The understanding of spin dynamics and relaxation mechanisms in clean graphene, and the upper time and length scales on which spin devices can operate, are prerequisites to realizing graphene-based spintronic technologies. Here we theoretically reveal the nature of fundamental spin relaxation mechanisms in clean graphene on different substrates with Rashba spin-orbit fields as low as a few tens...

Generalist pollinators are important in many habitats, but little research has been done on small-scale spatial variation in interactions between them and the plants that they visit. Here, using a spatially explicit approach, we examined whether multiple species of flowering plants occurring within a single meadow showed spatial structure in their generalist pollinator assemblages. We report th...

Aging affects all levels of neural processing including changes of intracortical inhibition and cortical excitability. The paired-pulse stimulation protocol, the application of 2 stimuli in close succession, is used to investigate cortical excitability. The paired-pulse behavior is characterized by the fact that the second response is significantly suppressed at short interstimulus intervals (I...

We describe direct imaging measurements of the collective and relative diffusion of two colloidal spheres near a flat plate. The bounding surface modifies the spheres' dynamics, even at separations of tens of radii. This behavior is captured by a stokeslet analysis of fluid flow driven by the spheres' and wall's no-slip boundary conditions. In particular, this analysis reveals surprising asymme...

Fine temporal patterns of firing in much of the brain are highly irregular. In some circuits, the precise pattern of irregularity contains information beyond that contained in mean firing rates. However, the capacity of neural circuits to use this additional information for computational purposes is not well understood. Here we employ computational methods to show that an ensemble of neurons fi...

years, like Lake Vostok, underneath the eponymous Russian research station at 77 degrees South. One of the largest lakes on our planet, Lake Vostok is comparable in volume to Lake Ontario. Back in 1998, a research team drilled around three kilometres deep into the ice shield stopping only a few hundred metres above the lake surface. The lower parts of the ice core, believed to consist of frozen...

At the wall in a hybrid nematic cell with strong anchoring, the nematic director is parallel to one wall and perpendicular to the other. Within the Landau-de Gennes theory, we have investigated the dynamics of s = ±1/2 wedge disclinations in such a cell, using the two-dimensional finite-difference iterative method. Our results show that with the cell gap decreasing, the core of the defect explo...

Over the last century, reindeer herding has provided a major economic base in Eskimo villages on the Seward Peninsula, Alaska, and has come to represent an important dimension of Native cultural identity. As a result of the current population explosion of caribou from the Western Arctic Caribou Herd, along with a shift in the herd's migratory patterns, reindeer ranges that were free of caribou ...

We study a sample of bright long BATSE GRB light curves in the 200 s before the detection of the GRB prompt emission. We find that in a sizable fraction of cases (∼ 20%) there is evidence of emission above the background coming from the same direction of the GRB. This emission is characterised by a softer spectrum with respect to the main one and contains a small fraction (0.1 − 1%) of the tota...