Abstract. We study the linear stability of flock and mill ring solutions of two individual based models for biological swarming. The individuals interact via a nonlocal interaction potential that is repulsive in the short range and attractive in the long range. We relate the instability of the flock rings with the instability of the ring solution of the first order model. We observe that repuls...

Two flocks of ewes were used as sources of embryos for embryo transfer programs: a Merino flock comprising 3 lines differentially selected on weaning weight and a Coopworth flock consisting of three lines differentially selected for backfat thickness. Effects of embryo genotype, year of transfer, sire and number of embryos transferred on embryo survival were examined. No significant line or sir...

It is known, via algebraic methods, that a flock of a quadratic cone in PGð3; qÞ gives rise to a family of qþ 1 ovals of PGð2; qÞ and similarly that a flock of a cone over a translation oval that is not a conic gives rise to an oval of PGð2; qÞ. In this paper we give a geometrical construction of these ovals and provide an elementary geometrical proof of the construction. Further we also give a...

Sheep production is present on all continents and has been practiced in Brazil since the colonization. In this study, the multitemporal dynamics of sheep production in Brazil is examined using official government data (Brazilian Institute for Geography and Statistics-IBGE) from 1976 to 2010. Maps of flock growth rates and growth acceleration maps by municipality were elaborated. The Southern st...

Avian song learning is an important model system for understanding vocal learning in humans and other animals. Laboratory studies indicate that social interactions are critical for song learning, but field observations show that territorial males are aggressive to intruders, raising the question of whether young birds are tolerated, much less tutored in the wild. We examined how adult song spar...

We describe a basic Geo-coding service encompassing a geo-parsing tool and integrated digital gazetteer service. The development of a geo-parser comes from the need to explicitly georeference large resource collections such as the Statistical Accounts of Scotland which currently only contain implicit georeferences in the form of placennames thus making such collections inherently geographically...

The wide deployment of location detection devices (for example, smartphones) leads to collecting of large datasets in the form of trajectories. There are a whole set of papers devoted to trajectory-based queries. Mostly, they are concentrated on similarity queries. In the same time, there is a constantly groving interest in getting various forms for aggregating behavior of trajectories as group...

Campylobacter successfully colonizes broiler chickens, but little is known about the longer term natural history of colonization, since most flocks are slaughtered at an immature age. In this study, the prevalence and genetic diversity of Campylobacter colonizing a single free-range broiler breeder flock was investigated over the course of a year. The age of the flock was the most important fac...

Flocking behavior is very common in nature, and there have been ongoing research efforts to simulate such behavior in computer animations and robotics applications. Generally, such work considers behaviors that can be determined independently by each flock member solely by observing its local environment, e.g., the speed and direction of its neighboring flock members. Since flock members are no...

The association of fleece characters with susceptibility to dermatophilosis was studied in two flocks located on the south coast of Western Australia. The characters examined were wax content, suint content, wax to suint ratio, suint pH, yield, fleece wettability, fibre diameter, coefficient of fibre diameter variation, suint direct extract, direct extract pH and electrical conductivity. The re...