56 research outputs found
Judgment of Learning Accuracy in High-functioning Adolescents and Adults with Autism Spectrum Disorder
This study explored whether adults and adolescents with autism spectrum disorder (ASD) demonstrate difficulties making metacognitive judgments, specifically judgments of learning. Across two experiments, the study examined whether individuals with ASD could accurately judge whether they had learnt a piece of information (in this case word pairs). In Experiment 1, adults with ASD demonstrated typical accuracy on a standard โcue-aloneโ judgment of learning (JOL) task, compared to age- and IQmatched neurotypical adults. Additionally, in Experiment 2, adolescents with ASD demonstrated typical accuracy on both a standard โcue-aloneโ JOL task, and a โcue-targetโ JOL task. These results suggest that JOL accuracy is unimpaired in ASD. These results have important implications for both theories of metacognition in ASD and educational practise
Uncovering the Dynamics of Cardiac Systems Using Stochastic Pacing and Frequency Domain Analyses
Alternans of cardiac action potential duration (APD) is a well-known arrhythmogenic mechanism which results from dynamical instabilities. The propensity to alternans is classically investigated by examining APD restitution and by deriving APD restitution slopes as predictive markers. However, experiments have shown that such markers are not always accurate for the prediction of alternans. Using a mathematical ventricular cell model known to exhibit unstable dynamics of both membrane potential and Ca2+ cycling, we demonstrate that an accurate marker can be obtained by pacing at cycle lengths (CLs) varying randomly around a basic CL (BCL) and by evaluating the transfer function between the time series of CLs and APDs using an autoregressive-moving-average (ARMA) model. The first pole of this transfer function corresponds to the eigenvalue (ฮปalt) of the dominant eigenmode of the cardiac system, which predicts that alternans occurs when ฮปaltโคโ1. For different BCLs, control values of ฮปalt were obtained using eigenmode analysis and compared to the first pole of the transfer function estimated using ARMA model fitting in simulations of random pacing protocols. In all versions of the cell model, this pole provided an accurate estimation of ฮปalt. Furthermore, during slow ramp decreases of BCL or simulated drug application, this approach predicted the onset of alternans by extrapolating the time course of the estimated ฮปalt. In conclusion, stochastic pacing and ARMA model identification represents a novel approach to predict alternans without making any assumptions about its ionic mechanisms. It should therefore be applicable experimentally for any type of myocardial cell
Investigating Executive Working Memory and Phonological Short-Term Memory in Relation to Fluency and Self-Repair Behavior in L2 Speech
This paper reports the findings of a study investigating the relationship of executive working memory (WM) and phonological short-term memory (PSTM) to fluency and self-repair behavior during an unrehearsed oral task performed by second language (L2) speakers of English at two levels of proficiency, elementary and lower intermediate. Correlational analyses revealed a negative relationship between executive WM and number of pauses in the lower intermediate L2 speakers. However, no reliable association was found in our sample between executive WM or PSTM and self-repair behavior in terms of either frequency or type of self-repair. Taken together, our findings suggest that while executive WM may enhance performance at the conceptualization and formulation stages of the speech production process, self-repair behavior in L2 speakers may depend on factors other than working memory
Dynamism in the solar core
Recent results of a mixed shell model heated asymmetrically by transient
increases in nuclear burning indicate the transient generation of small hot
spots inside the Sun somewhere between 0.1 and 0.2 solar radii. These hot
bubbles are followed by a nonlinear differential equation system with finite
amplitude non-homologous perturbations which is solved in a solar model. Our
results show the possibility of a direct connection between the dynamic
phenomena of the solar core and the atmospheric activity. Namely, an initial
heating about DQ_0 ~ 10^{31}-10^{37} ergs can be enough for a bubble to reach
the outer convective zone. Our calculations show that a hot bubble can arrive
into subphotospheric regions with DQ_final ~ 10^{28} - 10^{34} ergs with a high
speed, up to 10 km s-1, approaching the local sound speed. We point out that
the developing sonic boom transforms the shock front into accelerated particle
beam injected upwards into the top of loop carried out by the hot bubble above
its forefront traveling from the solar interior. As a result, a new perspective
arises to explain flare energetics. We show that the particle beams generated
by energetic deep-origin hot bubbles in the subphotospheric layers have masses,
energies, and chemical compositions in the observed range of solar
chromospheric and coronal flares. It is shown how the emergence of a hot bubble
into subphotospheric regions offers a natural mechanism that can generate both
the eruption leading to the flare and the observed coronal magnetic topology
for reconnection. We show a list of long-standing problems of solar physics
that our model explains. We present some predictions for observations, some of
which are planned to be realized in the near future.Comment: 44 pages, 20 figure
The role of tenascin-C in tissue injury and tumorigenesis
The extracellular matrix molecule tenascin-C is highly expressed during embryonic development, tissue repair and in pathological situations such as chronic inflammation and cancer. Tenascin-C interacts with several other extracellular matrix molecules and cell-surface receptors, thus affecting tissue architecture, tissue resilience and cell responses. Tenascin-C modulates cell migration, proliferation and cellular signaling through induction of pro-inflammatory cytokines and oncogenic signaling molecules amongst other mechanisms. Given the causal role of inflammation in cancer progression, common mechanisms might be controlled by tenascin-C during both events. Drugs targeting the expression or function of tenascin-C or the tenascin-C protein itself are currently being developed and some drugs have already reached advanced clinical trials. This generates hope that increased knowledge about tenascin-C will further improve management of diseases with high tenascin-C expression such as chronic inflammation, heart failure, artheriosclerosis and cancer
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