University of California, Davis

About: University of California, Davis is a education organization based out in Davis, California, United States. It is known for research contribution in the topics: Population & Gene. The organization has 78770 authors who have published 180033 publications receiving 8064158 citations. The organization is also known as: UC Davis & UCD.

Compositional stratification in the deep mantle

Abstract: A boundary between compositionally distinct regions at a depth of about 1600 kilometers may explain the seismological observations pertaining to Earth's lower mantle, produce the isotopic signatures of mid-ocean ridge basalts and oceanic island basalts, and reconcile the discrepancy between the observed heat flux and the heat production of the mid-ocean ridge basalt source region. Numerical models of thermochemical convection imply that a layer of material that is intrinsically about 4 percent more dense than the overlying mantle is dynamically stable. Because the deep layer is hot, its net density is only slightly greater than adiabatic and its surface develops substantial topography.

Three Cases of Enduring Memory Impairment after Bilateral Damage Limited to the Hippocampal Formation

Abstract: Patient RB (Human amnesia and the medial temporal region: enduring memory impairment following a bilaterial lesion limited to field CA1 of the hippocampus, S. Zola-Morgan, L. R. Squire, and D. G. Amaral, 1986, J Neurosci 6:2950–2967) was the first reported case of human amnesia in which detailed neuropsychological analyses and detailed postmortem neuropathological analyses demonstrated that damage limited to the hippocampal formation was sufficient to produce anterograde memory impairment. Neuropsychological and postmortem neuropathological findings are described here for three additional amnesic patients with bilateral damage limited to the hippocampal formation. Findings from these patients, taken together with the findings from patient RB and other amnesic patients, make three important points about memory. (1) Bilateral damage limited primarily to the CA1 region of the hippocampal formation is sufficient to produce moderately severe anterograde memory impairment. (2) Bilateral damage beyond the CA1 region, but still limited to the hippocampal formation, can produce more severe anterograde memory impairment. (3) Extensive, temporally graded retrograde amnesia covering 15 years or more can occur after damage limited to the hippocampal formation. Findings from studies with experimental animals are consistent with the findings from amnesic patients. The present results substantiate the idea that severity of memory impairment is dependent on locus and extent of damage within the hippocampal formation and that damage to the hippocampal formation can cause temporally graded retrograde amnesia.

Genome sequence of the hot pepper provides insights into the evolution of pungency in Capsicum species

Abstract: Doil Choi and colleagues report the genome sequence of the hot pepper, Capsicum annuum, as well as the resequencing of two cultivated peppers and a wild species, Capsicum chinense. Comparative genomic analysis across Solanaceae provides insights into genome expansion, pungency, ripening and disease resistance in hot peppers.