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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Microglial conditioned medium inhibited the dopamine- and Zn2+- induced PC12 cell death

MIN, HUI-JEN 06 February 2006 (has links)
Microglia have the potential to produce specific neurotrophic molecules in response to injury and brain diseases. Activated microglia are seen after brain injury or in neurological disease, such as Parkinson¡¦s disease (PD). PD is a progressive neurodegenerative disorder. Although its cause remains unknown, it is believed that enhanced oxidative stress is a major component in the pathogenesis of nigral cell death in PD. Previous results have shown that DA induces apoptosis of dopaminergic neurons in a time- and concentration- dependent manner. In addition, a number of studies have shown that Zn2+ may enter the cell to reach toxic concentrations and that Zn2+ concentration is higher in the striatum of the postmortem brains of PD patients than that of the control brains. We have previously shown that Zn2+ synergistically enhanced the dopamine- and H2O2- induced PC12 cell death. To study the role of microglia in the cell death, I have examined the effect of conditioned medium from a human microglia cell line on the PC12 cell death induced by dopamine and Zn2+. The result shows that conditioned medium inhibits the PC12 cell death and the phosphorylation of JNK induced by dopamine and Zn2+ is diminished by the conditioned medium. It appears that the factor(s) that are responsible for the protection is heat-stable because the conditioned medium heated in 70¢Jfor 30 minutes still has the ability to protect the cell death. Cell death induced by A23187 and C2-ceramide, but not by staurosporine can be protected by the conditioned medium. Results from this study suggest that the microglia secrete some factors which can protect neuron.
92

The strategic analysis of Taiwanese traditional small and medium scale industries¡¦operation under the impact of globalization - take Company M as an example.

Ho, Ming-Feng 26 June 2007 (has links)
In the previous time, the grand occasion of Taiwanese money flooding over the foot, which means the plenty of jobs were offered everywhere and money were absolutely easy to be earned in Taiwan, no longer exists nowadays. Moreover, along with mainland China emerging advantageously as playing the role of the world factory, the small and medium-scale Taiwanese enterprises, once reached the peak in issuing the economic miracle, have either closed the business, or moved out to other countries. Furthermore, the part of Taiwanese enterprises which still defends tenaciously in Taiwan, even including the Hi-Tech star's industry, has to conduct the business cautiously with frightened under Chinese market dramatic rising. That is to prove, it is certain to conclude that the small and medium-scale Taiwanese enterprises should make their effort carefully as well. It is fortunately for me to work for this sort of Taiwanese traditional small and medium- scale enterprise that is under the global economic overbearing tide seriously. Thus, from the specific experience of my service, I found the most essential concerned factor of regarding to plow Taiwan deeply or enter the mainland is frequently for survival besides seeking the development of enterprises. Within the fast change of the economic circumstance nowadays, the purpose of this study is to analyze the cause and effect of enterprises in accordance with economic environment of globalization and those fierce change. Additionally, this study also attempts to discovery a set of decision logic, which is suitable for the medium and small-scale industry according to the analysis. Initially, the chapter 2, literature review, tries to analyze the motivation and strategic module of Taiwanese traditional medium and small-scale industry proceeding globalization through reviewing the theory of economics and management. Moreover, the chapter 4, the strategy analysis of a case industry, intends to discovery the advantage and disadvantage of globalization by data analysis. One is to examine the impact and threaten on enterprises¡¦ operation and the other is to find opportunities brought under the wave of globalization from the operator¡¦s view of enterprises. Eventually, the chapter 6, revolution and conclusion, approaches to provide specific suggestions about the strategic operation for that case industry as well as to conclude with the influence of globalization on Taiwanese traditional medium and small-scale industry. Overall, due to the economic environment having the rapid change constantly, framing and executing the enterprise¡¦s conducting strategy must do some prediction to the future economic circumstance in addition to solve the problem which has been discovered. However, the focus point of prediction is not on the degree of accuracy but mainly on the direction. Thus, it can be illustrated in the other way, no matter whether the enterprise changes or not at present that is all for variable situations in the future. In conclusion, the basic principle of enterprises conducting continuously forever is only to control the direction and adjust their organization
93

How Small and Medium-Sized Enterprises Use Resource to Manage Business during Information Time

Liu, Jen-chien 12 August 2008 (has links)
The international business century is coming. The general business shall transfer, collect, manage a lot of information effectively and reduce the cost and impacts. Therefore, during the business century, how do we use the useful information and technology to have more and more opportunities to improve the structure of a business. However, the business style changing, the competiveness improving, and the capability value increasing is achieve. Using Information technologies(IT) to develop capability is a mean to cope with globalization. Small-and-medium enterprises (SMEs) in Taiwan have higher penetration and potential, however, as White Paper of E-Commercialization described, have lower penetration of infrastructures and applications of Information technologies(IT) than large enterprises. The purpose of this study is to understand what factors affect SMEs¡¦ e-business adoption and IT impacts, and how to formulate managerial regulation of diffuse e-business of SMEs. Following the purpose, this study develops and empirically tests a theoretical model to explain the SMEs¡¦ e-business adoption and impacts. For the e-business adoption, the theoretical model includes Institutional Theory, external e-business support, and relative advantage to investigate SME¡¦s intensity of e-business adoption. For the impacts, the model examines outcome performances through e-business usage, and the relative moderation effects which contain compatibility and training. Keyword: Small-and-medium enterprises (SMEs) , Information Technologies (IT) , e-business.
94

Ytterbium-dotierte Sesquioxide als hocheffiziente Lasermaterialien

Peters, Rigo January 2009 (has links)
Zugl.: Hamburg, Univ., Diss., 2009
95

Factors Effecting Small and Medium Enterprises, Selection of Market Entry Mode / Factors Effecting Small and Medium Enterprises, Selection of Market Entry Mode

Malik, Naveed Hussain, chaudhary, Masood Hussain January 2010 (has links)
Development in infrastructure limits the communication gap, speedy travel and low cost tariff barriers as well other drivers of globalization have made overseas markets easier to get small firms and gave more opportunities to SME´s internationalize. The market entry mode choice or selections have strong effect the success or failure of the company. For instance an insufficient or wrong entry mode selection can decrease opportunities and limit important choice for the firm and could lead to high financial loss as well as lose control on overseas market. The purpose of research study is to provide a deep and better understanding of the factors those effecting SME´s selection of market entry mode. Research question how can the influence of internal and external factors on the selection of market entry mode. A frame of reference led to the building of summary which in turn became the basis for data collection. Two qualitative case studies for Pakistani SME´s namely socks knitter Pakistan and RK International were undertaken. The main findings shows the clear link between the theories claim to be internal and external factors influencing market entry mode choice between SME´s. / C/O Kamran Anjum Norrekaer 14. 7 Tv 2610 Rodovre Denmark
96

Incline, o maiden--

Norman, James Duffy, 1980- 09 October 2012 (has links)
Incline, O Maiden is a large-scale work cast as a dramatic scene for mezzo-soprano and chamber ensemble. It is an exploration of space between music and drama, and the problems inherent in creating a single-character operatic scene. This paper, which serves as an accompaniment to the musical score, is a detailed analysis of the work and focuses on the ways in which form and recurring music motives are used to establish a dramatic conflict with only a single character. The libretto for this dramatic scene is extracted from the play, Faust: A Tragedy, by Johann Wolfgang von Goethe (1749-1832), written in 1808, with English translation by Bayard Taylor (1825-1878). This libretto is centered on the character of Margaret, an original addition to the Faust legend by Goethe, and is a depiction of her inner psychological turmoil as she becomes a willing victim of Faust's seduction. The story begins as Margaret has just met Faust and quickly becomes infatuated with him, and continues through the death of her mother. Composed as a single movement, this piece is divided into two major parts for each of the two sections of action in the libretto. Each major part is further divided into smaller formal sections that are supported and delineated by five major motives that serve as the vast majority of the musical material, and are at the forefront of each formal and dramatic division in the work. Recurring musical motives, sometimes known as leitmotivs, have a long history in opera dating back to Wagner, and in this work, explore how tradition is part of the modern creative process. In Incline, O Maiden, despite the absence of interplay between characters, and given the internal struggle at the heart of the libretto, an indelible link between the drama and music is made meaningful by the unified thematic nature of the music. / text
97

Experimental analysis of evaporation driven emulsion flow in porous media

Kulkarni, Akhil 21 November 2013 (has links)
In some configurations of compact, biofilm based photobioreactors, algae grow on a porous substrate that acts as the support system for the cells providing them with the necessary water and nutrients as well as carrying away their secreted products. The flow in these porous media can be driven by evaporation, mimicking the function of a synthetic leaf. The surface properties of the porous medium as well as the presence of a second immiscible phase in the fluid transported can significantly alter the transport capability and evaporative performance of the porous medium. The focus of this study is to investigate these effects through an experimental study. A dilute, 1% emulsion of lauric acid (chemical formula: C₁₂H₂₄O₂) in water was prepared using Tween® 80 surfactant. Evaporation driven flow of deionized water and the emulsion through two porous media, a hydrophilic glass fiber membrane and a less hydrophilic poly(vinylidene) fluoride (PVDF) membrane were studied. Experiments were conducted to determine the effect of porous medium and fluid properties on the rate of evaporation. The parameters investigated were the hydrophilicity of the porous medium and the area of the porous medium available for evaporation for both water and emulsion. During the experiment, the mass flow rate of the fluid as well as the temperature and the relative humidity of the ambient air were monitored. The results showed that for dilute emulsions, the rate of evaporation observed was the same as that for water and was dictated by the governing laws of convection applicable to the situation based on the geometry of the setup and the ambient conditions. The response of the porous medium to flow of dilute emulsion showed that the highly hydrophilic glass fiber porous medium rejected any accumulation of the oil phase in the pores, and ejected it out, whereas the lesser hydrophilic PVDF porous medium allowed the pores to be clogged by the oil phase, resulting in change in the properties of the medium. However, the dependence of this observation solely on surface properties of the medium cannot be ascertained as the glass fiber medium had a larger pore diameter than the PVDF medium, and this factor could be of effect. The relative humidity of ambient air affected the rate of evaporation, which implied that the flow was limited by evaporation rather than by the viscous losses in the porous medium. The response of change in rate of evaporation to change in relative humidity showed a high time lag. Also, it was seen that there was a maximum area over which evaporation occurred which was dictated by the capillary pressure generated by the porous medium and the viscous losses for the fluid flow through the medium. Any excess area available for evaporation did not have any effect on the rate of evaporation. Electrospinning, as a simple and effective process for generating fibrous porous media was presented and a sample porous medium was prepared using this method. A parametric analysis of the effect of the potential difference applied between the syringe tip and the collector electrode, and the distance between the tip and the collector on the diameter of fibers produced, was performed. / text
98

Strategic approach to purchaisng management in small and medium size enterprises : focus on supplier selection and supplier development functions

Zazulina, Maria January 2010 (has links)
Historically small and medium size enterprises have been playing a major role inwestern economies for years. The importance of SME for developed economies is obvious fromstatistic data. In instance, according to European Commission annual report on SMEs in 2008, in European Union there were over 20 million enterprises where about 99.8 % of them were small and medium sizeу enterprises. Taking into account importance of SME for economy, it becomes necessary to pay careful attention to academic studies of management practices in small to medium size enterprises. In our days, strategic purchasing is one of the foremost discussed topics of business development. Carr A. (2002) states that since the mid of 80th, strategic role of purchasing has continuously been in the focus of attention in academic and trade journals. However, despite of growth popularity of strategic approach to purchasing management, there is low amount of analysis on hybrid theme of purchasing management in SMEs. Thus, realizing the importance of small to medium size enterprises for national economies and understanding strategic purchasing management as the competitive advantage of the business, the purpose of current master thesis project is to analyze implementation of strategic purchasing and its supplier selection and supplier development functions in SME. In order to accomplish the research purpose, the analysis includes the profound literature on the studied topic; moreover additional effort is put to research the achievements of previous studies on purchasing management in SMEs. Finally, the empirical study of strategic purchasing in small to medium enterprises is performed through interviews with 5 (Five) top managers of small firms operating in Russia. Obtained primary data results are compared with secondary data, so that, cross regional comparison on implementation of strategic purchasing in SMEs of Russia, Denmark and United Kingdom was performed. During the research, the following conclusions were obtained. Cross regional comparison indicates similar level of implementation strategic purchasing, supplier selection, and supplier development functions in SMEs of studied countries. Different share of SMEs in economies of these countries does not impact on strategic purchasing practices. Small and medium size firms show partial implementation of strategic purchasing principles. Supplier selection in small to medium size enterprises is performed mostly in traditional way. No methods on rationalization of supply choice are held. Meanwhile, supplier development programmes are practiced broadly by SME. Small to medium size enterprises tend to undertake “indirect” supplier development programmes. Therefore, SMEs’ purchasing management consists of both traditional and strategic elements in their practices. Furthermore, such elements of strategic purchasing as top management involvement, cooperation with other functions in organization management, close collaborative and long term relations with few number of key suppliers, do not take additional resources from SME, and vice versa, they benefit to complement short internal resource by external in more efficient way, current research concludes that strategic approach to purchasing management is suitable approach to purchasing management in small to medium size enterprises.
99

PROCESS DEVELOPMENT FOR THE PRODUCTION AND SEPARATION OF MEDIUM-CHAIN-LENGTH POLY(3-HYDROXYALKANOATES) BY PSEUDOMONAS PUTIDA KT2440

JIANG, XUAN 31 August 2010 (has links)
A series of medium-chain-length poly(3-hydroxyalkanoates) (MCL-PHAs) with enriched 3-hydroxynonanoate (HN) content (up to 95.8 mol% compared to 68.6 mol% without acrylic acid) or 3-hydroxyoctanoate (HO) content (up to 97.5 mol% compared to 88.0 mol% without acrylic acid) was produced in continuous culture by co-feeding fatty acid and glucose plus inhibiting fatty acid β-oxidation using acrylic acid. Using a similar feeding strategy in fed-batch fermentation, similar monomeric compositions but a higher biomass concentration and PHA content could be obtained. However, at a lower growth rate (0.15 h-1 vs. 0.25 h-1), the biomass concentration and PHA content could be greatly enhanced from 17.1 to 71.4 g L-1 and from 64.4 to 75.5%, respectively, while the HN content decreased slightly from 92.2 to 88.9 mol%. PHAs produced under acrylic acid inhibition possessed improved physical properties including a higher melting point, faster crystallization rate, and greater tensile strength at break and Young’s modulus. Two recovery methods were developed for the recovery of MCL-PHA from Pseudomonas putida KT2440. One applied acetone extraction which was capable of recovering all the PHA from the cells with a purity of 91.6% and no detectable polymer molecular weight loss using Soxhlet extraction. Further purification was achieved by redissolving in acetone and reprecipitating in cold methanol. The other method used sodium hydroxide to solubilize the non-PHA cellular material. PHA purity of about 85% was obtained from a biomass containing 65.6% PHA after treatment with 0.2 N NaOH at 22 ± 1oC for 2 h or with 0.1 N at 80 ± 1oC for 15 min. However, a treatment at 22 ± 1oC followed by a second NaOH treatment at 80 ± 1oC resulted in higher PHA purity (94.7%) with a recovery efficiency of 88%. Under these conditions, NaOH digestion had a negligible effect on PHA molecular weight. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2010-08-30 22:44:44.501
100

Operating pH and feed composition as factors affecting stability of aerobic granular sludge

Lashkarizadeh, Monireh 03 1900 (has links)
In this study the stability and nutrient removal performance of aerobic granules under variable operating pH and variable growth medium was investigated. The results indicated that alkaline pH (pH=9) inhibited nitrogen and phosphorus removal. Moreover, high pH induced granules breakage and resulted in an increased biomass concentration in the effluent. On the other hand, acidic pH (pH=6) did not have significant impacts on stability and nutrient removal efficiency of granules. Changing the growth medium from acetate-based wastewater to municipal wastewater resulted in loss of biological phosphorus removal while ammonium and COD removal stayed the same. The granules disintegrated during the first two weeks after changing the feed; re-granulation of the biomass was observed after the acclimation of bacteria to the new growth medium. However, the granules breakage did not exert significant impact on settling property of biomass.

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