Volunteers are a core component of sport service delivery and an important element of the Olympic Games culture. However, little research has addressed the specific characteristics and experiences of individuals who dedicate their time and effort to volunteer at mega-sporting events, more specifically at the Olympic Games. The current study aims to contribute to the literature so that more effective volunteer recruitment and management strategies can be fostered. The purpose of the study was to investigate motives of volunteers at the Athens 2004 Olympics and examine the factorial structure of the Olympic Volunteer Motivation Scale (OVMS). Data were gathered from a volunteer sample of 146 individuals who offered their services in the Olympic Aquatic Center and the Olympic Village. Scores from the 18-item OVMS demonstrated satisfactory validity and reliability. The extracted factors (Olympic related, Egoistic, and Purposive) were well defined and interpreted in terms of the items included. Given the fact that volunteers at the Olympic Games might be motivated by reasons that differ from those at local sporting events, the OVMS will provide information that could further support the Olympic volunteer movement in terms of effective volunteer recruitment and satisfaction.
We had previously demonstrated that lung cancer cells, upon contact with macrophages, could be induced to secrete angiogenic factors to promote tumor angiogenesis. In this study, we focused on the paracrine and autocrine regulation of interleukin (IL)-8 expression in sensitized lung cancer cells after interacting with macrophages. We found that the IL-8 mRNA expression in lung cancer cells significantly increased after coculture with phorbol myristate acetate-treated THP-1 cells and human primary lung macrophages. Fresh lung cancer CL1-5 cells cocultured with macrophage-sensitized lung cancer cells still had a 35% of increase in IL-8 mRNA expression. The addition of anti-inflammatory agents pyrrolidine dithiocarbamate, pentoxifylline, aspirin, and dexamethasone could completely suppress the expression of IL-8 mRNA in fresh/sensitized lung cancer cell cocultures. Human recombinant tumor necrosis factor (TNF)-alpha and IL-1alpha could induce IL-8 expression in lung cancer cells in a dose-dependent manner. Neutralization with TNF-alpha and IL-1alpha antibodies in cocultures decreased the levels of IL-8 expression in sensitized lung cancer cells. Nuclear factor-kappaB transcriptional activity was also suppressed by the same antibodies, as confirmed by a reporter gene assay and the electrophoretic mobility shift assay. Our results highly suggest that both autocrine and paracrine regulation are involved in IL-8 expression of lung cancer cells cocultured with macrophage. Also, the regulations of IL-8 expression in lung cancer cells were through the nuclear factor-kappaB pathway and modulated by TNF-alpha and IL-1alpha.
This study investigated the transient transport phenomenon during the pile up of molten lead-free solder via the inkjet printing method. With regard to the droplet impact velocity, the distance from nozzle to substrate can be controlled by using the pulse voltage and distance control apparatus. A high-speed digital camera was used to record the solder impact and examine the accuracy of the pile up. These impact conditions correspond to We = 2.1-15.1 and Oh = 5.4 × 10 −3 -3.8 × 10 −3 . The effects of impact velocity and relative distance between two types of molten droplets on the shape of the impact mode are examined. The results show that the optimal parameters of the distance from nozzle to substrate and the spreading factor in this experiment are 0.5 mm and 1.33. The diameter, volume and velocity of the inkjet solder droplet are around 37-65 μm, 25-144 picoliters, and 2.0-3.7 m s −1 , respectively. The vertical and inclined column structures of molten lead-free solder can be fabricated using piezoelectric ink-jet printing systems. The end-shapes of the 3D micro structure have been found to be dependent upon the distance from nozzle to substrate and the impact velocity of the molten lead-free solder droplet.
Background: Theophylline has been used widely as a bronchodilator for the treatment of bronchial asthma and has been suggested to modulate immune response. While the importance of macrophages in asthma has been reappraised and emphasized, their significance has not been well investigated. We conducted a genome-wide profiling of the gene expressions of macrophages in response to theophylline.
This study aims to determine the effects of appropriate experimental parameters on the thermophysical properties of molten micro droplets, Sn-3Ag-0.5Cu solder balls with an average droplet diameter of 50 μm were prepared. The inkjet printing parameters of the molten micro droplets, such as the dot spacing, stage velocity and sample temperature, were optimized in the 1D and 2D printing of metallic microstructures. The impact and mergence of molten micro droplets were observed with a high-speed digital camera. The line width of each sample was then calculated using a formula over a temperature range of 30 to 70 °C. The results showed that a metallic line with a width of 55 μm can be successfully printed with dot spacing (50 μm) and the stage velocity (50 mm∙s−1) at the substrate temperature of 30 °C. The experimental results revealed that the height (from 0.63 to 0.58) and solidification contact angle (from 72° to 56°) of the metallic micro droplets decreased as the temperature of the sample increased from 30 to 70 °C. High-speed digital camera (HSDC) observations showed that the quality of the 3D micro patterns improved significantly when the droplets were deposited at 70 °C.
Abstract:It is well known that there is an intrinsic link between the financial and energy sectors, which can be analysed through their spillover effects, which are measures of how the shocks to returns in different assets affect each other's subsequent volatility in both spot and futures markets. Financial derivatives, which are not only highly representative of the underlying indices, but can also be traded on both the spot and futures markets, include Exchange Traded Funds (ETFs), a tradable spot index whose aim is to replicate the return of an underlying benchmark index. When ETF futures are not available to examine spillover effects, "generated regressors" are useful for constructing both financial ETF futures and energy ETF futures. The purpose of the paper is to investigate the co-volatility spillovers within and across the U.S. energy and financial sectors in both spot and futures markets, by using "generated regressors" and a multivariate conditional volatility model, namely diagonal BEKK. The daily data used are from 23 December 1998-22 April 2016. The dataset is analysed in its entirety and is also subdivided into three distinct subsets. The empirical results show there is a significant relationship between the financial ETF and energy ETF in the spot and futures markets. Therefore, financial and energy ETFs are suitable for constructing a financial portfolio from an optimal risk management perspective and also for dynamic hedging purposes.
It is well known that that there is an intrinsic link between the financial and energy sectors, which can be analyzed through their spillover effects, which are measures of how the shocks to returns in different assets affect each other's subsequent volatility in both spot and futures markets. Financial derivatives, which are not only highly representative of the underlying indices, but can also be traded on both the spot and futures markets, include Exchange Traded Funds (ETFs), a tradable spot index whose aim is to replicate the return of an underlying benchmark index. When ETF futures are not available to examine spillover effects, "generated regressors" are useful for constructing both Financial ETF futures and Energy ETF futures.The purpose of the paper is to investigate the co-volatility spillovers within and across the US energy and financial sectors in both spot and futures markets, by using "generated regressors" and a multivariate conditional volatility model, namely Diagonal BEKK. The daily data used are from 1998/12/23 to 2016/4/22. The data set is analyzed in its entirety, and are also subdivided into three distinct subsets. The empirical results show there is a significant relationship between the Financial ETF and Energy ETF in the spot and futures markets.Therefore, financial and energy ETFs are suitable for constructing a financial portfolio from an optimal risk management perspective, and also for dynamic hedging purposes.
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