Networking retinomorphic sensor with memristive crossbar for brain-inspired visual perception

Compared to human vision, conventional machine vision composed of an image sensor and processor suffers from high latency and large power consumption due to physically separated image sensing and processing. A neuromorphic vision system with brain-inspired visual perception provides a promising solution to the problem. Here we propose and demonstrate a prototype neuromorphic vision system by networking a retinomorphic sensor with a memristive crossbar. We fabricate the retinomorphic sensor by using WSe₂/h-BN/Al₂O₃ van der Waals heterostructures with gate-tunable photoresponses, to closely mimic the human retinal capabilities in simultaneously sensing and processing images. We then network the sensor with a large-scale Pt/Ta/HfO₂/Ta one-transistor-one-resistor (1T1R) memristive crossbar, which plays a similar role to the visual cortex in the human brain. The realized neuromorphic vision system allows for fast letter recognition and object tracking, indicating the capabilities of image sensing, processing and recognition in the full analog regime. Our work suggests that such a neuromorphic vision system may open up unprecedented opportunities in future visual perception applications.     

Kinetic function of the lower limbs during baseball tee-batting motion at different hitting-point heights

ABSTRACT

The aim of this study was to investigate the kinetic functions of the lower limbs at different hitting-point heights to provide key information for improving batting technique in baseball players. Three-dimensional coordinate data were acquired using a motion capture system (250 Hz) and ground reaction forces were measured using three force platforms (1000 Hz) in 22 male collegiate baseball players during tee-batting set at three different hitting-point heights (high, middle, and low). Kinetic data were used to calculate joint torque and mechanical work in the lower limbs by the inverse dynamics approach. The peak angular velocity of the lower trunk about the vertical axis was smaller under the low condition. The joint torques and mechanical works done by both hip adduction/abduction axes were different among the three conditions. These results indicate that hip adduction/abduction torques mainly contribute to a change in the rotational movement of the lower body about the vertical axis when adjusting for different hitting-point heights. In order to adjust for the low hitting-point height which would be difficult compared with other hitting-point heights, batters should focus on rotating the lower trunk slowly by increasing both hip abduction torques.     

Neural correlates for numerical processing in the manual mode

This paper reports a study designed to examine the neuronal correlates for comprehending the signs of American Sign Language representing numerals in deaf signers who acquired Japanese Sign Language as their first language. The participants were scanned by functional magnetic resonance imaging (fMRI) twice on the day of the experiment. The results of the measurements revealed that upon learning that the signs actually have numeric meaning, a network of brain areas is activated immediately. Many of these areas have been previously implicated in numerical processing. The similar neural network of brain regions responsible for numerical processing exists on a nonlinguistical basis and works to retrieve arithmetic facts from presented linguistic material regardless of the mode of the language.     

School reform for positive behaviour support through collaborative learning: utilising lesson study for a learning community

Recent research has emphasised educating children about positive behaviours to overcome delinquency issues, but there is little clarification of what factors lead to positive behaviours. This study analyses factors that led to children’s positive behaviours at a junior high school in Japan, which experienced a dramatic turnaround after implementing school reform using Lesson Study for Learning Community (LSLC). In this study, the results of a mixed-methods analysis show that if children receive psychological support they are likely to psychologically support others and, similarly, those who receive concrete help tend to offer concrete help to others. To foster learning cultures in which this happens, it is critical to engage the entire school in appropriate changes: for example, teachers’ positive attitudes towards children and learning are important factors encouraging children to support others.     

Foreign Communication

CSIS, two recent papers from

ELECTRONIC MEDIA AND POLITICS IN WESTERN EUROPE: EUROMEDIA RESEARCH GROUP HANDBOOK OF NATIONAL SYSTEMS edited by Hans J. Kleinsteuber, et al (Frankfurt and New York: Campus Verlag, 1986—price not given, paper)

THE POLITICS OF THE COMMUNICATION REVOLUTION IN WESTERN EUROPE edited by Kenneth Dyson and Peter Humphreys (London and Totowa, NJ: Frank Cass & Co., 1986—$29.50)

EMERGING CORPORATE INFORMATION NETWORKS: REGULATORY AND INDUSTRIAL POLICY IN JAPAN by Takashi Yokokura (Program on Information Resources Polic y, 200 Aiken, Harvard University, Cambridge, MA 02138—price not given, paper)

WORLD BROADCASTING SYSTEMS: Update Notes, December 1987 by Sydney W. Head (available from Martha Sanchez, Kinko's Copies, 1212 South Dixie Highway, Coral Gables, FL 33146—$7.00 spiral bound)     

The effects of different initial restrictive pressures used to reduce blood flow and thigh composition on tissue oxygenation of the quadriceps

Blood flow restriction training technique can be affected by several factors resulting in changes in responses to training; therefore it is necessary to investigate and reveal detailed information about this novel training technique. Participants had their thigh size, thickness of subcutaneous fat, and regional bone free muscle mass measured prior to testing. A Near-Infrared Spectrometer was used to measure tissue oxygenation and a cardiovascular profiling system was utilised to measure stroke volume and heart rate. Initial restrictive pressure of 30, 50, and 70 mmHg were set in random order on three separate days, and then six target pressures were sequentially applied. Tissue oxygenation decreased significantly as both initial restrictive pressure and target pressures increased, but the magnitude of decreases was stronger with higher initial restrictive pressure. There were significant negative correlations between tissue oxygenation and leg lean body mass, total lean body mass, and thigh circumference when initial restrictive pressure was set at 30 mmHg. The findings indicated that changes in initial restrictive pressure affected the amount of venous return verified by the decreases in tissue oxygenation and stroke volume. In addition, thigh composition and size had a significant impact on the effects of initial restrictive pressure.     

Early effects of oral administration of omeprazole and roxatidine on intragastric pH

Objective

The ideal medication for the treatment of acid-related diseases, e.g., peptic ulcers, stress-related gastric bleeding, functional dyspepsia, and gastroesophageal reflux disease, should have a rapid onset of action to promote hemostasis and relieve the symptoms. The aim of our study was to investigate the inhibitory effects on gastric acid secretion of a single oral administration of a proton pump inhibitor, omeprazole 20 mg, and an H₂-receptor antagonist, roxatidine 75 mg.

Methods

Ten Helicobacter pylori-negative male subjects participated in this randomized, two-way crossover study. Intragastric pH was monitored continuously for 6 h after single oral administration of omeprazole 20 mg and roxatidine 75 mg. Each administration was separated by a 7-d washout period.

Results

During the 6-h study period, the average pH after administration of roxatidine was higher than that after administration of omeprazole (median: 4.45 vs. 2.65; P=0.0367). Also during the 6-h study period, a longer duration of maintenance at pH above 2, 5, and 6 was observed after administration of roxatidine 75 mg than after administration of omeprazole 20 mg (median: 90.6% vs. 55.2%, P=0.0284; 43.7% vs. 10.6%, P=0.0125; 40.3% vs. 3.3%, P=0.0125; respectively).

Conclusions

In Helicobacter pylori-negative healthy male subjects, oral administration of roxatidine 75 mg increased the intragastric pH more rapidly than that of omeprazole 20 mg.     

Literacy activity and health among older adults in the USA

ABSTRACT

Health literacy skills are known to be a key mediator of the relationship between education and health in the general population. However, one aspect of health literacy skills—individuals’ actual literacy activities—remains understudied, especially among older adults. Health disparities that are driven by inequalities in education and level of health literacy skills are particularly problematic for older adults since they are exacerbated in old age by disadvantages that accumulate over the life course. This study examined a nationally representative sample of US adults age 50 years and older (n = 2,573) using data from the 2014 Program for International Assessment of Adult Competencies (PIAAC). Parallel mediation analysis was conducted to examine the partial mediation effects of health literacy skills and literacy activity (i.e., reading at home) on the relationship between education and health. Results showed that both health literacy skills and literacy activity mediated the education–health relationship. On average, literacy skills mediated 31.89% and literacy activities mediated 9.59% of the effect of education of self-rated health. Literacy activity, such as reading, is an easily accessible, autonomous, and sustainable option for promoting health in later life. Policies that support the intersection of public health and education may promote lifelong learning and well-being among US adults.     

Hamstring muscles’ function deficit during overground sprinting in track and field athletes with a history of strain injury

ABSTRACT

In this study, we aimed to clarify the characteristics of neuromuscular function, kinetics, and kinematics of the lower extremity during sprinting in track and field athletes with a history of strain injury. Ten male college sprinters with a history of unilateral hamstring injury performed maximum effort sprint on an athletic track. The electromyographic (EMG) activity of the long head of the biceps femoris (BFlh) and gluteus maximus (Gmax) muscles and three-dimensional kinematic data were recorded. Bilateral comparisons were performed for the EMG activities, pelvic anterior tilt angle, hip and knee joint angles and torques, and the musculotendon length of BFlh. The activity of BFlh in the previously injured limb was significantly lower than that in the uninjured limb during the late-swing phase of sprinting (p < 0.05). However, the EMG activity of Gmax was not significantly different between the previously injured and uninjured limbs. Furthermore, during the late-swing phase, a significantly more flexed knee angle (p < 0.05) and a decrease in BFlh muscle length (p < 0.05) were noted in the injured limb. It was concluded that previously injured hamstring muscles demonstrate functional deficits during the late swing phase of sprinting in comparison with the uninjured contralateral muscles.     

Postcontraction Influences on Reaction Time

Abstract

The purpose of this study was to compare reaction time (RT) and fractionated RT components (premotor and motor times) between normal and postcontraction conditions. Twelve participants performed 20 trials each of control and postcontraction RT conditions. For the control condition, participants executed a learned, rapid, knee-extension contraction response to an auditory stimulus. The postcontraction condition was identical to the control condition except that the participants performed a 3-s isometric contraction of the knee extensor muscles prior to an auditory stimulus. Muscle activity was recorded from the quadriceps muscle group. Results indicated that the postcontraction condition was significantly faster than the control condition for the average RT, premotor time, and motor time. It was concluded that reaction time, processing time, and muscle contraction time for a learned task could be significantly reduced following an isometric contraction.