Modeling the Effect of Bandwidth Allocation on Network Performance

In this paper, a new channel capacity model for interferencelimited systems was obtained by transforming the Shannon-Hartley theorem for channel capacity. To emulate an operational system, a dashboard Motorola monitoring device was used to collect data from a group of Base Stations (BSs) serving (a section of) the Nigerian air space and belonging to one of the existing network carriers. Our findings revealed that the uplink and downlink throughputs of the existing system were not impressive even when there was uniform sharing of bottlenecks across the BSs. Using MATLAB, simulations were then performed by extending these data, subject to ideal environmental constraints. Results obtained revealed the following: (i) The Shannon-Hartley model performed as expected for no-interference systems (TDMA and FDMA), but as the bandwidth improved, only limited number of users could access the network in the presence of increased SNR; (ii) The proposed model showed improved performance for CDMA networks, but further increase in the bandwidth did not benefit the network; (iii) A reliability measure such as the spectral efficiency is therefore useful to redeem the limitation in (ii).Keywords: Coverage Capacity, CDMA, Mobile Network, Network Throughpu

Towards Securing the Home Computer: a modification of the USB Port

Hundreds of millions of people use the home computer everyday for different purposes. These systems use the universal serial bus (USB) disk for day to day transfer of data, communication and other applications. The USB as a flexible tool for data transfer raises security concerns relatively to a potential loss of assets. This paper therefore demonstrates how a modification of the USB port can improve the security of the home computer.Keywords: home computer, operating system, threats, Universal Serial Bus (USB)Journal of the Nigerian Association of Mathematical Physics, Volume 20 (March, 2012), pp 461 – 46

Towards Securing the Home Computer: a modification of the USB Port

Hundreds of millions of people use the home computer everyday for different purposes. These systems use the universal serial bus (USB) disk for day to day transfer of data, communication and other applications. The USB as a flexible tool for data transfer raises security concerns relatively to a potential loss of assets. This paper therefore demonstrates how a modification of the USB port can improve the security of the home computer.Keywords: home computer, operating system, threats, Universal Serial Bus (USB)

Detecting and targeting senescent cells using molecularly imprinted nanoparticles

The progressive accumulation of senescent cells in tissues in response to damage importantly contributes to pathophysiological conditions such as fibrosis, diabetes, cancer, Alzheimer's and ageing. Consistent with this, eliminating senescent cells prolongs the lifespan and healthspan in animals and ameliorates certain diseases. Detecting and clearing senescent cells from human tissues could therefore have a significant diagnostic and prognostic impact. However, identifying senescent cells in vivo has proven to be complex. To address this, we characterized and validated a panel of novel membrane markers of senescence. Here, we show the application of molecularly imprinted nanoparticles (nanoMIPs) against an extracellular epitope of one of these markers, B2M, to detect senescent cells in vitro and in vivo. We show that nanoMIPs do not elicit toxic responses in the cells or in mice and successfully recognize old animals, which have a higher proportion of senescent cells in their organs. Importantly, nanoMIPs loaded with drugs can specifically kill senescent cells. Our results provide a proof-of-principle assessment of specific and safe nanotechnology-based approaches for senescent cell detection and clearance with potential clinical relevance