Despite continuing research efforts, knowledge of the transmission of the highly pathogenic avian influenza (HPAI) virus still has considerable gaps, which complicates epidemic control. The goal of this research was to develop a model to back-calculate the day HPAI virus is introduced into a flock, based on within-flock mortality data. The back-calculation method was based on a stochastic SEIR ...

Chimney swifts (Chaetura pelagica) are highly manoeuvrable birds notable for roosting overnight in chimneys, in groups of hundreds or thousands of birds, before and during their autumn migration. At dusk, birds gather in large numbers from surrounding areas near a roost site. The whole flock then employs an orderly, but dynamic, circling approach pattern before rapidly entering a small aperture...

Campylobacter isolates from diverse samples within broiler production and processing environments were typed by using flaA short variable region DNA sequence analysis. Sixteen flocks from four different farms representing two broiler producers in Arkansas and California were analyzed. Fourteen of the flocks (87.5%) were Campylobacter-positive; two remained negative throughout the 6-week rearing...

ABSTRACT: This study has demonstrated a design tool for turbulent flow detection in Flock 1 data using Multi-Objective Evolutionary Algorithm which based on Pareto optimal solutions. The Flock 1 data along the Suez Canal, Egypt and Farasan Islands, Saudi Arabia are involved in this study. The study also shows that Multi-Objective Evolutionary Algorithm provides an accurate pattern of turbulent ...

Each individual bird in a flock of birds updates its behavior based on the behaviors of its neighbors. Previous work has considered how a small set of algorithmically controlled influencing agents, or robot birds, can influence the flock to behave in a particular way — such as to avoid airports or wind farms. These robot birds are assumed to be seen by the flock as ordinary birds, and hence are...

In many sheep production operations in the Midwestern and Eastern U.S., lambs are managed for maximum body weight gain and fed high-energy diets continuously from shortly after birth until they are marketed as slaughter lambs. Flock owners will replace 20 to 25% of the ewes in their flock each year with ewe lambs raised in their flock or purchased from other producers. Since all lambs in a floc...

Amplified fragment length polymorphisms (AFLPs) were used to characterize the genotypic diversity of a total of 114 Gallibacterium anatis isolates originating from a reference collection representing 15 biovars from four countries and isolates obtained from tracheal and cloacal swab samples of chickens from an organic, egg-producing flock and a layer parent flock. A subset of strains was also c...

Genetic control programs for scrapie in sheep build on solid knowledge of how susceptibility to scrapie is modulated by the prion protein genotype at the level of an individual sheep. In order to satisfactorily analyze the effectivity of control programs at the population level, insight is needed at the flock level, i.e., how the grouping of sheep in flocks affects the population-level transmis...

Let K be a quadratic cone of PG(3, q) with vertex v. A flock F of K is a partition of K"[v] into q conics. If all planes containing the elements of the flock F share a common line, then F is called linear. Given a flock F there is a standard construction of a generalized quadrangle Q(F) associated with F ([19]), which is classical if and only if F is a linear flock. Article ID jcta.1998.2933, a...