263 research outputs found

    Foreign direct investment in services and manufacturing productivity growth: evidence for Chile

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    During the 1990s, foreign direct investment in producer service sectors in Latin America was massive. Such investment may increase the quality of services, reduce their cost, and offer opportunities for knowledge spillovers to downstream users of the services. This paper examines the effects of foreign direct investment in services on manufacturing productivity growth in Chile between 1992 and 2004. The authors estimate an extended production function where plant output growth depends on input growth and a weighted measure of foreign direct investment in services. The novelty of the approach is that the authors are able to assess the intensity of usage of various types of services at the plant level and use that information in the estimation of the importance of foreign direct investment in those services. The econometric results show a positive and significant effect of foreign direct investment in services on productivity growth of Chilean manufacturing plants which is robust to a multitude of tests. The economic impact of the estimates is that forward linkages from foreign direct investment in services account for almost 5 percent of the observed increase in Chilean manufacturing productivity growth during the sample period. This evidence therefore suggests that reducing the barriers restricting foreign direct investment in services in many developing economies may help accelerate productivity growth in their manufacturing sectors.Banks&Banking Reform,ICT Policy and Strategies,E-Business,Knowledge Economy,Education for the Knowledge Economy

    Does tougher import competition foster product quality upgrading ?

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    Over the past two decades, globalization, and more specifically the increased exposure to competition from low-price producers in China and India, has created a new economic environment for other emerging economies. The most advantageous way for manufacturing firms in those economies to position themselves in domestic and international markets is to offer upgraded and differentiated rather than"mundane"labor-intensive products. This paper investigates whether increased competitive pressure from imports forces firms to improve the quality of their products. The econometric analysis relies on a rich dataset of Chilean manufacturing plants and their products. Product quality is measured with unit values (average prices) and industry-level transport costs are used as an exogenous measure of import competition. The authors find a positive and robust effect of import competition on product quality. This effect is found to be particularly strong for non-exporting plants. The results also show that increased import competition from less advanced economies is the major cause for the positive impact on quality upgrading. The overall evidence points to the benefits of trade openness for product innovation but demonstrates at the same time that competitive pressure alone will not enable local plants to catch up with leading world producers.Transport Economics Policy&Planning,Markets and Market Access,Economic Theory&Research,Water and Industry,Access to Markets

    Nanotoxicity of polyelectrolyte-functionalized titania nanoparticles towards microalgae and yeast: Role of the particle concentration, size and surface charge

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    We studied the nanotoxicity of titania nanoparticles (TiO₂NPs) of various hydrodynamic diameters and crystallite sizes towards C. reinhardtii microalgae and S. cerevisiae (yeast) upon illumination with UV and visible light. The cell viability was assessed for a range of nanoparticle concentrations and incubation times. We found that bare TiO₂NPs affect the C. reinhardtii cell viability at much lower particle concentrations than for yeast. We observed an increase of the TiO₂NPs toxicity upon illumination with UV light compared with that in dark conditions due to the oxidative stress of the produced reactive oxygen species. We also found an increased TiO₂NPs nanotoxicity upon illumination with visible light which indicates that they may also interfere with the microalgae's photosynthetic system leading to decreased chlorophyll content upon exposure to TiO₂NPs. The results indicate that the larger the hydrodynamic diameter of the TiO₂NPs the lower is their nanotoxicity, with anatase TiO₂NPs generally being more toxic than rutile TiO₂NPs. We also prepared a range of polyelectrolyte-coated TiO₂NPs using a layer by-layer method and studied their nanotoxicity towards yeast and microalgae. We found that the toxicity of the coated TiO₂NPs changes with their surface charge. TiO₂NPs coated with cationic polyelectrolyte as an outer layer exhibit much higher nanotoxicity than the ones with an outer layer of anionic polyelectrolyte. TEM images of sectioned microalgae and yeast cells exposed to different polyelectrolyte-coated TiO₂NPs confirmed the formation of a significant build-up of nanoparticles on the cell surface for bare and cationic polyelectrolyte-coated TiO₂NPs. The effect comes from the increased adhesion of cationic nanoparticles to the cell walls. Significantly, coating the TiO₂NPs with anionic polyelectrolyte as an outer layer led to a reduced adhesion and much lower nanotoxicity due to electrostatic repulsion with the cell walls. This suggest a new way of making cationic TiO₂NPs safer for use in different formulations by pre-coating them with anionic polyelectrolytes. The results of this study give important insights into the various factors controlling the nanotoxicity of TiO₂NPs

    EPIDEMIOLOGICAL ASPECTS OF THE ZOONOTIC INFECTIONS IN VARNA REGION IN 1990-1997

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    Some epidemiological features of the zoonotic infections in Varna region in 1990-1997 were investigated. The analysis was based on the data of the officially registered incidence rate. A remarkable increase of the number of cases with Lyme borreliosis, boutonneous fever and other diseases in comparison with that in some previous years was estblished. This elevation was due to certain favourable epidemiological factors. Case distributions according to epidemiological indices were shown. This initial investigation serves as a basis for more profound research in the field of zoonotic-infection epidemiology in Varna region

    Artificial leaf device for hydrogen generation from immobilised C. reinhardtii microalgae

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    We developed a fully biomimetic leaf-like device for hydrogen production which allows incorporated fabric-immobilised microalgae culture to be simultaneously hydrated with media and harvested from the produced hydrogen in a continuous flow regime without the need to replace the algal culture. Our leaf device produces hydrogen by direct photolysis of water resulting from redirecting the photosynthetic pathways in immobilised microalgae due to the lack of oxygen. In contrast to the many other reports in the literature on batch photobioreactors producing hydrogen from suspension culture of microalgae, we present the first report where this is done in a continuous manner from a fabric-immobilised microalgae culture. The reported artificial leaf device maximises the sunlight energy utilisation per gram of algae and can be upscaled cheaply and easily to cover large areas. We compared the production of hydrogen from both immobilised and suspended cultures of C. reinhardtii microalgae under sulphur, phosphorus and oxygen deprived conditions. The viability and potential of this approach is clearly demonstrated. Even though this is a first prototype, the hydrogen yield of our artificial leaf device is twenty times higher per gram of algae than in previously the reported batch reactors. Such leaf-like devices could potentially be made from flexible plastic sheets and installed on roofs and other sun-exposed surfaces that are inaccessible by photovoltaic cells. The ability to continuously produce inexpensive hydrogen by positioning inexpensive sheets onto any surface could have an enormous importance in the field of biofuels. The proposed new concept can provide a cleaner and very inexpensive way of bio-hydrogen generation by flexible sheet-like devices

    Controlling the nanotoxicity of polyelectrolyte-functionalized titania nanoparticles

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    This study gives important insights of the various factors controlling the nanotoxicity of titania nanoparticles (TiO2NPs). We studied the nanotoxicity of TiO2NPs of various hydrodynamic diameters and crystallite sizes on C. Reinhardtii (microalgae) and S. cerevisiae (yeast) upon illumination with UV/visible light [1]. The cell viability was assessed for a range of nanoparticle concentrations and incubation times. Bare TiO2NPs affect the microalgae viability at much lower particle concentrations than for yeast. We also found an increased nanotoxicity upon illumination with visible light which indicates that they may also interfere with the microalgae photosynthetic system leading to decreased chlorophyll content upon exposure to TiO2NPs. The results indicate that the larger the hydrodynamic diameter of the TiO2NPs the lower is their nanotoxicity, with anatase TiO2NPs generally being more cytotoxic than rutile TiO2NPs. We also prepared a range of polyelectrolyte-coated TiO2NPs using the layer by-layer method and studied their nanotoxicity on yeast and microalgae. The toxicity of the coated TiO2NPs alternates with their surface charge. TiO2NPs coated with cationic polyelectrolyte as an outer layer exhibit much higher nanotoxicity than the ones with an outer layer of anionic polyelectrolyte. TEM images of sectioned microalgae and yeast cells exposed to different polyelectrolyte-coated TiO2NPs confirmed the formation of a significant build-up of nanoparticles on the cell surface for bare- and cationic polyelectrolyte-coated TiO2NPs. The effect is coming from the increased adhesion of cationic nanoparticles to the cell walls. Significantly, coating the TiO2NPs with an anionic polyelectrolyte as an outer layer led to a reduced adhesion and much lower nanotoxicity due to electrostatic repulsion with the cell walls. This suggest a new way of making the TiO2NPs potentially safer for use in different formulations by pre-coating them with anionic polyelectrolytes. Please click Additional Files below to see the full abstract

    Dual-functionalised shellac nanocarriers give a super-boost of the antimicrobial action of berberine

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    We have developed highly efficient antimicrobial nanocarriers for berberine (BRB) based on shellac nanoparticles (NPs) which were surface-functionalised with a surface active polymer, Poloxamer 407 (P407), and the cationic surfactant octadecyltrimethylammonium bromide (ODTAB). These shellac nanocarriers were produced in a two-step process which involves: (i) a pH change from aqueous ammonium shellac solution using P407 as a steric stabilizer in the presence of berberine chloride, and (ii) addition of ODTAB to yield shellac nanocarriers of cationic surface. We determined the BRB encapsulation efficiency and release profiles from such nanocarriers. We explored the antimicrobial action of these nanocarriers at different stages of their preparation which allowed us gain better understanding how they work, fine tune their design and reveal the impact of the nanoparticle coatings on to its antimicrobial effect. The antimicrobial action of BRB loaded within such shellac NPs with cationic surface functionality was examined on three different microorganisms, C. reinhardtii, S. cerevisiae and E. coli and compared with the effect of free BRB as well as non-coated BRB-loaded nanocarriers at the same BRB concentrations. We found that the cationic surface coating of the shellac NPs strongly amplified the efficiency of the encapsulated BRB across all tested microorganisms. The effect was attributed to the increased attraction between the ODTAB-coated BRB-loaded NPs and the anionic surface of the cell walls which delivers locally high BRB concentration. This nanotechnological approach could lead to more effective antimicrobial and disinfecting agents, dental formulations for plaque control, wound dressings, antialgal/antibiofouling formulations and antifungal agents

    The unequal effect of India's industrial liberalization on firms' decision to innovate: Do business conditions matter?

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    This paper examines the heterogeneous impact of industrial liberalization policy, the dismantling of the "License Raj" in India, on firms' innovation performance. Our results show that larger and more productive firms in liberalized industries were more likely to take up R&D while the smallest and least efficient firms were less likely to do so. We also show that this inequality of effects was strongest in economically less developed Indian states and where financial development and the knowledge base are weaker. This suggests business conditions shape heterogeneous impacts of liberalization policies to the advantage of initially larger and more efficient firms

    PECULIARITIES OF THE EPIDEMIC PROCESS OF EPIDEMIC PAROTITIS UNDER THE CONDITIONS OF MASS IMMUNOPROPHYLAXIS

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    Some specific features of the mumps epidemic process under the conditions of mass immunoprevention were analyzed. Incidence rates were higher when there was a remoteness of the primary immunization by live parotitis vaccine. Certain opportunities for amending the epidemic control with this vaccine to avoid infection were emphasized

    Enhanced antimicrobial effect of berberine in nanogel carriers with cationic surface functionality

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    We report a strong enhancement in the antimicrobial action of berberine encapsulated into polyacrylic acid-based nanogels followed by further surface functionalisation with a cationic polyelectrolyte (PDAC). Due to the highly developed surface area, the nanogel carrier amplifies the contact of berberine with microbial cells and increases its antimicrobial efficiency. We show that such cationic nanogel carriers of berberine can adhere directly to the cell membranes and maintain a very high concentration of berberine directly on the cell surface. We demonstrated that the antimicrobial action of the PDAC-coated nanogel loaded with berberine on E. coli and C. reinhardtii is much higher than that of the equivalent solution of free berberine due to the electrostatic adhesion between the positively charged nanogel particles and the cell membranes. Our results also showed a marked increase in their antimicrobial action at shorter incubation times compared to the non-coated nanogel particles loaded with berberine under the same conditions. We attribute this boost in the antimicrobial effect of these cationic nanocarriers to their accumulation on the cell membranes which sustains a high concentration of released berberine causing cell death within much shorter incubation times. This study can provide a blueprint for boosting the action of other cationic antimicrobial agents by encapsulating them into nanogel carriers functionalised with a cationic surface layer. This nanotechnology-based approach could lead to the development of more effective wound dressings, disinfecting agents, antimicrobial surfaces, and antiseptic and antialgal/antibiofouling formulations
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