The ratio of shear viscosity to entropy density η/s of any material in nature has been conjectured to have a lower bound of 1/4π, the famous KSS bound. We examine string theory models for evidence in favour of and against this conjecture. We show that in a broad class of models quantum corrections yield values of η/s just above the KSS bound. However, incorporating matter fields in the fundamen...

about the clinical presentation and central nervous system (CNS) imaging in 19 patients with Kearns-Sayre syndrome (KSS), of whom 12 were genetically confirmed. We have the following comments and concerns. The main disadvantage of the study was that the diagnosis was not genetically confirmed in all patients and mitochondrial DNA (mtDNA) deletion was detected in only 63% patients. What was the ...

Kearns-Sayre syndrome (KSS) is a rare mitochondrial myopathy that usually develops before 20 years of age. It demonstrates multisystemic involvement with a triad of cardinal features: progressive ophthalmoplegia, pigmentary retinopathy, and cardiac conduction abnormalities. In addition, patients might have cerebellar ataxia, a high content of protein in the cerebrospinal fluid, proximal myopath...