570 research outputs found
High or low? Comparing high and low-variability phonetic training in adult and child second language learners
Background
High talker variability (i.e., multiple voices in the input) has been found effective in training nonnative phonetic contrasts in adults. A small number of studies suggest that children also benefit from high-variability phonetic training with some evidence that they show greater learning (more plasticity) than adults given matched input, although results are mixed. However, no study has directly compared the effectiveness of high versus low talker variability in children.
Methods
Native Greek-speaking eight-year-olds (N = 52), and adults (N = 41) were exposed to the English /i/-/ɪ/ contrast in 10 training sessions through a computerized word-learning game. Pre- and post-training tests examined discrimination of the contrast as well as lexical learning. Participants were randomly assigned to high (four talkers) or low (one talker) variability training conditions.
Results
Both age groups improved during training, and both improved more while trained with a single talker. Results of a three-interval oddity discrimination test did not show the predicted benefit of high-variability training in either age group. Instead, children showed an effect in the reverse direction—i.e., reliably greater improvements in discrimination following single talker training, even for untrained generalization items, although the result is qualified by (accidental) differences between participant groups at pre-test. Adults showed a numeric advantage for high-variability but were inconsistent with respect to voice and word novelty. In addition, no effect of variability was found for lexical learning. There was no evidence of greater plasticity for phonetic learning in child learners.
Discussion
This paper adds to the handful of studies demonstrating that, like adults, child learners can improve their discrimination of a phonetic contrast via computerized training. There was no evidence of a benefit of training with multiple talkers, either for discrimination or word learning. The results also do not support the findings of greater plasticity in child learners found in a previous paper (Giannakopoulou, Uther & Ylinen, 2013a). We discuss these results in terms of various differences between training and test tasks used in the current work compared with previous literature
Inhibition by botulinum toxin of depolarization-evoked release of (14C)acetylcholine from synaptosomes in vitro
Onomatopoeia, gestures, actions and words: How do caregivers use multimodal cues to communicate with their children
Most research on how children learn the mapping between
words and world has assumed that language is arbitrary, and
has investigated language learning in contexts in which objects
referred to are present in the environment. Here, we report
analyses of a semi-naturalistic corpus of caregivers talking to
their 2-3 year-old. We focus on caregivers’ use of non-arbitrary
cues across different expressive channels: both iconic
(onomatopoeia and representational gestures) and indexical
(points and actions with objects). We ask if these cues are used
differently when talking about objects known or unknown to
the child, and when the referred objects are present or absent.
We hypothesize that caregivers would use these cues more
often with objects novel to the child. Moreover, they would use
the iconic cues especially when objects are absent because
iconic cues bring to the mind’s eye properties of referents. We
find that cue distribution differs: all cues except points are more
common for unknown objects indicating their potential role in
learning; onomatopoeia and representational gestures are more
common for displaced contexts whereas indexical cues are
more common when objects are present. Thus, caregivers
provide multimodal non-arbitrary cues to support children’s
vocabulary learning and iconicity – specifically – can support
linking mental representations for objects and labels
Onomatopoeia, gestures, actions and words: how do caregivers use multimodal cues in their communication to children?
Most research on how children learn the mapping between words and world has assumed that language is arbitrary, and has investigated language learning in contexts in which objects referred to are present in the environment. Here, we report analyses of a semi-naturalistic corpus of caregivers talking to their 2-3 year-old. We focus on caregivers’ use of non-arbitrary cues across different expressive channels: both iconic (onomatopoeia and representational gestures) and indexical (points and actions with objects). We ask if these cues are used differently when talking about objects known or unknown to the child, and when the referred objects are present or absent. We hypothesize that caregivers would use these cues more often with objects novel to the child. Moreover, they would use the iconic cues especially when objects are absent because iconic cues bring to the mind’s eye properties of referents. We find that cue distribution differs: all cues except points are more common for unknown objects indicating their potential role in learning; onomatopoeia and representational gestures are more common for displaced contexts whereas indexical cues are more common when objects are present. Thus, caregivers provide multimodal non-arbitrary cues to support children’s vocabulary learning and iconicity – specifically – can support linking mental representations for objects and labels
Guest Editorial
This is an editorial which introduces original papers produced on the theme of the supervision of social work practiceThis is an Accepted Manuscript of an article published by Taylor & Francis in Practice: Social Work in Action on September 2015, available online: http://dx.doi.org/10.1080/09503153.2015.1048053This guest editorial introduces the special edition on the supervision of social work practic
Do acute elevations of serum creatinine in primary care engender an increased mortality risk?
Background: The significant impact Acute Kidney Injury (AKI) has on patient morbidity and mortality emphasizes the need for early recognition and effective treatment. AKI presenting to or occurring during hospitalisation has been widely studied but little is known about the incidence and outcomes of patients experiencing acute elevations in serum creatinine in the primary care setting where people are not subsequently admitted to hospital. The aim of this study was to define this incidence and explore its impact on mortality. Methods: The study cohort was identified by using hospital data bases over a six month period. Inclusion criteria: People with a serum creatinine request during the study period, 18 or over and not on renal replacement therapy. The patients were stratified by a rise in serum creatinine corresponding to the Acute Kidney Injury Network (AKIN) criteria for comparison purposes. Descriptive and survival data were then analysed. Ethical approval was granted from National Research Ethics Service (NRES) Committee South East Coast and from the National Information Governance Board. Results: The total study population was 61,432. 57,300 subjects with ‘no AKI’, mean age 64.The number (mean age) of acute serum creatinine rises overall were, ‘AKI 1’ 3,798 (72), ‘AKI 2’ 232 (73), and ‘AKI 3’ 102 (68) which equates to an overall incidence of 14,192 pmp/year (adult). Unadjusted 30 day survival was 99.9% in subjects with ‘no AKI’, compared to 98.6%, 90.1% and 82.3% in those with ‘AKI 1’, ‘AKI 2’ and ‘AKI 3’ respectively. After multivariable analysis adjusting for age, gender, baseline kidney function and co-morbidity the odds ratio of 30 day mortality was 5.3 (95% CI 3.6, 7.7), 36.8 (95% CI 21.6, 62.7) and 123 (95% CI 64.8, 235) respectively, compared to those without acute serum creatinine rises as defined. Conclusions: People who develop acute elevations of serum creatinine in primary care without being admitted to hospital have significantly worse outcomes than those with stable kidney function
Sampling molecular conformations and dynamics in a multiuser virtual reality framework
Copyright © 2018 The Authors, some rights reserved. We describe a framework for interactive molecular dynamics in a multiuser virtual reality (VR) environment, combining rigorous cloud-mounted atomistic physics simulations with commodity VR hardware, which we have made accessible to readers (see isci.itch.io/nsb-imd). It allows users to visualize and sample, with atomic-level precision, the structures and dynamics of complex molecular structures “on the fly” and to interact with other users in the same virtual environment. A series of controlled studies, in which participants were tasked with a range of molecular manipulation goals (threading methane through a nanotube, changing helical screw sense, and tying a protein knot), quantitatively demonstrate that users within the interactive VR environment can complete sophisticated molecular modeling tasks more quickly than they can using conventional interfaces, especially for molecular pathways and structural transitions whose conformational choreographies are intrinsically three-dimensional. This framework should accelerate progress in nanoscale molecular engineering areas including conformational mapping, drug development, synthetic biology, and catalyst design. More broadly, our findings highlight the potential of VR in scientific domains where three-dimensional dynamics matter, spanning research and education
The motivations to study and expectations of studying of undergraduate students in business and management
Expression of the α7 nicotinic acetylcholine receptor in human lung cells
BACKGROUND: We and others have shown that one of the mechanisms of growth regulation of small cell lung cancer cell lines and cultured pulmonary neuroendocrine cells is by the binding of agonists to the α7 neuronal nicotinic acetylcholine receptor. In addition, we have shown that the nicotine-derived carcinogenic nitrosamine, 4(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is a high affinity agonist for the α7 nicotinic acetylcholine receptor. In the present study, our goal was to determine the extent of α7 mRNA and protein expression in the human lung. METHODS: Experiments were done using reverse transcription polymerase chain reaction (RT-PCR), a nuclease protection assay and western blotting using membrane proteins. RESULTS: We detected mRNA for the neuronal nicotinic acetylcholine receptor α7 receptor in seven small cell lung cancer (SCLC) cell lines, in two pulmonary adenocarcinoma cell lines, in cultured normal human small airway epithelial cells (SAEC), one carcinoid cell line, three squamous cell lines and tissue samples from nine patients with various types of lung cancer. A nuclease protection assay showed prominent levels of α7 in the NCI-H82 SCLC cell line while α7 was not detected in SAEC, suggesting that α7 mRNA levels may be higher in SCLC compared to normal cells. Using a specific antibody to the α7 nicotinic receptor, protein expression of α7 was determined. All SCLC cell lines except NCI-H187 expressed protein for the α7 receptor. In the non-SCLC cells and normal cells that express the α7 nAChR mRNA, only in SAEC, A549 and NCI-H226 was expression of the α7 nicotinic receptor protein shown. When NCI-H69 SCLC cell line was exposed to 100 pm NNK, protein expression of the α7 receptor was increased at 60 and 150 min. CONCLUSION: Expression of mRNA for the neuronal nicotinic acetylcholine receptor α7 seems to be ubiquitously expressed in all human lung cancer cell lines tested (except for NCI-H441) as well as normal lung cells. The α7 nicotinic receptor protein is expressed in fewer cell lines, and the tobacco carcinogen NNK increases α7 nicotinic receptor protein levels
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