHD) is closely linked to executive function deficits, it has recently been attributed to procedural learning impairments that are quite distinct from the former. These observations challenge the ability of the executive function framework solely to account for the diverse range of symptoms observed in ADHD. A recent neurocomputational model emphasizes the role of striatal dopamine (DA) in explaining ADHD's broad range of deficits, but the link between this model and procedural learning impairments remains unclear. Significantly, feedback-based procedural learning is hypothesized to be disrupted in ADHD because of the involvement of striatal DA in this type of learning. In order to test this assumption, we employed two variants of a probabilistic category learning task known from the neuropsychological literature. Feedback-based (FB) and paired associate-based (PA) probabilistic category learning were employed in a non-medicated sample of ADHD participants and neurotypical participants. In the FB task, participants learned associations between cues and outcomes initially by guessing and subsequently through feedback indicating the correctness of the response. In the PA learning task, participants viewed the cue and its associated outcome simultaneously without receiving an overt response or corrective feedback. In both tasks, participants were trained across 150 trials. Learning was assessed in a subsequent test without a presentation of the outcome or corrective feedback. Results revealed an interesting disassociation in which ADHD participants performed as well as control participants in the PA task, but were impaired compared with the controls in the FB task. The learning curve during FB training differed between the two groups. Taken together, these results suggest that the ability to incrementally learn by feedback is selectively disrupted in ADHD participants. These results are discussed in relation to both the ADHD dopaminergic dysfunction model and recent findings implicating procedural learning impairments in those with ADHD. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Changes in Liver Volume in Patients with Chronic Hepatitis C Undergoing Antiviral Therapy

    PubMed Central

    Fitzpatrick, Julie A.; Kim, Jin Un; Cobbold, Jeremy F.L.; McPhail, Mark J.W.; Crossey, Mary M.E.; Bak-Bol, Aluel A.; Zaky, Ashraf; Taylor-Robinson, Simon D.

    2016-01-01

    Aim Liver volumetric analysis has not been used to detect hepatic remodelling during antiviral therapy before. We measured liver volume (LV) changes on volumetric magnetic resonance imaging during hepatitis C antiviral therapy. Methods 22 biopsy-staged patients (median [range] age 4519–65 years; 9F, 13M) with chronic hepatitis C virus infection were studied. LV was measured at the beginning, end of treatment and 6 months post-treatment using 3D T1-weighted acquisition, normalised to patient weight. Liver outlines were drawn manually on 4 mm thick image slices and LV calculated. Inter-observer agreement was analysed. Patients were also assessed longitudinally using biochemical parameters and liver stiffness using Fibroscan™. Results Sustained viral response (SVR) was achieved in 13 patients with a mean baseline LV/kg of 0.022 (SD 0.004) L/kg. At the end of treatment, the mean LV/kg was 0.025 (SD 0.004, P = 0.024 cf baseline LV/kg) and 0.026 (SD 0.004, P = 0.008 cf baseline LV/kg) 6 months post-treatment (P = 0.030 cf baseline, P = 0.004). Body weight-corrected end of treatment LV change was significantly higher in patients with SVR compared to patients not attaining SVR (P = 0.050). End of treatment LV change was correlated to initial ALT (R2 = 0.479, P = 0.037), but not APRI, AST, viral load or liver stiffness measurements. There was a correlation of 0.89 between observers for measured slice thickness. Conclusions LV increased during anti-viral treatment, while the body weight-corrected LV increase persisted post-antiviral therapy and was larger in patients with SVR. PMID:27194891

  4. Changes in Liver Volume in Patients with Chronic Hepatitis C Undergoing Antiviral Therapy.

    PubMed

    Fitzpatrick, Julie A; Kim, Jin Un; Cobbold, Jeremy F L; McPhail, Mark J W; Crossey, Mary M E; Bak-Bol, Aluel A; Zaky, Ashraf; Taylor-Robinson, Simon D

    2016-03-01

    Liver volumetric analysis has not been used to detect hepatic remodelling during antiviral therapy before. We measured liver volume (LV) changes on volumetric magnetic resonance imaging during hepatitis C antiviral therapy. 22 biopsy-staged patients (median [range] age 45(19-65) years; 9F, 13M) with chronic hepatitis C virus infection were studied. LV was measured at the beginning, end of treatment and 6 months post-treatment using 3D T1-weighted acquisition, normalised to patient weight. Liver outlines were drawn manually on 4 mm thick image slices and LV calculated. Inter-observer agreement was analysed. Patients were also assessed longitudinally using biochemical parameters and liver stiffness using Fibroscan™. Sustained viral response (SVR) was achieved in 13 patients with a mean baseline LV/kg of 0.022 (SD 0.004) L/kg. At the end of treatment, the mean LV/kg was 0.025 (SD 0.004, P = 0.024 cf baseline LV/kg) and 0.026 (SD 0.004, P = 0.008 cf baseline LV/kg) 6 months post-treatment (P = 0.030 cf baseline, P = 0.004). Body weight-corrected end of treatment LV change was significantly higher in patients with SVR compared to patients not attaining SVR (P = 0.050). End of treatment LV change was correlated to initial ALT (R (2) = 0.479, P = 0.037), but not APRI, AST, viral load or liver stiffness measurements. There was a correlation of 0.89 between observers for measured slice thickness. LV increased during anti-viral treatment, while the body weight-corrected LV increase persisted post-antiviral therapy and was larger in patients with SVR.

  5. Computed tomography correlates with improvement with ivacaftor in cystic fibrosis patients with G551D mutation.

    PubMed

    Sheikh, Shahid I; Long, Frederick R; McCoy, Karen S; Johnson, Terri; Ryan-Wenger, Nancy A; Hayes, Don

    2015-01-01

    Ivacaftor corrects the cystic fibrosis transmembrane conductance regulator (CFTR) gating defect associated with G551D mutation and is quickly becoming an important treatment in patients with cystic fibrosis (CF) due to this genetic mutation. A single-center study was performed in CF patients receiving ivacaftor to evaluate the usefulness of high resolution computed tomography (HRCT) of the chest as a way to gauge response to ivacaftor therapy. Ten patients with CF were enrolled for at least one year before and after starting ivacaftor. At time of enrollment, mean age was 20.9 ± 10.8 (range 10-44) years. There were significant improvements from baseline to 6 months in mean %FVC (93 ± 16 to 99 ± 16) and %FEV1 (79 ± 26 to 87 ± 28) but reverted to baseline at one year. Mean sweat chloride levels decreased significantly from baseline to one year. Mean weight and BMI improved at 6 months. Weight continued to improve with stabilization of BMI at one year. Chest HRCT showed significant improvement at one year in mean modified Brody scores for bronchiectasis, mucous plugging, airway wall thickness, and total Brody scores. Elevated bronchiectasis and airway wall thickness scores correlated significantly with lower %FEV1, while higher airway wall thickness and mucus plugging scores correlated with more pulmonary exacerbations requiring IV and oral antibiotics respectively. Based on our findings, HRCT imaging is a useful tool in monitoring response to ivacaftor therapy that corrects the gating defect associated with the G551D-CFTR mutation. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  6. Gene delivery to the lungs: pulmonary gene therapy for cystic fibrosis.

    PubMed

    Villate-Beitia, Ilia; Zarate, Jon; Puras, Gustavo; Pedraz, José Luis

    2017-07-01

    Cystic fibrosis (CF) is a monogenic autosomal recessive disorder where the defective gene, the cystic fibrosis transmembrane conductance regulator (CFTR), is well identified. Moreover, the respiratory tract can be targeted through noninvasive aerosolized formulations for inhalation. Therefore, gene therapy is considered a plausible strategy to address this disease. Conventional gene therapy strategies rely on the addition of a correct copy of the CFTR gene into affected cells in order to restore the channel activity. In recent years, genome correction strategies have emerged, such as zinc-finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats associated to Cas9 nucleases. These gene editing tools aim to repair the mutated gene at its original genomic locus with high specificity. Besides, the success of gene therapy critically depends on the nucleic acids carriers. To date, several clinical studies have been carried out to add corrected copies of the CFTR gene into target cells using viral and non-viral vectors, some of them with encouraging results. Regarding genome editing systems, preliminary in vitro studies have been performed in order to repair the CFTR gene. In this review, after briefly introducing the basis of CF, we discuss the up-to-date gene therapy strategies to address the disease. The review focuses on the main factors to take into consideration when developing gene delivery strategies, such as the design of vectors and plasmid DNA, in vitro/in vivo tests, translation to human use, administration methods, manufacturing conditions and regulatory issues.

  7. Why do beliefs about intelligence influence learning success? A social cognitive neuroscience model

    PubMed Central

    Mangels, Jennifer A.; Butterfield, Brady; Lamb, Justin; Good, Catherine; Dweck, Carol S.

    2006-01-01

    Students’ beliefs and goals can powerfully influence their learning success. Those who believe intelligence is a fixed entity (entity theorists) tend to emphasize ‘performance goals,’ leaving them vulnerable to negative feedback and likely to disengage from challenging learning opportunities. In contrast, students who believe intelligence is malleable (incremental theorists) tend to emphasize ‘learning goals’ and rebound better from occasional failures. Guided by cognitive neuroscience models of top–down, goal-directed behavior, we use event-related potentials (ERPs) to understand how these beliefs influence attention to information associated with successful error correction. Focusing on waveforms associated with conflict detection and error correction in a test of general knowledge, we found evidence indicating that entity theorists oriented differently toward negative performance feedback, as indicated by an enhanced anterior frontal P3 that was also positively correlated with concerns about proving ability relative to others. Yet, following negative feedback, entity theorists demonstrated less sustained memory-related activity (left temporal negativity) to corrective information, suggesting reduced effortful conceptual encoding of this material–a strategic approach that may have contributed to their reduced error correction on a subsequent surprise retest. These results suggest that beliefs can influence learning success through top–down biasing of attention and conceptual processing toward goal-congruent information. PMID:17392928

  8. The FARE Software

    ERIC Educational Resources Information Center

    Pitarello, Adriana

    2015-01-01

    This article highlights the importance of immediate corrective feedback in tutorial software for language teaching in an academic learning environment. We aim to demonstrate that, rather than simply reporting on the performance of the foreign language learner, this feedback can act as a mediator of students' cognitive and metacognitive activity.…

  9. Aspheric figure generation using feedback from an infrared phase-shifting interferometer.

    NASA Astrophysics Data System (ADS)

    Stahl, H. P.; Ketelsen, D.

    This paper discusses the usefulness of the infrared phase-shifting interferometric system for providing figure correcting feedback to the optician during the generation of the off-axis parabolic segments and how it is affected by the surface roughness produced by each generator tool.

  10. Impaired Feedforward Control and Enhanced Feedback Control of Speech in Patients with Cerebellar Degeneration

    PubMed Central

    Agnew, Zarinah; Nagarajan, Srikantan; Houde, John; Ivry, Richard B.

    2017-01-01

    The cerebellum has been hypothesized to form a crucial part of the speech motor control network. Evidence for this comes from patients with cerebellar damage, who exhibit a variety of speech deficits, as well as imaging studies showing cerebellar activation during speech production in healthy individuals. To date, the precise role of the cerebellum in speech motor control remains unclear, as it has been implicated in both anticipatory (feedforward) and reactive (feedback) control. Here, we assess both anticipatory and reactive aspects of speech motor control, comparing the performance of patients with cerebellar degeneration and matched controls. Experiment 1 tested feedforward control by examining speech adaptation across trials in response to a consistent perturbation of auditory feedback. Experiment 2 tested feedback control, examining online corrections in response to inconsistent perturbations of auditory feedback. Both male and female patients and controls were tested. The patients were impaired in adapting their feedforward control system relative to controls, exhibiting an attenuated anticipatory response to the perturbation. In contrast, the patients produced even larger compensatory responses than controls, suggesting an increased reliance on sensory feedback to guide speech articulation in this population. Together, these results suggest that the cerebellum is crucial for maintaining accurate feedforward control of speech, but relatively uninvolved in feedback control. SIGNIFICANCE STATEMENT Speech motor control is a complex activity that is thought to rely on both predictive, feedforward control as well as reactive, feedback control. While the cerebellum has been shown to be part of the speech motor control network, its functional contribution to feedback and feedforward control remains controversial. Here, we use real-time auditory perturbations of speech to show that patients with cerebellar degeneration are impaired in adapting feedforward control of speech but retain the ability to make online feedback corrections; indeed, the patients show an increased sensitivity to feedback. These results indicate that the cerebellum forms a crucial part of the feedforward control system for speech but is not essential for online, feedback control. PMID:28842410

  11. Movement goals and feedback and feedforward control mechanisms in speech production

    PubMed Central

    Perkell, Joseph S.

    2010-01-01

    Studies of speech motor control are described that support a theoretical framework in which fundamental control variables for phonemic movements are multi-dimensional regions in auditory and somatosensory spaces. Auditory feedback is used to acquire and maintain auditory goals and in the development and function of feedback and feedforward control mechanisms. Several lines of evidence support the idea that speakers with more acute sensory discrimination acquire more distinct goal regions and therefore produce speech sounds with greater contrast. Feedback modification findings indicate that fluently produced sound sequences are encoded as feedforward commands, and feedback control serves to correct mismatches between expected and produced sensory consequences. PMID:22661828

  12. Movement goals and feedback and feedforward control mechanisms in speech production.

    PubMed

    Perkell, Joseph S

    2012-09-01

    Studies of speech motor control are described that support a theoretical framework in which fundamental control variables for phonemic movements are multi-dimensional regions in auditory and somatosensory spaces. Auditory feedback is used to acquire and maintain auditory goals and in the development and function of feedback and feedforward control mechanisms. Several lines of evidence support the idea that speakers with more acute sensory discrimination acquire more distinct goal regions and therefore produce speech sounds with greater contrast. Feedback modification findings indicate that fluently produced sound sequences are encoded as feedforward commands, and feedback control serves to correct mismatches between expected and produced sensory consequences.

  13. 78 FR 1901 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... Direct Edge ECN LLC (``DE ECN''), DE ECN is no longer a facility of the Exchange, and ISE (including its...-reference number in paragraph (a), as well as to add non-substantive words to correct the sentence structure..., competition, and capital formation. See 15 U.S.C. 78c(f). At any time within 60 days of the filing of the...

  14. Analytically exploiting noise correlations inside the feedback loop to improve locked-oscillator performance.

    PubMed

    Sastrawan, J; Jones, C; Akhalwaya, I; Uys, H; Biercuk, M J

    2016-08-01

    We introduce concepts from optimal estimation to the stabilization of precision frequency standards limited by noisy local oscillators. We develop a theoretical framework casting various measures for frequency standard variance in terms of frequency-domain transfer functions, capturing the effects of feedback stabilization via a time series of Ramsey measurements. Using this framework, we introduce an optimized hybrid predictive feedforward measurement protocol that employs results from multiple past measurements and transfer-function-based calculations of measurement covariance to improve the accuracy of corrections within the feedback loop. In the presence of common non-Markovian noise processes these measurements will be correlated in a calculable manner, providing a means to capture the stochastic evolution of the local oscillator frequency during the measurement cycle. We present analytic calculations and numerical simulations of oscillator performance under competing feedback schemes and demonstrate benefits in both correction accuracy and long-term oscillator stability using hybrid feedforward. Simulations verify that in the presence of uncompensated dead time and noise with significant spectral weight near the inverse cycle time predictive feedforward outperforms traditional feedback, providing a path towards developing a class of stabilization software routines for frequency standards limited by noisy local oscillators.

  15. Fringe-jump corrected far infrared tangential interferometer/polarimeter for a real-time density feedback control system of NSTX plasmasa)

    NASA Astrophysics Data System (ADS)

    Juhn, J.-W.; Lee, K. C.; Hwang, Y. S.; Domier, C. W.; Luhmann, N. C.; Leblanc, B. P.; Mueller, D.; Gates, D. A.; Kaita, R.

    2010-10-01

    The far infrared tangential interferometer/polarimeter (FIReTIP) of the National Spherical Torus Experiment (NSTX) has been set up to provide reliable electron density signals for a real-time density feedback control system. This work consists of two main parts: suppression of the fringe jumps that have been prohibiting the plasma density from use in the direct feedback to actuators and the conceptual design of a density feedback control system including the FIReTIP, control hardware, and software that takes advantage of the NSTX plasma control system (PCS). By investigating numerous shot data after July 2009 when the new electronics were installed, fringe jumps in the FIReTIP are well characterized, and consequently the suppressing algorithms are working properly as shown in comparisons with the Thomson scattering diagnostic. This approach is also applicable to signals taken at a 5 kHz sampling rate, which is a fundamental constraint imposed by the digitizers providing inputs to the PCS. The fringe jump correction algorithm, as well as safety and feedback modules, will be included as submodules either in the gas injection system category or a new category of density in the PCS.

  16. Molecular Modeling of Aerospace Polymer Matrices Including Carbon Nanotube-Enhanced Epoxy

    NASA Astrophysics Data System (ADS)

    Radue, Matthew S.

    Carbon fiber (CF) composites are increasingly replacing metals used in major structural parts of aircraft, spacecraft, and automobiles. The current limitations of carbon fiber composites are addressed through computational material design by modeling the salient aerospace matrix materials. Molecular Dynamics (MD) models of epoxies with and without carbon nanotube (CNT) reinforcement and models of pure bismaleimides (BMIs) were developed to elucidate structure-property relationships for improved selection and tailoring of matrices. The influence of monomer functionality on the mechanical properties of epoxies is studied using the Reax Force Field (ReaxFF). From deformation simulations, the Young's modulus, yield point, and Poisson's ratio are calculated and analyzed. The results demonstrate an increase in stiffness and yield strength with increasing resin functionality. Comparison between the network structures of distinct epoxies is further advanced by the Monomeric Degree Index (MDI). Experimental validation demonstrates the MD results correctly predict the relationship in Young's moduli for all epoxies modeled. Therefore, the ReaxFF is confirmed to be a useful tool for studying the mechanical behavior of epoxies. While epoxies have been well-studied using MD, there has been no concerted effort to model cured BMI polymers due to the complexity of the network-forming reactions. A novel, adaptable crosslinking framework is developed for implementing 5 distinct cure reactions of Matrimid-5292 (a BMI resin) and investigating the network structure using MD simulations. The influence of different cure reactions and extent of curing are analyzed on the several thermo-mechanical properties such as mass density, glass transition temperature, coefficient of thermal expansion, elastic moduli, and thermal conductivity. The developed crosslinked models correctly predict experimentally observed trends for various properties. Finally, the epoxies modeled (di-, tri-, and tetra-functionalresins) are simulated with embedded CNT to understand how the affinity to nanoparticles affects the mechanical response. Multiscale modeling techniques are then employed to translate the molecular phenomena observed to predict the behavior of realistic composites. The effective stiffness of hybrid composites are predicted for CNT/epoxy composites with randomly oriented CNTs, for CF/CNT/epoxy systems with aligned CFs and randomly oriented CNTs, and for woven CF/CNT/epoxy fabric with randomly oriented CNTs. The results indicate that in the CNT/epoxy systems the epoxy type has a significant influence on the elastic properties. For the CF/CNT/epoxy hybrid composites, the axial modulus is highly influenced by CF concentration, while the transverse modulus is primarily affected by the CNT weight fraction.

  17. Influence of feedback characteristics on perceived learning value of feedback in clerkships: does culture matter?

    PubMed

    Suhoyo, Yoyo; Van Hell, Elisabeth A; Kerdijk, Wouter; Emilia, Ova; Schönrock-Adema, Johanna; Kuks, Jan B M; Cohen-Schotanus, Janke

    2017-04-05

    Various feedback characteristics have been suggested to positively influence student learning. It is not clear how these feedback characteristics contribute to students' perceived learning value of feedback in cultures classified low on the cultural dimension of individualism and high on power distance. This study was conducted to validate the influence of five feedback characteristics on students' perceived learning value of feedback in an Indonesian clerkship context. We asked clerks in Neurology (n = 169) and Internal Medicine (n = 132) to assess on a 5-point Likert scale the learning value of the feedback they received. We asked them to record whether the feedback provider (1) informed the student what went well, (2) mentioned which aspects of performance needed improvement, (3) compared the student's performance to a standard, (4) further explained or demonstrated the correct performance, and (5) prepared an action plan with the student to improve performance. Data were analyzed using multilevel regression. A total of 250 students participated in this study, 131 from Internal Medicine (response rate 99%) and 119 from Neurology (response rate 70%). Of these participants, 225 respondents (44% males, 56% females) completed the form and reported 889 feedback moments. Students perceived feedback as more valuable when the feedback provider mentioned their weaknesses (β = 0.153, p < 0.01), compared their performance to a standard (β = 0.159, p < 0.01), explained or demonstrated the correct performance (β = 0.324, p < 0.001) and prepared an action plan with the student (β =0.496, p < 0.001). Appraisal of good performance did not influence the perceived learning value of feedback. No gender differences were found for perceived learning value. In Indonesia, we could validate four out of the five characteristics for effective feedback. We argue that our findings relate to culture, in particular to the levels of individualism and power distance. The recognized characteristics of what constitutes effective feedback should be validated across cultures.

  18. Balanced cortical microcircuitry for spatial working memory based on corrective feedback control.

    PubMed

    Lim, Sukbin; Goldman, Mark S

    2014-05-14

    A hallmark of working memory is the ability to maintain graded representations of both the spatial location and amplitude of a memorized stimulus. Previous work has identified a neural correlate of spatial working memory in the persistent maintenance of spatially specific patterns of neural activity. How such activity is maintained by neocortical circuits remains unknown. Traditional models of working memory maintain analog representations of either the spatial location or the amplitude of a stimulus, but not both. Furthermore, although most previous models require local excitation and lateral inhibition to maintain spatially localized persistent activity stably, the substrate for lateral inhibitory feedback pathways is unclear. Here, we suggest an alternative model for spatial working memory that is capable of maintaining analog representations of both the spatial location and amplitude of a stimulus, and that does not rely on long-range feedback inhibition. The model consists of a functionally columnar network of recurrently connected excitatory and inhibitory neural populations. When excitation and inhibition are balanced in strength but offset in time, drifts in activity trigger spatially specific negative feedback that corrects memory decay. The resulting networks can temporally integrate inputs at any spatial location, are robust against many commonly considered perturbations in network parameters, and, when implemented in a spiking model, generate irregular neural firing characteristic of that observed experimentally during persistent activity. This work suggests balanced excitatory-inhibitory memory circuits implementing corrective negative feedback as a substrate for spatial working memory. Copyright © 2014 the authors 0270-6474/14/346790-17$15.00/0.

  19. Coaching, Not Correcting: An Alternative Model for Minority Students

    ERIC Educational Resources Information Center

    Dresser, Rocío; Asato, Jolynn

    2014-01-01

    The debate on the role of oral corrective feedback or "repair" in English instruction settings has been going on for over 30 years. Some educators believe that oral grammar correction is effective because they have noticed that students who learned a set of grammar rules were more likely to use them in real life communication (Krashen,…

  20. The Effects of Focused and Unfocused Written Corrective Feedback in an English as a Foreign Language Context

    ERIC Educational Resources Information Center

    Ellis, Rod; Sheen, Younghee; Murakami, Mihoko; Takashima, Hide

    2008-01-01

    Truscott [Truscott, J., 1996. "The case against grammar correction in L2 writing classes.' "Language Learning" 46, 327-369; Truscott, J., 1999. "The case for "the case for grammar correction in L2 writing classes": a response to Ferris." "Journal of Second Language Writing" 8, 111-122] laid down the…

  1. Kennedy Space Center ITC-1 Internship Overview

    NASA Technical Reports Server (NTRS)

    Ni, Marcus

    2011-01-01

    As an intern for Priscilla Elfrey in the ITC-1 department, I was involved in many activities that have helped me to develop many new skills. I supported four different projects during my internship, which included the Center for Life Cycle Design (CfLCD), SISO Space Interoperability Smackdown, RTI Teacher Mentor Program, and the Discrete Event Simulation Integrated Visualization Environment Team (DIVE). I provided the CfLCD with web based research on cyber security initiatives involving simulation, education for young children, cloud computing, Otronicon, and Science, Technology, Engineering, and Mathematics (STEM) education initiatives. I also attended STEM meetings regarding simulation courses, and educational course enhancements. To further improve the SISO Simulation event, I provided observation feedback to the technical advisory board. I also helped to set up a chat federation for HLA. The third project involved the RTI Teacher Mentor program, which I helped to organize. Last, but not least, I worked with the DIVE team to develop new software to help visualize discrete event simulations. All of these projects have provided experience on an interdisciplinary level ranging from speech and communication to solving complex problems using math and science.

  2. Usefulness of circulating free DNA for monitoring epidermal growth factor receptor mutations in advanced non-small cell lung cancer patients: a case report

    PubMed Central

    Gonzalez-Cao, Maria; Ramirez, Santiago Viteri; Ariza, Nuria Jordana; Balada, Ariadna; Garzón, Mónica; Teixidó, Cristina; Karachaliou, Niki; Morales-Espinosa, Daniela; Molina-Vila, Miguel Ángel; Rosell, Rafael

    2016-01-01

    Genomic analysis of circulating tumor DNA (ctDNA) released from cancer cells into the bloodstream has been proposed as a useful method to capture dynamic changes during the course of the disease. In particular, the ability to monitor epidermal growth factor receptor (EGFR) mutation status in cell-free circulating DNA (cfDNA) isolated from advanced non-small cell lung cancer (NSCLC) patients EGFR can help to the correct management of the disease and overcome the challenges associated with tumor heterogeneity and insufficient biopsied material to perform key molecular diagnosis. Here, we report a case of long term monitorization of EGFR mutation status in cfDNA from peripheral blood in an NSCLC patient in, with excellent correlation with clinical evolution. PMID:27826535

  3. Instructive Feedback Embedded within Group Instruction for Children Diagnosed with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Leaf, Justin B.; Cihon, Joseph H.; Alcalay, Aditt; Mitchell, Erin; Townley-Cochran, Donna; Miller, Kevin; Leaf, Ronald; Taubman, Mitchell; McEachin, John

    2017-01-01

    The present study evaluated the effects of instructive feedback embedded within a group discrete trial teaching to teach tact relations to nine children diagnosed with autism spectrum disorder using a nonconcurrent multiple-baseline design. Dependent variables included correct responses for: primary targets (directly taught), secondary targets…

  4. Self-Explanation and Explanatory Feedback in Games: Individual Differences, Gameplay, and Learning

    ERIC Educational Resources Information Center

    Killingsworth, Stephen S.; Clark, Douglas B.; Adams, Deanne M.

    2015-01-01

    Previous research has demonstrated the efficacy of two explanation-based approaches for increasing learning in educational games. The first involves asking students to explain their answers (self-explanation) and the second involves providing correct explanations (explanatory feedback). This study (1) compared self-explanation and explanatory…

  5. The Role of Feedback on Studying, Achievement and Calibration.

    ERIC Educational Resources Information Center

    Chu, Stephanie T. L.; Jamieson-Noel, Dianne L.; Winne, Philip H.

    One set of hypotheses examined in this study was that various types of feedback (outcome, process, and corrective) supply different information about performance and have different effects on studying processes and on achievement. Another set of hypotheses concerned students' calibration, their accuracy in predicting and postdicting achievement…

  6. Self-assessing target with automatic feedback

    DOEpatents

    Larkin, Stephen W.; Kramer, Robert L.

    2004-03-02

    A self assessing target with four quadrants and a method of use thereof. Each quadrant containing possible causes for why shots are going into that particular quadrant rather than the center mass of the target. Each possible cause is followed by a solution intended to help the marksman correct the problem causing the marksman to shoot in that particular area. In addition, the self assessing target contains possible causes for general shooting errors and solutions to the causes of the general shooting error. The automatic feedback with instant suggestions and corrections enables the shooter to improve their marksmanship.

  7. Quantum error correction for continuously detected errors with any number of error channels per qubit

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

    Ahn, Charlene; Wiseman, Howard; Jacobs, Kurt

    2004-08-01

    It was shown by Ahn, Wiseman, and Milburn [Phys. Rev. A 67, 052310 (2003)] that feedback control could be used as a quantum error correction process for errors induced by weak continuous measurement, given one perfectly measured error channel per qubit. Here we point out that this method can be easily extended to an arbitrary number of error channels per qubit. We show that the feedback protocols generated by our method encode n-2 logical qubits in n physical qubits, thus requiring just one more physical qubit than in the previous case.

  8. Taxonomic evaluation of selected Ganoderma species and database sequence validation

    PubMed Central

    Jargalmaa, Suldbold; Eimes, John A.; Park, Myung Soo; Park, Jae Young; Oh, Seung-Yoon

    2017-01-01

    Species in the genus Ganoderma include several ecologically important and pathogenic fungal species whose medicinal and economic value is substantial. Due to the highly similar morphological features within the Ganoderma, identification of species has relied heavily on DNA sequencing using BLAST searches, which are only reliable if the GenBank submissions are accurately labeled. In this study, we examined 113 specimens collected from 1969 to 2016 from various regions in Korea using morphological features and multigene analysis (internal transcribed spacer, translation elongation factor 1-α, and the second largest subunit of RNA polymerase II). These specimens were identified as four Ganoderma species: G. sichuanense, G. cf. adspersum, G. cf. applanatum, and G. cf. gibbosum. With the exception of G. sichuanense, these species were difficult to distinguish based solely on morphological features. However, phylogenetic analysis at three different loci yielded concordant phylogenetic information, and supported the four species distinctions with high bootstrap support. A survey of over 600 Ganoderma sequences available on GenBank revealed that 65% of sequences were either misidentified or ambiguously labeled. Here, we suggest corrected annotations for GenBank sequences based on our phylogenetic validation and provide updated global distribution patterns for these Ganoderma species. PMID:28761785

  9. Theoretical study on the dissociation energies, ionization potentials and electron affinities of three perfluoroalkyl iodides

    NASA Astrophysics Data System (ADS)

    Cheng, Li; Shen, Zuochun; Lu, Jianye; Gao, Huide; Lü, Zhiwei

    2005-11-01

    Dissociation energies, ionization potentials and electron affinities of three perfluoroalkyl iodides, CF 3I, C 2F 5I, and i-C 3F 7I are calculated accurately with B3LYP, MP n ( n = 2-4), QCISD, QCISD(T), CCSD, and CCSD(T) methods. Calculations are performed by using large-core correlation-consistent pseudopotential basis set (SDB-aug-cc-pVTZ) for iodine atom. In all energy calculations, the zero point vibration energy is corrected. And the basis set superposition error is corrected by counterpoise method in the calculation of dissociation energy. Theoretical results are compared with the experimental values.

  10. Halogenation effects on electron collisions with CF3Cl, CF2Cl2, and CFCl3

    NASA Astrophysics Data System (ADS)

    Freitas, T. C.; Lopes, A. R.; Azeredo, A. D.; Bettega, M. H. F.

    2016-04-01

    We report differential and integral elastic cross sections for low-energy electron collisions with CF3Cl, CF2Cl2, and CFCl3 molecules for energies ranging from 0.1 eV to 30 eV. The calculations were performed using the Schwinger multichannel method with pseudopotentials in the static-exchange and static-exchange plus polarization approximations. The influence of the permanent electric dipole moment on the cross sections was included using the Born closure scheme. A very good agreement between our calculations and the experimental results of Jones [J. Chem. Phys. 84, 813 (1986)], Mann and Linder [J. Phys. B 25, 1621 (1992); 25, 1633 (1992)] and Hoshino et al. [J. Chem. Phys. 138, 214305 (2013)] was found. We also compare our results with the calculations of Beyer et al. [Chem. Phys. 255, 1 (2000)] using the R-matrix method, where we find good agreement with respect to the location of the resonances, and with the calculations of Hoshino et al. using the independent atom method with screening corrected additivity rule, where we find qualitative agreement at energies above 20 eV. Additional electronic structure calculations were carried out in order to help in the interpretation of the scattering results. The stabilization the lowest σ∗ resonance due to the exchange of fluorine by chlorine atoms (halogenation effect) follows a simple linear relation with the energy of the lowest unoccupied molecular orbitals and can be considered as a signature of the halogenation effect.

  11. Biological variability of the sweat chloride in diagnostic sweat tests: A retrospective analysis.

    PubMed

    Vermeulen, F; Lebecque, P; De Boeck, K; Leal, T

    2017-01-01

    The sweat test is the current gold standard for the diagnosis of cystic fibrosis (CF). CF is unlikely when sweat chloride (Cl sw ) is lower than 30mmol/L, Cl sw >60 is suggestive of CF, with intermediate values between 30 and 60mmol/L. To correctly interpret a sweat chloride value, the biological variability of the sweat chloride has to be known. Sweat tests performed in two centers using the classic Gibson and Cooke method were retrospectively reviewed (n=5904). Within test variability of Cl sw was measured by comparing results from right and left arm collected on the same day. Between test variability was calculated from subjects with sweat tests performed on more than one occasion. Within test variability of Cl sw calculated in 1022 subjects was low with differences between -3.2 (p5) and +3.6mmol/L (p95). Results from left and right arm were classified differently in only 3 subjects. Between test variability of Cl sw in 197 subjects was larger, with differences between -18.2mmol/L (p5) and +14.1mmol/L (p95) between repeat tests. Changes in diagnostic conclusion were seen in 55/197 subjects, the most frequent being changing from indeterminate to 'CF unlikely' range (48/102). Variability of sweat chloride is substantial, with frequent changes in diagnostic conclusion, especially in the intermediate range. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  12. Fermi wave vector for the partially spin-polarized composite-fermion Fermi sea

    NASA Astrophysics Data System (ADS)

    Balram, Ajit C.; Jain, J. K.

    2017-12-01

    The fully spin-polarized composite-fermion (CF) Fermi sea at the half-filled lowest Landau level has a Fermi wave vector kF*=√{4 π ρe } , where ρe is the density of electrons or composite fermions, supporting the notion that the interaction between composite fermions can be treated perturbatively. Away from ν =1 /2 , the area is seen to be consistent with kF*=√{4 π ρe } for ν <1 /2 but kF*=√{4 π ρh } for ν >1 /2 , where ρh is the density of holes in the lowest Landau level. This result is consistent with particle-hole symmetry in the lowest Landau level. We investigate in this article the Fermi wave vector of the spin-singlet CF Fermi sea (CFFS) at ν =1 /2 , for which particle-hole symmetry is not a consideration. Using the microscopic CF theory, we find that for the spin-singlet CFFS the Fermi wave vectors for up- and down-spin CFFSs at ν =1 /2 are consistent with kF*↑,↓=√{4 π ρe↑,↓ } , where ρe↑=ρe↓=ρe/2 , which implies that the residual interactions between composite fermions do not cause a nonperturbative correction for spin-singlet CFFS either. Our results suggest the natural conjecture that for arbitrary spin polarization the CF Fermi wave vectors are given by kF*↑=√{4 π ρe↑ } and kF*↓=√{4 π ρe↓ } .

  13. Control circuit maintains unity power factor of reactive load

    NASA Technical Reports Server (NTRS)

    Kramer, M.; Martinage, L. H.

    1966-01-01

    Circuit including feedback control elements automatically corrects the power factor of a reactive load. It maintains power supply efficiency where negative load reactance changes and varies by providing corrective error signals to the control windings of a power supply transformer.

  14. The use of real-time ultrasound feedback in teaching abdominal hollowing exercises to healthy subjects.

    PubMed

    Henry, Sharon M; Westervelt, Karen C

    2005-06-01

    Randomized controlled trial. To determine if supplementing typical clinical instruction with real-time ultrasound feedback facilitates performance and retention of the abdominal hollowing exercise (AHE). Increasingly clinicians are using real-time ultrasound imaging as a form of feedback when teaching patients trunk stabilization exercises; however, there has been no justification for this practice. Forty-eight subjects were divided randomly into 3 groups that received different types of feedback: group 1 received minimal verbal feedback, group 2 received verbal and palpatory feedback, and group 3 received real-time ultrasound, verbal, and palpatory feedback. If the subject performed 3 consecutive correct AHEs during the initial session, she/he returned for a retention test. The performance of 3 consecutive, correct AHEs was the criterion measure; the number of trials to criterion was also recorded during the initial and retention test sessions. The ability to perform the AHE differed among groups (P<.001). During the initial session, 12.5% of subjects in group 1, 50.0% of subjects in group 2, and 87.5% of subjects in group 3 were able to perform 3 consecutive AHEs. Group 3 subjects achieved the criterion in fewer trials than the other 2 groups (P = .0006). No differences among groups were found for the retention testing; however, low power due to fewer subjects precluded a strong interpretation of this finding. Real-time ultrasound feedback can decrease the number of trials needed to consistently perform the AHE; however, the data are inconclusive with regard to retention of this skill.

  15. Object discrimination using electrotactile feedback.

    PubMed

    Arakeri, Tapas J; Hasse, Brady A; Fuglevand, Andrew J

    2018-04-09

    A variety of bioengineering systems are being developed to restore tactile sensations in individuals who have lost somatosensory feedback because of spinal cord injury, stroke, or amputation. These systems typically detect tactile force with sensors placed on an insensate hand (or prosthetic hand in the case of amputees) and deliver touch information by electrically or mechanically stimulating sensate skin above the site of injury. Successful object manipulation, however, also requires proprioceptive feedback representing the configuration and movements of the hand and digits. Therefore, we developed a simple system that simultaneously provides information about tactile grip force and hand aperture using current amplitude-modulated electrotactile feedback. We evaluated the utility of this system by testing the ability of eight healthy human subjects to distinguish among 27 objects of varying sizes, weights, and compliances based entirely on electrotactile feedback. The feedback was modulated by grip-force and hand-aperture sensors placed on the hand of an experimenter (not visible to the subject) grasping and lifting the test objects. We were also interested to determine the degree to which subjects could learn to use such feedback when tested over five consecutive sessions. The average percentage correct identifications on day 1 (28.5%  ±  8.2% correct) was well above chance (3.7%) and increased significantly with training to 49.2%  ±  10.6% on day 5. Furthermore, this training transferred reasonably well to a set of novel objects. These results suggest that simple, non-invasive methods can provide useful multisensory feedback that might prove beneficial in improving the control over prosthetic limbs.

  16. Reality Monitoring and Feedback Control of Speech Production Are Related Through Self-Agency.

    PubMed

    Subramaniam, Karuna; Kothare, Hardik; Mizuiri, Danielle; Nagarajan, Srikantan S; Houde, John F

    2018-01-01

    Self-agency is the experience of being the agent of one's own thoughts and motor actions. The intact experience of self-agency is necessary for successful interactions with the outside world (i.e., reality monitoring) and for responding to sensory feedback of our motor actions (e.g., speech feedback control). Reality monitoring is the ability to distinguish internally self-generated information from outside reality (externally-derived information). In the present study, we examined the relationship of self-agency between lower-level speech feedback monitoring (i.e., monitoring what we hear ourselves say) and a higher-level cognitive reality monitoring task. In particular, we examined whether speech feedback monitoring and reality monitoring were driven by the capacity to experience self-agency-the ability to make reliable predictions about the outcomes of self-generated actions. During the reality monitoring task, subjects made judgments as to whether information was previously self-generated (self-agency judgments) or externally derived (external-agency judgments). During speech feedback monitoring, we assessed self-agency by altering environmental auditory feedback so that subjects listened to a perturbed version of their own speech. When subjects heard minimal perturbations in their auditory feedback while speaking, they made corrective responses, indicating that they judged the perturbations as errors in their speech output. We found that self-agency judgments in the reality-monitoring task were higher in people who had smaller corrective responses ( p = 0.05) and smaller inter-trial variability ( p = 0.03) during minimal pitch perturbations of their auditory feedback. These results provide support for a unitary process for the experience of self-agency governing low-level speech control and higher level reality monitoring.

  17. A hybrid solution using computational prediction and measured data to accurately determine process corrections with reduced overlay sampling

    NASA Astrophysics Data System (ADS)

    Noyes, Ben F.; Mokaberi, Babak; Mandoy, Ram; Pate, Alex; Huijgen, Ralph; McBurney, Mike; Chen, Owen

    2017-03-01

    Reducing overlay error via an accurate APC feedback system is one of the main challenges in high volume production of the current and future nodes in the semiconductor industry. The overlay feedback system directly affects the number of dies meeting overlay specification and the number of layers requiring dedicated exposure tools through the fabrication flow. Increasing the former number and reducing the latter number is beneficial for the overall efficiency and yield of the fabrication process. An overlay feedback system requires accurate determination of the overlay error, or fingerprint, on exposed wafers in order to determine corrections to be automatically and dynamically applied to the exposure of future wafers. Since current and future nodes require correction per exposure (CPE), the resolution of the overlay fingerprint must be high enough to accommodate CPE in the overlay feedback system, or overlay control module (OCM). Determining a high resolution fingerprint from measured data requires extremely dense overlay sampling that takes a significant amount of measurement time. For static corrections this is acceptable, but in an automated dynamic correction system this method creates extreme bottlenecks for the throughput of said system as new lots have to wait until the previous lot is measured. One solution is using a less dense overlay sampling scheme and employing computationally up-sampled data to a dense fingerprint. That method uses a global fingerprint model over the entire wafer; measured localized overlay errors are therefore not always represented in its up-sampled output. This paper will discuss a hybrid system shown in Fig. 1 that combines a computationally up-sampled fingerprint with the measured data to more accurately capture the actual fingerprint, including local overlay errors. Such a hybrid system is shown to result in reduced modelled residuals while determining the fingerprint, and better on-product overlay performance.

  18. Visual Reliance for Balance Control in Older Adults Persists When Visual Information Is Disrupted by Artificial Feedback Delays

    PubMed Central

    Balasubramaniam, Ramesh

    2014-01-01

    Sensory information from our eyes, skin and muscles helps guide and correct balance. Less appreciated, however, is that delays in the transmission of sensory information between our eyes, limbs and central nervous system can exceed several 10s of milliseconds. Investigating how these time-delayed sensory signals influence balance control is central to understanding the postural system. Here, we investigate how delayed visual feedback and cognitive performance influence postural control in healthy young and older adults. The task required that participants position their center of pressure (COP) in a fixed target as accurately as possible without visual feedback about their COP location (eyes-open balance), or with artificial time delays imposed on visual COP feedback. On selected trials, the participants also performed a silent arithmetic task (cognitive dual task). We separated COP time series into distinct frequency components using low and high-pass filtering routines. Visual feedback delays affected low frequency postural corrections in young and older adults, with larger increases in postural sway noted for the group of older adults. In comparison, cognitive performance reduced the variability of rapid center of pressure displacements in young adults, but did not alter postural sway in the group of older adults. Our results demonstrate that older adults prioritize vision to control posture. This visual reliance persists even when feedback about the task is delayed by several hundreds of milliseconds. PMID:24614576

  19. Delayed, but not immediate, feedback after multiple-choice questions increases performance on a subsequent short-answer, but not multiple-choice, exam: evidence for the dual-process theory of memory.

    PubMed

    Sinha, Neha; Glass, Arnold Lewis

    2015-01-01

    Three experiments, two performed in the laboratory and one embedded in a college psychology lecture course, investigated the effects of immediate versus delayed feedback following a multiple-choice exam on subsequent short answer and multiple-choice exams. Performance on the subsequent multiple-choice exam was not affected by the timing of the feedback on the prior exam; however, performance on the subsequent short answer exam was better following delayed than following immediate feedback. This was true regardless of the order in which immediate versus delayed feedback was given. Furthermore, delayed feedback only had a greater effect than immediate feedback on subsequent short answer performance following correct, confident responses on the prior exam. These results indicate that delayed feedback cues a student's prior response and increases subsequent recollection of that response. The practical implication is that delayed feedback is better than immediate feedback during academic testing.

  20. Metacognitive unawareness of the errorful generation benefit and its effects on self-regulated learning.

    PubMed

    Yang, Chunliang; Potts, Rosalind; Shanks, David R

    2017-07-01

    Generating errors followed by corrective feedback enhances retention more effectively than does reading-the benefit of errorful generation-but people tend to be unaware of this benefit. The current research explored this metacognitive unawareness, its effect on self-regulated learning, and how to alleviate or reverse it. People's beliefs about the relative learning efficacy of generating errors followed by corrective feedback compared to reading, and the effects of generation fluency, are also explored. In Experiments 1 and 2, lower judgments of learning (JOLs) were consistently given to incorrectly generated word pairs than to studied (read) pairs and led participants to distribute more study resources to incorrectly generated pairs, even though superior recall of these pairs was exhibited in the final test. In Experiment 3, a survey revealed that people believe that generating errors followed by corrective feedback is inferior to reading. Experiment 4 was designed to alter participants' metacognition by informing them of the errorful generation benefit prior to study. Although metacognitive misalignment was partly countered, participants still tended to be unaware of this benefit when making item-by-item JOLs. In Experiment 5, in a delayed JOL condition, higher JOLs were given to incorrectly generated pairs and read pairs were more likely to be selected for restudy. The current research reveals that people tend to underestimate the learning efficiency of generating errors followed by corrective feedback relative to reading when making immediate item-by-item JOLs. Informing people of the errorful generation benefit prior to study and asking them to make delayed JOLs are effective ways to alleviate this metacognitive miscalibration. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  1. Computational technique for stepwise quantitative assessment of equation correctness

    NASA Astrophysics Data System (ADS)

    Othman, Nuru'l Izzah; Bakar, Zainab Abu

    2017-04-01

    Many of the computer-aided mathematics assessment systems that are available today possess the capability to implement stepwise correctness checking of a working scheme for solving equations. The computational technique for assessing the correctness of each response in the scheme mainly involves checking the mathematical equivalence and providing qualitative feedback. This paper presents a technique, known as the Stepwise Correctness Checking and Scoring (SCCS) technique that checks the correctness of each equation in terms of structural equivalence and provides quantitative feedback. The technique, which is based on the Multiset framework, adapts certain techniques from textual information retrieval involving tokenization, document modelling and similarity evaluation. The performance of the SCCS technique was tested using worked solutions on solving linear algebraic equations in one variable. 350 working schemes comprising of 1385 responses were collected using a marking engine prototype, which has been developed based on the technique. The results show that both the automated analytical scores and the automated overall scores generated by the marking engine exhibit high percent agreement, high correlation and high degree of agreement with manual scores with small average absolute and mixed errors.

  2. L2 Teaching in the Wild: A Closer Look at Correction and Explanation Practices in Everyday L2 Interaction

    ERIC Educational Resources Information Center

    Theodorsdottor, Gudrun

    2018-01-01

    This article argues for a reconceptualization of the concept of "corrective feedback" for the investigation of correction practices in everyday second language (L2) interaction ("in the wild"). Expanding the dataset for L2 research as suggested by Firth and Wagner (1997) to include interactions from the wild has consequences…

  3. Students' Preferences and Attitude toward Oral Error Correction Techniques at Yanbu University College, Saudi Arabia

    ERIC Educational Resources Information Center

    Alamri, Bushra; Fawzi, Hala Hassan

    2016-01-01

    Error correction has been one of the core areas in the field of English language teaching. It is "seen as a form of feedback given to learners on their language use" (Amara, 2015). Many studies investigated the use of different techniques to correct students' oral errors. However, only a few focused on students' preferences and attitude…

  4. Improved memory for error feedback.

    PubMed

    Van der Borght, Liesbet; Schouppe, Nathalie; Notebaert, Wim

    2016-11-01

    Surprising feedback in a general knowledge test leads to an improvement in memory for both the surface features and the content of the feedback (Psychon Bull Rev 16:88-92, 2009). Based on the idea that in cognitive tasks, error is surprising (the orienting account, Cognition 111:275-279, 2009), we tested whether error feedback would be better remembered than correct feedback. Colored words were presented as feedback signals in a flanker task, where the color indicated the accuracy. Subsequently, these words were again presented during a recognition task (Experiment 1) or a lexical decision task (Experiments 2 and 3). In all experiments, memory was improved for words seen as error feedback. These results are compared to the attentional boost effect (J Exp Psychol Learn Mem Cogn 39:1223-12231, 2013) and related to the orienting account for post-error slowing (Cognition 111:275-279, 2009).

  5. Regulating recognition decisions through incremental reinforcement learning.

    PubMed

    Han, Sanghoon; Dobbins, Ian G

    2009-06-01

    Does incremental reinforcement learning influence recognition memory judgments? We examined this question by subtly altering the relative validity or availability of feedback in order to differentially reinforce old or new recognition judgments. Experiment 1 probabilistically and incorrectly indicated that either misses or false alarms were correct in the context of feedback that was otherwise accurate. Experiment 2 selectively withheld feedback for either misses or false alarms in the context of feedback that was otherwise present. Both manipulations caused prominent shifts of recognition memory decision criteria that remained for considerable periods even after feedback had been altogether removed. Overall, these data demonstrate that incremental reinforcement-learning mechanisms influence the degree of caution subjects exercise when evaluating explicit memories.

  6. A Feedback Intervention to Increase Digital and Paper Checklist Performance in Technically Advanced Aircraft Simulation

    ERIC Educational Resources Information Center

    Rantz, William G.; Van Houten, Ron

    2011-01-01

    This study examined whether pilots operating a flight simulator completed digital or paper flight checklists more accurately after receiving postflight graphic and verbal feedback. The dependent variable was the number of checklist items completed correctly per flight. Following treatment, checklist completion with paper and digital checklists…

  7. Written Corrective Feedback: The Perception of Korean EFL Learners

    ERIC Educational Resources Information Center

    Chung, Bohyon

    2015-01-01

    This paper reports on the perception of Korean EFL learners toward feedback types on their written errors. The survey was administered using an adopted questionnaire from previous studies (Ishii 2011; Leki, 1991). This further allows a comparison of Korean EFL learners' attitudes with the responses to an identical questionnaire by Japanese EFL…

  8. Spelling: Computerised Feedback for Self-Correction

    ERIC Educational Resources Information Center

    Lawley, Jim

    2016-01-01

    Research has shown that any assumption that L2 learners of English do well to rely on the feedback provided by generic spell checkers (for example, the MS Word spell checker) is misplaced. Efforts to develop spell checkers specifically for L2 learners have focused on training software to offer more appropriate suggestion lists for replacing…

  9. Digital Literacies and Generational Micro-Cultures: Email Feedback in Lebanon

    ERIC Educational Resources Information Center

    De Coursey, Christina; Dandashly, Nadine

    2015-01-01

    This study reports on the introduction of email feedback, in a private university in Lebanon with marked generational differences and a traditional instructor culture focused on grammar correction. The instructor profile showed insufficient ELT training and a disjuncture between those with low and those with long service. Instructors were trained,…

  10. How Does Early Feedback in an Online Programming Course Change Problem Solving?

    ERIC Educational Resources Information Center

    Ebrahimi, Alireza

    2012-01-01

    How does early feedback change the programming problem solving in an online environment and help students choose correct approaches? This study was conducted in a sample of students learning programming in an online course entitled Introduction to C++ and OOP (Object Oriented Programming) using the ANGEL learning management system platform. My…

  11. The Design of Scaffolding in Game-Based Learning: A Formative Evaluation

    ERIC Educational Resources Information Center

    Weppel, Sheri; Bishop, Mj; Munoz-Avila, Hector

    2012-01-01

    Instructional games fluctuate between "restricted play" and "free play." Highly structured games with lots of corrective feedback can be less engaging, whereas unstructured games with minimal feedback can lead to frustration. This mixed methods, formative evaluation study investigated how designers might find the balance between too much and too…

  12. The Effects of Item by Item Feedback Given during an Ability Test.

    ERIC Educational Resources Information Center

    Whetton, C.; Childs, R.

    1981-01-01

    Answer-until-correct (AUC) is a procedure for providing feedback during a multiple-choice test, giving an increased range of scores. The performance of secondary students on a verbal ability test using AUC procedures was compared with a group using conventional instructions. AUC scores considerably enhanced reliability but not validity.…

  13. Preferences for Interactional Feedback: Differences between Learners and Teachers

    ERIC Educational Resources Information Center

    Kaivanpanah, Shiva; Alavi, Sayyed Mohammad; Sepehrinia, Sajjad

    2015-01-01

    The present study examines Iranian language learners' views on different types of oral corrective feedback and explores the relationship with learners' language proficiency. It then compares the learners' views with those of their teachers. The study is based on a 36-item questionnaire completed by 154 English as a foreign language (EFL) learners…

  14. On the Feed-back Mechanism of Chinese Stock Markets

    NASA Astrophysics Data System (ADS)

    Lu, Shu Quan; Ito, Takao; Zhang, Jianbo

    Feed-back models in the stock markets research imply an adjustment process toward investors' expectation for current information and past experiences. Error-correction and cointegration are often used to evaluate the long-run relation. The Efficient Capital Market Hypothesis, which had ignored the effect of the accumulation of information, cannot explain some anomalies such as bubbles and partial predictability in the stock markets. In order to investigate the feed-back mechanism and to determine an effective model, we use daily data of the stock index of two Chinese stock markets with the expectational model, which is one kind of geometric lag models. Tests and estimations of error-correction show that long-run equilibrium seems to be seldom achieved in Chinese stock markets. Our result clearly shows the common coefficient of expectations and fourth-order autoregressive disturbance exist in the two Chinese stock markets. Furthermore, we find the same coefficient of expectations has an autoregressive effect on disturbances in the two Chinese stock markets. Therefore the presence of such feed-back is also supported in Chinese stock markets.

  15. CFTR fails to inhibit the epithelial sodium channel ENaC expressed in Xenopus laevis oocytes

    PubMed Central

    Nagel, G; Barbry, P; Chabot, H; Brochiero, E; Hartung, K; Grygorczyk, R

    2005-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) plays a crucial role in regulating fluid secretion by the airways, intestines, sweat glands and other epithelial tissues. It is well established that the CFTR is a cAMP-activated, nucleotide-dependent anion channel, but additional functions are often attributed to it, including regulation of the epithelial sodium channel (ENaC). The absence of CFTR-dependent ENaC inhibition and the resulting sodium hyperabsorption were postulated to be a major electrolyte transport abnormality in cystic fibrosis (CF)-affected epithelia. Several ex vivo studies, including those that used the Xenopus oocyte expression system, have reported ENaC inhibition by activated CFTR, but contradictory results have also been obtained. Because CFTR–ENaC interactions have important implications in the pathogenesis of CF, the present investigation was undertaken by our three independent laboratories to resolve whether CFTR regulates ENaC in oocytes and to clarify potential sources of previously reported dissimilar observations. Using different experimental protocols and a wide range of channel expression levels, we found no evidence that activated CFTR regulates ENaC when oocyte membrane potential was carefully clamped. We determined that an apparent CFTR-dependent ENaC inhibition could be observed when resistance in series with the oocyte membrane was not low enough or the feedback voltage gain was not high enough. We suggest that the inhibitory effect of CFTR on ENaC reported in some earlier oocyte studies could be attributed to problems arising from high levels of channel expression and suboptimal recording conditions, that is, large series resistance and/or insufficient feedback voltage gain. PMID:15746174

  16. Potential for improving the carbon footprint of butter and blend products.

    PubMed

    Flysjö, A

    2011-12-01

    To reduce the environmental impact of a product efficiently, it is crucial to consider the entire value chain of the product; that is, to apply life cycle thinking, to avoid suboptimization and identify the areas where the largest potential improvements can be made. This study analyzed the carbon footprint (CF) of butter and dairy blend products, with the focus on fat content and size and type of packaging (including product waste at the consumer level). The products analyzed were butter with 80% fat in 250-g wrap, 250-g tub, and 10-g mini tub, and blends with 80% and 60% fat in 250-g tubs. Life cycle assessment was used to account for all greenhouse gas emissions from cow to consumer. A critical aspect when calculating the CF is how emissions are allocated between different products. Here, allocation of raw milk between products was based on a weighted fat and protein content (1:1.7), based on the price paid for raw milk to dairy farmers. The CF (expressed as carbon dioxide equivalents, CO₂e) for 1 kg of butter or blend (assuming no product waste at consumer) ranged from 5.2 kg (blend with 60% fat content) to 9.3 kg of CO₂e (butter in 250-g tub). When including product waste at the consumer level, the CF ranged from 5.5 kg of CO₂e (blend with 60% fat content) to 14.7 kg of CO₂e (butter in mini tub). Fat content and the proportion of vegetable oil in products had the greatest effect on CF of the products, with lower fat content and a higher proportion of vegetable oil resulting in lower CF. Hence, if the same functionality as butter could be retained while shifting to lower fat and higher proportions of vegetable oil, the CF of the product would be decreased. Size and type of packaging were less important, but it is crucial to have the correct size and type of packaging to avoid product losses at the consumer. The greatest share of greenhouse gas emissions associated with butter production occurred at the farm level; thus, minimizing product losses in the whole value chain--from cow to consumer--is essential for efficient production. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. A Simplified Algorithm for Statistical Investigation of Damage Spreading

    NASA Astrophysics Data System (ADS)

    Gecow, Andrzej

    2009-04-01

    On the way to simulating adaptive evolution of complex system describing a living object or human developed project, a fitness should be defined on node states or network external outputs. Feedbacks lead to circular attractors of these states or outputs which make it difficult to define a fitness. The main statistical effects of adaptive condition are the result of small change tendency and to appear, they only need a statistically correct size of damage initiated by evolutionary change of system. This observation allows to cut loops of feedbacks and in effect to obtain a particular statistically correct state instead of a long circular attractor which in the quenched model is expected for chaotic network with feedback. Defining fitness on such states is simple. We calculate only damaged nodes and only once. Such an algorithm is optimal for investigation of damage spreading i.e. statistical connections of structural parameters of initial change with the size of effected damage. It is a reversed-annealed method—function and states (signals) may be randomly substituted but connections are important and are preserved. The small damages important for adaptive evolution are correctly depicted in comparison to Derrida annealed approximation which expects equilibrium levels for large networks. The algorithm indicates these levels correctly. The relevant program in Pascal, which executes the algorithm for a wide range of parameters, can be obtained from the author.

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

    Gecow, Andrzej

    On the way to simulating adaptive evolution of complex system describing a living object or human developed project, a fitness should be defined on node states or network external outputs. Feedbacks lead to circular attractors of these states or outputs which make it difficult to define a fitness. The main statistical effects of adaptive condition are the result of small change tendency and to appear, they only need a statistically correct size of damage initiated by evolutionary change of system. This observation allows to cut loops of feedbacks and in effect to obtain a particular statistically correct state instead ofmore » a long circular attractor which in the quenched model is expected for chaotic network with feedback. Defining fitness on such states is simple. We calculate only damaged nodes and only once. Such an algorithm is optimal for investigation of damage spreading i.e. statistical connections of structural parameters of initial change with the size of effected damage. It is a reversed-annealed method--function and states (signals) may be randomly substituted but connections are important and are preserved. The small damages important for adaptive evolution are correctly depicted in comparison to Derrida annealed approximation which expects equilibrium levels for large networks. The algorithm indicates these levels correctly. The relevant program in Pascal, which executes the algorithm for a wide range of parameters, can be obtained from the author.« less

  19. Functional anatomy of nonvisual feedback loops during reaching: a positron emission tomography study.

    PubMed

    Desmurget, M; Gréa, H; Grethe, J S; Prablanc, C; Alexander, G E; Grafton, S T

    2001-04-15

    Reaching movements performed without vision of the moving limb are continuously monitored, during their execution, by feedback loops (designated nonvisual). In this study, we investigated the functional anatomy of these nonvisual loops using positron emission tomography (PET). Seven subjects had to "look at" (eye) or "look and point to" (eye-arm) visual targets whose location either remained stationary or changed undetectably during the ocular saccade (when vision is suppressed). Slightly changing the target location during gaze shift causes an increase in the amount of correction to be generated. Functional anatomy of nonvisual feedback loops was identified by comparing the reaching condition involving large corrections (jump) with the reaching condition involving small corrections (stationary), after subtracting the activations associated with saccadic movements and hand movement planning [(eye-arm-jumping minus eye-jumping) minus (eye-arm-stationary minus eye-stationary)]. Behavioral data confirmed that the subjects were both accurate at reaching to the stationary targets and able to update their movement smoothly and early in response to the target jump. PET difference images showed that these corrections were mediated by a restricted network involving the left posterior parietal cortex, the right anterior intermediate cerebellum, and the left primary motor cortex. These results are consistent with our knowledge of the functional properties of these areas and more generally with models emphasizing parietal-cerebellar circuits for processing a dynamic motor error signal.

  20. Optimization methodology for the global 10 Hz orbit feedback in RHIC

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

    Liu, Chuyu; Hulsart, R.; Mernick, K.

    To combat beam oscillations induced by triplet vibrations at the Relativistic Heavy Ion Collider (RHIC), a global orbit feedback system was developed and applied at injection and top energy in 2011, and during beam acceleration in 2012. Singular Value Decomposition (SVD) was employed to determine the strengths and currents of the applied corrections. The feedback algorithm was optimized for different magnetic configurations (lattices) at fixed beam energies and during beam acceleration. While the orbit feedback performed well since its inception, corrector current transients and feedback-induced beam oscillations were observed during the polarized proton program in 2015. In this paper, wemore » present the feedback algorithm, the optimization of the algorithm for various lattices and the solution adopted to mitigate the observed current transients during beam acceleration.« less

  1. Optimization methodology for the global 10 Hz orbit feedback in RHIC

    DOE PAGES

    Liu, Chuyu; Hulsart, R.; Mernick, K.; ...

    2018-05-08

    To combat beam oscillations induced by triplet vibrations at the Relativistic Heavy Ion Collider (RHIC), a global orbit feedback system was developed and applied at injection and top energy in 2011, and during beam acceleration in 2012. Singular Value Decomposition (SVD) was employed to determine the strengths and currents of the applied corrections. The feedback algorithm was optimized for different magnetic configurations (lattices) at fixed beam energies and during beam acceleration. While the orbit feedback performed well since its inception, corrector current transients and feedback-induced beam oscillations were observed during the polarized proton program in 2015. In this paper, wemore » present the feedback algorithm, the optimization of the algorithm for various lattices and the solution adopted to mitigate the observed current transients during beam acceleration.« less

  2. A Comparison of Chest Compression Quality Delivered During On-Scene and Ground Transport Cardiopulmonary Resuscitation

    PubMed Central

    Russi, Christopher S.; Myers, Lucas A.; Kolb, Logan J.; Lohse, Christine M.; Hess, Erik P.; White, Roger D.

    2016-01-01

    Introduction American Heart Association (AHA) guidelines recommend cardiopulmonary resuscitation (CPR) chest compressions 1.5 to 2 inches (3.75–5 cm) deep at 100 to 120 per minute. Recent studies demonstrated that manual CPR by emergency medical services (EMS) personnel is substandard. We hypothesized that transport CPR quality is significantly worse than on-scene CPR quality. Methods We analyzed adult patients receiving on-scene and transport chest compressions from nine EMS sites across Minnesota and Wisconsin from May 2008 to July 2010. Two periods were analyzed: before and after visual feedback. CPR data were collected and exported with the Zoll M series monitor and a sternally placed accelerometer measuring chest compression rate and depth. We compared compression data with 2010 AHA guidelines and Zoll RescueNet Code Review software. CPR depth and rate were “above (deep),” “in,” or “below (shallow)” the target range according to AHA guidelines. We paired on-scene and transport data for each patient; paired proportions were compared with the nonparametric Wilcoxon signed rank test. Results In the pre-feedback period, we analyzed 105 of 140 paired cases (75.0%); in the post-feedback period, 35 of 140 paired cases (25.0%) were analyzed. The proportion of correct depths during on-scene compressions (median, 41.9%; interquartile range [IQR], 16.1–73.1) was higher compared to the paired transport proportion (median, 8.7%; IQR, 2.7–48.9). Proportions of on-scene median correct rates and transport median correct depths did not improve in the post-feedback period. Conclusion Transport chest compressions are significantly worse than on-scene compressions. Implementation of visual real-time feedback did not affect performance. PMID:27625733

  3. A feedback intervention to increase digital and paper checklist performance in technically advanced aircraft simulation.

    PubMed

    Rantz, William G; Van Houten, Ron

    2011-01-01

    This study examined whether pilots operating a flight simulator completed digital or paper flight checklists more accurately after receiving postflight graphic and verbal feedback. The dependent variable was the number of checklist items completed correctly per flight. Following treatment, checklist completion with paper and digital checklists increased from 38% and 39%, respectively, to nearly 100% and remained close to 100% after feedback and praise for improvement were withdrawn. Performance was maintained at or near 100% during follow-up probes.

  4. The FONT5 Bunch-by-Bunch Position and Angle Feedback System at ATF2

    NASA Astrophysics Data System (ADS)

    Apsimon, R. J.; Bett, D. R.; Burrows, P. N.; Christian, G. B.; Constance, B.; Davis, M. R.; Gerbershagen, A.; Perry, C.; Resta-Lopez, J.

    The FONT5 upstream beam-based feedback system at ATF2 is designed to correct the position and angle jitter at the entrance to the ATF2 final-focus system, and also to demonstrate a prototype intra-train feedback system for the International Linear Collider interaction point. We discuss the hardware, from stripline BPMs to kickers, and RF and digital signal processing, as well as presenting results from the latest beam tests at ATF2.

  5. Do errors matter? Errorless and errorful learning in anomic picture naming.

    PubMed

    McKissock, Stephen; Ward, Jamie

    2007-06-01

    Errorless training methods significantly improve learning in memory-impaired patients relative to errorful training procedures. However, the validity of this technique for acquiring linguistic information in aphasia has rarely been studied. This study contrasts three different treatment conditions over an 8 week period for rehabilitating picture naming in anomia: (1) errorless learning in which pictures are shown and the experimenter provides the name, (2) errorful learning with feedback in which the patient is required to generate a name but the correct name is then supplied by the experimenter, and (3) errorful learning in which no feedback is given. These conditions are compared to an untreated set of matched words. Both errorless and errorful learning with feedback conditions led to significant improvement at a 2-week and 12-14-week retest (errorful without feedback and untreated words were similar). The results suggest that it does not matter whether anomic patients are allowed to make errors in picture naming or not (unlike in memory impaired individuals). What does matter is that a correct response is given as feedback. The results also question the widely held assumption that it is beneficial for a patient to attempt to retrieve a word, given that our errorless condition involved no retrieval effort and had the greatest benefits.

  6. Intrinsic interactive reinforcement learning - Using error-related potentials for real world human-robot interaction.

    PubMed

    Kim, Su Kyoung; Kirchner, Elsa Andrea; Stefes, Arne; Kirchner, Frank

    2017-12-14

    Reinforcement learning (RL) enables robots to learn its optimal behavioral strategy in dynamic environments based on feedback. Explicit human feedback during robot RL is advantageous, since an explicit reward function can be easily adapted. However, it is very demanding and tiresome for a human to continuously and explicitly generate feedback. Therefore, the development of implicit approaches is of high relevance. In this paper, we used an error-related potential (ErrP), an event-related activity in the human electroencephalogram (EEG), as an intrinsically generated implicit feedback (rewards) for RL. Initially we validated our approach with seven subjects in a simulated robot learning scenario. ErrPs were detected online in single trial with a balanced accuracy (bACC) of 91%, which was sufficient to learn to recognize gestures and the correct mapping between human gestures and robot actions in parallel. Finally, we validated our approach in a real robot scenario, in which seven subjects freely chose gestures and the real robot correctly learned the mapping between gestures and actions (ErrP detection (90% bACC)). In this paper, we demonstrated that intrinsically generated EEG-based human feedback in RL can successfully be used to implicitly improve gesture-based robot control during human-robot interaction. We call our approach intrinsic interactive RL.

  7. Investigation of the construct of trait emotional intelligence in children.

    PubMed

    Mavroveli, Stella; Petrides, K V; Shove, Chloe; Whitehead, Amanda

    2008-12-01

    This paper discusses the construct of trait emotional intelligence (trait EI or trait emotional self-efficacy) with emphasis on measurement in children. The Trait Emotional Intelligence Questionnaire-Child Form (TEIQue-CF) is introduced and its development and theoretical background are briefly explained. It is shown in two independent studies that the TEIQue-CF has satisfactory levels of internal consistency (alpha = 0.76 and alpha = 0.73, respectively) and temporal stability [r = 0.79 and r ((corrected)) = 1.00]. Trait EI scores were generally unrelated to proxies of cognitive ability, as hypothesized in trait EI theory (Petrides et al. in Matthews et al. (eds) Emotional intelligence: knowns and unknowns -- series in affective science. Oxford University Press, Oxford, pp 151-166). They also differentiated between pupils with unauthorized absences or exclusions from school and controls. Trait EI correlated positively with teacher-rated positive behavior and negatively with negative behavior (emotional symptoms, conduct problems, peer problems, and hyperactivity).

  8. Standard Reference Line Combined with One-Point Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) to Quantitatively Analyze Stainless and Heat Resistant Steel.

    PubMed

    Fu, Hongbo; Wang, Huadong; Jia, Junwei; Ni, Zhibo; Dong, Fengzhong

    2018-01-01

    Due to the influence of major elements' self-absorption, scarce observable spectral lines of trace elements, and relative efficiency correction of experimental system, accurate quantitative analysis with calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is in fact not easy. In order to overcome these difficulties, standard reference line (SRL) combined with one-point calibration (OPC) is used to analyze six elements in three stainless-steel and five heat-resistant steel samples. The Stark broadening and Saha - Boltzmann plot of Fe are used to calculate the electron density and the plasma temperature, respectively. In the present work, we tested the original SRL method, the SRL with the OPC method, and intercept with the OPC method. The final calculation results show that the latter two methods can effectively improve the overall accuracy of quantitative analysis and the detection limits of trace elements.

  9. A Special Kind of Tutor

    ERIC Educational Resources Information Center

    Anderson, Linda Brown

    2007-01-01

    Tutoring has long been recognized as superior to group instruction, especially for students with special needs. Tutors can adapt instruction to the learner's pace, learning style and level of understanding. Feedback and correction are immediate. Basic misunderstandings can be quickly identified and corrected. Tutoring also has emotional benefits:…

  10. Exploring the role of quantitative feedback in inhaler technique education: a cluster-randomised, two-arm, parallel-group, repeated-measures study.

    PubMed

    Toumas-Shehata, Mariam; Price, David; Basheti, Iman Amin; Bosnic-Anticevich, Sinthia

    2014-11-13

    Feedback is a critical component of any educational intervention. When it comes to feedback associated with inhaler technique education, there is a lack of knowledge on its role or its potential to solve the major issue of poor inhaler technique. This study aims to explore the role of feedback in inhaler technique education and its impact on the inhaler technique of patients over time. A parallel-group, repeated-measures study was conducted in the community pharmacy in which the effectiveness of current best practice inhaler technique education utilising qualitative visual feedback (Group 1) was compared with a combination of qualitative and quantitative visual feedback (Group 2). The impact of these two interventions on inhaler technique maintenance was evaluated. Community pharmacists were randomly allocated to recruit people with asthma who were using a dry powder inhaler. At Visit 1 their inhaler technique was evaluated and education delivered and they were followed up at Visit 2 (1 month later). Both educational interventions resulted in an increase in the proportion of patients with correct inhaler technique: from 4% to 51% in Group 1 and from 6% to 83% in Group 2 (Pearson's Chi-Squared, P=0.03, n=49, and Pearson's Chi-Squared, P=0.01, n=48, respectively). The magnitude of improvement was statistically significantly higher for Group 2 compared with Group 1 (n=97, P=0.02, Pearson's Chi-Square test). The nature of feedback has an impact on the effectiveness of inhaler technique education with regard to correct inhaler technique maintenance over time.

  11. Enhancement of motor-imagery ability via combined action observation and motor-imagery training with proprioceptive neurofeedback.

    PubMed

    Ono, Yumie; Wada, Kenya; Kurata, Masaya; Seki, Naoto

    2018-06-01

    Varied individual ability to control the sensory-motor rhythms may limit the potential use of motor-imagery (MI) in neurorehabilitation and neuroprosthetics. We employed neurofeedback training of MI under action observation (AO: AOMI) with proprioceptive feedback and examined whether it could enhance MI-induced event-related desynchronization (ERD). Twenty-eight healthy young adults participated in the neurofeedback training. They performed MI while watching a video of hand-squeezing motion from a first-person perspective. Eleven participants received correct proprioceptive feedback of the same hand motion with the video, via an exoskeleton robot attached to their hand, upon their successful generation of ERD. Another nine participants received random feedback. The training lasted for approximately 20 min per day and continued for 6 days within an interval of 2 weeks. MI-ERD power was evaluated separately, without AO, on each experimental day. The MI-ERD power of the participants receiving correct feedback, as opposed to random feedback, was significantly increased after training. An additional experiment in which the remaining eight participants were trained with auditory instead of proprioceptive feedback failed to show statistically significant increase in MI-ERD power. The significant training effect obtained in shorter training time relative to previously proposed methods suggests the superiority of AOMI training and physiologically-congruent proprioceptive feedback to enhance the MI-ERD power. The proposed neurofeedback training could help patients with motor deficits to attain better use of brain-machine interfaces for rehabilitation and/or prosthesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Impaired Feedforward Control and Enhanced Feedback Control of Speech in Patients with Cerebellar Degeneration.

    PubMed

    Parrell, Benjamin; Agnew, Zarinah; Nagarajan, Srikantan; Houde, John; Ivry, Richard B

    2017-09-20

    The cerebellum has been hypothesized to form a crucial part of the speech motor control network. Evidence for this comes from patients with cerebellar damage, who exhibit a variety of speech deficits, as well as imaging studies showing cerebellar activation during speech production in healthy individuals. To date, the precise role of the cerebellum in speech motor control remains unclear, as it has been implicated in both anticipatory (feedforward) and reactive (feedback) control. Here, we assess both anticipatory and reactive aspects of speech motor control, comparing the performance of patients with cerebellar degeneration and matched controls. Experiment 1 tested feedforward control by examining speech adaptation across trials in response to a consistent perturbation of auditory feedback. Experiment 2 tested feedback control, examining online corrections in response to inconsistent perturbations of auditory feedback. Both male and female patients and controls were tested. The patients were impaired in adapting their feedforward control system relative to controls, exhibiting an attenuated anticipatory response to the perturbation. In contrast, the patients produced even larger compensatory responses than controls, suggesting an increased reliance on sensory feedback to guide speech articulation in this population. Together, these results suggest that the cerebellum is crucial for maintaining accurate feedforward control of speech, but relatively uninvolved in feedback control. SIGNIFICANCE STATEMENT Speech motor control is a complex activity that is thought to rely on both predictive, feedforward control as well as reactive, feedback control. While the cerebellum has been shown to be part of the speech motor control network, its functional contribution to feedback and feedforward control remains controversial. Here, we use real-time auditory perturbations of speech to show that patients with cerebellar degeneration are impaired in adapting feedforward control of speech but retain the ability to make online feedback corrections; indeed, the patients show an increased sensitivity to feedback. These results indicate that the cerebellum forms a crucial part of the feedforward control system for speech but is not essential for online, feedback control. Copyright © 2017 the authors 0270-6474/17/379249-10$15.00/0.

  13. Building inhabitant feedback: Creating a reflective practice for environmental design using activity theory

    NASA Astrophysics Data System (ADS)

    Cunningham, Dara Suzanne

    The way buildings are designed now, there is little feedback from use involved in the design process. Attempts to correct this problem have been made in the form of Post Occupancy Evaluations (POEs) for 50-years but have largely failed. POEs are the accepted method for environmental designers to collect feedback about buildings in use. They are infrequently conducted, after the building is built, in a one-time only evaluation, and not funded as part of the build process. Other products receive feedback about the design in use from online critiques. Online critiques could provide a platform for feedback from actors engaged with buildings in use for environmental designers to utilize in developing reflective design rationale to avoid adverse consequences in future designs or correct consequences in past and current designs. Since buildings constitute such a large part of the human environment, it's important to research the effects of buildings on their inhabitants. In order for environmental designers to act on feedback from situated use, designers need to have access to that feedback and all actors interacting with the building design need to have an easy, inexpensive, and accessible method to submit feedback. These needs can be addressed by utilizing modern networked and mobile computing to collect and access building feedback. The analysis presented in this dissertation is informed by a thorough evaluation of the theory of reflective practice, activity theory, environmental design, and cognitive science research. From this analysis, I developed the following contributions. First, I expanded Schon's reflective practice by combining his theory with a modified version of activity theory, using activity theory to enrich reflective practice and create Reflective Activity Systems Theory (RAST), which provides a new framework to develop design rationale based on feedback from use and a focus on the activity. Second, I suggest the design of an activity information system, Socio-Technical Environments for Evolutionary Design (STEED), which provides an interactive platform for actor and artifact feedback from the use situation. Third, I discuss implications for practice by discussing how the feedback from actors and artifacts in situated use can be used to create reflective design rationale.

  14. Beam Stability R&D for the APS MBA Upgrade

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

    Sereno, Nicholas S.; Arnold, Ned D.; Bui, Hanh D.

    2015-01-01

    Beam diagnostics required for the APS Multi-bend acromat (MBA) are driven by ambitious beam stability requirements. The major AC stability challenge is to correct rms beam motion to 10% the rms beam size at the insertion device source points from0.01 to 1000 Hz. The vertical plane represents the biggest challenge forAC stability, which is required to be 400 nm rms for a 4-micron vertical beam size. In addition to AC stability, long-term drift over a period of seven days is required to be 1 micron or less. Major diagnostics R&D components include improved rf beam position processing using commercially availablemore » FPGA-based BPM processors, new X-ray beam position monitors based on hard X-ray fluorescence from copper and Compton scattering off diamond, mechanical motion sensing to detect and correct long-term vacuum chamber drift, a new feedback system featuring a tenfold increase in sampling rate, and a several-fold increase in the number of fast correctors and BPMs in the feedback algorithm. Feedback system development represents a major effort, and we are pursuing development of a novel algorithm that integrates orbit correction for both slow and fast correctors down to DC simultaneously. Finally, a new data acquisition system (DAQ) is being developed to simultaneously acquire streaming data from all diagnostics as well as the feedback processors for commissioning and fault diagnosis. Results of studies and the design effort are reported.« less

  15. Development and Evaluation of a Feedback Support System with Audio and Playback Strokes

    ERIC Educational Resources Information Center

    Li, Kai; Akahori, Kanji

    2008-01-01

    This paper describes the development and evaluation of a handwritten correction support system with audio and playback strokes used to teach Japanese writing. The study examined whether audio and playback strokes have a positive effect on students using honorific expressions in Japanese writing. The results showed that error feedback with audio…

  16. 75 FR 13075 - Notice of Intent To Hold Public Forums To Solicit Feedback From the Public Regarding the Section...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... DEPARTMENT OF AGRICULTURE Rural Housing Service Notice of Intent To Hold Public Forums To Solicit Feedback From the Public Regarding the Section 523 Mutual Self-Help Housing Program; Correction AGENCY... request for comments regarding the Section 523 Mutual Self-Help Housing Program. There has been a change...

  17. The Effects of Feedback and Selected Personality Variables on Aesthetic Judgment.

    ERIC Educational Resources Information Center

    West, Charles K.; And Others

    This study is an attempt to investigate the extent of which knowledge of results in various forms (true, none, and false) may modify aesthetic judgment. Seventy-two graduate students were administered an aesthetic judgment test of fifty items. On half of the test, twenty-four subjects received correct feedback and twenty-four received false…

  18. Computer-Mediated Synchronous and Asynchronous Corrective Feedback Provided by Trainee Teachers to Learners of French: A Preliminary Study

    ERIC Educational Resources Information Center

    Vidal, Julie; Thouësny, Sylvie

    2015-01-01

    In this paper, we investigate whether trainee teachers' practices, with respect to multimodal feedback, differ from current research, and to what extent it may affect students' language development. More specifically, the goal of the present study is threefold: (1) it observes how trainee teachers responded, whether synchronously, asynchronously,…

  19. A Preliminary Report on a New Grammar Checker to Help Students of English as a Foreign Language

    ERIC Educational Resources Information Center

    Lawley, Jim

    2004-01-01

    Whereas many pre-intermediate and intermediate level students of English as a Foreign Language (EFL) might benefit from receiving detailed feedback on mistakes in their written compositions, there are obvious practical limits to the amount of corrective feedback that teachers in schools and universities can provide. This article briefly describes…

  20. Screening for Sex Chromosome Aneuploidy by Cell-Free DNA Testing: Patient Choice and Performance.

    PubMed

    Bevilacqua, Elisa; Ordóñez, Elena; Hurtado, Ivan; Rueda, Laura; Mazzone, Eléonora; Cirigliano, Vincenzo; Jani, Jacques C

    2017-08-23

    To study patient choice regarding testing for sex chromosome aneuploidy (SCA) and the performance of cell-free DNA (cfDNA) screening for SCA. Patient choice regarding screening for SCA and factors influencing this choice were evaluated in a single center. In a subsequent two-center study, cases that screened positive for SCA were analyzed to determine the positive predictive value (PPV) for each SCA. In all, 1,957 (61.9%) of the 3,162 patients undergoing cfDNA testing opted for SCA screening. Regression analysis demonstrated that independent predictors of a patient's decision for SCA were earlier gestational age, spontaneous conception, and cfDNA chosen as a primary method of screening. A total of 161 cases screened positive for SCA and follow-up data were available for 118 (73.3%). Forty-six of the 61 cases of 45,X were false-positive results and 15 were concordant with the fetal karyotype (PPV = 24.6%). Seventeen of the 22 cases of 47,XXX were false positive and 5 concordant (PPV = 22.7%). Eleven of the 30 cases of 47,XXY were false positive and 19 concordant (PPV = 63.3%). All 5 cases of 47,XYY were correctly identified, thus yielding a PPV of 100%. More than half of the patients undergoing cfDNA aneuploidy screening also opted for SCA testing, but they were less likely to do so in the presence of an increased risk of trisomy. SCAs involving the X chromosome had a lower PPV than those involving the Y chromosome. © 2017 S. Karger AG, Basel.

  1. Value of circulating cell-free DNA analysis as a diagnostic tool for breast cancer: a meta-analysis

    PubMed Central

    Ma, Xuelei; Zhang, Jing; Hu, Xiuying

    2017-01-01

    Objectives The aim of this study was to systematically evaluate the diagnostic value of cell free DNA (cfDNA) for breast cancer. Results Among 308 candidate articles, 25 with relevant diagnostic screening qualified for final analysis. The mean sensitivity, specificity and area under the curve (AUC) of SROC plots for 24 studies that distinguished breast cancer patients from healthy controls were 0.70, 0.87, and 0.9314, yielding a DOR of 32.31. When analyzed in subgroups, the 14 quantitative studies produced sensitivity, specificity, AUC, and a DOR of 0.78, 0.83, 0.9116, and 24.40. The 10 qualitative studies produced 0.50, 0.98, 0.9919, and 68.45. For 8 studies that distinguished malignant breast cancer from benign diseases, the specificity, sensitivity, AUC and DOR were 0.75, 0.79, 0.8213, and 9.49. No covariate factors had a significant correlation with relative DOR. Deek's funnel plots indicated an absence of publication bias. Materials and Methods Databases were searched for studies involving the use of cfDNA to diagnose breast cancer. The studies were analyzed to determine sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and the summary receiver operating characteristic (SROC). Covariates were evaluated for effect on relative DOR. Deek's Funnel plots were generated to measure publication bias. Conclusions Our analysis suggests a promising diagnostic potential of using cfDNA for breast cancer screening, but this diagnostic method is not yet independently sufficient. Further work refining qualitative cfDNA assays will improve the correct diagnosis of breast cancers. PMID:28460452

  2. Halogenation effects on electron collisions with CF{sub 3}Cl, CF{sub 2}Cl{sub 2}, and CFCl{sub 3}

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

    Freitas, T. C., E-mail: tcf03@fisica.ufpr.br; Lopes, A. R.; Bettega, M. H. F.

    2016-04-28

    We report differential and integral elastic cross sections for low-energy electron collisions with CF{sub 3}Cl, CF{sub 2}Cl{sub 2}, and CFCl{sub 3} molecules for energies ranging from 0.1 eV to 30 eV. The calculations were performed using the Schwinger multichannel method with pseudopotentials in the static-exchange and static-exchange plus polarization approximations. The influence of the permanent electric dipole moment on the cross sections was included using the Born closure scheme. A very good agreement between our calculations and the experimental results of Jones [J. Chem. Phys. 84, 813 (1986)], Mann and Linder [J. Phys. B 25, 1621 (1992); 25, 1633 (1992)]more » and Hoshino et al. [J. Chem. Phys. 138, 214305 (2013)] was found. We also compare our results with the calculations of Beyer et al. [Chem. Phys. 255, 1 (2000)] using the R-matrix method, where we find good agreement with respect to the location of the resonances, and with the calculations of Hoshino et al. using the independent atom method with screening corrected additivity rule, where we find qualitative agreement at energies above 20 eV. Additional electronic structure calculations were carried out in order to help in the interpretation of the scattering results. The stabilization the lowest σ{sup ∗} resonance due to the exchange of fluorine by chlorine atoms (halogenation effect) follows a simple linear relation with the energy of the lowest unoccupied molecular orbitals and can be considered as a signature of the halogenation effect.« less

  3. Personalized or Precision Medicine? The Example of Cystic Fibrosis

    PubMed Central

    Marson, Fernando A. L.; Bertuzzo, Carmen S.; Ribeiro, José D.

    2017-01-01

    The advent of the knowledge on human genetics, by the identification of disease-associated variants, culminated in the understanding of human variability. With the genetic knowledge, the specificity of the clinical phenotype and the drug response of each individual were understood. Using the cystic fibrosis (CF) as an example, the new terms that emerged such as personalized medicine and precision medicine can be characterized. The genetic knowledge in CF is broad and the presence of a monogenic disease caused by mutations in the CFTR gene enables the phenotype–genotype association studies (including the response to drugs), considering the wide clinical and laboratory spectrum dependent on the mutual action of genotype, environment, and lifestyle. Regarding the CF disease, personalized medicine is the treatment directed at the symptoms, and this treatment is adjusted depending on the patient’s phenotype. However, more recently, the term precision medicine began to be widely used, although its correct application and understanding are still vague and poorly characterized. In precision medicine, we understand the individual as a response to the interrelation between environment, lifestyle, and genetic factors, which enabled the advent of new therapeutic models, such as conventional drugs adjustment by individual patient dosage and drug type and response, development of new drugs (read through, broker, enhancer, stabilizer, and amplifier compounds), genome editing by homologous recombination, zinc finger nucleases, TALEN (transcription activator-like effector nuclease), CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-associated endonuclease 9), and gene therapy. Thus, we introduced the terms personalized medicine and precision medicine based on the CF. PMID:28676762

  4. THE EFFECT OF FEEDBACK ON THE ACCURACY OF CHECKLIST COMPLETION DURING INSTRUMENT FLIGHT TRAINING

    PubMed Central

    Rantz, William G; Dickinson, Alyce M; Sinclair, Gilbert A; Van Houten, Ron

    2009-01-01

    This study examined whether pilots completed airplane checklists more accurately when they receive postflight graphic and verbal feedback. Participants were 8 college students who are pilots with an instrument rating. The task consisted of flying a designated flight pattern using a personal computer aviation training device (PCATD). The dependent variables were the number of checklist items completed correctly. A multiple baseline design across pairs of participants with withdrawal of treatment was employed in this study. During baseline, participants were given postflight technical feedback. During intervention, participants were given postflight graphic feedback on checklist use and praise for improvements along with technical feedback. The intervention produced near perfect checklist performance, which was maintained following a return to the baseline conditions. PMID:20190914

  5. Organic rankine cycle fluid

    DOEpatents

    Brasz, Joost J.; Jonsson, Ulf J.

    2006-09-05

    A method of operating an organic rankine cycle system wherein a liquid refrigerant is circulated to an evaporator where heat is introduced to the refrigerant to convert it to vapor. The vapor is then passed through a turbine, with the resulting cooled vapor then passing through a condenser for condensing the vapor to a liquid. The refrigerant is one of CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2, (CF.sub.3).sub.2 CFC(O)CF(CF.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.2C(O)CF(CF.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.3C(O)CF(CG.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.5C(O)CF.sub.3, CF.sub.3CF.sub.2C(O)CF.sub.2CF.sub.2CF.sub.3, CF.sub.3C(O)CF(CF.sub.3).sub.2.

  6. Technical Adequacy of Response to Intervention Decisions

    ERIC Educational Resources Information Center

    VanDerHeyden, Amanda M.

    2011-01-01

    Perhaps the greatest value of response to intervention (RTI) as a decision framework is that it brings attention to variables (e.g., mastery of prerequisite skills, frequency of instructional corrective feedback, reinforcement schedules for correct responding) that if changed might make a meaningful difference for students (e.g., child rate of…

  7. Recasts, Field Dependence/Independence Cognitive Style, and L2 Development

    ERIC Educational Resources Information Center

    Rassaei, Ehsan

    2015-01-01

    While previous research has indicated that learners with field-dependence (FD) and field-independence (FI) cognitive styles benefit differentially from different instructional modes, previous corrective feedback studies have ignored the issue of matching error correction strategies to learners' cognitive style. To shed some light on this issue,…

  8. Calibration of visually guided reaching is driven by error-corrective learning and internal dynamics.

    PubMed

    Cheng, Sen; Sabes, Philip N

    2007-04-01

    The sensorimotor calibration of visually guided reaching changes on a trial-to-trial basis in response to random shifts in the visual feedback of the hand. We show that a simple linear dynamical system is sufficient to model the dynamics of this adaptive process. In this model, an internal variable represents the current state of sensorimotor calibration. Changes in this state are driven by error feedback signals, which consist of the visually perceived reach error, the artificial shift in visual feedback, or both. Subjects correct for > or =20% of the error observed on each movement, despite being unaware of the visual shift. The state of adaptation is also driven by internal dynamics, consisting of a decay back to a baseline state and a "state noise" process. State noise includes any source of variability that directly affects the state of adaptation, such as variability in sensory feedback processing, the computations that drive learning, or the maintenance of the state. This noise is accumulated in the state across trials, creating temporal correlations in the sequence of reach errors. These correlations allow us to distinguish state noise from sensorimotor performance noise, which arises independently on each trial from random fluctuations in the sensorimotor pathway. We show that these two noise sources contribute comparably to the overall magnitude of movement variability. Finally, the dynamics of adaptation measured with random feedback shifts generalizes to the case of constant feedback shifts, allowing for a direct comparison of our results with more traditional blocked-exposure experiments.

  9. VAPOR PRESSURES, LIQUID MOLAR VOLUMES, VAPOR NON- IDEALITY, AND CRITICAL PROPERTIES OF CF3OCF2CF2CF3, c-CF2CF2CF2CF2O, CF3OCF2OCF3, AND CF3OCF2CF2H

    EPA Science Inventory

    New measurements of the thermophysical properties of CF3OCF2CF2CF3 and c -CF2CF2CF2CF2O are reported from T ≈ 235 K to the critical region. Liquid-phase volumetric results for CF3OCF2OCF3 and CF3OCF2CF2H (235 < T/K < 303) are reported to supplement the information already availab...

  10. Activation of 3-Phosphoinositide-dependent Kinase 1 (PDK1) and Serum- and Glucocorticoid-induced Protein Kinase 1 (SGK1) by Short-chain Sphingolipid C4-ceramide Rescues the Trafficking Defect of ΔF508-Cystic Fibrosis Transmembrane Conductance Regulator (ΔF508-CFTR)*

    PubMed Central

    Caohuy, Hung; Yang, Qingfeng; Eudy, Yvonne; Ha, Thien-An; Xu, Andrew E.; Glover, Matthew; Frizzell, Raymond A.; Jozwik, Catherine; Pollard, Harvey B.

    2014-01-01

    Cystic fibrosis (CF) is due to a folding defect in the CF transmembrane conductance regulator (CFTR) protein. The most common mutation, ΔF508, prevents CFTR from trafficking to the apical plasma membrane. Here we show that activation of the PDK1/SGK1 signaling pathway with C4-ceramide (C4-CER), a non-toxic small molecule, functionally corrects the trafficking defect in both cultured CF cells and primary epithelial cell explants from CF patients. The mechanism of C4-CER action involves a series of mutual autophosphorylation and phosphorylation events between PDK1 and SGK1. Detailed mechanistic studies indicate that C4-CER initially induces autophosphorylation of SGK1 at Ser422. SGK1[Ser(P)422] and C4-CER coincidently bind PDK1 and permit PDK1 to autophosphorylate at Ser241. Then PDK1[Ser(P)241] phosphorylates SGK1[Ser(P)422] at Thr256 to generate fully activated SGK1[Ser422, Thr(P)256]. SGK1[Ser(P)422,Thr(P)256] phosphorylates and inactivates the E3 ubiquitin ligase Nedd4-2. ΔF508-CFTR is thus free to traffic to the plasma membrane. Importantly, C4-CER-mediated activation of both PDK1 and SGK1 is independent of the PI3K/Akt/mammalian target of rapamycin signaling pathway. Physiologically, C4-CER significantly increases maturation and stability of ΔF508-CFTR (t½ ∼10 h), enhances cAMP-activated chloride secretion, and suppresses hypersecretion of interleukin-8 (IL-8). We suggest that candidate drugs for CF directed against the PDK1/SGK1 signaling pathway, such as C4-CER, provide a novel therapeutic strategy for a life-limiting disorder that affects one child, on average, each day. PMID:25384981

  11. The role of video in facilitating perception and action of a novel coordination movement.

    PubMed

    Hodges, Nicola J; Chua, Romeo; Franks, Ian M

    2003-09-01

    Two groups (n = 10 in each) practiced a novel, bimanual coordination pattern that was demonstrated on video. One of the groups received augmented video feedback of their own responses after each trial following a demonstration. The video-feedback group showed better performance in acquisition and retention than the no-feedback group. On error-detection tests, the video-feedback group was better able to distinguish between correct and incorrect movement patterns. The authors concluded that video feedback helps to make relative phase information salient by aiding the discrimination process. Prepractice ability on a scanning task revealed that individuals who persevered with in-phase-type movements, even though the task demands dictated otherwise, had the most difficulty determining and subsequently performing the required movement. Video feedback helped them to compensate for those difficulties.

  12. [Research on the application of grey system theory in the pattern recognition for chromatographic fingerprints of traditional Chinese medicine].

    PubMed

    Wei, Hang; Lin, Li; Zhang, Yuan; Wang, Lianjing; Chen, Qinqun

    2013-02-01

    A model based on grey system theory was proposed for pattern recognition in chromatographic fingerprints (CF) of traditional Chinese medicine (TCM). The grey relational grade among the data series of each testing CF and the ideal CF was obtained by entropy and norm respectively, then the principle of "maximal matching degree" was introduced to make judgments, so as to achieve the purpose of variety identification and quality evaluation. A satisfactory result in the high performance liquid chromatographic (HPLC) analysis of 56 batches of different varieties of Exocarpium Citrus Grandis was achieved with this model. The errors in the chromatographic fingerprint analysis caused by traditional similarity method or grey correlation method were overcome, as the samples of Citrus grandis 'Tomentosa' and Citrus grandis (L.) Osbeck were correctly distinguished in the experiment. Furthermore in the study on the variety identification of Citrus grandis 'Tomentosa', the recognition rates were up to 92.85%, although the types and the contents of the chemical compositions of the samples were very close. At the same time, the model had the merits of low computation complexity and easy operation by computer programming. The research indicated that the grey system theory has good applicability to pattern recognition in the chromatographic fingerprints of TCM.

  13. Experimental clean combustor program, phase 2

    NASA Technical Reports Server (NTRS)

    Gleason, C. C.; Rogers, D. W.; Bahr, D. W.

    1976-01-01

    The primary objectives of this three-phase program are to develop technology for the design of advanced combustors with significantly lower pollutant emission levels than those of current combustors, and to demonstrate these pollutant emission reductions in CF6-50C engine tests. The purpose of the Phase 2 Program was to further develop the two most promising concepts identified in the Phase 1 Program, the double annular combustor and the radial/axial staged combustor, and to design a combustor and breadboard fuel splitter control for CF6-50 engine demonstration testing in the Phase 3 Program. Noise measurement and alternate fuels addendums to the basic program were conducted to obtain additional experimental data. Twenty-one full annular and fifty-two sector combustor configurations were evaluated. Both combustor types demonstrated the capability for significantly reducing pollutant emission levels. The most promising results were obtained with the double annular combustor. Rig test results corrected to CF-50C engine conditions produced EPA emission parameters for CO, HC, and NOX of 3.4, 0.4, and 4.5 respectively. These levels represent CO, HC, and NOX reductions of 69, 90, and 42 percent respectively from current combustor emission levels. The combustor also met smoke emission level requirements and development engine performance and installation requirements.

  14. Candida albicans ethanol stimulates Pseudomonas aeruginosa WspR-controlled biofilm formation as part of a cyclic relationship involving phenazines.

    PubMed

    Chen, Annie I; Dolben, Emily F; Okegbe, Chinweike; Harty, Colleen E; Golub, Yuriy; Thao, Sandy; Ha, Dae Gon; Willger, Sven D; O'Toole, George A; Harwood, Caroline S; Dietrich, Lars E P; Hogan, Deborah A

    2014-10-01

    In chronic infections, pathogens are often in the presence of other microbial species. For example, Pseudomonas aeruginosa is a common and detrimental lung pathogen in individuals with cystic fibrosis (CF) and co-infections with Candida albicans are common. Here, we show that P. aeruginosa biofilm formation and phenazine production were strongly influenced by ethanol produced by the fungus C. albicans. Ethanol stimulated phenotypes that are indicative of increased levels of cyclic-di-GMP (c-di-GMP), and levels of c-di-GMP were 2-fold higher in the presence of ethanol. Through a genetic screen, we found that the diguanylate cyclase WspR was required for ethanol stimulation of c-di-GMP. Multiple lines of evidence indicate that ethanol stimulates WspR signaling through its cognate sensor WspA, and promotes WspR-dependent activation of Pel exopolysaccharide production, which contributes to biofilm maturation. We also found that ethanol stimulation of WspR promoted P. aeruginosa colonization of CF airway epithelial cells. P. aeruginosa production of phenazines occurs both in the CF lung and in culture, and phenazines enhance ethanol production by C. albicans. Using a C. albicans adh1/adh1 mutant with decreased ethanol production, we found that fungal ethanol strongly altered the spectrum of P. aeruginosa phenazines in favor of those that are most effective against fungi. Thus, a feedback cycle comprised of ethanol and phenazines drives this polymicrobial interaction, and these relationships may provide insight into why co-infection with both P. aeruginosa and C. albicans has been associated with worse outcomes in cystic fibrosis.

  15. Quantification of mid and late evoked sinks in laminar current source density profiles of columns in the primary auditory cortex

    PubMed Central

    Schaefer, Markus K.; Hechavarría, Julio C.; Kössl, Manfred

    2015-01-01

    Current source density (CSD) analysis assesses spatiotemporal synaptic activations at somatic and/or dendritic levels in the form of depolarizing current sinks. Whereas many studies have focused on the short (<50 ms) latency sinks, associated with thalamocortical projections, sinks with longer latencies have received less attention. Here, we analyzed laminar CSD patterns for the first 600 ms after stimulus onset in the primary auditory cortex of Mongolian gerbils. By applying an algorithm for contour calculation, three distinct mid and four late evoked sinks were identified in layers I, III, Va, VIa, and VIb. Our results further showed that the patterns of intracortical information-flow remained qualitatively similar for low and for high sound pressure level stimuli at the characteristic frequency (CF) as well as for stimuli ± 1 octave from CF. There were, however, differences associated with the strength, vertical extent, onset latency, and duration of the sinks for the four stimulation paradigms used. Stimuli one octave above the most sensitive frequency evoked a new, and quite reliable, sink in layer Va whereas low level stimulation led to the disappearance of the layer VIb sink. These data indicate the presence of input sources specifically activated in response to level and/or frequency parameters. Furthermore, spectral integration above vs. below the CF of neurons is asymmetric as illustrated by CSD profiles. These results are important because synaptic feedback associated with mid and late sinks—beginning at 50 ms post stimulus latency—is likely crucial for response modulation resulting from higher order processes like memory, learning or cognitive control. PMID:26557058

  16. Quality of Life and Compassion Satisfaction in Clinicians: A Pilot Intervention Study for Reducing Compassion Fatigue.

    PubMed

    Klein, Colleen J; Riggenbach-Hays, Jami J; Sollenberger, Laura M; Harney, Diane M; McGarvey, Jeremy S

    2018-06-01

    Compassion fatigue (CF) is prevalent in healthcare professionals, particularly in those caring for chronic, acutely ill, and/or those patients who might be moving toward comfort care. Over time, CF can lead to burnout (BO) and secondary traumatic stress and an overall decrease in professional quality of life. In this pilot study, participants completed a resiliency program focused on education about CF and self-awareness of its individualized impact and were expected to develop ongoing self-care practices to prevent/address the untoward effects. Healthcare professionals ( N = 15) participated in a formalized educational program consisting of three 90-minute educational sessions held 2 weeks apart. Preassessment and postintervention data were collected electronically in survey format. A postprogram evaluation was also offered. Upon completion of the program, participants noted an increase in compassion satisfaction (CS) and a small reduction in BO. Secondary traumatic stress remained unchanged. Feedback about the program was positive, and participants reported the impact on their clinical practice and life to be moderately high. At 6 months, over half of the participants continued to report positive impact on their personal/professional lives. While the small sample size of this pilot study limits the generalizability of the findings, there were positive effects for CS and BO in participants over time, indicating possible benefits of providing self-care education to healthcare providers. Additional research with a larger sample size is needed to address how healthcare providers might further benefit from resiliency education and interventions to improve professional quality of life.

  17. Microscale Heat Conduction Models and Doppler Feedback

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

    Hawari, Ayman I.; Ougouag, Abderrafi

    2015-01-22

    The objective of this project is to establish an approach for providing the fundamental input that is needed to estimate the magnitude and time-dependence of the Doppler feedback mechanism in Very High Temperature reactors. This mechanism is the foremost contributor to the passive safety of gas-cooled, graphite-moderated high temperature reactors that use fuel based on Tristructural-Isotropic (TRISO) coated particles. Therefore, its correct prediction is essential to the conduct of safety analyses for these reactors. Since the effect is directly dependent on the actual temperature reached by the fuel during transients, the underlying phenomena of heat deposition, heat transfer and temperaturemore » rise must be correctly predicted. To achieve the above objective, this project will explore an approach that accounts for lattice effects as well as local temperature variations and the correct definition of temperature and related local effects.« less

  18. Hypercorrection of high-confidence errors in the classroom.

    PubMed

    Carpenter, Shana K; Haynes, Cynthia L; Corral, Daniel; Yeung, Kam Leung

    2018-05-19

    People often have erroneous knowledge about the world that is firmly entrenched in memory and endorsed with high confidence. Although strong errors in memory would seem difficult to "un-learn," evidence suggests that errors are more likely to be corrected through feedback when they are originally endorsed with high confidence compared to low confidence. This hypercorrection effect has been predominantly studied in laboratory settings with general knowledge (i.e., trivia) questions, however, and has not been systematically explored in authentic classroom contexts. In the current study, college students in an introductory horticulture class answered questions about the course content, rated their confidence in their answers, received feedback of the correct answers, and then later completed a posttest. Results revealed a significant hypercorrection effect, along with a tendency for students with higher prior knowledge of the material to express higher confidence in, and in turn more effective correction of, their error responses.

  19. Vibrotactile Feedback for Brain-Computer Interface Operation

    PubMed Central

    Cincotti, Febo; Kauhanen, Laura; Aloise, Fabio; Palomäki, Tapio; Caporusso, Nicholas; Jylänki, Pasi; Mattia, Donatella; Babiloni, Fabio; Vanacker, Gerolf; Nuttin, Marnix; Marciani, Maria Grazia; Millán, José del R.

    2007-01-01

    To be correctly mastered, brain-computer interfaces (BCIs) need an uninterrupted flow of feedback to the user. This feedback is usually delivered through the visual channel. Our aim was to explore the benefits of vibrotactile feedback during users' training and control of EEG-based BCI applications. A protocol for delivering vibrotactile feedback, including specific hardware and software arrangements, was specified. In three studies with 33 subjects (including 3 with spinal cord injury), we compared vibrotactile and visual feedback, addressing: (I) the feasibility of subjects' training to master their EEG rhythms using tactile feedback; (II) the compatibility of this form of feedback in presence of a visual distracter; (III) the performance in presence of a complex visual task on the same (visual) or different (tactile) sensory channel. The stimulation protocol we developed supports a general usage of the tactors; preliminary experimentations. All studies indicated that the vibrotactile channel can function as a valuable feedback modality with reliability comparable to the classical visual feedback. Advantages of using a vibrotactile feedback emerged when the visual channel was highly loaded by a complex task. In all experiments, vibrotactile feedback felt, after some training, more natural for both controls and SCI users. PMID:18354734

  20. Effects of Vibrotactile Feedback on Human Learning of Arm Motions

    PubMed Central

    Bark, Karlin; Hyman, Emily; Tan, Frank; Cha, Elizabeth; Jax, Steven A.; Buxbaum, Laurel J.; Kuchenbecker, Katherine J.

    2015-01-01

    Tactile cues generated from lightweight, wearable actuators can help users learn new motions by providing immediate feedback on when and how to correct their movements. We present a vibrotactile motion guidance system that measures arm motions and provides vibration feedback when the user deviates from a desired trajectory. A study was conducted to test the effects of vibrotactile guidance on a subject’s ability to learn arm motions. Twenty-six subjects learned motions of varying difficulty with both visual (V), and visual and vibrotactile (VVT) feedback over the course of four days of training. After four days of rest, subjects returned to perform the motions from memory with no feedback. We found that augmenting visual feedback with vibrotactile feedback helped subjects reduce the root mean square (rms) angle error of their limb significantly while they were learning the motions, particularly for 1DOF motions. Analysis of the retention data showed no significant difference in rms angle errors between feedback conditions. PMID:25486644

Top