Humans don't time subsecond intervals like a stopwatch.

Many activities require the ability to estimate intervals of time in an accurate and flexible manner. A traditional and popular account suggests that humans possess a kind of internal stopwatch that can be started, paused, and stopped at will. Here we test this idea by measuring variable performance errors in 3 experiments.

Neurofibrillary tangle pathology and Braak staging in chronic epilepsy in relation to traumatic brain injury and hippocampal sclerosis: a post-mortem study.

The long-term pathological effects of chronic epilepsy on normal brain ageing are unknown. Previous clinical and epidemiological studies show progressive cognitive decline in subsets of patients and an increased prevalence of Alzheimer's disease in epilepsy. In a post-mortem series of 138 patients with long-term, mainly drug-resistant epilepsy, we carried out Braak staging for Alzheimer's disease neurofibrillary pathology using tau protein immunohistochemistry.

Tetrapod trackways from the early Middle Devonian period of Poland.

The fossil record of the earliest tetrapods (vertebrates with limbs rather than paired fins) consists of body fossils and trackways. The earliest body fossils of tetrapods date to the Late Devonian period (late Frasnian stage) and are preceded by transitional elpistostegids such as Panderichthys and Tiktaalik that still have paired fins. Claims of tetrapod trackways predating these body fossils have remained controversial with regard to both age and the identity of the track makers.

Is there any relationship between lipids and vitamin B levels in persons with elevated risk of atherosclerosis?

Background: There is increasing evidence that plasma homocysteine level is an independent risk factor for atherosclerosis. Low levels of serum folates, cobalamin and pyridoxine are associated with increased risk of cardiovascular disease. Most dietary products contain cholesterol as well as methionine, so hyperlipidemia could be associated with a higher level of homocysteine and inversely with lower levels of B vitamins.

Atrial fibrillation after conventional and off-pump coronary artery bypass grafting: two opposite trends in timing of atrial fibrillation occurrence?

Background: Atrial fibrillation (AF) is one of the most common complications after cardiac surgery. It occurs most often between the 2nd and 3rd postoperative day. The aim of this study was to compare the daily distribution of AF incidence between patients operated on with the standard coronary artery bypass grafting (CABG) technique and off-pump coronary artery bypass grafting on the beating heart (OPCABG) without extracorporeal circulation.