Improved AURA k-Nearest Neighbour approach

The k-Nearest Neighbour (kNN) approach is a widely-used technique for pattern classification. Ranked distance measurements to a known sample set determine the classification of unknown samples. Though effective, kNN, like most classification methods does not scale well with increased sample size. This is due to their being a relationship between the unknown query and every other sample in the data space. In order to make this operation scalable, we apply AURA to the kNN problem. AURA is a highly-scalable associative-memory based binary neural-network intended for high-speed approximate search and match operations on large unstructured datasets. Previous work has seen AURA methods applied to this problem as a scalable, but approximate kNN classifier. This paper continues this work by using AURA in conjunction with kernel-based input vectors, in order to create a fast scalable kNN classifier, whilst improving recall accuracy to levels similar to standard kNN implementations

Density fluctuations and the structure of a nonuniform hard sphere fluid

We derive an exact equation for density changes induced by a general external field that corrects the hydrostatic approximation where the local value of the field is adsorbed into a modified chemical potential. Using linear response theory to relate density changes self-consistently in different regions of space, we arrive at an integral equation for a hard sphere fluid that is exact in the limit of a slowly varying field or at low density and reduces to the accurate Percus-Yevick equation for a hard core field. This and related equations give accurate results for a wide variety of fields

A study of Public Relations and the Yankee Atomic Electric Company

Thesis (M.S.)--Boston Universit

Two-Particle Microrheology of quasi-2D Viscous Systems

We study the correlated motions of colloidal particles in a quasi-2D system (Human Serum Albumin (HSA) protein molecules at an air-water interface) for different surface viscosities $\eta_{s}$. We observe a transition in the behavior of the correlated motion, from 2-D interface dominated at high $\eta_{s}$ to bulk fluid-dependent at low $\eta_{s}$. The correlated motions can be scaled onto a master curve which captures the features of this transition. This master curve also characterizes the spatial dependence of the flow field of a viscous interface in response to a force. From the flow field and the correlated particle motions, we calculate a two-particle MSD (mean square displacement) for direct comparison with rheological measurements.Comment: 4 pages, 4 figures, submitted to PR

Divine Competition: Religious Organisations and Service Provision in India

This paper examines religious and non-religious service provision by religious organisations in India. We present a stylized Hotelling-style model in which two religious organisations differentiate hemselves on the strength of religious beliefs in order to compete in attracting adherents. We show in the model two central predictions: first,that the organisations will differentiate themselves on the strength of religious beliefs. Second, that in equilibrium, economic inequality makes the organisations increase their provision of non-religious services. To test this, we present unique primary survey dataon the economics of religion, collected by us between 2006 and 2010 from 568 Hindu, Muslim, Christian, Sikh and Jain religious organisations spread across 7 Indian states. We use these data to demonstrate that the organisations have substantially increasedtheir provision of non-religious services. We also provide quantitative evidence based oneconometric testing to highlight that religious organisations are differenting themselves on the strength of religious beliefs with respect to other organisations, and are also providing higher education and health services as economic inequality increases in India

More to cohesin than meets the eye: complex diversity for fine-tuning of function

Recent years have witnessed a dramatic expansion in our understanding of gene control. It is now widely appreciated that the spatial organization of the genome and the manner in which genes and regulatory elements are embedded therein has a critical role in facilitating the regulation of gene expression. The loop structures that underlie chromosome organization are anchored by cohesin complexes. Several components of the cohesin complex have multiple paralogs, leading to different levels of cohesin complex variants in cells. Here we review the current literature around cohesin variants and their known functions. We further discuss how variation in cohesin complex composition can result in functional differences that can impact genome organization and determine cell fate

Satellite-observed vegetation as an indicator of climate variability over southern Africa

The satellite-derived normalised difference vegetation index (NDVI) offers new opportunities to assess the impact of year-to-year climate fluctuations. In this study the NDVI is mapped over southern Africa for the period 1981-1994. Sharp upward and downward trends follow the cycle of summer flood and drought. January to March NDVI values are correlated at +0.82 with harvested maize yield for the North West Province of central South Africa. Departures of late summer NDVI from the historical mean illustrates the distribution and intensity of the influence of the Southern Oscillation, in alternating seasons of vegetative growth and depletion. The first principal component of the NDVI field time series contains a broad signal covering all of Africa south of 15 degrees S, and appears related to the low frequency component of the global El Nino phenomenon