Investigation of the plant species diversity, density, abundance and distribution in Grahamstown, South Africa

The plant species play very important role as they are not just planted to make the streets look beautiful but are a vital part of the ecosystem. They are a major source of the oxygen, help control, stabilise the climate and feed animals. The choice of planting alien trees instead of indigenous trees on the street was a big mistake. Therefore there is a need to pay attention on it now that there is high growth of urbanisation. This research has the primary objectives to investigate the plant species diversity, density, abundance and distribution in the Grahamstown streets and identify the key challenges faced by local forestry officials concerned with the provision of street trees. Streets were randomly sampled in the Grahamstown area. A total of 1467 plants were sighted in 17 streets comprising of only 15 indigenous species and 20 alien species. This means the 57% of trees were alien species and only 43% of the trees were indigenous. Significant differences in tree density and species richness were evident across suburbs (Grahamstown West), differences being more significantly different in the more affluent suburbs and poorly represented in the township (Grahamstown East area).Keywords: Plant species diversity, abundance and distributio

The effect of fire on two Eastern Cape Cyclopia species (Fabaceae)

Seedling recruitment of the Eastern Cape endemics Cyclopia longifolia J.R.T. Vogel and Cyclopia pubescens Eckl. & Zeyh. was analysed after fire. Cyclopia longifolia seedling recruitment after treatments of fire; cleared and smoked; and cleared only was comparatively low; recruitment of 2.8 (after 10weeks) to 3.8 seedlings (after 13months) per adult was recorded. Cyclopia longifolia was found to be a resprouter as well as seeder. A population of Cyclopia pubescens was exposed to a veld-fire, with a resultant recruitment of 61 seedlings (5months after burn) to 227 seedlings (17months after burn) per adult. The difference in recruitment success can be ascribed, in part, to environmental conditions that strongly influenced seed germination and seedling survival. Cyclopia longifolia preferentially allocates its resources to regeneration rather than reproduction

Negative effects of urbanisation on diurnal and nocturnal pollen‐transport networks

Pollinating insects are declining due to habitat loss and climate change, and cities with limited habitat and floral resources may be particularly vulnerable. The effects of urban landscapes on pollination networks remain poorly understood, and comparative studies of taxa with divergent niches are lacking. Here, for the first time, we simultaneously compare nocturnal moth and diurnal bee pollen-transport networks using DNA metabarcoding and ask how pollination networks are affected by increasing urbanisation. Bees and moths exhibited substantial divergence in the communities of plants they interact with. Increasing urbanisation had comparable negative effects on pollen-transport networks of both taxa, with significant declines in pollen species richness. We show that moths are an important, but overlooked, component of urban pollen-transport networks for wild flowering plants, horticultural crops, and trees. Our findings highlight the need to include both bee and non-bee taxa when assessing the status of critical plant-insect interactions in urbanised landscapes

Challenges of open innovation: the paradox of firm investment in open-source software

Open innovation is a powerful framework encompassing the generation, capture, and employment of intellectual property at the firm level. We identify three fundamental challenges for firms in applying the concept of open innovation: finding creative ways to exploit internal innovation, incorporating external innovation into internal development, and motivating outsiders to supply an ongoing stream of external innovations. This latter challenge involves a paradox, why would firms spend money on R&D efforts if the results of these efforts are available to rival firms? To explore these challenges, we examine the activity of firms in opensource software to support their innovation strategies. Firms involved in open-source software often make investments that will be shared with real and potential rivals. We identify four strategies firms employ – pooled R&D/product development, spinouts, selling complements and attracting donated complements – and discuss how they address the three key challenges of open innovation. We conclude with suggestions for how similar strategies may apply in other industries and offer some possible avenues for future research on open innovation

The ground state energy of the Edwards-Anderson spin glass model with a parallel tempering Monte Carlo algorithm

We study the efficiency of parallel tempering Monte Carlo technique for calculating true ground states of the Edwards-Anderson spin glass model. Bimodal and Gaussian bond distributions were considered in two and three-dimensional lattices. By a systematic analysis we find a simple formula to estimate the values of the parameters needed in the algorithm to find the GS with a fixed average probability. We also study the performance of the algorithm for single samples, quantifying the difference between samples where the GS is hard, or easy, to find. The GS energies we obtain are in good agreement with the values found in the literature. Our results show that the performance of the parallel tempering technique is comparable to more powerful heuristics developed to find the ground state of Ising spin glass systems.Comment: 30 pages, 17 figures. A new section added. Accepted for publication in Physica

Phenomenological glass model for vibratory granular compaction

A model for weakly excited granular media is derived by combining the free volume argument of Nowak et al. [Phys. Rev. E 57, 1971 (1998)] and the phenomenological model for supercooled liquids of Adam and Gibbs [J. Chem. Phys. 43, 139 (1965)]. This is made possible by relating the granular excitation parameter \Gamma, defined as the peak acceleration of the driving pulse scaled by gravity, to a temperature-like parameter \eta(\Gamma). The resulting master equation is formally identical to that of Bouchaud's trap model for glasses [J. Phys. I 2, 1705 (1992)]. Analytic and simulation results are shown to compare favourably with a range of known experimental behaviour. This includes the logarithmic densification and power spectrum of fluctuations under constant \eta, the annealing curve when \eta is varied cyclically in time, and memory effects observed for a discontinuous shift in \eta. Finally, we discuss the physical interpretation of the model parameters and suggest further experiments for this class of systems.Comment: 2 references added; some figure labels tweaked. To appear in PR

Towards a Criminology of the Domestic

Criminology has paid insufficient attention to the ‘domestic’ arena, as a locale that is being reconfigured through technological and social developments in ways that require us to reconsider offending and victimisation. This article addresses this lacuna. We take up Campbell's (2016) challenge that criminology needs to develop more sophisticated models of place and space, particularly in relation to changing patterns of consumption and leisure activity and the opportunities to offend in relation to these from within the domestic arena

Measurements of the Production, Decay and Properties of the Top Quark: A Review

With the full Tevatron Run II and early LHC data samples, the opportunity for furthering our understanding of the properties of the top quark has never been more promising. Although the current knowledge of the top quark comes largely from Tevatron measurements, the experiments at the LHC are poised to probe top-quark production and decay in unprecedented regimes. Although no current top quark measurements conclusively contradict predictions from the standard model, the precision of most measurements remains statistically limited. Additionally, some measurements, most notably the forward-backward asymmetry in top quark pair production, show tantalizing hints of beyond-the-Standard-Model dynamics. The top quark sample is growing rapidly at the LHC, with initial results now public. This review examines the current status of top quark measurements in the particular light of searching for evidence of new physics, either through direct searches for beyond the standard model phenomena or indirectly via precise measurements of standard model top quark properties