University of Kentucky

About: University of Kentucky is a education organization based out in Lexington, Kentucky, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 43933 authors who have published 92195 publications receiving 3256087 citations. The organization is also known as: UK.

Alzheimer's neurofibrillary pathology and the spectrum of cognitive function: Findings from the Nun Study

Abstract: The development of interventions designed to delay the onset of dementia highlights the need to determine the neuropathologic characteristics of individuals whose cognitive function ranges from intact to demented, including those with mild cognitive impairments. We used the Braak method of staging Alzheimer's disease pathology in 130 women ages 76-102 years who were participants in the Nun Study, a longitudinal study of aging and Alzheimer's disease. All participants had complete autopsy data and were free from neuropathologic conditions other than Alzheimer's disease lesions that could affect cognitive function. Findings showed a strong relationship between Braak stage and cognitive state. The presence of memory impairment was associated with more severe Alzheimer's disease pathology and higher incidence of conversion to dementia in the groups classified as having mild or global cognitive impairments. In addition to Braak stage, atrophy of the neocortex was significantly related to the presence of dementia. Our data indicate that Alzheimer's neurofibrillary pathology is one of the neuropathologic substrates of mild cognitive impairments. Additional studies are needed to help explain the variability in neuropathologic findings seen in individuals whose cognitive performance falls between intact function and dementia.

Acetaminophen Reduces Social Pain Behavioral and Neural Evidence

Abstract: Pain, whether caused by physical injury or social rejection, is an inevitable part of life. These two types of pain-physical and social-may rely on some of the same behavioral and neural mechanisms that register pain-related affect. To the extent that these pain processes overlap, acetaminophen, a physical pain suppressant that acts through central (rather than peripheral) neural mechanisms, may also reduce behavioral and neural responses to social rejection. In two experiments, participants took acetaminophen or placebo daily for 3 weeks. Doses of acetaminophen reduced reports of social pain on a daily basis (Experiment 1). We used functional magnetic resonance imaging to measure participants' brain activity (Experiment 2), and found that acetaminophen reduced neural responses to social rejection in brain regions previously associated with distress caused by social pain and the affective component of physical pain (dorsal anterior cingulate cortex, anterior insula). Thus, acetaminophen reduces behavioral and neural responses associated with the pain of social rejection, demonstrating substantial overlap between social and physical pain.

Insights into evolution of multicellular fungi from the assembled chromosomes of the mushroom Coprinopsis cinerea (Coprinus cinereus)

Abstract: The mushroom Coprinopsis cinerea is a classic experimental model for multicellular development in fungi because it grows on defined media, completes its life cycle in 2 weeks, produces some 10(8) synchronized meiocytes, and can be manipulated at all stages in development by mutation and transformation. The 37-megabase genome of C. cinerea was sequenced and assembled into 13 chromosomes. Meiotic recombination rates vary greatly along the chromosomes, and retrotransposons are absent in large regions of the genome with low levels of meiotic recombination. Single-copy genes with identifiable orthologs in other basidiomycetes are predominant in low-recombination regions of the chromosome. In contrast, paralogous multicopy genes are found in the highly recombining regions, including a large family of protein kinases (FunK1) unique to multicellular fungi. Analyses of P450 and hydrophobin gene families confirmed that local gene duplications drive the expansions of paralogous copies and the expansions occur in independent lineages of Agaricomycotina fungi. Gene-expression patterns from microarrays were used to dissect the transcriptional program of dikaryon formation (mating). Several members of the FunK1 kinase family are differentially regulated during sexual morphogenesis, and coordinate regulation of adjacent duplications is rare. The genomes of C. cinerea and Laccaria bicolor, a symbiotic basidiomycete, share extensive regions of synteny. The largest syntenic blocks occur in regions with low meiotic recombination rates, no transposable elements, and tight gene spacing, where orthologous single-copy genes are overrepresented. The chromosome assembly of C. cinerea is an essential resource in understanding the evolution of multicellularity in the fungi.

Shear Modulus and Damping in Soils: Measurement and Parameter Effects (Terzaghi Leture)

Abstract: Based on numerous tests on a spectrum of disturbed and undisturbed soils, the shear modulus decreases and the damping ratio increases very rapidly with increasing strain amplitude. The rate of increase or decrease depends on many parameters: (1) Effective mean principal stress; (2) degree of saturation; (3) void ratio; and (4) number of cycles of loading. Ambient states of octahedral shear stress, overconsolidation ratio, effective strength envelope, frequency of loading, and time effects have a less important influence on these properties. Cohesive soils are affected differently than clean sands. The apparatus used to measure shear modulus and damping must be capable of making accurate measurements at very small shearing strains, the range being defined by practical problems in earthquake and foundation vibrations. A pseudo static simple shear apparatus and two different resonant column apparatus were used.