Hierarchical convolutional neural networks represent a well-known robust image-recognition model. In order to apply this model to robot vision or various intelligent vision systems, its VLSI ...implementation with high performance and low power consumption is required. This paper proposes a VLSI convolutional network architecture using a hybrid approach composed of pulse-width modulation (PWM) and digital circuits. We call this approach merged/mixed analog-digital architecture. The VLSI chip includes PWM neuron circuits, PWM/digital converters, digital adder-subtracters, and digital memory. We have designed and fabricated a VLSI chip by using a 0.35 mum CMOS process. The VLSI chip can perform 6-bit precision convolution calculations for an image of 100 X 100 pixels with a receptive field area of up to 20 X 20 pixels within 5 ms, which means a performance of 2 GOPS. Power consumption of PWM neuron circuits was measured to be 20 mW. We have verified successful operations using a fabricated VLSI chip.
Lack of Adenosine Causes Myocardial Refractoriness Vogt, Achim M; Ando, Hiroshi; Arras, Margarete ...
Journal of the American College of Cardiology,
04/1998, Volume:
31, Issue:
5
Journal Article, Conference Proceeding
Peer reviewed
Open access
Objectives. This study sought to investigate the myocardial mechanisms causing refractoriness to ischemic preconditioning in pigs.
Background. Ischemic preconditioning in the pig vanishes after 60 ...min and cannot be reinstated by a second cycle of brief coronary occlusions at this time point. Ischemic preconditioning has been shown to be mediated by adenosine A1-receptors. Because myocardial adenosine production during ischemia ceases as the number of repeated brief ischemic episodes increases, we hypothesized that this lack of adenosine may cause this myocardial refractoriness.
Methods. In open chest pigs, ischemic preconditioning was achieved by repeated brief coronary occlusions. Myocardial adenosine content was assessed by high performance liquid chromatographic analysis of serial myocardial biopsy samples; infarct size (percent infarcted area of the area at risk) was determined using tetrazolium salts.
Results. Ischemic preconditioning by two cycles of occlusion of the left anterior descending coronary artery (10 min) and reperfusion (30 min) decreased infarct size (mean ± SEM 40.4 ± 2.9%; control: 76.9 ± 1.8%, p < 0.001). Prolonging the second reperfusion period to 60 min caused ischemic preconditioning to vanish (79.0 ± 0.5%) and caused refractoriness to a second cycle of preconditioning (70.0 ± 2.0%). Myocardial adenosine content increased only during the first coronary occlusion (baseline: 110.9 ± 42.0 nmol/g dry weight; first coronary occlusion: 1,686.2 ± 244.1, p < 0.001) but not during subsequent coronary occlusions. In refractory myocardium, intramyocardial microinfusion of the adenosine A1-receptor agonist N6-cyclohexyladenosine (CHA 0.3 mmol/liter) again decreased infarct size (27.4 ± 7.0%, p < 0.001 vs. control).
Conclusions. Myocardial refractoriness may be caused by the inability to produce adenosine endogenously. In refractory myocardium, application of CHA reinduces cardioprotection.
Our research focuses on ambient sounds as a key to implementing an ambient atmosphere of people, that is, the feeling of another’s proximity or presence. Such knowledge is sought for constructing an ...ultra-realistic communication system with shared reality. This study examines whether people’s impressions and behaviors are affected by (a) the existence or (b) non-existence of ambient sounds. A pilot study is conducted by using the ambient sounds of a newspaper’s pages being turned and a glass being placed on a table in an adjacent room. No difference in the subjects’ surface behavior between the two ambient-sound conditions is observed explicitly. However, the preliminary results suggest that participants feel an ambient atmosphere of people in the next room when the ambient sounds are output. They also suggest that the participants become nervous as they feel the presence of other people. This study demonstrates the importance of investigating the fundamentals of an ambient atmosphere in interaction via an ultra-realistic communication system.
A segmental wall motion abnormality is an unusual finding in patients with hypertrophic cardiomyopathy. To clarify its clinical significance, 48 patients with hypertrophic cardiomyopathy were ...analyzed. Eight patients (Group A) had apical segmental dysfunction; 40 (Group B) had normal wall motion. No patient in either group had coronary artery sterocis on selective coronary arteriography. In all patients in Group A, apical segmental dysfunction was revealed by left ventriculography; however, it could be detected by echocardiography in only two patients in Group A.
Left ventricular hypertrophy by electrocardiogram (ECG) was more common in Group B (p < 0.05). Abnormal Q waves were more frequently discovered in Group A (p < 0.005) and were recognized predominantly in the lateral leads. On serial ECGs, a gradual development of abnormal Q waves was noted in six of eight patients in Group A. Malignant arrhythmias were more common in Group A (p < 0.001). In two patients in Group A, left ventricular dilation and congestive heart failure developed during the follow-up period.
Thus, the presence of a Q wave in the lateral leads on an ECG in patients with hypertrophic cardiomyopathy may indicate the presence of apical segmental dysfunction. Left ventriculography should be performed to examine the presence of this abnormality and 24 h ambulatory ECG monitoring should be done to detect malignant arrhythmias in patients who have abnormal Q waves in the lateral leads. Patients with this unique type of hypertrophic cardiomyopathy need careful follow-up evaluation.
Recordings of b-wave and ganglion cell activities were made in order to investigate whether hypersensitivity could be observed in the proximal region of the frog retina or not. Increase in the ...amplitude of the b-wave and shortening of the response latency of ganglion cells were observed after the termination of adequate adapting light illumination, suggesting the existence of hypersensitivity in proximal elements of the retina.
OFDM (Orthogonal Frequency Division Multiplexing) is the modulation scheme that is widely used in broadband power line communication (PLC). In OFDM transmission, influence of the additive impulsive ...noise appears on every subcarriers that are the outputs of the DFT in the receiver because of the broad band spectrum of the impulsive noise. As the result, it causes significant degradation of the performance of OFDM transmission. Therefore, an appropriate measure to reduce the influence of impulsive noise is required and many schemes for impulsive noise reduction are proposed. In order to reduce the influence of the impulsive noise effectively from the received signal, precise estimation of transmission channel is necessary. However, the pilot symbols for channel estimation are also affected by impulsive noise and the scheme to estimate transmission channel under impulsive noise channel is required. In this paper, a channel estimation scheme for OFDM transmission under the class A impulsive noise channel using the pilot symbols is proposed. In the proposed scheme, channel estimation and reduction of impulsive noise is iteratively applied in order to increase the precision of channel estimation. As the results of simulation, the precision of channel estimation was improved and the bit error performance almost equivalent to the ideal channel estimation case could be achieved for data symbols.
The adenomatous polyposis coli (APC) gene at chromosome 5q21 that is responsible for familial adenomatous polyposis (FAP) was recently isolated, and germ-line mutations in a substantial number of FAP ...families were characterized. Based on this information, the authors attempted to develop a presymptomatic diagnosis test for members of families that carry FAP.
A rapid screening procedure using a polymerase chain reaction (PCR) method without radioisotopes, if necessary, coupled with digestion of restriction enzymes has been performed by detection of germ-line mutations that alter the size of DNA fragments or affect the recognition site of restriction enzymes in the APC locus.
A rapid screening procedure to detect germ-line mutations at 12 loci that cause adenomatous polyposis was established.
Using these 12 systems, presymptomatic diagnoses can be made with 100% accuracy within 24 hours. The procedures will be useful for counselling of members in some FAP families, which accounted for nearly 40% of the 95 FAP kindreds that have been detected by the germ-line mutations so far.
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