BACKGROUND Outdoor production of poultry is rapidly increasing, which could be associated with increased risks for exposure to different environmental sources of Salmonella. We report a comparison on the occurrence of Salmonella during 2007-2015 in broilers and laying hens in outdoor and indoor production subjected to the same requirements for the prevention and control of Salmonella as applied...

In this note, we consider the critical function of the selection from an entire visual scene of visual locations or objects for detailed or attentive processing. Such selection of some places at the expense of others is necessary because attention has only a meagre capacity (estimated at just 40 bits/second; Sziklai 1956). The same bottleneck implies that the selection process itself cannot gen...

ion methods, handpumps for example, where operation costs are minimal. For this reason gravity flow water systems are included in this category even though they may develop into networks delivering to houses. Some urban areas, particularly secondary towns and peri-urban areas, also access water through point sources and therefore require a similar approach to cost recovery. In larger urban area...

For a family of geometric objects in the plane F = {S1, . . . , Sn}, define χ(F) as the least integer l such that the elements of F can be colored with l colors, in such a way that any two intersecting objects have distinct colors. When F is a set of Jordan regions that may only intersect on their boundaries, and such that any point of the plane is contained in at most k regions, it can be prov...

We developed a model of pathogen dissemination in the outpatient clinic that incorporates key kinetic aspects of the transmission process, as well as uncertainty regarding whether or not each incident patient is contagious. Assigning appointments late in the day to patients suspected of being infectious should decrease pathogen dissemination.

We examine the behaviour of the zeros of the real and imaginary parts of ξ(s) on the vertical line Rs = 1/2 + λ, for λ 6= 0. This can be rephrased in terms of studying the zeros of families of entire functions A(s) = 1 2 (ξ(s+λ)+ξ(s−λ)) and B(s) = 1 2i (ξ(s+λ)−ξ(s−λ)). We will prove some unconditional analogues of results appearing in [3], specifically that the normalized spacings of the zeros ...

A boundary sequence is a good representation of arbitrary shaped regions, but not directly used in computing shape features such as area, centroid, orientation, and so forth. In this paper, we show that the shape features can be easily computed by using cross-sections derived from a boundary sequence. The cross-sections are vertical line segments in the region and can be determined by tracing t...

Previous experimental research has shown that thin financial markets fail to fully equilibrate, in contrast with thick markets. A specific type of market risk is conjectured to be the reason, namely, the risk of partial execution of desired portfolio rearrangements in a system of parallel, unconnected double auction markets. This market risk causes liquidity to dry up before equilibrium is reac...