Mixed product Poisson structures associated to Poisson Lie groups and Lie bialgebras

We introduce and study some mixed product Poisson structures on product manifolds associated to Poisson Lie groups and Lie bialgebras. For quasitriangular Lie bialgebras, our construction is equivalent to that of fusion products of quasi-Poisson G-manifolds introduced by Alekseev, Kosmann- Schwarzbach, and Meinrenken. Our primary examples include four series of holomorphic Poisson structures on products of flag varieties and related spaces of complex semi-simple Lie groups.Comment: 37 pages, submitted to IMR

A New Approach to Coding in Content Based MANETs

In content-based mobile ad hoc networks (CB-MANETs), random linear network coding (NC) can be used to reliably disseminate large files under intermittent connectivity. Conventional NC involves random unrestricted coding at intermediate nodes. This however is vulnerable to pollution attacks. To avoid attacks, a brute force approach is to restrict the mixing at the source. However, source restricted NC generally reduces the robustness of the code in the face of errors, losses and mobility induced intermittence. CB-MANETs introduce a new option. Caching is common in CB MANETs and a fully reassembled cached file can be viewed as a new source. Thus, NC packets can be mixed at all sources (including the originator and the intermediate caches) yet still providing protection from pollution. The hypothesis we wish to test in this paper is whether in CB-MANETs with sufficient caches of a file, the performance (in terms of robustness) of the restricted coding equals that of unrestricted coding. In this paper, we examine and compare unrestricted coding to full cache coding, source only coding, and no coding. As expected, we find that full cache coding remains competitive with unrestricted coding while maintaining full protection against pollution attacks

International Diversification: An Extreme Value Approach

.Diversification; Downside Risk; Correlation Complexity; Extreme Value; Systemic Risk

International Diversification: A Copula Approach

.Diversification; Copula; Correlation Complexity; Downside Risk; Systemic Risk

Towards Effective Online Learning Implementation in Tanzanian Higher Learning Institutions: Obstacles, Challenges and Opportunities

This paper identifies and discusses several influential factors as well as opportunities, associated with effective- online learning implementation in Tanzanian Higher Learning Institutions (THUs). Fourteen (14) THUs were surveyed, using face-to-face interviews in focus groups. The groups included Lecturers, Heads of ICT Departments, ICT Technical Personnel as well as Admi/:listrative Staff. Results indicate that mostly, problems with effective online implementation in THUs are centred on a severe scarcity of online resources and tools and that the main challenges lie in going beyond the process of integrating technology with their teaching curricular, so that training of both teaching and supporting staffs also poses a big challenge in the process. In addition, opportunities for e-learning are totally unexplored because of the low pace of THUs' online learning practices. In this respect, THUs are required to devise and implement clear and welldefined e-learning strategies before they can move a step further

Anti-VEGF Therapy in Cancer: A Double-Edged Sword

Vascular endothelial growth factor (VEGF) is a mitogen that plays a crucial role in angiogenesis and lymphangiogenesis. It is involved in tumor survival through inducing tumor angiogenesis and by increasing chemoresistance through autocrine signaling. Because of its importance in tumor formation and survival, several medications have been developed to inhibit VEGF and reduce blood vessel formation in cancer. Although these medications have proven to be effective for late-stage and metastatic cancers, they have been shown to cause side effects such as hypertension, artery clots, complications in wound healing, and, more rarely, gastrointestinal perforation and fistulas. Current research in using anti-VEGF medication as a part of cancer treatments is focusing on elucidating the mechanisms of tumor resistance to VEGF medication, developing predictive biomarkers that assess whether a patient will respond to VEGF therapy and creating novel treatments and techniques that increase the efficacy of antiangiogenic medication. This chapter aims to review the role of VEGF in tumor angiogenesis and metastasis, the structure and function of VEGF and its receptors, and VEGF’s role in cancer are discussed. Furthermore, tumor therapies targeting VEGF along with their side effects are presented and, finally, new directions in anti-VEGF therapy are considered along with the challenges