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A visual prosthesis is an auxiliary device for patients with blinding diseases that cannot be treated with conventional surgery or drugs. It converts captured images into corresponding electrical stimulation patterns, according to which phosphenes are generated through the action of internal electrodes on the visual pathway to form visual perception. However, due to some restrictions such as the few implantable electrodes that the biological tissue can accommodate, the induced perception is far from ideal. Therefore, an important issue in visual prosthesis research is how to detect and present useful information in low‐resolution prosthetic vision to improve the visual function of the wearer. In recent years, with the development and broad application of computer vision methods, researchers have investigated the possibility of their utilization in visual prostheses by simulating prosthetic visual percepts. Through the optimization of visual perception by image processing, the efficiency of visual prosthesis devices can be further improved to better meet the needs of prosthesis wearers. In this article, recent works on prosthetic vision centering on implementing computer vision methods are reviewed. Differences, strengths, and weaknesses of the mentioned methods are discussed. The development directions of optimizing prosthetic vision and improving methods of visual perception are analyzed. [ABSTRACT FROM AUTHOR]

With the advantages of environmental protection, small size, and light weight, the vacuum circuit breaker has been widely used in power systems. At present, it is developing toward the direction of high voltage and high current. In this paper, the magnetic field simulation model of a cup-shaped axial magnetic contact system is established, and the actual magnetic field data in the arc area are obtained as the boundary conditions, and then a three-dimensional steady-state magnetohydrodynamic model of the vacuum arc is established. The plasma parameter distribution characteristics in the vacuum arc area are studied by changing the number of slots in the contact plate, the angle of the contact cup chute, the length of the slot in the contact plate, and the central process hole. On this basis, a new type of embedded axial magnetic contact system including an embedded magnetic ring and a reverse contact cup is proposed, and the influence of changing the angle and number of inclined slots of the embedded contact cup on the arc distribution characteristics at the peak current and current zero is further studied. The simulation results show that the new structure contact is helpful to the breaking capacity of the vacuum switch and has a guiding significance for the design of the vacuum circuit breaker. By comparison, our simulation results have the same trend with the experimental results of other researchers. [ABSTRACT FROM AUTHOR]

When short current is interrupted in three-phase vacuum interrupter in switchgear, the “U”-type loop composed of external busbar, conductive rod, and vacuum interrupter, and its adjacent phases will generate external actual transverse magnetic field (EATMF) in the interrupter. The existence of EATMF will deflect the vacuum arc, which will affect the breaking performance of vacuum switch. In view of this situation, this article establishes two kinds of electrode system simulation models considering and not considering EATMF. The simulation results show that EATMF is not uniformly distributed in the interelectrode region, but is stronger in the contact cup edge area outside the “U”-type loop, weaker in the “U”-type loop, and mainly affects ${B} _{x}$. In different short-circuit cases, EATMF is also different due to the difference of phase distance and short current. In the case of three-phase short circuit, the magnetic field in the interelectrode region of the middle phase is most significantly affected by EATMF. EATMF is closely related to the structure size of vacuum switch. By changing the structure size of vacuum switch (e.g., phase spacing ${d}$ , conductive rod length ${h} _{1}$ , ${h} _{2}$), EATMF can be weakened to some extent. [ABSTRACT FROM AUTHOR]

The authors designed and ran an experiment to measure social influence in online recommender systems, specifically, how often people’s choices are changed by others’ recommendations when facing different levels of confirmation and conformity pressures. In this experiment, participants were first asked to provide their preference from pairs of items. They were then asked to make second choices about the same pairs with knowledge of other people’s preferences. The results show that other people’s opinions significantly sway people’s own choices. The influence is stronger when people are required to make their second decision sometime later (22.4%) rather than immediately (14.1%). Moreover, people seem to be most likely to reverse their choices when facing a moderate, as opposed to large, number of opposing opinions. Finally, the time people spend making the first decision significantly predicts whether they will reverse their decisions later on, whereas demographics such as age and gender do not. These results have implications for consumer behavior research as well as online marketing strategies. [ABSTRACT FROM PUBLISHER]

Objective: The objective of the paper is to understand leadership in an online community, specifically, Wikipedia. Background: Wikipedia successfully aggregates millions of volunteers’ efforts to create the largest encyclopedia in human history. Without formal employment contracts and monetary incentives, one significant question for Wikipedia is how it organizes individual members with differing goals, experience, and commitment to achieve a collective outcome. Rather than focusing on the role of the small set of people occupying a core leadership position, we propose a shared leadership model to explain the leadership in Wikipedia. Members mutually influence one another by exercising leadership behaviors, including rewarding, regulating, directing, and socializing one another. Method: We conducted a two-phase study to investigate how distinct types of leadership behaviors (transactional, aversive, directive, and person-focused), the legitimacy of the people who deliver the leadership, and the experience of the people who receive the leadership influence the effectiveness of shared leadership in Wikipedia. Results: Our results highlight the importance of shared leadership in Wikipedia and identify trade-offs in the effectiveness of different types of leadership behaviors. Aversive and directive leadership increased contribution to the focal task, whereas transactional and person-focused leadership increased general motivation. We also found important differences in how newcomers and experienced members responded to leadership behaviors from peers. Application: These findings extend shared leadership theories, contribute new insight into the important underlying mechanisms in Wikipedia, and have implications for practitioners who wish to design more effective and successful online communities. [ABSTRACT FROM AUTHOR]

Objective: The objective of the paper is to understand leadership in an online community, specifically, Wikipedia.Background: Wikipedia successfully aggregates millions of volunteers' efforts to create the largest encyclopedia in human history. Without formal employment contracts and monetary incentives, one significant question for Wikipedia is how it organizes individual members with differing goals, experience, and commitment to achieve a collective outcome. Rather than focusing on the role of the small set of people occupying a core leadership position, we propose a shared leadership model to explain the leadership in Wikipedia. Members mutually influence one another by exercising leadership behaviors, including rewarding, regulating, directing, and socializing one another.Method: We conducted a two-phase study to investigate how distinct types of leadership behaviors (transactional, aversive, directive, and person-focused), the legitimacy of the people who deliver the leadership, and the experience of the people who receive the leadership influence the effectiveness of shared leadership in Wikipedia.Results: Our results highlight the importance of shared leadership in Wikipedia and identify trade-offs in the effectiveness of different types of leadership behaviors. Aversive and directive leadership increased contribution to the focal task, whereas transactional and person-focused leadership increased general motivation. We also found important differences in how newcomers and experienced members responded to leadership behaviors from peers.Application: These findings extend shared leadership theories, contribute new insight into the important underlying mechanisms in Wikipedia, and have implications for practitioners who wish to design more effective and successful online communities. [ABSTRACT FROM AUTHOR]

Background: Although research shows that the Covid-19 pandemic has led to declines in mental health, the existing research has not identified the pathways through which this decline happens. Aims: The current study identifies the distinct pathways through which COVID-induced stressors (i.e., social distancing, disease risk, and financial stressors) trigger mental distress and examines the causal impact of these stressors on mental distress. Methods: We combined evidence of objective pandemic-related stressors collected at the county level (e.g., lack of social contact, infection rates, and unemployment rates) with self-reported survey data from over 11.5 million adult respondents in the United States collected daily for eight months. We used mediation analysis to examine the extent to which the objective stressors influenced mental health by influencing individual respondents' behavior and fears. Results: County-level, day-to-day social distancing predicted significantly greater mental distress, both directly and indirectly through its effects on individual social contacts, worries about getting ill, and concerns about finances. Economic hardships were indirectly linked to increased mental distress by elevating people's concerns about their household's finances. Disease threats were both directly linked to mental distress and indirectly through its effects on individual worries about getting ill. Although one might expect that social distancing from people outside the home would have a greater influence on people who live alone, sub-analyses based on household composition do not support this expectation. Conclusion: This research provides evidence consistent with the thesis that the COVID-19 pandemic harmed the mental well-being of adults in the United States and identifies specific stressors associated with the pandemic that are responsible for increasing mental distress. [ABSTRACT FROM AUTHOR]

The degradation of the electrical contact in a gas insulated switchgear (GIS) is closely related to overheating at the contact. However, the disconnector contact is one of the hot contacts in GIS. Therefore, in this paper, the finite element method was used to solve the three-dimensional multiphysics coupling temperature rise field and flow field in the Single Phase in One Tank (SPIOT) type GIS disconnector under different operating conditions. From the perspective of temperature rise field and flow field, this paper analyzed the temperature rise characteristics under different working conditions and explored the feasibility of the direct application of air, CO2 and C4F7N/CO2 mixed gas to an electrical device. The disconnector temperature rise experiment platform was then built to verify the simulation. The results showed that the temperature rise field and the flow field distribution were similar in four gas environments. SF6 gas had the smallest temperature rise, followed by C4F7N/CO2 mixed gas, and the temperature rise of CO2 and air was relatively large. Therefore, from the perspective of the temperature rise field and flow field, it was feasible to directly apply C4F7N/CO2 mixed gas to an electrical device in order to meet insulation requirements. [ABSTRACT FROM AUTHOR]

Abstract Objective Salvanic Acid B (Sal B) was proved to show significant effect against fibrosis and myocardial injury. This study aimed to investigate the protective effects and the mechanisms of Sal B on myocardial fibrosis. Methods The mice were randomly assigned to five groups: control group, model group, positive group, low-dose group, high-dose group. Hematoxylin-Eosin (HE) staining and Masson staining were used to assess the myocardial physiological changes and measure the myocardial fibrosis area. Expression of transforming growth factor-beta (TGF-β), drosophila mothers against decapentaplegic (Smad)2, Smad3 and Smad7 were analyzed by immunohistochemistry and real-time PCR. On the other hand, mouse cardiac fibroblasts (CFs) cells were co-treated with 20 ng/mL TGF-β1 and different concentrations of Sal B (5, 10, and 20 ng/mL) for 24 h. The cells morphology changes were assessed under a microscope, and the protein expressions induced by TGF-β1 were detected by Western blot. Results Compared with the model group, myocardial collagen fibers decreased obviously with Sal B treatment (p < 0.05). Moreover, the expression of key signal molecules of the TGF-β/Smads signaling pathway, including TGF-β1, Smad2 and Smad3 proteins decreased, while the expression of Smad7 increased in Sal B treatment groups as compared to those of the model group (p < 0.05). On the other hand, results of CFs studies were also consistent with those animals. Conclusions Sal B could inhibit the myocardial fibrosis process through regulating TGF-β/Smads signal transduction pathways. [ABSTRACT FROM AUTHOR]