The influence of shc proteins on the whole body energetic response to calorie restriction initiated in 3-month-old mice.

There is increasing evidence that Shc proteins play a role in energy metabolism, and we have previously reported that knockdown of Shc proteins influences the energetic response to acute (3 days) calorie restriction (CR) in 18-month-old mice. Whether Shc proteins play a role in the metabolic response to CR in younger mice has yet to be elucidated. Hence, we sought to determine the impact of 3 days and longer term (2 months) CR on energy expenditure (EE) and respiratory quotient (RQ) in 3 month-old Shc knockout (ShcKO) and wild-type (WT) mice. ShcKO mice decreased (P < 0.001) EE normalized for body weight (EEBW) by 3 days of CR, while no such change was observed in WT animals. However, both ShcKO and WT mice decreased (P < 0.001) EEBW at 2 months of CR and there were no differences in body weight between the ShcKO and WT mice at either 3 days or 2 months of CR. Consistent with increased fatty acid oxidation, only ShcKO mice maintained decreased (P < 0.001) 24 h RQ through 2 months of CR, suggesting that they were able to maintain increased fatty acid oxidation for a longer period of time than WT mice. These results indicate that Shc proteins may contribute to some of the acute energetic responses to CR

The influence of shc proteins and aging on whole body energy expenditure and substrate utilization in mice.

While it has been proposed that Shc family of adaptor proteins may influence aging by regulating insulin signaling and energy metabolism, the overall impact of Shc proteins on whole body energy metabolism has yet to be elucidated. Thus, the purpose of this study was to determine the influence of Shc proteins and aging on whole body energy metabolism in a mouse model under ambient conditions (22°C) and acute cold exposure (12°C for 24 hours). Using indirect respiration calorimetry, we investigated the impact of Shc proteins and aging on EE and substrate utilization (RQ) in p66 Shc-/- (ShcKO) and wild-type (WT) mice. Calorimetry measurements were completed in 3, 15, and 27 mo mice at 22°C and 12°C. At both temperatures and when analyzed across all age groups, ShcKO mice demonstrated lower 24 h total EE values than that of WT mice when EE data was expressed as either kJ per mouse, or adjusted by body weight or crude organ mass (ORGAN) (P≤0.01 for all). The ShcKO mice also had higher (P<0.05) fed state RQ values than WT animals at 22°C, consistent with an increase in glucose utilization. However, Shc proteins did not influence age-related changes in energy expenditure or RQ. Age had a significant impact on EE at 22°C, regardless of how EE data was expressed (P<0.05), demonstrating a pattern of increase in EE from age 3 to 15 mo, followed by a decrease in EE at 27 mo. These results indicate a decline in whole body EE with advanced age in mice, independent of changes in body weight (BW) or fat free mass (FFM). The results of this study indicate that both Shc proteins and aging should be considered as factors that influence energy expenditure in mice

An Assessment of Control Methods for Cape Ivy in Coastal Riparian Ecosystems

The goals of this research were to quantify the achievable outcomes and associated costs of controlling Cape ivy (Delairea odorata), a non-native invasive plant. Current gaps in the knowledge-base limit decision makers from assigning appropriate costs, and therefore funding, for invasive species control (D’Antonio and Chambers 2006). Towards these goals, I measured and compared the success and cost-effectiveness of three control methods on Cape ivy in riparian areas along the Central Coast region of California. The control methods used in this study included hand removal, herbicide application (glyphosate), and a combination of these two methods. Control methods were applied to Cape ivy infestations at three research sites; two within Santa Cruz County and one in Monterey County, beginning July 2008 and concluding September 2009. Success of each control method was measured by comparison of pre and post-treatment vegetation sampling. The costs associated with each method (labor, herbicides, materials) were also recorded for each method. After twelve months, the hand removal method achieved the highest reduction of Cape ivy cover and resulted in the highest native plant cover. However, the most cost-effective method (per dollar) for the first twelve months of Cape ivy control was the herbicide only method. The results of this study will be provided to staff at California State Parks, the Land Trust of Santa Cruz County, and the Big Sur Land Trust to inform future management of Cape ivy on their properties. Additionally, this research will contribute to needed guidelines for restoration of Cape-ivy infested riparian ecosystems, and serve as a resource for researchers interested in control of invasive plants and restoration of disturbed areas

Differing Effects of Education on Cognitive Decline in Diverse Elders with Low Versus High Educational Attainment

OBJECTIVE: In light of growing debate over whether and how early life educational experiences alter late-life cognitive trajectories, this study sought to more thoroughly investigate the relationship between educational attainment and rates of late-life cognitive decline in a racially, ethnically, and educationally diverse population. METHOD: Older adults (N = 3,435) in the community-based Washington Heights-Inwood Columbia Aging Project were administered neuropsychological tests of memory, language, visuospatial function, and processing speed at approximate 24-month intervals for up to 18 years. Second-order latent growth curves estimated direct and indirect (through income) effects of educational attainment on rates of global cognitive decline separately in individuals with low (0-8 years) and high (9-20 years) educational attainment. RESULTS: More years of education were associated with higher cognitive level and slower cognitive decline in individuals with low or high educational attainment. The association between having more than 9 years of education and exhibiting slower cognitive decline was fully mediated by income. Although having additional years of education up to 8 years was also associated with higher income, this did not explain associations between education and cognitive change in the low-education group. CONCLUSIONS: Early education (i.e., up to 8 years) may promote aspects of development during a sensitive period of childhood that protect against late-life cognitive decline independent of income. In contrast, later education (i.e., 9 years and beyond) is associated with higher income, which may influence late-life cognitive health through multiple, nonmutually exclusive pathways

The Relationship of MHC-Peptide Binding and T Cell Activation Probed Using Chemically Defined MHC Class II Oligomers

AbstractA series of novel chemically defined soluble oligomers of the human MHC class II protein HLA-DR1 was constructed to probe the molecular requirements for initiation of T cell activation. MHC dimers, trimers, and tetramers stimulated T cells, as measured by upregulation of the activation markers CD69 and CD25, and by internalization of activated T cell receptor subunits. Monomeric MHC-peptide complexes engaged T cell receptors but did not induce activation. For a given amount of receptor engagement, the extent of activation was equivalent for each of the oligomers and correlated with the number of T cell receptor cross-links induced. These results suggest that formation or rearrangement of a T cell receptor dimer is necessary and sufficient for initiation of T cell signaling

Literacy and Memory Decline among Ethnically Diverse Elders

Literacy may be a more powerful indicator of brain reserve than years of education. Literacy level may be a proxy for native intellectual capacity or life experience that can compensate for brain damage or provide brain reserve. Alternately, the experience of acquiring literacy skills may in itself change the organization of the brain and increase protection against cognitive decline. However, because people with low levels of literacy obtain poor scores on most cognitive measures, only longitudinal studies can elucidate the role of reading ability in reserve. We determined whether literacy skills could predict cognitive change in a sample of 136 English-speaking African American, Caucasian, and Hispanic elders selected from a longitudinal aging study in New York City. According to a physician’s independent examination, all participants were nondemented throughout the four longitudinal assessments. Literacy level was assessed using the WRAT-3 reading subtest. After accounting for age at baseline and years of education, GEE analyses showed that elders with low levels of literacy had a steeper decline in both immediate and delayed recall of a word list over time as compared to high literacy elders. Our findings suggest that literacy skills are protective against memory decline among nondemented elders

Tonality in the first book of Debussy's preludes

Thesis (M.Mus)-University of Natal, Durban, 1978.This paper attempts to explore the extent to which Rudolph Reti's concepts of melodic and harmonic tonality are useful in describing Debussy's Preludes. It is hoped that this work will provide a basis for the examination and comparison of various other musical compositions, representative of different styles, in terms of tonality

Similar patterns of linkage disequilibrium and nucleotide diversity in native and introduced populations of the pea aphid, Acyrthosiphon pisum

<p>Abstract</p> <p>Background</p> <p>The pea aphid, <it>Acyrthosiphon pisum</it>, is an emerging genomic model system for studies of polyphenisms, bacterial symbioses, host-plant specialization, and the vectoring of plant viruses. Here we provide estimates of nucleotide diversity and linkage disequilibrium (LD) in native (European) and introduced (United States) populations of the pea aphid. Because introductions can cause population bottlenecks, we hypothesized that U.S. populations harbor lower levels of nucleotide diversity and higher levels of LD than native populations.</p> <p>Results</p> <p>We sampled four non-coding loci from 24 unique aphid clones from the U. S. (12 from New York and 12 from California) and 24 clones from Europe (12 alfalfa and 12 clover specialists). For each locus, we sequenced approximately 1 kb from two amplicons spaced ~10 kb apart to estimate both short range and longer range LD. We sequenced over 250 kb in total. Nucleotide diversity averaged 0.6% across all loci and all populations. LD decayed slowly within ~1 kb but reached much lower levels over ~10 kb. Contrary to our expectations, neither LD nor nucleotide diversity were significantly different between native and introduced populations.</p> <p>Conclusion</p> <p>Both introduced and native populations of pea aphids exhibit low levels of nucleotide diversity and moderate levels of LD. The introduction of pea aphids to North America has not led to a detectable reduction of nucleotide diversity or increase in LD relative to native populations.</p

Stable Carbon Isotopic Signatures of Abiotic Organics from Hydrothermal Synthesis Experiments

Stable carbon isotopes can be powerful biogeochemical markers in the study of life's origins. Biogenic carbon fixation produces organics that are depleted in C-13 by about -20 to -30%0. Less attention has been paid to the isotopic signatures of abiotic processes. The possibility of abiotic processes producing organics with morphologies and isotopic signatures in the biogenic range has been at the center of recent debate over the Earth's earliest microfossils. The abiotic synthesis of organic compounds in hydrothermal environments is one possible source of endogenous organic matter to the prebiotic earth. Simulated hydrothermal settings have been shown to synthesize, among other things, single chain amphiphiles and simple lipids from a mix of CO, CO2, and H2. A key characteristic of these amphiphilic molecules is the ability to self-assemble in aqueous phases into more organized structures called vesicles, which form a selectively permeable boundary and serve the function of containing and concentrating other organic molecules. The ability to form cell like structures also makes these compounds more likely to be mistaken for biogenic. Hydrothermal simulation experiments were conducted from oxalic or formic acid in water at 175 C for 72 hr. The molecular and isotopic composition of the products of these reactions were determined and compared to biogenic fractionations . Preliminary results indicate isotopic fractionation during abiotic hydrocarbon synthesis in hydrothermal environments is on par with biological carbon fixation