377 research outputs found

    Control optimization model for greenhouse microclimate

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    In this paper, greenhouse microclimate change is studied and discussed in the context of greenhouse. Based on the hydrodynamic model and mathematical model, a climate-like control model with adjustable parameters is established. The greenhouse environment under different conditions was simulated by adjusting the numerical parameters. In this paper, a glass greenhouse with a length of 10 meters, a width of 3 meters and a height of 2 meters is simulated. Due to the need to consider greenhouse crops, this paper uses the finite difference method to establish a mathematical model of “no crops” in the greenhouse, and the distribution of temperature and wind speed in the greenhouse can be observed through the cross-sectional data. Based on this, crops are added in this paper and the factors of crop canopy are taken into account. Taking the crop canopy as a porous medium model, the temperature field and velocity field are updated based on Dracy’s law, and the temperature and humidity distribution model is established by simulation. The relevant parameters were adjusted to make the whole greenhouse reach a more suitable environment for the healthy growth of plants. Combined with the location, size and number of greenhouse fans for discussion and analysis, the team adjusted the number of fans and the position of the two fans to make the temperature and wind speed distribution in a relatively appropriate situation, meet the “U” shape, which has certain rationality and scientific. By analyzing the greenhouse environment and how to use mathematical models to solve the related problems of fluid dynamics and heat conduction, and using simulation to simulate, a series of theoretical and simulation results are analyzed, and the relevant optimization scheme is designed. Based on this model, the model can be verified by experimental data and can be extended to more complex physical models

    Immunization of Chlamydia pneumoniae (Cpn)-infected Apob(tm2Sgy)Ldlr(tm1Her)/J mice with a combined peptide of Cpn significantly reduces atherosclerotic lesion development

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    OBJECTIVE: To investigate the antigenic effect of a peptide containing two epitopes of Chlamydia pneumoniae (Cpn) on atherosclerotic lesion formation in mice infected with Cpn. MATERIALS AND METHODS: Six-week-old Apob(tm2Sgy)Ldlr(tm1Her)/J mice were immunized using a repetitive immunization multiple-sites strategy with KLH-conjugated peptides derived from the major outer membrane protein and the putative outer membrane protein 5 of Cpn. Mice were fed a high-fat diet and infected with Cpn twice during the 10-week diet period. Lesions were evaluated histologically; local and systemic immune responses were analyzed by immunohistochemistry of aorta samples and cytokine measurements in plasma samples and splenocyte supernatants. RESULTS: Mice immunized with the combined Cpn peptide showed a greater reduction in lesion size compared to mice immunized with either epitope alone [54.7% vs 39.8% or 41.72%] and was also associated with a significant decrease in lesion area in descending aortas compared with those in controls (88.9% for combined Cpn peptide, 81.9% for MOMP peptide and 75.7% for Omp5, respectively). This effect was associated with a shift in the cellular composition of plaques towards decreased inflammatory cell and increased regulatory T-cell content. Additionally, the effect was also connected with decreased secretion of proinflammatory cytokines and increased production of anti-inflammatory cytokines demonstrated in plasma and in supernatant on stimulated spleen cells. CONCLUSIONS: Atherosclerotic lesion formation may be promoted by Cpn infection in the presence of a high-fat diet, and reduced by immunization with the combined Cpn peptide. The combined peptide has more potential than either epitope alone in reducing atherosclerotic lesion development through Treg expansion

    Technology adoption in socially sustainable supply chain management: Towards an integrated conceptual framework

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    This study aims to systematically review existing literature on digital technology adoption for socially sustainable supply chain management (SSSCM) and propose a theoretical framework that outlines the central concepts. A content analysis-based systematic literature review approach was adopted to analyze 49 articles published from 2017 to 2024. The findings of this study identify critical antecedents, barriers, practices, enablers, and outcomes of digital technology adoption for SSSCM. The proposed conceptual model based on technology–organization–environment (TOE) framework and diffusion of innovation (DOI) theory captures these relationships among the identified factors and provides insights into how they can support the development of a socially sustainable supply chain. Furthermore, this study explores the potential positive and negative effects of technology adoption for SSSCM. It highlights the opportunities and challenges that arise from using digital technology in SSSCM, such as the emergence of Industry 4.0 and the need to ensure the ethical use of technology. This study is the first comprehensive review of the role of digital technology in SSSCM. The suggested framework offers guidance for upcoming research in this field, outlining the key areas that require further investigation

    Enhancing firms’ innovation persistence in the circular economy through government-supported green supply chain demonstrations: cost leadership or differentiation?

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    Government support is pivotal in guiding firms towards adopting green supply chain (GSC) practices aligned with the circular economy. Our study addressed this critical issue through a quasi-natural experiment of GSC demonstration in China. We conducted a difference-in-differences estimation to assess the variation in the persistent innovation capabilities between the treatment and control groups. The results indicate that the GSC demonstration, as an external policy change, stimulated the development of firms’ persistent innovation capabilities. These capabilities have positive effects on both innovation input and output dimensions. Additionally, we explored the interaction between firms’ competitive strategies and government support. Findings indicate that differentiation strategies have a stronger positive impact on innovation persistence, while cost leadership strategies weaken this link. These results emphasize the government's critical role in fostering GSC adoption, offering implications for effective government-business collaboration towards a circular economy and sustainable planning across social, environmental, and technological innovation factors

    Enrofloxacin Induces Intestinal Microbiota-Mediated Immunosuppression in Zebrafish

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    The immunosuppressive effects of antibiotics and the potential associations with the intestinal microbiota of the host have been increasingly recognized in recent years. However, the detailed underlying mechanisms of immune interference of antibiotics in environmental organisms remain unclear, particularly at the early life stage of high sensitivity. To better understand the gut microbiome and immune function interactions, the vertebrate model, zebrafish, was treated with environmentally relevant concentrations of a frequently detected antibiotic, enrofloxacin (ENR), ranging from 0.01 to 100 ÎŒg/L. 16S ribosomal RNA sequencing indicated diminished diversity, richness, and evenness of intestinal flora following ENR treatment. Twenty-two taxa of gut bacteria including Rickettsiales, Pseudomonadales, and Flavobacteriales were significantly correlated with immunosuppressive biomarkers, including a significant decrease in the abundance of macrophages and neutrophils. To validate the immunomodulatory effects due to altered intestinal microbial populations, zebrafish reared under sterile and non-sterile husbandry conditions were compared after ENR treatment. A significant inhibitory effect was induced by ENR treatment under non-sterile conditions, while the number of macrophages and neutrophils, as well as biomarkers of immunosuppressive effects, were significantly salved in zebrafish under sterile conditions, confirming for the first time that immunosuppression by ENR was closely mediated through alterations of the intestinal microbiome in fish.publishedVersio

    Leveraging social media in new product development: organisational learning processes, mechanisms and evidence from China

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    Purpose The main purpose of this paper is to investigate how social media can provide important platforms to facilitate organisational learning and innovation in new product development (NPD) process. Design/methodology/approach Using a multiple case-study approach, this study assesses qualitative data collected via 56 interviews from 13 world-leading Chinese companies in the high-technology industry. Findings The study identified three distinct types of organisational learning mechanisms for firms to extract potential innovation inherent in social media. It further determined various organisational enablers that facilitate the connections between these mechanisms and NPD performance. Research limitations/implications This research contributes to the emerging literature on digital product development and organisational learning. The cases were conducted in the Chinese context, hence, the results may not be fully generalisable to other organisations, industries and countries without appropriate re-contextualisation. Practical implications The empirical evidence showcases the various mechanisms adopted by managers in different NPD phases. It identifies several technological and organisational adaptations that managers can apply to smartly scale their social presence and facilitate NPD. Originality/value Despite the exponential growth of social media use in identifying and interacting with external stakeholders, managerial practice and academic research have paid little attention to how social media can be leveraged for NPD. The value of this research comes from applying a qualitative method to gain in-depth insights into the mechanisms for leveraging social media to facilitate innovation in NPD
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