We propose a mean-field method to calculate approximately the spacing distribution functions p((n))(s) in one-dimensional classical many-particle systems. We compare our method with two other commonly used methods, the independent interval approximation and the extended Wigner surmise. In our mean-field approach, p((n))(s) is calculated from a set of Langevin equations, which are decoupled by u...

OBJECTIVES This paper examines the effect of household crowding on inter-pregnancy spacing and its association with socioeconomic indicators, among parous mothers delivered in an urban environment. DESIGN Cross sectional survey. METHODS Sociodemographic data were obtained on 2466 parous women delivering at eight hospitals in Greater Beirut over a one year period. Statistical methodology com...

We establish a numerically explicit version of the Pólya–Vinogradov inequality for the sum of values of a Dirichlet character on an interval. While the technique of proof is essentially that of Landau from 1918, the result we obtain has better constants than in other numerically explicit versions that have been found more recently. – Dedicated to Mel Nathanson on his 65th birthday

A finite subset A of an abelian group G is said to be zero-free if the identity element of G cannot be written as a sum of distinct elements from A. In this article we study the structure of zero-free subsets of Z/pZ, the cardinalities of which are close to the largest possible. In particular, we determine the cardinality of the largest zero-free subset of Z/pZ, when p is a sufficiently large p...

in order to evaluate the intercropping of corn (zea mays l.) and bean cultivars (phaseolus spp.) an experiment was carried out in a randomized complete block design with three replicaties at sari agricultural sciences and natural resources university during growing season of 2010. the experimental treatments consisted of sole cropping of corn, white bean, bush bean, red bean, pinto bean and swo...

This is Part II of the two-part feature on Paul Erdős following his centennial. Part I had contributions from Krishnaswami Alladi and Steven G. Krantz, Vera T. Sós and László Lovász, Ronald Graham and Joel Spencer, Jean-Pierre Kahane, and Mel Nathanson. Here in Part II we have six articles from contributors Noga Alon, Dan Goldston, András Sárközy, József Szabados, Gérald Tenenbaum, and Stephan ...

We introduce a method for extracting information about human hands present in colour images largely based on work done by Daniel Heckenberg and Brian Lovell. It relies heavily on isolating the hand in the image using a statistical model of skin colour. Following this, it employs solely imagebased techniques to determine the locations of the fingers, and performs a simplistic gesture recognition...

This study was initiated owing to concern that removal of the invasive ground cover, Tradescantia fluminensis, might adversely effect the rare, giant predatory land snail, Powelliphanta traversi. Of 18 sites surveyed in the Horowhenua District, seven sites provide habitat for P. traversi and do not contain Tradescantia. Five colonies of P. traversi are affected by Tradescantia, these are: Waiop...

1 Bush A, Hedlin G, Carlsen KH, et al. Severe childhood asthma: a common international approach? Lancet 2008; 372: 1019–1021. 2 Hedlin G, Bush A, Lødrup Carlsen K, et al. Problematic severe asthma in children, not one problem but many: a GALEN initiative. Eur Respir J 2010; 36: 196–201. 3 Lang AM, Konradsen J, Carlsen KH, et al. Identifying problematic severe asthma in the individual child – do...