43 research outputs found

    Spatial distribution and ecological risks of polychlorinated biphenyls in a river basin affected by traditional and emerging electronic waste recycling in South China

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    With development of e-waste related legislation in China, formal recycling activities are designated in some areas while informal ones are illegally transferred to emerging areas to avoid supervision. However, the resulting environmental impact and ecological risks are not clear. Here, we investigated the discharge of polychlorinated biphenyls (PCBs) to soil and aquatic environments by e-waste recycling activities in the Lian River Basin, China. The study area included a designated industrial park in the traditional e-waste recycling area (Guiyu, known as the world's largest e-waste center), several emerging informal recycling zones, and their surrounding areas and coastal area. A total of 27 PCBs were analyzed, and the highest concentration was found in an emerging site for soil (354 ng gāˆ’1) and in a traditional site for sediment (1350 ng gā€āˆ’1) respectively. The pollution levels were significantly higher in both the traditional and emerging recycling areas than in their respective upstream countryside areas (p = 0.0356 and 0.0179, respectively). Source analysis revealed that the traditional and emerging areas had similar PCB sources mainly associated with three PCB technical mixtures manufactured in Japan (KC600) and the USA (Aroclor 1260 and Aroclor 1262). The PCB pollution in their downstream areas including the coastal area was evidently affected by the formal and informal recycling activities through river runoff. The ecological risk assessments showed that PCBs in soils and sediments in the Lian River Basin could cause adverse ecotoxicological consequences to humans and aquatic organisms

    Recommendation in context-rich environment: An information network analysis approach

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    Recommendation has received tremendous attention recently due to its wide and successful applications across different domains. Different from traditional setting of recommendation tasks, modern recommendation tasks are usually exposed in a context-rich environment. For example, in addition to a user-item rating matrix, users and items are connected to other objects via different relationships and they are usually associated with rich attributes, such as text and spatio-temporal information. It turns out that heterogeneous information network serves a natural data model to capture the rich context of these recommendation tasks. In this tutorial, we will systematically introduce the methodologies of using heterogeneous information network mining approach to solve recommendation tasks, and demonstrate the effectiveness of such methods using different applications, ranging from collaboration recommendation in scientific research network to job recommendation in professional social network, and to drug discovery in biomedical networks. The topics to be covered in the tutorial include: (1) overall introduction; (2) recommendation in heterogeneous information networks, which introduces the general methodology of how to model the recommendation problem as a heterogeneous information network mining problem; (3) recommendation in a text-rich setting, where the information network is further enriched by refined analysis of text information; (4) recommendation with spatio-temporal information, where entities and relationships in the network are associated with spatio-temporal attributes; and (5) research frontiers for context-rich recommendation

    Exploring effective implementation pathways to become an excellent chief financial officer in public hospital: a qualitative comparative analysis (QCA) from China

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    Abstract Background Hospital chief financial officer (CFO) contributes to improving health system performance. However, how to become an excellent hospital CFO has rarely been considered from a holistic perspective. This paper aims to identify competencies required by hospital CFO to fulfil the positionā€™s responsibilities and explore effective implementation pathways to generate high performance and improve healthcare service. Methods We conducted 61 semi-structured interviews with individuals in key leadership positions in Chinaā€™s hospitals and researchers focusing on healthcare system management to identify core competencies necessary for hospital CFO. Interviews were analysed through a multi-stage review process and modified via expert vetting using a national panel of 23 professors. Subsequently, interviews were conducted with 32 hospital CFOs from 14 provinces throughout September 2021 to May 2022. We scored the performance of 32 hospital CFOs in various aspects of competency and used the fuzzy-set qualitative comparative analysis to explore the competency configurations of excellent CFOs. Results We identify seven core competencies necessary for a hospital CFO to fulfil management practices, including personal morality, resource management, strategy management, learning ability, negotiating skill, leadership skill, and financial management. The findings indicate that a single competency factor is not a necessary condition to become an excellent hospital CFO. The results of qualitative comparative analysis then make it possible to propose four configurational paths, namely, supportive, interpersonal, all-around development, and technical, to become an excellent hospital CFO and achieve effective managerial performance. Conclusions The responsibilities of hospital CFOs are complex and varied, hence, a better understanding of competencies required by CFO is essential to implement their responsibilities effectively. The identification in this study of the four effective implementation pathways to becoming an excellent hospital CFO enriches the literature on hospital management and provides implications for Chinaā€™s hospitals and their CFOs

    Impact of the New International Landā€“Sea Transport Corridor on Port Competition between Neighboring Countries Based on a Spatial Duopoly Model

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    The development of international landā€“sea transport corridors has provided more convenient access to the sea for inland areas and promoted the improvement of transportation efficiency, environmental improvement, and the strengthening of international cooperation. However, the construction of international landā€“sea transport corridors has also intensified competition among the ports, which has extended from the local and regional to the national and even international levels. This paper explores the impact of international landā€“sea transport corridors on oligopolistic port competition between neighboring countries using the Hotelling model. By setting up the utility of the shipperā€™s port selection, the equilibrium price, market share, and profit of duopoly ports in neighboring countries are analyzed under different conditions of cross-border land transportation and maritime transportation. It is found that the high cross-border transportation cost of the international landā€“sea transport corridor is not conducive to increasing the market share of the overseas oligopolistic ports in the region. If the maritime transportation cost of overseas oligopoly ports is too high compared with domestic oligopoly ports, it will offset the land transport advantages brought by international landā€“sea transport corridors. The findings in this paper could provide support for strategic decision making in port markets and cross-border transport corridor development

    Local variational feature-based similarity models for recommending top-N new items

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    The top-N recommendation problem has been studied extensively. Item-based collaborative filtering recommendation algorithms show promising results for the problem. They predict a user's preferences by estimating similarities between a target and user-rated items. Top-N recommendation remains a challenging task in scenarios where there is a lack of preference history for new items. Feature-based Similarity Models (FSMs) address this particular problem by extending item-based collaborative filtering by estimating similarity functions of item features. The quality of the estimated similarity function determines the accuracy of the recommendation. However, existing FSMs only estimate global similarity functions; i.e., they estimate using preference information across all users. Moreover, the estimated similarity functions are linear; hence, they may fail to capture the complex structure underlying item features. In this article, we propose to improve FSMs by estimating local similarity functions, where each function is estimated for a subset of like-minded users. To capture global preference patterns, we extend the global similarity function from linear to nonlinear, based on the effectiveness of variational autoencoders. We propose a Bayesian generativemodel, called the Local Variational Feature-based Similarity Model, to encapsulate local and global similarity functions. We present a variational Expectation Minimization algorithm for efficient approximate inference. Extensive experiments on a large number of real-world datasets demonstrate the effectiveness of our proposed model

    Biofilm Formation of <i>Listeria monocytogenes</i> and <i>Pseudomonas aeruginosa</i> in a Simulated Chicken Processing Environment

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    This study aims to investigate the mono- and dual-species biofilm formation of Listeria monocytogenes and Pseudomonas aeruginosa incubated in different culture mediums, inoculum ratios, and incubation time. The planktonic cell population and motility were examined to understand the correlation with biofilm formation. The results showed that chicken juice significantly inhibited the biofilm formation of L. monocytogenes (p Pseudomonas aeruginosa was the dominant bacteria in the dual-species biofilm formation in the trypticase soy broth medium. The dynamic changes in biofilm formation were not consistent with the different culture conditions. The growth of planktonic L. monocytogenes and P. aeruginosa in the suspension was inconsistent with their growth in the biofilms. There was no significant correlation between motility and biofilm formation of L. monocytogenes and P. aeruginosa. Moreover, scanning electron microscopy (SEM) results revealed that the biofilm structure of L. monocytogenes was loose. At the same time, P. aeruginosa formed a relatively dense network in mono-species biofilms in an initial adhesion stage (24 h). SEM results also showed that P. aeruginosa was dominant in the dual-species biofilms. Overall, these results could provide a theoretical reference for preventing and controlling the biofilm formation of L. monocytogenes and P. aeruginosa in the food processing environment in the future

    Multiple spotty lesions of the spinal cord in a Chinese patient with human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis

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    The case of a Chinese patient with human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), who showed typical neurological symptoms of the disease, is reported here. Since the presence of anti-HTLV-1 antibody was not investigated, this patientā€™s diagnosis of HAM/TSP was delayed for 4 years. Magnetic resonance imaging revealed multiple spotty lesions in the cervical spinal cord, probably reflecting pathological changes known as perivascular lymphocytic infiltrations of the spinal cord. As this is the first case report of a HAM/TSP patient in China, it is suggested that serological testing for HTLV-1 should be considered in patients with spastic paraparesis even in areas that are non-endemic for HTLV-1. Keywords: HTLV-1, HAM/TSP, China, MRI, Multiple spotty lesion

    Valproic Acid Attenuates Traumatic Brain Injury-Induced Inflammation in Vivo: Involvement of Autophagy and the Nrf2/ARE Signaling Pathway

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    Microglial activation and the inflammatory response in the central nervous system (CNS) play important roles in secondary damage after traumatic brain injury (TBI). Transcriptional activation of genes that limit secondary damage to the CNS are mediated by a cis-acting element called the antioxidant responsive element (ARE). ARE is known to associate with the transcription factor NF-E2-related factor 2 (Nrf2), a transcription factor that is associated with histone deacetylases (HDACs). This pathway, known as the Nrf2/ARE pathway, is a critical antioxidative factor pathway that regulates the balance of oxygen free radicals and the inflammatory response, and is also related to autophagic activities. Although valproic acid (VPA) is known to inhibit HDACs, it is unclear whether VPA plays a role in the microglia-mediated neuroinflammatory response after TBI via regulating oxidative stress and autophagy induced by the Nrf2/ARE signaling pathway. In this study, we demonstrate that microglial activation, oxidative stress, autophagy, and the Nrf2/ARE signaling pathway play essential roles in secondary injury following TBI. Treatment with VPA alleviated TBI-induced secondary brain injury, including neurological deficits, cerebral edema, and neuronal apoptosis. Moreover, VPA treatment upregulated the occurrence of autophagy and Nrf2/ARE pathway activity after TBI, and there was an increase in H3, H4 histone acetylation levels, accompanied by decreased transcriptional activity of the HDAC3 promoter in cortical lesions. These results suggest that VPA-mediated up-regulation of autophagy and antioxidative responses are likely due to increased activation of Nrf2/ARE pathway, through direct inhibition of HDAC3. This inhibition further reduces TBI-induced microglial activation and the subsequent inflammatory response, ultimately leading to neuroprotection
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