2,007 research outputs found
Worst-case User Analysis in Poisson Voronoi Cells
In this letter, we focus on the performance of a worst-case mobile user (MU)
in the downlink cellular network. We derive the coverage probability and the
spectral efficiency of the worst-case MU using stochastic geometry. Through
analytical and numerical results, we draw out interesting insights that the
coverage probability and the spectral efficiency of the worst-case MU decrease
down to 23% and 19% of those of a typical MU, respectively. By applying a
coordinated scheduling (CS) scheme, we also investigate how much the
performance of the worst-case MU is improved.Comment: Accepted, IEEE Communications Letter
Towards Neural Decoding of Imagined Speech based on Spoken Speech
Decoding imagined speech from human brain signals is a challenging and
important issue that may enable human communication via brain signals. While
imagined speech can be the paradigm for silent communication via brain signals,
it is always hard to collect enough stable data to train the decoding model.
Meanwhile, spoken speech data is relatively easy and to obtain, implying the
significance of utilizing spoken speech brain signals to decode imagined
speech. In this paper, we performed a preliminary analysis to find out whether
if it would be possible to utilize spoken speech electroencephalography data to
decode imagined speech, by simply applying the pre-trained model trained with
spoken speech brain signals to decode imagined speech. While the classification
performance of imagined speech data solely used to train and validation was
30.5 %, the transferred performance of spoken speech based classifier to
imagined speech data displayed average accuracy of 26.8 % which did not have
statistically significant difference compared to the imagined speech based
classifier (p = 0.0983, chi-square = 4.64). For more comprehensive analysis, we
compared the result with the visual imagery dataset, which would naturally be
less related to spoken speech compared to the imagined speech. As a result,
visual imagery have shown solely trained performance of 31.8 % and transferred
performance of 26.3 % which had shown statistically significant difference
between each other (p = 0.022, chi-square = 7.64). Our results imply the
potential of applying spoken speech to decode imagined speech, as well as their
underlying common features.Comment: 4 pages, 2 figure
MMP-3 Contributes to Nigrostriatal Dopaminergic Neuronal Loss, BBB Damage, and Neuroinflammation in an MPTP Mouse Model of Parkinson\u27s Disease
The present study examined whether matrix metalloproteinase-3 (MMP-3) participates in the loss of dopaminergic (DA) neurons in the nigrostriatal pathway in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson\u27s disease with blood brain barrier (BBB) damage and infiltration of peripheral immune cells. Tyrosine hydroxylase (TH) immunostaining of brain sections from MPTP-treated mice showed that MPTP induced significant degeneration of nigrostriatal DA neurons. Moreover, FITC-labeled albumin detection and immunostaining revealed that MPTP caused damage to the BBB and increased the number of ED-1- and CD-3-immunopositive cells in the substantia nigra (SN). Genetic ablation of MMP-3 reduced the nigrostriatal DA neuron loss and improved motor function. This neuroprotective effect afforded by MMP-3 deletion was associated with the suppression of BBB disruption and a decrease in the number of ED-1- and CD-3-immunopositive cells in the SN. These data suggest that MMP-3 could play a crucial role in neurodegenerative diseases such as PD in which BBB damage and neuroinflammation are implicated
Comparison of air pollution and the prevalence of allergy-related diseases in Incheon and Jeju City
PurposeA high level of air pollutants can increase the number of patients with allergy-related diseases such as asthma and allergic rhinitis (AR). To analyze the association between air pollution and allergic disease, we investigated 2 areas in Korea: Incheon, an industrial area, and Jeju, a non-industrialized area.MethodsSecond grade students at elementary schools (11 schools in Incheon and 45 schools in Jeju) were examined in a cross-sectional study. A questionnaire was used and a skin prick test was performed. The levels of NO2, CO2, O3, particulate matter (PM) PM10/2.5, formaldehyde, tVOCs, and dust mites in the classrooms and grounds were determined.ResultsThe levels of outdoor CO, PM10, and PM2.5 were significantly higher in Incheon (P<0.01). The levels of indoor CO, CO2, PM10, PM2.5 were significantly higher in Incheon (P<0.01). The prevalence rates of AR symptoms at any time, AR symptoms during the last 12 months, diagnosis of rhinitis at any time, and AR treatment during the last 12 months were significantly higher in Incheon (P<0.01). The prevalence rate of wheezing or whistling at any time, and wheezing during the last 12 months were significantly higher in Incheon (P<0.01).ConclusionWe found that the children living in Incheon, which was more polluted than Jeju, had a higher rate of AR and asthma symptoms compared to children in Jeju. To determine the effect of air pollution on the development of the AR and asthma, further studies are needed
Insulin and glucagon secretions, and morphological change of pancreatic islets in OLETF rats, a model of type 2 diabetes mellitus.
This study was performed to observe the changes of glucose-related hormones and the morphological change including ultrastructure of the pancreatic islets in the male Otsuka Long-Evans Tokushima Fatty rat. Area under the curve (AUC) of glucose at the 30th (709 plus minus 73 mg.h/dL) and at the 40th week (746 plus minus 87 mg.h/ dL) of age were significantly higher than that at the 10th week (360 plus minus 25 mg.h/ dL). AUC of insulin of the 10th week was 2.4 plus minus 0.9 ng.h/mL, increased gradually to 10.8 plus minus 8.3 ng.h/mL at the 30th week, and decreased to 1.8 plus minus 1.2 ng.h/mL at the 40th week. The size of islet was increased at 20th week of age and the distribution of peripheral alpha cells and central beta cells at the 10th and 20th weeks was changed to a mixed pattern at the 40th week. On electron microscopic examination, beta cells at the 20th week showed many immature secretory granules, increased mitochondria, and hypertrophied Golgi complex and endoplasmic reticulum. At the 40th week, beta cell contained scanty intracellular organelles and secretory granules and apoptosis of acinar cell was observed. In conclusion, as diabetes progressed, increased secretion of insulin was accompanied by increases in size of islets and number of beta-cells in male OLETF rats showing obese type 2 diabetes. However, these compensatory changes could not overcome the requirement of insulin according to the continuous hyperglycemia after development of diabetes
Clinical Approach to the Standardization of Oriental Medical Diagnostic Pattern Identification in Stroke Patients
In Korea, many stroke patients receive oriental medical care, in which pattern-identification plays a major role. Pattern-identification is Oriental Medicine's unique diagnostic system. This study attempted to standardize oriental medical pattern-identification for stroke patients. This was a community-based multicenter study that enrolled stroke patients within 30 days after their ictus. We assessed the patients' general characteristics and symptoms related to pattern-identification. Each patient's pattern was determined when two doctors had the same opinion. To determine which variables affect the pattern-identification, binary logistic regression analysis was used with the backward method. A total of 806 stroke patients were enrolled. Among 480 patients who were identified as having a certain pattern, 100 patients exhibited the Fire Heat Pattern, 210 patients the Phlegm Dampness Pattern, nine patients the Blood Stasis Pattern, 110 patients the Qi Deficiency Pattern, and 51 patients the Yin Deficiency Pattern. After the regression analysis, the predictive logistic equations for the Fire Heat, Phlegm Dampness, Qi Deficiency, and Yin Deficiency patterns were determined. The Blood Stasis Pattern was omitted because the sample size was too small. Predictive logistic equations were suggested for four of the patterns. These criteria would be useful in determining each stroke patient's pattern in clinics. However, further studies with large samples are necessary to validate and confirm these criteria
The Effect of Calcipotriol on the Expression of Human β Defensin-2 and LL-37 in Cultured Human Keratinocytes
Background. Vitamin D has been reported to regulate innate immunity by controlling the expression of antimicrobial peptides (AMPs). Objective. We investigated the effect of calcipotriol on the expression of AMPs in human cultured keratinocytes. Methods. Keratinocytes were treated with lipopolysaccharide (LPS), TNF-α, Calcipotriol and irradiated with UVB, cultured, and harvested. To assess the expression of human beta defensin-2 and LL-37 in the control group, not exposed to any stimulants, the experimental group was treated with LPS, TNF-α, or UVB, and another group was treated again with calcipotriol; reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemical staining were performed. Results. In the experimental group treated with LPS, UVB irradiation, and TNF-α, the expression of β-defensin and LL-37 was increased more than in the control group and then decreased in the experimental group treated with calcipotriol. Conclusions. Calcipotriol suppressed HBD-2 and LL-37, which were stimulated by UVB, LPS, and TNF-α
Subclinical Cervical Osteochondroma Presenting as Brown-Sequard Syndrome after Trivial Neck Trauma
Osteochondroma is a rare condition in the spine that may be indolent due to its slow growth. The authors present a case of 32-year-old man with subclinical osteochondroma in the cervical spine presenting as Brown-Sequard syndrome after trivial neck trauma. After resection of the tumor through hemilaminectomy, his symptoms were improved with mild residual sequelae
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