BACKGROUND Biomarkers based on the underlying pathology of Alzheimer's disease (AD) and Dementia with Lewy Bodies (DLB) have the potential to improve diagnosis and understanding of the substrate for cognitive impairment in these disorders. The objective of this study was to compare the patterns of amyloid and dopamine PET imaging in patients with AD, DLB and Parkinson's disease (PD) using the a...

Identifying the steady states of a population is a key issue in theoretical ecology, that includes the study of spatially heterogeneous populations. There are several examples of real ecosystems in patchy environments where the habitats are heterogeneous in their local density dependence. We investigate a multi-patch model of a single species with spatial dispersal, where the growth of the loca...

Three intervals of polar patch formation, as observed by the CUTLASS Finland HF coherent radar, are presented. Simultaneous observations from a vertical ionosonde located at Longyearbyen on Svalbard, situated in the dayside convection throat region, allow for F-region plasma structuring, leading to polar cap patch formation to be determined. Solar wind and interplanetary magnetic field (IMF) pr...

The Teakettle Ecosystem Experiment in the southern Sierra Nevada is using thinning and prescribed fire to recreate historical stand conditions. As part of Teakettle we assessed pretreatment diversity and density of the soil arthropod community in 1998 and 2000. We determined the density and diversity of soil microarthropods among treatment plots, the influence of patch type (closed canopy, cano...

Functional response describes the number of prey or hosts attacked by a predator or parasitoid as a function of prey or host density. Using three different experimental designs, we found a linear functional response by two insect parasitoids (the pteromalid Pachycrepoideus vindemiae and the diapriid Trichopria drosophilae) to their hosts (the drosophilids Drosophila suzukii and D. melanogaster)...

which is valid for any arbitrary volume, so the integrand is zero and we recover a classical continuity equation similar to that derived for mass conservation in hydrodynamics. (1) is the equivalent to a Lagrangian conservation of bird density with dρ/dt = 0, hence, a flock of birds traveling at speed U with an initial density ρn−1 = ρ(xn−1 + ǫ, tn−1) at the interface of patch Pn−1 at time tn−1...

A new path-density diagnostic for atmospheric surface-to-surface transport is formulated. The path density h gives the joint probability that air whose last surface contact occurred on patch Vi at time ti will make its next surface contact with patch Vf after a residence time t 2 (t, t 1 dt) and that it can be found in dr during its surface-to-surface journey. The dependence on t allows the ave...

We compute the equilibrium phase diagram of two simple models for patchy particles with three and five patches in a very broad range of pressure and temperature. The phase diagram presents low-density crystal structures which compete with the fluid phase. The phase diagram of the five-patch model shows re-entrant melting, in analogy with the previously studied four-patch case, a metastable gas-...

The evolution of forest landscape patterns can reveal the stability dynamics undergoing complex ecological processes. Analysis in regions under restoration evaluate impact large-scale afforestation on habitat quality and provide a scientific basis for achieving sustainable eco-environment development. In this study, method assessing by characterizing changes was proposed. Toeplitz inverse covar...

We examine the assumptions that the fovea contains equal numbers of inner (invaginating or ON) and outer (flat or OFF) midget bipolar cells and equal numbers of inner and outer diffuse bipolar cells. Based on reconstruction from electron photomicrographs of serial thin sections through the fovea of a macaque monkey, we reject both assumptions. First, every foveal L and M cone is presynaptic to ...