Sensors and Systems for Monitoring Mental Fatigue: A systematic review

Mental fatigue is a leading cause of motor vehicle accidents, medical errors, loss of workplace productivity, and student disengagements in e-learning environment. Development of sensors and systems that can reliably track mental fatigue can prevent accidents, reduce errors, and help increase workplace productivity. This review provides a critical summary of theoretical models of mental fatigue, a description of key enabling sensor technologies, and a systematic review of recent studies using biosensor-based systems for tracking mental fatigue in humans. We conducted a systematic search and review of recent literature which focused on detection and tracking of mental fatigue in humans. The search yielded 57 studies (N=1082), majority of which used electroencephalography (EEG) based sensors for tracking mental fatigue. We found that EEG-based sensors can provide a moderate to good sensitivity for fatigue detection. Notably, we found no incremental benefit of using high-density EEG sensors for application in mental fatigue detection. Given the findings, we provide a critical discussion on the integration of wearable EEG and ambient sensors in the context of achieving real-world monitoring. Future work required to advance and adapt the technologies toward widespread deployment of wearable sensors and systems for fatigue monitoring in semi-autonomous and autonomous industries is examined.Comment: 19 Pages, 3 Figure

Deterministic dynamics of the magnetosphere: results of the 0–1 test

A test for deterministic dynamics in a time series data, namely the 0–1 test (Gottawald and Melbourne, 2004, 2005), is used to study the magnetospheric dynamics. The data, corresponding to the same time period, of the auroral electrojet index <i>AL</i> and the magnetic field component <i>B<sub>z</sub></i> of the solar wind magnetic field measured at 1 AU are used to compute the parameter <i>K</i>, which is zero for non-chaotic and unity for chaotic systems. For the magnetosphere and also for the turbulent solar wind, <i>K</i> has values corresponding to a nonlinear dynamical system with chaotic behaviour. This result is consistent with the Lyapunov exponents computed from the same time series data

Microstructure and Fracture Properties of Semi-Hard Cheese: Differentiating the Effects of Primary Proteolysis and Calcium Solubilization

The individual roles of hydrolysis of αS1- and β-caseins, and calcium solubilization on the fracture properties of semi-hard cheeses, such as Maasdam and other eye-type cheeses, remain unclear. In this study, the hydrolysis patterns of casein were selectively altered by adding a chymosin inhibitor to the curd/whey mixture during cheese manufacture, by substituting fermentation-produced bovine chymosin (FPBC) with fermentation-produced camel chymosin (FPCC), or by modulating ripening temperature. Moreover, the level of insoluble calcium during ripening was quantified in all cheeses. Addition of a chymosin inhibitor, substitution of FPBC with FPCC, or ripening of cheeses at a consistent low temperature (8 °C) decreased the hydrolysis of αS1-casein by ~95%, ~45%, or ~30%, respectively, after 90 d of ripening, whereas ~35% of β-casein was hydrolysed in that time for all cheeses, except for those ripened at a lower temperature (~17%). The proportion of insoluble calcium as a percentage of total calcium decreased significantly from ~75% to ~60% between 1 and 90 d. The rigidity or strength of the cheese matrix was found to be higher (as indicated by higher fracture stress) in cheeses with lower levels of proteolysis or higher levels of intact caseins, primarily αS1-casein. However, contrary to the expectation that shortness of cheese texture is associated with αS1-casein hydrolysis, fracture strain was significantly positively correlated with the level of intact β-casein and insoluble calcium content, indicating that the cheeses with low levels of intact β-casein or insoluble calcium content were more likely to be shorter in texture (i.e., lower fracture strain). Overall, this study suggests that the fracture properties of cheese can be modified by selective hydrolysis of caseins, altering the level of insoluble calcium or both. Such approaches could be applied to design cheese with specific properties

Everest tourism: forging links to sustainable mountain development. A critical discourse on politics of places and peoples

This paper explores the relationships between tourism interventions and the changes in socioeconomic power relations of stakeholders of Everest tourism. The consequences of tourism intervention have been analyzed and interpreted through dialectical phenomenology. Political ecology framework is used as an analytical model for inductive logic generation from the observations of social interactions on Everest tourism. Impacts of tourism interventions on local environment, culture, livelihood of the indigenous people and overall socioeconomic power relations of the people in this region have been interpreted and discussed with the theoretical perspectives of political economy and bio-environmental relationships. Through critical realism on political ecology it is concluded that the interventions of Everest tourism cannot assure the sustainability of the indigenous society, environment and economy of the region. The findings are interpreted in the line of rhetoric on Ecological Modernization Theory

Student Engagement Detection Using Emotion Analysis, Eye Tracking and Head Movement with Machine Learning

With the increase of distance learning, in general, and e-learning, in particular, having a system capable of determining the engagement of students is of primordial importance, and one of the biggest challenges, both for teachers, researchers and policy makers. Here, we present a system to detect the engagement level of the students. It uses only information provided by the typical built-in web-camera present in a laptop computer, and was designed to work in real time. We combine information about the movements of the eyes and head, and facial emotions to produce a concentration index with three classes of engagement: "very engaged", "nominally engaged" and "not engaged at all". The system was tested in a typical e-learning scenario, and the results show that it correctly identifies each period of time where students were "very engaged", "nominally engaged" and "not engaged at all". Additionally, the results also show that the students with best scores also have higher concentration indexes.Comment: 9 pages, 9 Figures, 2 table

Effects of different rates of nitrogen and pinching on yield and yield attributes of African marigold (Tagetes erecta L.)

Proper pinching practice and the optimum rate of nitrogen (N) enhance the production of marigold. An experiment was conducted at a farmer’s field in Gadawa-4, Gangaparaspur, Dang, Nepal from July 2018 to November 2018 to investigate the effects of different rates of nitrogen and pinching on yield and yield attributes of African marigold (cv. Kolkata Local). Two factorial experiment was laid in the Randomized Complete Block Design (RCBD) with three replications. There were eight treatments, consist of four rates of nitrogen (0, 50, 100 and 150 kg/ha) and two levels of pinching (pinching and non-pinching). The maximum plant height (89.70 cm), the diameter of flower (4.29 cm) and the fresh weight per flower (4.32 g) and early days to 50% flowering (61.58) were obtained at non- pinching. The highest number of flowers (60.66), yield per plant (237.49 g) and yield per hectare (9.89 t/ha) were obtained with pinching. The highest plant height (92.20 cm) was recorded at 150 kg/ha of N but the highest yield per plant (238.18 g) and yield per ha (9.91 t/ha) was obtained at 50 kg/ha of nitrogen application. No significant effect was noted on the days to 50% flowering, number of flowers per plant, fresh weight per flower and diameter of flowers by different rates of nitrogen. The interaction of pinching and different rates of nitrogen showed non- significant effect on yield per plant and yield per ha. But, the combination of pinching and nitrogen rates at 50 kg/ha recorded the maximum yield per plant (249.20 g) and yield per ha (10.36 t/ha). Hence it is suggested to use pinching practice with optimum application of nitrogen @ 50 kg/ha to obtain high yield of marigold

Herbage mass and chemical composition of the heterogeneous grasslands affected by harvesting time in Subtropical terrain Nepal

A study was carried out to evaluate the productivity and chemical composition of heterogeneous grasslands at Agriculture and Forestry University (AFU) livestock farm. The four grassland ecotypes were chosen as upland north, upland south, lowland south and lowland north. The dominating herbage species and cover abundance by the botanical groups were studied on day before the harvesting. Later, the herbage dry matter productivity was estimated by quadrat cutting during May and June, 2017. Chemical analysis was done by using the proximate method for dry matter (DM), crude protein (CP), crude fiber (CF) and ether extract (EE) content. Research results showed that the AFU grassland dominated by perennial grasses and sedges followed by the forbs. The mean coverage of grasses and sedges was about 55%, whilst that of forbs was about 29% and the least was for legumes (about 4%). The cumulative herbage mass was about 1.53 t/ ha on the DM basis, whilst the highest DM was found in the upland-south (1.74 t/ha) and the least was in the upland-north (1.334 t/ha). The proximate analysis further revealed that the site had no effect on CF content, whilst the CP was significant only at the second harvest for the lowland north (8.34%).  Data revealed that the herbage composition might depend upon the soil moisture availability and geographical aspect. The dominance of perennial grasses at AFU grasslands revealed the yield stability, but needs the improvement through inoculation with leguminous forages for improved feed quality