1,263 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
Neuronal ensemble decoding using a dynamical maximum entropy model
As advances in neurotechnology allow us to access the ensemble activity of multiple neurons simultaneously, many neurophysiologic studies have investigated how to decode neuronal ensemble activity. Neuronal ensemble activity from different brain regions exhibits a variety of characteristics, requiring substantially different decoding approaches. Among various models, a maximum entropy decoder is known to exploit not only individual firing activity but also interactions between neurons, extracting information more accurately for the cases with persistent neuronal activity and/or low-frequency firing activity. However, it does not consider temporal changes in neuronal states and therefore would be susceptible to poor performance for nonstationary neuronal information processing. To address this issue, we develop a novel decoder that extends a maximum entropy decoder to take time-varying neural information into account. This decoder blends a dynamical system model of neural networks into the maximum entropy model to better suit for nonstationary circumstances. From two simulation studies, we demonstrate that the proposed dynamic maximum entropy decoder could cope well with time-varying information, which the conventional maximum entropy decoder could not achieve. The results suggest that the proposed decoder may be able to infer neural information more effectively as it exploits dynamical properties of underlying neural networks.open0
Bone-added osteotome sinus floor elevation with simultaneous placement of non-submerged sand blasted with large grit and acid etched implants: a 5-year radiographic evaluation
PURPOSE: Implant survival rates using a bone-added osteotome sinus floor elevation (BAOSFE) procedure with simultaneous placement of a non-submerged sand blasted with large grit and acid etched (SLA) implant are well documented at sites where native bone height is less than 5 mm. This study evaluated the clinical results of non-submerged SLA Straumann implants placed at the time of the BAOSFE procedure at sites where native bone height was less than 4 mm. Changes in graft height after the BAOSFE procedure were also assessed using radiographs for 5 years after the implant procedure. METHODS: The BAOSFE procedure was performed on 4 patients with atrophic posterior maxillas with simultaneous placement of 7 non-submerged SLA implants. At least 7 standardized radiographs were obtained from each patient as follows: before surgery, immediately after implant placement, 6 months after surgery, every year for the next 3 years, and after more than 5 years had passed. Clinical and radiographic examinations were performed at every visit. Radiographic changes in graft height were calculated with respect to the implant's known length and the original sinus height. RESULTS: All implants were stable functionally, as well as clinically and radiographically, during the follow-up. Most of the radiographic reduction in the grafted bone height occurred in the first 2 years; reduction after 2 years was slight. CONCLUSIONS: The simultaneous placement of non-submerged SLA implants using the BAOSFE procedure is a feasible treatment option for patients with severe atrophic posterior maxillas. However, the grafted bone height is reduced during the healing period, and patients must be selected with care.ope
Selective Kernel Attention for Robust Speaker Verification
Recent state-of-the-art speaker verification architectures adopt multi-scale
processing and frequency-channel attention techniques. However, their full
potential may not have been exploited because these techniques' receptive
fields are fixed where most convolutional layers operate with specified kernel
sizes such as 1, 3 or 5. We aim to further improve this line of research by
introducing a selective kernel attention (SKA) mechanism. The SKA mechanism
allows each convolutional layer to adaptively select the kernel size in a
data-driven fashion based on an attention mechanism that exploits both
frequency and channel domain using the previous layer's output. We propose
three module variants using the SKA mechanism whereby two modules are applied
in front of an ECAPA-TDNN model, and the other is combined with the Res2Net
backbone block. Experimental results demonstrate that our proposed model
consistently outperforms the conventional counterpart on the three different
evaluation protocols in terms of both equal error rate and minimum detection
cost function. In addition, we present a detailed analysis that helps
understand how the SKA module works.Comment: Submitted to INTERSPEECH 2022. 5 pages, 3 figures, 1 tabl
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
Treadmill Exercise Alleviates Aging-induced Apoptosis in Rat Cardiac Myocytes
SummaryBackgroundThe incidence and prevalence of heart failure increases with age. Cardiomyocyte apoptosis contributes to the pathogenesis of heart failure. In the end-stage of human heart failure, increased cardiomyocyte apoptosis is observed. Exercise training is one of the nonpharmacological treatments for chronic heart failure.MethodsIn the present study, we investigated the effect of treadmill exercise on the aging-induced apoptosis within cardiac myocytes in relation to the expression of heat shock protein 70 (HSP70) using rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and Western blotting for the expression of Bcl-2, Bax, HSP70, and phosphorylated p38 (p-p38) in the cardiac myocardium were conducted.ResultsAging induced apoptosis in the myocardium, which was confirmed by increased TUNEL-positive cells and the enhancement of Bax. Expression of HSP70 was suppressed and p-p38 expression was enhanced by aging. Treadmill exercise alleviated aging-induced apoptosis with enhancing HSP70 expression and suppressing p-p38 expression in the cardiac myocytes.ConclusionBased on the present results, it can be inferred that treadmill exercise can provide a cardioprotective effect on aging-induced apoptosis through the enhancement of HSP70 expression in the heart. Thus, regular exercise may be a useful strategy for preventing heart problems in the elderly
Dietary Intake and Serum Levels of Iron in Relation to Oxidative Stress in Breast Cancer Patients
Iron may induce oxidative stress via production of reactive oxygen species, facilitating mammary carcinogenesis. This study investigated the role of iron in relation to oxidative stress as a potential risk factor in the development of breast cancer (BC). BC patients (n = 121) and healthy age-matched controls (n = 149) were entered into the study. Iron and antioxidant vitamins intakes were estimated using a quantitative food frequency questionnaire. Thirty one subjects from each group provided blood samples for measurement of serum iron, plasma malondialdehyde (MDA) and ferric reducing ability of plasma (FRAP). Total and non-heme iron intake of BC patients were lower than those of the controls. However, the serum iron level was significantly higher in BC patients. Plasma MDA levels were also significantly higher in BC patients whereas no significant difference in FRAP values were observed between the two groups. Log-transformed serum iron concentration showed no significant correlation with MDA or FRAP. These results suggest that serum iron overload may be a breast cancer risk factor possibly due to increased oxidative stress
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