2,800 research outputs found
Working memory and its relation to interference and facilitation effects on a Stroop task in persons with mild cognitive impairments and normal elderly adults
The current study investigated working memory(WM) and its relation to interference and facilitation effects using a Stroop-like token task in persons with mild cognitive impairments(MCI) and normal elderly adults(NEA). Both groups demonstrated interference effects. MCI group showed greater interference effects than NEA in the accuracy analysis. The results are consistent with the previous findings (Belleville et al., 2010). Both groups showed no facilitation effects in the accuracy rate. However, they showed longer response times in 75%Congruent than neutral condition. Among WM measures, subtract-2 span task was most highly correlated with the incongruent trials of 75%Congruent condition with the highest cognitive demands
Working Memory Capacity and its Relation to Passive Sentence Comprehension in Persons with Mild Cognitive Impairment
The purpose of the study was to investigate working memory capacity (WMC) and its relation to Korean passive sentence (PS) comprehension in persons with mild cognitive impairment (MCI). Results revealed that persons with MCI performed significantly more poorly than normal elderly individuals (NEI) in PS compared to active sentences with intransitive verbs. However, the group differences were not significant between PS and active sentences with transitive verbs. WMC significantly predicted performance on PS for both groups. The current study indicated that Korean-speaking persons with MCI could use information of case markers and WMC was related to PS comprehension abilities
Multiple Functions of Nm23-H1 Are Regulated by Oxido-Reduction System
Nucleoside diphosphate kinase (NDPK, Nm23), a housekeeping enzyme, is known to be a multifunctional protein, acting as a metastasis suppressor, transactivation activity on c-myc, and regulating endocytosis. The cellular mechanisms regulating Nm23 functions are poorly understood. In this study, we identified the modifications and interacting proteins of Nm23-H1 in response to oxidative stress. We found that Cys109 in Nm23-H1 is oxidized to various oxidation states including intra- and inter-disulfide crosslinks, glutathionylation, and sulfonic acid formation in response to H2O2 treatment both in vivo and in vitro. The cross-linking sites and modifications of oxidized Nm23-H1 were identified by peptide sequencing using UPLC-ESI-q-TOF tandem MS. Glutathionylation and oxidation of Cys109 inhibited the NDPK enzymatic activity of Nm23-H1. We also found that thioredoxin reductase 1 (TrxR1) is an interacting protein of Nm23-H1, and it binds specifically to oxidized Nm23-H1. Oxidized Nm23 is a substrate of NADPH-TrxR1-thioredoxin shuttle system, and the disulfide crosslinking is reversibly reduced and the enzymatic activity is recovered by this system. Oxidation of Cys109 in Nm23-H1 inhibited its metastatic suppressor activity as well as the enzymatic activities. The mutant, Nm23-H1 C109A, retained both the enzymatic and metastasis suppressor activities under oxidative stress. This suggests that key enzymatic and metastasis suppressor functions of Nm23-H1 are regulated by oxido-reduction of its Cys109
‘Evidence of an auxin signal pathway, microRNA167-ARF8-GH3, and its response to exogenous auxin in cultured rice cells’
MicroRNA167 (miR167) was shown to cleave auxin responsive factor 8 (ARF8) mRNA in cultured rice cells. MiR167 level was found to be controlled by the presence of auxin in the growth medium. When cells grew in auxin-free medium, miR167 level decreased, resulting in an increase in the level of ARF8 mRNA. Cells growing in the normal growth medium containing auxin showed a reversed trend. It was also shown that expression of OsGH3-2, an rice IAA-conjugating enzyme, was positively regulated by ARF8. Delivery of synthesized miR167 into cells led to decrease of both ARF8 mRNA and OsGH3-2 mRNA. This study provides an evidence in which the exogeneous auxin signal is transduced to OsGH3-2 through miR167 and ARF8 in sequence. This proposed auxin signal transduction pathway, auxin-miR167-ARF8-OsGH3-2, could be, in conjunction with the other microRNA-mediated auxin signals, an important one for responding to exogeneous auxin and for determining the cellular free auxin level which guides appropriate auxin responses
Catalytic pyrolysis of Laminaria japonica over nanoporous catalysts using Py-GC/MS
The catalytic pyrolysis of Laminaria japonica was carried out over a hierarchical meso-MFI zeolite (Meso-MFI) and nanoporous Al-MCM-48 using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The effect of the catalyst type on the product distribution and chemical composition of the bio-oil was examined using Py-GC/MS. The Meso-MFI exhibited a higher activity in deoxygenation and aromatization during the catalytic pyrolysis of L. japonica. Meanwhile, the catalytic activity of Al-MCM-48 was lower than that of Meso-MFI due to its weak acidity
Deficits of case marker processing in persons with mild cognitive impairment
The purpose of the current study was to investigate whether persons with mild cognitive impairment (MCI) showed deficits in processing case markers compared to normal elderly adults (NEA). Results revealed that individuals with MCI presented significantly lower accuracy than the NEA group on a case marker processing (CMP) task. Both groups showed greater difficulties in the passive sentences than sentences with the transitive verbs. The current results suggested that individuals with early stage of dementia started presenting deficits in case marker processing compared to the control group
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