The outbreak of a novel corona Virus Disease 2019 (COVID-19) in the city of Wuhan, China has resulted in more than 1.7 million laboratory confirmed cases all over the world. Recent studies showed ...that SARS-CoV-2 was likely originated from bats, but its intermediate hosts are still largely unknown. In this study, we assembled the complete genome of a coronavirus identified in 3 sick Malayan pangolins. The molecular and phylogenetic analyses showed that this pangolin coronavirus (pangolin-CoV-2020) is genetically related to the SARS-CoV-2 as well as a group of bat coronaviruses but do not support the SARS-CoV-2 emerged directly from the pangolin-CoV-2020. Our study suggests that pangolins are natural hosts of Betacoronaviruses. Large surveillance of coronaviruses in pangolins could improve our understanding of the spectrum of coronaviruses in pangolins. In addition to conservation of wildlife, minimizing the exposures of humans to wildlife will be important to reduce the spillover risks of coronaviruses from wild animals to humans.
Osteosarcoma is a rare malignant bone tumor in adolescents and children. Poor prognosis has always been a difficult problem for patients with osteosarcoma. Recent studies have shown that tumor ...infiltrating immune cells (TIICs) are associated with the clinical outcome of osteosarcoma patients. The aim of our research was to construct a risk score model based on TIICs to predict the prognosis of patients with osteosarcoma.
CIBERSORTX algorithm was used to calculate the proportion of 22 TIIC types in osteosarcoma samples. Kaplan-Meier curves were drawn to investigate the prognostic value of 22 TIIC types. Forward stepwise approach was used to screen a minimal set of immune cell types. Multivariate Cox PHR analysis was performed to construct an immune risk score model.
Osteosarcoma samples with CIBERSORTX output p value less than 0.05 were selected for research. Kaplan-Meier curves indicated that naive B cells (p = 0.047) and Monocytes (p = 0.03) in osteosarcoma are associated with poor prognosis. An immune risk score model was constructed base on eight immune cell types, and the ROC curve showed that the immune risk score model is reliable in predicting the prognosis of patients with osteosarcoma (AUC = 0.724). Besides, a nomogram model base on eight immune cell types was constructed to predict the survival rate of patients with osteosarcoma.
TIICs are closely related to the prognosis of osteosarcoma. The immune risk score model based on TIICs is reliable in predicting the prognosis of osteosarcoma.
Bat algorithm has disadvantages of slow convergence rate, low convergence precision and weak stability. In this paper, we designed an improved bat algorithm with a logarithmic decreasing strategy and ...Cauchy disturbance. In order to meet the requirements of global optimal and dynamic obstacle avoidance in path planning for a mobile robot, we combined bat algorithm (BA) and dynamic window approach (DWA). An undirected weighted graph is constructed by setting virtual points, which provide path switch strategies for the robot. The simulation results show that the improved bat algorithm is better than the particle swarm optimization algorithm (PSO) and basic bat algorithm in terms of the optimal solution. Hybrid path planning methods can significantly reduce the path length compared with the dynamic window approach. Path switch strategy is proved effective in our simulations.
The effects of the ongoing digital revolution have been profound and have been studied in many contexts such as government interaction with the public (e-participation) and administrative structures ...(e-administration). However, the study of how the digital revolution has changed leaders’ interactions with followers via information and communication technologies (ICTs) has been modest, and the theory building in organizational studies and public administration has been, for the most part, nonexistent. A major reason for this lack of progress is the inability to produce an operational definition of e-leadership that spans telework, team, and enterprise settings. The article examines an exploratory case study to propose an operational definition based on six factors (or broad e-competencies) for e-leadership. Research limitations and future research opportunities are discussed.
Points for practitioners
E-leadership, technology-mediated leadership, has become critically important for leaders at all levels, both inside and outside of the organization.
E-leadership is as much about blending technologies and traditional communication as it is about simply using more ICT-mediated communication.
While there is a lot of consistency in the types of leadership skills needed in traditional and virtual environments, they are not the same and the differences are critical to success and failure.
The areas in which competence in e-skills were most important included: e-communication, e-social skills, e-team building, e-change management, e-technology skills, and e-trustworthiness.
Based on the Girsanov theorem, this paper obtains the exact distribution of the maximum likelihood estimator of structural break point in a continuous time model. The exact distribution is asymmetric ...and tri-modal, indicating that the estimator is biased. These two properties are also found in the finite sample distribution of the least squares (LS) estimator of structural break point in the discrete time model, suggesting the classical long-span asymptotic theory is inadequate. The paper then builds a continuous time approximation to the discrete time model and develops an in-fill asymptotic theory for the LS estimator. The in-fill asymptotic distribution is asymmetric and tri-modal and delivers good approximations to the finite sample distribution. To reduce the bias in the estimation of both the continuous time and the discrete time models, a simulation-based method based on the indirect estimation (IE) approach is proposed. Monte Carlo studies show that IE achieves substantial bias reductions.
Mercury intrusion porosimetry (MIP) is questioned for possibly damaging the micro structure of cement-based materials (CBMs), but this theme still has a lack of quantitative evidence. By using X-ray ...computed tomography (XCT), this study reported an experimental investigation on probing the pore structure damages in paste and mortar samples after a standard MIP test. XCT scans were performed on the samples before and after mercury intrusion. Because of its very high mass attenuation coefficient, mercury can greatly enhance the contrast of XCT images, paving a path to probe the same pores with and without mercury fillings. The paste and mortar showed the different MIP pore size distributions but similar intrusion processes. A grey value inverse for the pores and material skeletons before and after MIP was found. With the features of excellent data reliability and robustness verified by a threshold analysis, the XCT results characterized the surface structure of voids, and diagnosed the pore structure damages in terms of pore volume and size of the paste and mortar samples. The findings of this study deepen the understandings in pore structure damages in CBMs by mercury intrusion, and provide methodological insights in the microstructure characterization of CBMs by XCT.
The high sensitivity flexible capacitive pressure sensor (FCPS) manufactured in a fast and efficient way has friendly man-machine interaction function. In this paper, a high-sensitivity FCPS is ...developed by using a two-step template method to reproduce biomimetic microtower polydimethylsiloxane (PDMS) from the lotus leaf surface. The capacitive sensor is composed of a PDMS dielectric layer and the Cu nanowire electrodes sandwiching in the middle, with a high sensitivity of ~1.207 kPa−1, a low detection limit of less than 0.02 kPa and a fast response time of 61.6 ms. Particularly, the sensing performance can be kept basically unchanged when bent at a 5 mm radius. Moreover, the FCPS can withstand 4000 repeated tests and maintain stable performance, and the sensitivity is almost the same in the process of loading and unloading, suggesting the high robustness. These results demonstrates the FCPSs have potential applications in electronic wearables, human health monitoring and uneven surface applications.
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•A high-sensitivity FCPS is developed by using a two-step template method to reproduce biomimetic microtower structure.•The flexible capacitive sensor has a high sensitivity of ~1.207 kPa-1 and a fast response time of 61.6 ms.•Particularly, the sensing performance can be kept basically unchanged when bent at a 5 mm radius.
CNC machining center linear axis thermal positioning errors, seen as the synthetic consequences of geometric and thermal errors, respectively generated due to the manufacturing and assembling ...inaccuracies and the asymmetric thermal deformation of the machining center structure, are significantly affected by varying position of the cutting point and shifting state of temperature field. Hence, developing a practical approach to reduce or even to eliminate thermal positioning errors is crucial. This paper proposes an approach to decouple and separate machining center linear axis thermal positioning errors, based on which a highly accurate prediction model of the thermal positioning error is formulated. A sensitivity analysis-based thermal critical point optimization method is presented where grey theory is borrowed to characterize the mapping between thermal positioning error and varying temperature fields, according to which the highly related temperature sensors are derived. The thermal positioning errors are then decoupled and separated into geometric and thermal errors by adopting multiple regression algorithm and linear fitting approach, respectively. Accordingly, the comprehensive thermal positioning error prediction model is constrcuted, based on which the compensation approach is also proposed. Next, the corresponding compensation module is developed within the SIEMENS 840D CNC system to realize the online compensation strategy, providing the engineering applications. Experimental validations are performed on a commercial machining center, where the thermal positioning errors of the Z-axis are measured with the help of a laser interferometer testing kit and a thermal inspection instrument. The data comparisons indicate that the maximum thermal positioning errors of the Z-axis in the cold and warm state are respectively decreased for 87.09
%
and 49.87
%
after activating the compensation module, which also suggests that the proposed approach is adequate and accurate to decouple and separate the thermal positioning errors.
Interleukin 17 (IL-17) is important in infection and autoimmunity; how it signals remains poorly understood. In this study, we identified the ubiquitin-specific protease USP25 as a negative regulator ...of IL-17-mediated signaling and inflammation. Overexpression of USP25 inhibited IL-17-triggered signaling, whereas USP25 deficiency resulted in more phosphorylation of the inhibitor IκBα and kinase Jnk and higher expression of chemokines and cytokines, as well as a prolonged half-life for chemokine CXCL1-encoding mRNA after treatment with IL-17. Consistent with that, Usp25(-/-) mice showed greater sensitivity to IL-17-dependent inflammation and autoimmunity in vivo. Mechanistically, stimulation with IL-17 induced the association of USP25 with the adaptors TRAF5 and TRAF6, and USP25 induced removal of Lys63-linked ubiquitination in TRAF5 and TRAF6 mediated by the adaptor Act1. Thus, our results demonstrate that USP25 is a deubiquitinating enzyme (DUB) that negatively regulates IL-17-triggered signaling.
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