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Slovenian Research Agency; Ministry of Education, Science and Technological Development of the Republic of Serbia

Density functional theory was applied to compute the nucleus independent chemical shifts of fullerene (C60) the fullerene ion C60 10+ and the Jahn–Teller active fullerene anion C60 - and cation C60 +. Positioning a 3He nucleus inside the cage of each of these fullerene species facilitates investigations of the substantial differences among them 3He NMR chemical shifts can provide important data on the aromatic behavior of these molecular cages. Thus we also calculated the NMR chemical shift of a 3He atom positioned at the center of each fullerene species investigated (C60 C60 10+ C60 - and C60 +). The data obtained revealed significant differences in the aromatic behavior of the C60 (moderately aromatic) and C60 10+ (highly aromatic) species. The values of the nucleus independent chemical shift parameters were also scanned along the intrinsic distortion path for the C60 - and C60 + species. In both cases antiaromatic character decreases with increasing deviation from high symmetry structures to low symmetry global minimum points resulting in the antiaromatic C60 - and weakly aromatic C60 +.

This qualitative study of networks of entrepreneurs in the mobile technology industry in three ecosystems—Kathmandu, Nairobi and London—examines perceptions and attitudes of entrepreneurs related to their networking activities. The focus is on understanding the entrepreneurs' motivations for, and benefits and risks of networking, as well as the overall trends of development of the three ecosystems, which are very different from each other in terms of socioeconomic circumstances. The findings provide new insights into the link between the concept of a community of supportive peers and the acquisition of subjective resources, such as self-efficacy and legitimacy, while also supporting conclusions of earlier empirical and theoretical work linking networks with the acquisition of resources necessary for founding and building a new firm. A comparison of results across the three ecosystems uncovers a strong tendency towards institutional convergence of the three ecosystems based on a model inspired by the Silicon Valley experience. The mechanisms through which this is found to occur are mimesis and storytelling, motivated primarily by learning goals and the pursuit of legitimacy for entrepreneurial action in the mobile technology industry, as well as for the individual ventures. The overall finding emerging from the cases is that, despite significant differences, the three ecosystems are reliant on a shared pool of relevant information and knowledge, via the Internet and through personal and organizational connections. They resemble one another not only in terms of resources sought by entrepreneurs through their networks, but also in the ways entrepreneurs signal their purpose and value to their community, and in the way the describe their environment—through references to other entrepreneurship ecosystems. In the absence of an existing theoretical approach to analyzing convergence of diverse entrepreneurship ecosystems, the study proposes a framework based on DiMaggio and Powell's theory of institutional isomorphism, and integrating the works of Wiewel and Hunter, on legitimacy-building by association through networks, and Djelic, on the process of cross-national transfer, or export, of economic models. The type of isomorphism perceived is termed "aspirational," since it is found to occur in the context of pursuing a specific outcome previously achieved by the application of a particular institutional model. The difference between "aspirational isomorphism" and behaviours described by DiMaggio and Powell lies in the interpretation and adaptation of a model that can then be embedded in a nascent institutional environment (in this case, an entrepreneurial ecosystem). Rather than pure mimesis, aspirational isomorphism is a flexible and creative endeavor.

Aim. The purpose of the current study was to examine the effect of Astaxanthin (Asx) supplementation on muscle enzymes as indirect markers of muscle damage, oxidative stress markers and antioxidant response in elite young soccer players. Methods. Thirty-two male elite soccer players were randomly assigned in a double-blind fashion to Asx and placebo (P) group. After the 90 days of supplementation, the athletes performed a 2 hour acute exercise bout. Blood samples were obtained before and after 90 days of supplementation and after the exercise at the end of observational period for analysis of thiobarbituric acid-reacting substances (TBARS), advanced oxidation protein products (AOPP), superoxide anion (O-2(center dot-)), total antioxidative status (TAS), sulphydril groups (SH), superoxide-dismutase (SOD), serum creatine kinase (CK) and aspartate aminotransferase (AST). Results. TBARS and AOPP levels did not change throughout the study. Regular training significantly increased O-2(center dot-) levels (main training effect, P lt 0.01). O-2(center dot-) increased after the soccer exercise (main exercise effect, P lt 0.01), but these changes reached statistical significance only in the P group (exercise x supplementation effect, P lt 0.05). TAS levels decreased significantly post- exercise only in P group (P lt 0.01). Both Asx and P groups experienced increase in total SH groups content (by 21% and 9%, respectively) and supplementation effect was marginally significant (P=0.08). Basal SOD activity significantly decreased both in P and in Asx group by the end of the study (main training effect, P lt 0.01). All participants showed a significant decrease in basal CK and AST activities after 90 days (main training effect, P lt 0.01 and P lt 0.001, respectively). CK and AST activities in serum significantly increased as result of soccer exercise (main exercise effect, P lt 0.001 and P lt 0.01, respectively). Postexercise CK and AST levels were significantly lower in Asx group compared to P group (P lt 0.05) Conclusion. The results of the present study suggest that soccer training and soccer exercise are associated with excessive production of free radicals and oxidative stress, which might diminish antioxidant system efficiency. Supplementation with Asx could prevent exercise induced free radical production and depletion of non-enzymatic antioxidant defense in young soccer players