2,117 research outputs found

    Knowledge Maps as Scaffolds for Cognitive Processing

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    Knowledge Maps Are Node-Link Representations in Which Ideas Are Located in Nodes and Connected to Other Related Ideas through a Series of Labeled Links. the Research on Knowledge Mapping in the Last 12 Years Has Produced a Number of Consistent Findings. Students Recall More Central Ideas When They Learn from a Knowledge Map Than When They Learn from Text and Those with Low Verbal Ability or Low Prior Knowledge Often Benefit the Most. the Use of Knowledge Maps Also Appears to Amplify the Benefits Associated with Scripted Cooperation. Learning from Maps is Enhanced by Active Processing Strategies Such as Summarization or Annotation and by Designing Maps According to Gestalt Principles of Organization. Fruitful Areas for Future Research on Knowledge Mapping Include Examining Whether Knowledge Maps Reduce Cognitive Load, How Map Learning is Influenced by the Structure of the Information to Be Learned, and the Possibilities for Transfer. Implications for Practice Are Briefly Delineated

    Frequency Domain Functional Near-Infrared Spectrometer (fNIRS) for Crew State Monitoring

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    A frequency domain functional near-infrared spectrometer (fNIRS) and accompanying software have been developed by the NASA Glenn Research Center as part of the Airspace Operations and Safety Program (AOSP) Technologies for Airplane State Awareness (TASA)SE211 Crew State Monitoring (CSM) Project. The goal of CSM was to develop a suite of instruments to measure the cognitive state of operators while performing operational activities. The fNIRS was one of the instruments intended for the CSM, developed to measure changes in oxygen levels in the brain noninvasively

    The Effect of Textual Errors on Dyadic and Individual Learning

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    The Major Objective of the Present Experiment Was to Assess the Effects of Textual Errors on Dyadic and Individual Learning. One Hundred Undergraduates Were Taught a Four-Step Learning Strategy, after Which They Studied a Text Passage Either Dyadically or Individually. Half of the Passages within Both Conditions Contained Syntactic Errors. Total Recall Measures Indicated that Dyads Performed Better Than Individuals on Recall of Text in Sections Not Containing Errors, Whereas the Groups Did Not Differ on Recall of the Material in Text Sections Containing Errors. Further, Dyads Outscored Individuals on Measures of Recall of Error Location, Error Frequency, and Perceived Difficulty of the Text Sections Which Contained Errors. in Addition, Subjective Processing Measures Indicated that Motivation and Interest Were Strongly Related to Recall. © 1989, SAGE Publications. All Rights Reserved

    Sexually dimorphic effect of aging on skeletal muscle protein synthesis

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    BACKGROUND: Although there appear to be no differences in muscle protein turnover in young and middle aged men and women, we have reported significant differences in the rate of muscle protein synthesis between older adult men and women. This suggests that aging may affect muscle protein turnover differently in men and women. METHODS: We measured the skeletal muscle protein fractional synthesis rate (FSR) by using stable isotope-labeled tracer methods during basal postabsorptive conditions and during a hyperaminoacidemic-hyperinsulinemic-euglycemic clamp in eight young men (25–45 y), ten young women (25–45 y), ten old men (65–85 y) and ten old women (65–85 y). RESULTS: The basal muscle protein FSR was not different in young and old men (0.040 ± 0.004 and 0.043 ± 0.005%·h(-1), respectively) and combined insulin, glucose and amino acid infusion significantly increased the muscle protein FSR both in young (to 0.063 ± 0.006%·h(-1)) and old (to 0.051 ± 0.008%·h(-1)) men but the increase (0.023 ± 0.004 vs. 0.009 ± 0.004%·h(-1), respectively) was ~60% less in the old men (P = 0.03). In contrast, the basal muscle protein FSR was ~30% greater in old than young women (0.060 ± 0.003 vs. 0.046 ± 0.004%·h(-1), respectively; P < 0.05) and combined insulin, glucose and amino acid infusion significantly increased the muscle protein FSR in young (P < 0.01) but not in old women (P = 0.10) so that the FSR was not different between young and old women during the clamp (0.074 ± 0.006%·h(-1) vs. 0.072 ± 0.006%·h(-1), respectively). CONCLUSIONS: There is sexual dimorphism in the age-related changes in muscle protein synthesis and thus the metabolic processes responsible for the age-related decline in muscle mass

    ChREBP refines the hepatic response to fructose to protect the liver from injury

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    Transorganogenesis and transdifferentiation in C. elegans are dependent on differentiated cell identity

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    AbstractThe differentiated cell identities and structure of fully formed organs are generally stable after their development. In contrast, we report here that development of the C. elegans proximal somatic gonad (hermaphrodite uterus and spermathecae, and male vas deferens) can be redirected into intestine-like organs by brief expression of the ELT-7 GATA transcription factor. This process converts one developing organ into another and can hence be considered “transorganogenesis.” We show that, following pulsed ELT-7 expression, cells of the uterus activate and maintain intestine-specific gene expression and are transformed at the ultrastructural level to form an epithelial tube resembling the normal intestine formed during embryogenesis. Ubiquitous ELT-7 expression activates intestinal markers in many different cell types but only cells in the somatic gonad and pharynx appear to become fully reprogrammed. We found that ectopic expression of other endoderm-promoting transcription factors, but not muscle- or ectoderm- promoting transcription factors, redirects the fate of these organs, suggesting that pharyngeal and somatic gonad cells are specifically competent to adopt intestine identity. Although the intestine, pharynx, and somatic gonad are derived from distant cell lineages, they all express the PHA-4/FoxA transcription factor. While we found that post-embryonic PHA-4 is not necessary for pharynx or uterus reprogramming and PHA-4 is not sufficient in combination with ELT-7 to induce reprogramming in other cells types, knock down of PHA-4 during embryogenesis, which abolishes normal pharynx differentiation, prevents pharyngeal precursors from being reprogrammed into intestine. These results suggest that differentiated cell identity determines susceptibility to transdifferentiation and highlight the importance of cellular context in controlling competency for reprogramming
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