The poorly known fossil record of fur seals and sea lions (Otariidae) does not reflect their current diversity and widespread abundance. This limited fossil record contrasts with the more complete fossil records of other pinnipeds such as walruses (Odobenidae). The oldest known otariids appear 5-6 Ma after the earliest odobenids, and the remarkably derived craniodental morphology of otariids of...

BACKGROUND Recent findings suggest that Alzheimer's disease (AD) neuropathological features (neuritic plaques and NFTs) are not strongly associated with dementia in extreme old (over 90 years of age) and compel a search for neurobiological indices of dementia in this rapidly growing segment of the elderly population. We sought to characterize transcriptional and protein profiles of dementia in ...

This study examined the maintenance of retest learning benefits in young old and oldest old adults over an 8-month period in 3 cognitive abilities: reasoning, perceptual-motor speed, and visual attention. Twenty-four young old (aged 70-79 years, M = 74.2) and 23 oldest old adults (aged 80-90 years, M = 83.6) who participated in a previously published study (Yang, L., Krampe, R. T., & Baltes, P....

The possibility of observing solar neutrinos began to be discussed seriously following the 1958 experimental discovery by Holmgren and Johnston that the cross section for production of the isotope Be by the fusion reaction He + He → Be+ γ was more than a thousand times larger than was previously believed. This result led Willy Fowler and Al Cameron to suggest that B might be produced in the sun...

Die Probleme, die ein computerzentrierter Informatikunterricht mit sich bringt, sind ein unter verschiedenen Gesichtspunkten immer wieder diskutiertes Thema der Fachdidaktik Informatik. Dabei wird jedoch die Wahl des PCs als Informatiksystem nicht hinterfragt. Aber der PC ist im Informatikunterricht nicht ohne Alternativen, und die Frage, welche Auswirkung die Wahl eines anderen vollständigen u...

Humans have a skewed view of viruses because we only notice them if they cause disease. In reality, however, viruses are much more than pathogens. HIV and influenza cause frightening health threats, but 1019 HIV particles worldwide are basically nothing compared to 1033 total number of viruses on our planet. Viruses are present in every species and every ecological niche, and affect every organ...