We propose and analyze in detail a method to measure the in-air spatial spread parameter of clinical electron beams. Measurements are performed at the center of the beam and below the adjustable collimators sited in asymmetrical configuration in order to avoid distortions due to the presence of the applicator. The main advantage of our procedure lies in the fact that the dose profiles are fitte...

Spatial structure and hence the spatial position of host populations plays a vital role in the spread of infection. In the majority of situations, it is only possible to predict the spatial spread of infection using simulation models, which can be computationally demanding especially for large population sizes. Here we develop an approximation method that vastly reduces this computational burde...

Spatial quality and spectral quality are the two important indexes that are used to evaluate the quality of any fused image. Most of the existing methods for this purpose, however, considered only the spectral quality except for that proposed by Zhou et al., while the latter cannot be used to compare directly the spatial resolution between the fused image and original high-resolution. A new spa...

The motor neuron disease amyotrophic lateral sclerosis (ALS) typically begins with localized muscle weakness. Progressive, widespread paralysis often follows over a few years. Does the disease begin with local changes in a small piece of neural tissue and then spread? Or does neural decay happen independently across diverse spatial locations? The distinction matters, because local initiation ma...

There are many concerns about the spread and establishment of exotic mosquito species in Europe, some of which are highly competent to transmit pathogens. The fast spread of some invasive mosquito species, e.g. the Asian bush mosquito, might be explained by a combination of natural dispersal and human transport. Therefore, the aim of this study was the development of a software tool that is cap...

The temporal and spatial distributions of the 2003 severe acute respiratory syndrome (SARS) outbreak in Amoy Gardens of Hong Kong was reexamined using all confirmed cases. The outbreak actually extended to nearby residential complexes. Airborne spread was the most likely explanation, and the SARS coronavirus could have spread over a distance of 200 m.

Vorticity-driven lateral fire spread (VLS) is a form of dynamic fire behaviour, during which a wildland fire spreads rapidly across a steep leeward slope in a direction approximately transverse to the background winds. VLS is often accompanied by a downwind extension of the active flaming region and intense pyro-convection. In this study, the WRF-Fire (WRF stands for Weather Research and Foreca...

The motor neuron disease amyotrophic lateral sclerosis (ALS) typically begins with localized muscle weakness. Progressive, widespread paralysis often follows over a few years. Does the disease begin with local changes in a small piece of neural tissue and then spread? Or does neural decay happen independently across diverse spatial locations? The distinction matters, because local initiation ma...

Based on an interferometric spatial autocorrelation of two shifted point-spread functions combined with confocal detection, we demonstrate that the point-spread autocorrelation function technique provides improved axial resolution compared with conventional confocal imaging. The principle of the technique is demonstrated for a one-sided f luorescing step object.