This paper presents spatio-temporal measurements for the peer-to-peer radio channel at a center frequency of 1920 MHz with 140 MHz of radio-frequency bandwidth. The measurements were taken using a spread-spectrum channel sounder and an automated spatial probing system that uses precise computer-controlled positioning and orientation of omnidirectional and directional (30 beamwidth) antennas to ...

1. The success of locally applied treatments for exotic weed control depends on the effectiveness of the method used and workers’ abilities to find plants within infested sites. Detectability of exotic plants, however, depends on aspects of a plant’s spatial distribution such as the number and size of patches. We lack an explicit examination of how incomplete detection affects the spread of exo...

To activate clot formation and maintain hemostasis, platelets adhere and spread onto sites of vascular injury. Although this process is well-characterized biochemically, how the physical and spatial cues in the microenvironment affect platelet adhesion and spreading remain unclear. In this study, we applied deep UV photolithography and protein micro/nanostamping to quantitatively investigate an...

According to perdurantism, objects persist by being spread out over time just as composite three-dimensional objects are spread out over space. Just as a composite threedimensional object is spread out over space by having spatial parts, objects persist, according to perdurantism, by having temporal parts. Perdurantism can be stated more precisely by saying what exactly a temporal part is. In t...

Biological invasions are governed by spatial processes that tend to be distributed in non-random ways across landscapes. Characterizing the spatial and temporal heterogeneities of the introduction, establishment, and spread of non-native insect species is a key aspect of effectively managing their geographic expansion. The Asian citrus psyllid (Diaphorina citri), a vector of the bacterium assoc...

Spatial structure and local migration are predicted to promote the evolution of less aggressive host exploitation strategies in horizontally transmitted pathogens. Here we explore the effect of spatial structure on the evolution of pathogens that can use both horizontal and vertical routes of transmission. First, we analyse theoretically how vertical transmission can alter evolutionary trajecto...

PURPOSE In the studies of spatial integration an increase in the spatial extent of the stimulus usually results in a decrease in the spatial frequency bandwidth of the stimulus. The authors investigated separately the effects of these two factors on contrast detectability. METHODS Efficiencies were measured for a circular grating at 4 c/deg and for bandpass-filtered point stimuli having a con...

Research questions regarding temporal change in spatial patterns are increasingly common in geographical analysis. In this research, we explore and extend an approach to the spatial–temporal analysis of polygons that are spatially distinct and experience discrete changes though time. We present five new movement events for describing spatial processes: displacement, convergence, divergence, fra...

Sudden Oak Death is a new and virulent disease affecting hardwood forests in coastal California. The spatial–temporal dynamics of oak mortality at the landscape scale are crucial indicators of disease progression. Modeling disease spread requires accurate mapping of the dynamic pattern of oak mortality in time through multi-temporal image analysis. Traditional mapping approaches using per-pixel...