Comparative Demography and Life history Evolution of Plants

Explaining the origin and maintenance of biodiversity is a central goal in ecology and evolutionary biology. Some of the most important, theoretical explanations for this diversity centre on the evolution of life histories. Comparative studies on life history evolution, have received significant attention in the zoological literature, but have lagged in plants. Recent developments, however, have emphasised the value of comparative analysis of data for many species to test existing theories of life history evolution, as well as to provide the basis for developing additional or alternative theories. The primary goal of this study was to explore existing theories of life history evolution using a dataset of demographic information in the form of matrix population models for a large number of plant species. By projecting average matrix population models for 207 plant species, life tables and fecundity schedules were obtained and, in turn, were used to estimate relevant life history parameters. These parameters were then used to explore the i) lability of life history traits in plants ii) their continuum of life history variation, iii) the evolution of senescence and iv) the significance of demographic entropy in population ecology. Elasticities and sensitivities of life history traits showed significant phylogenetic signal compared to other life history traits, although, all the values of phylogenetic signal observed were < 1 indicating that life history traits are generally labile. Eighty one percent of species in the datset had mortality curves that increased with age compared to one hundred percent of species that showed a reproductive value curve that decreases with age at the end of life. In particular, the parameters that measured pace and duration were inversely related suggesting in general, the presence of senescence in our data set. Finally, the tenets of the directionality theory based on demographic entropy were generally not confirmed. This study provides an important contribution to the life history evolution of iteroparous perennial plants and confirms existing theories on life history evolutio

Tangible and Intangible Boundaries: The Case of Baoshan Port-City Interface in Shanghai

Instead of stressing that port cities are characterised by institutional fragmentations with many resulting conflicts, we claim that port cities might be highly constructive in terms of changing tangible and intangible boundaries. To capture this quality, we use the concept of ‘penumbral,’ a combination of perceptional aspects as well as tangible and intangible spatial constellations. This perspective is applied in the case of the Shanghai Baoshan port-city interface through the investigation of the changing tangible and intangible boundaries, and how planning relates to boundary changes in a context of spatial, industrial, and institutional multi-layered structures. Tangible refers to physical boundaries between the port and urban structure or district, while intangible refers to immaterial boundaries created by actors’ views on ports. Based on planning documents, direct observations, and 17 in-depth semi-structured interviews with local governments, port authority, planning departments, and companies, we find that one can indeed speak of penumbral boundaries, based on port-related values and ideas, and particularly on perceptions of the port and port businesses. Those perceptions are the initial power of changing and, following the idea of penumbral boundaries, blurring tangible and intangible boundaries. Finally, we suggest that, following the idea of penumbral boundaries, planning can play a stronger role in connecting the port and the city by first investigating how actors view the port and port businesses carefully, paying full attention to the specific relational context before formulating plans in the usual manner

Nigerian Cash-Less Policy Prospects and Challenges

This paper examines the viability of an operational cashless policy in the Nigerian economy and the importance of a cash-based to cash-less transition that has been pursued by the Central Bank of Nigeria over the last few years. The cash-less policy, initially piloted in Lagos, and accentuated by e-banking schemes, is examined in this paper in the context of a country malaised with pressing developmental challenges including illiteracy, low standards of living, poverty and insecurity and a still developing financial and banking system. The study takes a descriptive look at the benefits to be derived from such an initiative, as well as the various challenges that have to be surmounted in order to fully harness these positive outcomes, which would aid towards the attainment of the country’s developmental goals. Additionally, particular focus is given to the issue of security, and thus a section has been dedicated to explicating on the importance of electronic identity and the recently introduced Bank Verification Number system. Keywords: e-banking, CBN, Nigerian economy, cash-less, BVN, developmen