We calculate the expected white dwarf luminosity functions and discovery functions in photometric passbands, if these stellar remnants provide a substantial fraction of the sought Galactic dark matter, as suggested on various observational grounds. We demonstrate the extremely rapid variation of the photometic signature of halo white dwarfs with time and thus the powerful diagnostic of white dw...

White matter (WM) tracts are bundles of myelinated axons that provide for rapid communication throughout the CNS and integration in grey matter (GM). The main cells in myelinated tracts are oligodendrocytes and astrocytes, with small populations of microglia and oligodendrocyte precursor cells. The prominence of neurotransmitter signaling in WM, which largely exclude neuronal cell bodies, indic...

Diffusion tensor imaging (DTI) provides information about cerebral white matter integrity in vivo, and fractional anisotropy (FA) is a commonly used index to describe the anisotropy of diffusion. Past studies have reported microstructural white matter abnormalities in widespread prefrontal regions in late-life depression [1, 2] and found prefrontal white matter alterations to be associated with...

BACKGROUND Fragile-X syndrome (FXS) is a neurodevelopmental disorder associated with intellectual disability and neurobiological abnormalities including white matter microstructural differences. White matter differences have been found relative to neurotypical individuals. AIMS To examine whether FXS white matter differences are related specifically to FXS or more generally to the presence of...

We lack a mechanistic explanation for the stereotyped pattern of white matter loss seen in Huntington's disease (HD). While the earliest white matter changes are seen around the striatum, within the corpus callosum, and in the posterior white matter tracts, the order in which these changes occur and why these white matter connections are specifically vulnerable is unclear. Here, we use diffusio...

Based on the identification of 38 white dwarfs with halo kinematics, in a survey covering 10% of the sky near the south galactic pole, Oppenheimer et al. (1) argued that at least 2% of the dark matter in the Milky Way galaxy has now been detected directly. Put into context, the Oppenheimer et al. result implies that the stellar remnant mass of the halo may be comparable to that of the entire di...

Case-control studies showed that migraine is associated with ischemic stroke. Studies assessing the prevalence of white matter lesions (WML) in migraine however, reported conflicting results, possibly attributable to selection bias by recruiting only severe cases. We conducted a population-based MRI study of migraineurs with aura (N=161), migraineurs without aura (N=134) and controls (N=140), 3...

Diffusion tensor imaging (DTI) has become a powerful tool for analyzing the structure of white matter. We have proposed a method for detecting nerve fiber bundles in white matter using diffusion tensor images and have applied the method to in vivo brain measurements. Although there are many methods to investigate the connectivity of white matter that are based on principal eigenvector or full t...

The CNS white matter makes up about half of the human brain, and with advances in human imaging it is increasingly becoming clear that changes in the white matter play a major role in shaping human behavior and learning. However, the mechanisms underlying these white matter changes remain poorly understood. Within this special issue of Neuroscience on white matter, recent advances in our knowle...

Depressive symptoms, even at a subclinical level, have been associated with structural brain abnormalities. However, previous studies have used regions of interest or small sample sizes, limiting the ability to generalize the results. In this study, we examined neuroanatomical structures of both gray matter and white matter associated with depressive symptoms across the whole brain in a large s...