Keypoint Detection and Local Feature Matching for Textured 3D Face Recognition

In this study we concentrate on qualitative topological analysis of the local behavior of the space of natural images. To this end, we use a space of 3 by 3 high-contrast patches ℳ. We develop a theoretical model for the high-density 2-dimensional submanifold of ℳ showing that it has the topology of the Klein bottle. Using our topological software package PLEX we experimentally verify our theoretical conclusions. We use polynomial representation to give coordinatization to various subspaces of ℳ. We find the best-fitting embedding of the Klein bottle into the ambient space of ℳ. Our results are currently being used in developing a compression algorithm based on a Klein bottle dictionary.     

Innovative Food Procurement Strategies of Women Living in Khayelitsha,Cape Town

The combination of persistent levels of inequality and poverty, alongside the advent of rapid urbanisation, mean urban food insecurity is set to be one of the biggest development challenges of this century. As women play a crucial role in the food security status of urban poor households, understanding and supporting the life-sustaining food procurement practices used by women ought to be a key strategy in addressing urban food insecurity. Particularly, the paper draws on primary qualitative research I conducted with women from Khayelitsha, Cape Town’s largest informal settlement. This case study explored the beliefs, practices and preferences that govern women’s food procurement choices. The study found that women adopt a range of innovative food procurement strategies, which significantly improve household food security prospects. These include buying in bulk, skilfully navigating the informal and the formal food economies, utilising their social networks and trading off food with other important non-food expenses. Understanding these practices can provide greater insight into how best to enhance urban food security. The implications are that women need to be better supported rather than, as most mainstream programmes suggest, encouraged to take on more work outside the household, whilst still faced with the lion’s share of housework.     

Nanoparticle Transport in Epithelial Cells: Pathway Switching Through Bioconjugation

The understanding and control of nanoparticle transport into and through cellular compartments is central to biomedical applications of nanotechnology. Here, it is shown that the transport pathway of 50 nm polystyrene nanoparticles decorated with vitamin B₁₂ in epithelial cells is different compared to both soluble B₁₂ ligand and unmodified nanoparticles, and this is not attributable to B₁₂ recognition alone. Importantly, the study indicates that vitamin B₁₂‐conjugated nanoparticles circumnavigate the lysosomal compartment, the destination of soluble vitamin B₁₂ ligand. Whereas cellular trafficking of soluble B₁₂ is confirmed to occur via the clathrin‐mediated pathway, transport of B₁₂‐conjugated nanoparticles appears to predominantly take place by a route that is perturbed by caveolae‐specific inhibitors. This data suggests that, following its conjugation to nanoparticles, in addition to dramatically increasing the cellular uptake of nanoparticles, the normal cell trafficking of B₁₂ is switched to an alternative pathway, omitting the lysosomal stage: a result with important implications for oral delivery of nanoparticulate diagnostics and therapeutics.     

Single and biphoton imaging and high dimensional quantum communication

Here, we present recent developments in the field of quantum imaging focusing on the high dimensionality aspects of single and biphoton imaging. We discuss some systems that have a ??quantum advantage?? over classical counterparts. We highlight some recent experiments in single-photon image discrimination, large alphabet quantum key distribution and image buffering.     

Conjugate gradient eigenstructure tracking for adaptive spectralestimation

A conjugate gradient iteration is derived that converges to the set of r dominant/subdominant eigenpairs. This iteration is used to construct two eigenstructure tracking algorithms that track the r-dimensional dominant or subdominant subspaces of time-varying data or data-covariance matrices. The two eigenstructure tracking algorithms have update complexities O(m²r) and the other O(mr²), where m is the data dimension. The algorithms are customized to solve high resolution temporal and spatial frequency tracking problems. They are compared with existing techniques by tying into published simulation based performance tests. The algorithms demonstrate rapid convergence and tracking characteristics at a competitive cost     

Greater than the sum of its parts [outsourced manufacturing]

In the world of electronics manufacturing, numerous complex supply chains encompassing product specifiers and designers, manufacturers, material suppliers, transporters, packagers, and distributors are evident. Each link in the supply chain has its own cost base with a desire to keep costs down while increasing profit. To help companies calculate the best manufacturing strategy tailored to their needs, Flextronics has developed a global supply chain analysis tool called Simplex. This tool provides a complete cost analysis of the total supply chains, including the best source for raw material, turnaround time, logistics cost, cost of capital, and inventory.     

Response of Male Domestic Rabbits (Oryctolagus cuniculus) to Inguinal Gland Secretion from Intact and Ovariectomized Females

European rabbits (Oryctolagus cuniculus) of both sexes possess a variety of skin glands important in chemical communication. These include sizable inguinal glands, the strong-smelling secretion from which accumulates in conspicuous pouches of skin on either side of the genital opening. To test the hypothesis that this secretion advertises sexual receptivity in females, inguinal gland secretions from nine intact and six ovariectomized females were presented on dummy rabbits or in a simultaneous choice paradigm, and the responses of nine stud males to these secretions were recorded. Although the males clearly perceived the stimuli, no differences in responses to secretions from the intact and ovariectomized does were observed, and no differences were found in the size, weight, or secretory activity of the does' glands. It is concluded that inguinal gland secretion plays little role in communicating sexual receptivity in female rabbits and that ovarian steroids play little part in regulating inguinal gland activity.