138 research outputs found

    Inter-disciplinary study on open source software development in developing countries: a case study of Chinese Linux

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    This research provides a detailed account of Open Source Software (OSS) development in the context of developing countries (DCs) by exploring the specific case of Chinese indigenous Linux design and development. It builds an interdisciplinary, socio-technical, analytical framework from the perspective of science and technology studies (STS), in particular the social shaping of technology (SST), infrastructural studies and international technology transfer. It also covers the fields of economic analysis, policy studies and development studies. The research investigates the adaptation process of a unique OSS with infrastructural features – Linux in the context of China by conducting case studies on both embedded Linux and platform Linux products developed by two Chinese Linux providers. Drawing upon the concepts developed in the SST perspective and infrastructural studies, this research addresses both the dynamism and continuity of OSS. In order to avoid the shortcomings of existing social scientific study on OSS, we applied social and biography of artefacts (BoA) approaches to examine the evolution of Chinese Linux by mapping out the key actors, investigating the linkages between them, and probing deeply into the intricate interplays among these actors over time. A detailed longitudinal and contextual analysis has been undertaken through a qualitative historical case study of the evolution of both Chinese embedded Linux and platform Linux from 1998-2008. The empirical data reveals that the local adaptation and further innovation of Chinese Linux is a ‘generification’ process, i.e. a process of design and developing generic Linux solutions for diverse local users. Theoretically, the understanding of the socio-technical interfaces of the software (seeking, identifying, categorising local users/intermediaries, as well as collaborating with key players associated with the particular software) are central elements for software technology transfer and local technological capabilities building. The findings also throw the light on the crucial importance of government role in providing incentives and institutional measures for Linux adaptation in China. In particular, it highlights the challenges concerning the socio-technical specificities of infrastructural software, like Linux OS (operating system) and the particular relevance to DCs as technology adapters. Finally, this study throws light on the policy and practice for China’s future Linux development, and the implications for other DCs

    Hegemony in the marketplace of biomedical innovation:Consumer demand and stem cell science

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    AbstractThe global political economy of stem cell therapies is characterised by an established biomedical hegemony of expertise, governance and values in collision with an increasingly informed health consumer demand able to define and pursue its own interest. How does the hegemony then deal with the challenge from the consumer market and what does this tell us about its modus operandi? In developing a theoretical framework to answer these questions, the paper begins with an analysis of the nature of the hegemony of biomedical innovation in general, its close relationship with the research funding market, the current political modes of consumer incorporation, and the ideological role performed by bioethics as legitimating agency. Secondly, taking the case of stem cell innovation, it explores the hegemonic challenge posed by consumer demand working through the global practice based market of medical innovation, the response of the national and international institutions of science and their reassertion of the values of the orthodox model, and the supporting contribution of bioethics. Finally, the paper addresses the tensions within the hegemonic model of stem cell innovation between the key roles and values of scientist and clinician, the exacerbation of these tensions by the increasingly visible demands of health consumers, and the emergence of political compromise

    Construction of stable Ta3N5/g-C3N4 metal/non-metal nitride hybrids with enhanced visible-light photocatalysis

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    In this paper, a novel Ta3N5/g-C3N4 metal/non-metal nitride hybrid was successfully synthesized by a facile impregnation method. The photocatalytic activity of Ta3N5/g-C3N4 hybrid nitrides was evaluated by the degradation of organic dye rhodamine B (RhB) under visible light irradiation, and the result indicated that all Ta3N5/g-C3N4 samples exhibited distinctly enhanced photocatalytic activities for the degradation of RhB than pure g-C3N4. The optimal Ta3N5/g-C3N4 composite sample, with Ta3N5 mass ratio of 2%, demonstrated the highest photocatalytic activity, and its degradation rate constant was 2.71 times as high as that of pure g-C3N4. The enhanced photocatalytic activity of this Ta3N5/g-C3N4 metal/metal-free nitride was predominantly attributed to the synergistic effect which increased visible-light absorption and facilitated the efficient separation of photoinduced electrons and holes. The Ta3N5/g-C3N4 hybrid nitride exhibited excellent photostability and reusability. The possible mechanism for improved photocatalytic performance was proposed. Overall, this work may provide a facile way to synthesize the highly efficient metal/metal-free hybrid nitride photocatalysts with promising applications in environmental purification and energy conversion

    A potential anti-tumor herbal medicine, Corilagin, inhibits ovarian cancer cell growth through blocking the TGF-β signaling pathways

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    BACKGROUND: Phyllanthus niruri L. is a well-known hepatoprotective and antiviral medicinal herb. Recently, we identified Corilagin as a major active component with anti-tumor activity in this herbal medicine. Corilagin is a member of the tannin family that has been discovered in many medicinal plants and has been used as an anti-inflammatory agent. However, there have been few reports of the anti-tumor effects of Corilagin, and its anti-tumor mechanism has not been investigated clearly. The aim of the present study is to investigate the anticancer properties of Corilagin in ovarian cancer cells. METHODS: The ovarian cancer cell lines SKOv3ip, Hey and HO-8910PM were treated with Corilagin and analyzed by Sulforhodamine B (SRB) cell proliferation assay, flow cytometry, and reverse phase protein array (RPPA). Corilagin was delivered intraperitoneally to mice bearing SKOv3ip xenografts. RESULTS: Corilagin inhibited the growth of the ovarian cancer cell lines SKOv3ip and Hey, with IC50 values of less than 30 μM, while displaying low toxicity against normal ovarian surface epithelium cells, with IC50 values of approximately 160 μM. Corilagin induced cell cycle arrest at the G2/M stage and enhanced apoptosis in ovarian cancer cells. Immunoblotting assays demonstrated that Cyclin B1, Myt1, Phospho-cdc2 and Phospho-Weel were down-regulated after Corilagin treatment. Xenograft tumor growth was significantly lower in the Corilagin-treated group compared with the untreated control group (P <0.05). More interestingly, Corilagin inhibited TGF-β secretion into the culture supernatant of all tested ovarian cancer cell lines and blocked the TGF-β-induced stabilization of Snail. In contrast, a reduction of TGF-β secretion was not observed in cancer cells treated with the cytotoxic drug Paclitaxel, suggesting that Corilagin specifically targets TGF-β secretion. Corilagin blocked the activation of both the canonical Smad and non-canonical ERK/AKT pathways. CONCLUSIONS: Corilagin extracted from Phyllanthus niruri L. acts as a natural, effective therapeutic agent against the growth of ovarian cancer cells via targeted action against the TGF-β/AKT/ERK/Smad signaling pathways

    Design and optimization of a type-C tank for liquid hydrogen marine transport

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    As one of the most promising renewable energy sources, hydrogen has the excellent environmental benefit of producing zero emissions. A key technical challenge in using hydrogen across sectors is placed on its storage technology. The storage temperature of liquid hydrogen (20 K, or −253 °C) is close to absolute zero so the storage materials and the insulation layers are subjected to extremely stringent requirements against the cryogenic behaviour of the medium. In this context, this research proposed to design a large liquid hydrogen type-C tank with AISI (American Iron and Steel Institution) type 316 L stainless steel as the metal barrier, using Vapor-Cooled Shield (VCS) and Rigid Polyurethane Foams (RPF) as the insulation layer. A parametric study on the design of the insulation layer was carried out by establishing a thermodynamic model. The effects of VCS location on heat ingress to the liquid hydrogen transport tank and insulation temperature distribution were investigated, and the optimal location of the VCS in the insulation was identified. Research outcomes finally suggest two optimal design schemes: (1) when the thickness of the insulation layer is determined, Self-evaporation Vapor-Cooled Shield (SVCS) and Forced-evaporation Vapor-Cooled Shield (FVCS) can reduce heat transfer by 47.84% and 85.86% respectively; (2) when the liquid hydrogen evaporation capacity is determined, SVCS and FVCS can reduce the thickness of the insulation layer by 50% and 67.93% respectively

    Compound dietary fiber and high-grade protein diet improves glycemic control and ameliorates diabetes and its comorbidities through remodeling the gut microbiota in mice

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    Dietary intervention with a low glycemic index and full nutritional support is emerging as an effective strategy for diabetes management. Here, we found that the treatment of a novel compound dietary fiber and high-grade protein diet (CFP) improved glycemic control and insulin resistance in streptozotocin-induced diabetic mice, with a similar effect to liraglutide. In addition, CFP treatment ameliorated diabetes-related metabolic syndromes, such as hyperlipidemia, hepatic lipid accumulation and adipogenesis, systemic inflammation, and diabetes-related kidney damage. These results were greatly associated with enhanced gut barrier function and altered gut microbiota composition and function, especially those bacteria, microbial functions, and metabolites related to amino acid metabolism. Importantly, no adverse effect of CFP was found in our study, and CFP exerted a wider arrange of protection against diabetes than liraglutide. Thereby, fortification with balanced dietary fiber and high-grade protein, like CFP, might be an effective strategy for the management and treatment of diabetes

    Bioinformatics and the politics of innovation in the life sciences: Science and the state in the United Kingdom, China, and India

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    The governments of China, India, and the United Kingdom are unanimous in their belief that bioinformatics should supply the link between basic life sciences research and its translation into health benefits for the population and the economy. Yet at the same time, as ambitious states vying for position in the future global bioeconomy they differ considerably in the strategies adopted in pursuit of this goal. At the heart of these differences lies the interaction between epistemic change within the scientific community itself and the apparatus of the state. Drawing on desk-based research and thirty-two interviews with scientists and policy makers in the three countries, this article analyzes the politics that shape this interaction. From this analysis emerges an understanding of the variable capacities of different kinds of states and political systems to work with science in harnessing the potential of new epistemic territories in global life sciences innovation

    Structural Analysis of the UBA Domain of X-linked Inhibitor of Apoptosis Protein Reveals Different Surfaces for Ubiquitin-Binding and Self-Association

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    BACKGROUND: Inhibitor of apoptosis proteins (IAPs) belong to a pivotal antiapoptotic protein family that plays a crucial role in tumorigenesis, cancer progression, chemoresistance and poor patient-survival. X-linked inhibitor of apoptosis protein (XIAP) is a prominent member of IAPs attracting intense research because it has been demonstrated to be a physiological inhibitor of caspases and apoptosis. Recently, an evolutionarily conserved ubiquitin-associated (UBA) domain was identified in XIAP and a number of RING domain-bearing IAPs. This has placed the IAPs in the group of ubiquitin binding proteins. Here, we explore the three-dimensional structure of the XIAP UBA domain (XIAP-UBA) and how it interacts with mono-ubiquitin and diubiquitin conjugates. PRINCIPAL FINDINGS: The solution structure of the XIAP-UBA domain was determined by NMR spectroscopy. XIAP-UBA adopts a typical UBA domain fold of three tightly packed alpha-helices but with an additional N-terminal 3(10) helix. The XIAP-UBA binds mono-ubiquitin as well as Lys48-linked and linear-linked diubiquitins at low-micromolar affinities. NMR analysis of the XIAP-UBA-ubiquitin interaction reveals that it involves the classical hydrophobic patches surrounding Ile44 of ubiquitin and the conserved MGF/LV motif surfaces on XIAP-UBA. Furthermore, dimerization of XIAP-UBA was observed. Mapping of the self-association surface of XIAP-UBA reveals that the dimerization interface is formed by residues in the N-terminal 3(10) helix, helix alpha1 and helix alpha2, separate from the ubiquitin-binding surface. CONCLUSION: Our results provide the first structural information of XIAP-UBA and map its interaction with mono-ubiquitin, Lys48-linked and linear-linked diubiquitins. The notion that XIAP-UBA uses different surfaces for ubiquitin-binding and self-association provides a plausible model to explain the reported selectivity of XIAP in binding polyubiquitin chains with different linkages.published_or_final_versio
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