In the Shadow of the Transiting Disk: Imaging epsilon Aurigae in Eclipse

Eclipses of the single-line spectroscopic binary star, epsilon Aurigae, provide an opportunity to study the poorly-defined companion. We used the MIRC beam combiner on the CHARA array to create interferometric images during eclipse ingress. Our results demonstrate that the eclipsing body is a dark disk that is opaque and tilted, and therefore exclude alternative models for the system. These data constrain the geometry and masses of the components, providing evidence that the F-star is not a massive supergiant star.Comment: As submitted to Nature. Published in Nature April 8, 2010

Risk and protective factors for structural brain ageing in the eighth decade of life

Individuals differ markedly in brain structure, and in how this structure degenerates during ageing. In a large sample of human participants (baseline n = 731 at age 73 years; follow-up n = 488 at age 76 years), we estimated the magnitude of mean change and variability in changes in MRI measures of brain macrostructure (grey matter, white matter, and white matter hyperintensity volumes) and microstructure (fractional anisotropy and mean diffusivity from diffusion tensor MRI). All indices showed significant average change with age, with considerable heterogeneity in those changes. We then tested eleven socioeconomic, physical, health, cognitive, allostatic (inflammatory and metabolic), and genetic variables for their value in predicting these differences in changes. Many of these variables were significantly correlated with baseline brain structure, but few could account for significant portions of the heterogeneity in subsequent brain change. Physical fitness was an exception, being correlated both with brain level and changes. The results suggest that only a subset of correlates of brain structure are also predictive of differences in brain ageing

Honeycomb-like appearance in the brain of a former boxer with hyperhomocysteinemia, severe carotid disease and hemorrhagic stroke

Dear editor, Brain perivascular spaces (PVSs) or Virchow-Robin spaces are pial-lined, interstitial fluid-filled structures surrounding the arteries entering brain parenchyma.1 Enlarged PVSs are radiological manifestation of posttraumatic encephalopathy2 and a common biomarker of small vessel disease (SVD).3 Exuberant forms of PVSs are rarely reported. A 55-year-old male truck driver, retired professional boxer with a history of severe untreated hypertension, obesity, brainstem lacunar stroke, dyslipidemia, heavy smoking, right sided severe internal carotid stenosis (SICS) (90–99%) and hyperhomocysteinemia was brought to the emergency room because of sudden onset of right hemiparesis followed by focal complex hemiconvulsio