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PurposeThe authors investigated a psychological process that links characteristics of events related to the coronavirus disease (2019) COVID-19 pandemic (i.e. perceived novelty, disruptiveness and criticality) to compassion fatigue [(CF), a form of caregiver burnout] and subsequent post-traumatic stress disorder (PTSD) in nurses.Design/methodology/approachAdministering two online surveys (October and November 2020) resulted in matched data from 175 nurses responsible for patient care during the COVID-19 pandemic.FindingsPerceived disruptiveness and criticality of COVID-19 events were positively associated with nurses' CF, which also mediated those characteristics' effects on PTSD instigated by COVID-19. Contrary to the authors' hypothesis, the perceived novelty of COVID-19 events was not significantly associated with CF nor was the indirect effect of perceived novelty on PTSD mediated by CF.Originality/valueThe authors extend event system theory by investigating the psychological processes linking event features and resultant outcomes while providing practical implications on preparations for future unexpected and potentially life-altering events.

Learning powerful discriminative features is the key for remote sensing scene classification. Most existing approaches based on convolutional neural network (CNN) have achieved great results. However, they mainly focus on global-based visual features while ignoring object-based location features, which is important for large-scale scene classification. There are a large number of scene-related ground objects in remote sensing images, as well as Graph convolutional network (GCN) has the potential to capture the dependencies among objects. This article introduces a novel two-stream architecture that combines global-based visual features and object-based location features, so as to improve the feature representation capability. First, we extract appearance visual features from whole scene image based on CNN. Second, we detect ground objects and construct a graph to learn the spatial location features based on GCN. As a result, the network can jointly capture appearance visual information and spatial location information. To the best of authors' knowledge, we are the first to investigate the dependencies among objects in remote sensing scene classification task. Extensive experiments on two datasets show that our framework improves the discriminative ability of features and achieves competitive accuracy against other state-of-the-art approaches.

The electronic structure and optical properties of the sphalerite structures I n x G a 1 − x A s (x = 3.125%, 6.25%, 9.375%, 12.5%) were studied based on the first-principles method of density functional theory. The results demonstrate that the band-gap width of I n x G a 1 − x A s decrease and the optical absorption frequency (absorption edge) emerges an obvious red-shift compared with GaAs due to the existence of impurity energy levels in the material. With the increase in Indium component ratio, the outer electronic hybridization degree of In and As decrease, and the band-gap width of I n x G a 1 − x A s increases. As the component ratio of Indium increases from 6.25% to 9.375%, the band-gap magnitude increases from 0.55 eV to 0.63 eV. In terms of optical properties, the maximum peak values of the real and imaginary parts of dielectric function are 22.6 along [0 0 1] crystal direction and 25.71 along [1 0 0] crystal direction, respectively. The proportion of In component affects the material properties of crystal orientation and make the crystal gradually exhibit noticeable anisotropy. With increase in the proportion of In component, both the static dielectric constant of the material and the maximum peak of the refractive index decreases. In the region of higher energy, the reflection of the doped material is relatively weak for electromagnetic wave, and the average value of refractive index is around 0.7 with a high transmittance characteristic. The results show that the energy loss has a significant peak at the photon energy of 14.9 eV. Therefore, this calculation can provide a reference for the research and application of InGaAs optical detector.

Yufan Deng,1,2 Yumeng Zhang,1,2 Jay Pan1,2 1HEOA Group, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2Institute for Healthy Cities and West China Research Center for Rural Health Development, Sichuan University, Chengdu, Sichuan, People’s Republic of ChinaCorrespondence: Jay PanWest China School of Public Health, Sichuan University, No. 17, Section 3, Ren Min Nan Road, Chengdu, 610041, Sichuan, People’s Republic of ChinaEmail panjie.jay@scu.edu.cnPurpose: Rational location of emergency medical service (EMS) facilities could improve access to EMS, and thus assist in saving patients’ lives and improving their health outcomes. A considerable amount of spatial optimization research has been devoted to the development of models to support location planning in the context of EMS, with extensive applications in policy making around the world. However, in China, studies on the location of EMS facilities have not been paid enough attention to, let alone their practical applications. This paper conducted location optimization for EMS facilities in Chengdu, one of the biggest cities in southwest China with more than 16.5 million population, aiming to optimize the EMS system by adding (upgrading) a minimum number of EMS facilities to achieve a given population coverage.Methods: Location optimization was conducted according to regional health policy goal for the EMS system in Chengdu, China, 2017. The nearest-neighbor approach was used to calculate the shortest travel time based on geographical information system (GIS). The location set covering model was used to formulate the optimization problem under China’s context, and genetic algorithm (GA) was employed to determine the optimized locations.Results: The results showed that a minimum number of 55 new facilities were required to upgrade to EMS facilities to achieve the policy goal of 90% population coverage of EMS within 15 minutes. Access to EMS also improved substantially in terms of shortest travel time after facility upgrading. The weighted median shortest travel time to EMS facilities in Chengdu decreased by 14.57%, from 6.45 minutes to 5.51 minutes.Conclusion: Our study showed that the solution could effectively achieve the policy goal of population coverage with a minimum number of new EMS facilities. Our findings would support evidence-based decision-making in future EMS planning in China.Keywords: emergency medical care, EMS location, genetic algorithm, location set covering problem

Timely access to emergency care can substantially improve overall population’s health outcomes. However, currently existed evidence focusing on access to emergency care in China remains insufficient. A better understanding of emergency care from the perspective of spatial accessibility is therefore essential to assist in future healthcare planning. This study provided a brief introduction to the emergency medical service system of China, and assessed the spatial accessibility of emergency care as well as its associated social-economic characteristics based on Sichuan province. Based on populational and hospital administrative data in 2018, we employed the nearest-neighbor method to measure the spatial accessibility while identifying its associated social-economic factors via conventional Ordinary Least Square (OLS) model. The shortest travel time analysis reported a relatively high level of overall spatial accessibility to emergency care in Sichuan. However, substantial geographical disparity in accessibility could nevertheless be observed throughout the province, with the eastern area presenting much higher accessibility than the western area. Regression results suggested that county-level discrepancies in accessibility could be significantly attributed to the variance in local economic development, urbanization level and administrative area. These findings indicated that long-term efforts need to be made by central government on optimizing the allocation of healthcare resources, as well as on fortifying financial support and providing preferential policies for economically disadvantaged regions.

A first-principles projector augmented wave method in the framework of density functional theory is performed to study electronic structures, magnetic and optical properties of Cr-doped GaAs in three different positions. The complex dielectric function, absorption coefficient and electron energy-loss are discussed for optical properties. The results predict that (Ga, Cr)As systems exhibit typical half-metallic properties and stable ferromagnetism when Cr atoms doping in the interior of the supercell, in which deep levels are formed in the forbidden band and reduces the energy gap, increases static dielectric constant greatly and red-shifts the absorption edge obviously. In addition, a smaller magnetic moments from As and Ga atoms are generated by p-d hybridization, and Cr atoms interact antiferromagnetically with As atoms and ferromagnetically with Ga atoms respectively. While the metallic character is observed that Cr atoms are doped on the surface of the supercell.

The electronic structure and optical properties of the sphalerite structured C u x G a 1 − x A s (x = 3.125%, 6.25% and 12.5%) were studied based on the first-principles method of density functional theory. The results show that the C u x G a 1 − x A s materials exhibit direct band-gaps, from valence band top to guide band low (solid blue line) i.e., 1.30 eV, 0.82 eV, 0.97 eV. It contains impurity levels in the middle, reaching the second transition. The calculated results also show that the energy required for electrons to jump from valence band to impurity levels, i.e., 0.42 eV, 0.36 eV, 0.31 eV. In addition, higher impurity levels resulted from copper doping reduces GaAs band-gaps in a great extent, which is beneficial to the transition and migration of electrons. At the same time, the static dielectric constant and refractive index of the doped system escalate with the increase of Cu doping ratio. Moreover, the absorption spectrum is red-shifted and the absorption of light is enhanced. In the system doped with 6.25% Cu, the electrons in Cu-3d orbital form a strong localization in the energy range of −3.9 eV ~ −1.8 eV. Indeed, the least influence on the complex dielectric function of the [010] is achieved when the ratio of doped Cu decreases to 3.125%, which makes the change of optical properties of the material in this crystal direction smaller than those in [100] and [001] orientations. The C u x G a 1 − x A s transition layer between GaAs devices and copper wires can substantially improve the electrode contact and subsequently the photoelectric characteristics of GaAs photoelectric devices.

Morphology of Two Eschaneustyla Species (Ciliophora, Urostylida), with Notes on Morphogenesis of Eschaneustyla lugeri

Based on career construction theory, the current research examined individual and contextual predictors for the professional competence of Chinese undergraduates majoring in social work (N = 270). Results showed that career concern and career curiosity predicted social work students' professional competence, with these relations mediated by the calling in social work. It was also found that the positive effect of calling on professional competence was stronger among students who perceived a lower level of career-oriented learning environment. The corresponding moderated mediation model was supported such that the indirect effects of career concern and career curiosity on professional competence were stronger among students who perceived a lower level of career-oriented learning environment. These findings carry implications for research on career construction theory, as well as career education and career counseling practices.

To investigate the mechanisms through which the basic traits (big-five personality and approach/avoidance traits) predict career adaptability, and develop a more systematic view of the components of career adaptivity, we conducted a two-wave survey study among 206 Chinese university students. Drawing on career construction theory and the distal-proximal framework of motivation, we incorporated core self-evaluation (CSE), proactive personality and learning goal orientation (LGO) as the key mediators and tested their relations with basic traits and career adaptability. It was found that these dispositional predictors (measured at Time 1) account for 43% (adjusted R2) of the variance in career adaptability (measured at Time 2). In addition, CSE mediates the effects of conscientiousness, neuroticism, approach and avoidance traits on career adaptability; LGO and proactive personality mediate the effects of openness to experience, conscientiousness as well as approach trait on career adaptability. When the three mediators (CSE, LGO and proactive personality) are put into the model, only extraversion has a remaining direct effect on career adaptability. Implications of the findings are discussed.

As Wireless Fidelity (Wi-Fi)-enabled handheld devices have been widely used, the mobile social networks (MSNs) has been attracting extensive attention. Fractal approaches have also been widely applied to characterierize natural networks as useful tools to depict their spatial distribution and scaling properties. Moreover, when the complexity of the spatial distribution of MSNs cannot be properly charaterized by single fractal dimension, multifractal analysis is required. For further research, we introduced a multifractal analysis method based on box-covering algorithm to describe the structure of MSNs. Using this method, we find that the networks are multifractal at different time interval. The simulation results demonstrate that the proposed method is efficient for analyzing the multifractal characteristic of MSNs, which provides a distribution of singularities adequately describing both the heterogeneity of fractal patterns and the statistics of measurements across spatial scales in MSNs.