Relationship between hippocampal structure and memory function in elderly humans

With progressing age, the ability to recollect personal events declines, whereas familiarity-based memory remains relatively intact. It has been hypothesized that age-related hippocampal atrophy may contribute to this pattern because of its critical role for recollection in younger humans and after acute injury. Here, we show that hippocampal volume loss in healthy older persons correlates with gray matter loss (estimated with voxel-based morphometry) of the entire limbic system and shows no correlation with an electrophysiological (event-related potential [ERP]) index of recollection. Instead, it covaries with more substantial and less specific electrophysiological changes of stimulus processing. Age-related changes in another complementary structural measure, hippocampal diffusion, on the other hand, seemed to be more regionally selective and showed the expected correlation with the ERP index of recollection. Thus, hippocampal atrophy in older persons accompanies limbic atrophy, and its functional impact on memory is more fundamental than merely affecting recollection

An improved technique for microbiological sampling of surfaces - Agar spray Research report, period ending 30 Sep. 1968

Improved agar spray technique for sampling surface microorganis

Temporal changes in fruit production between recurrent prescribed burns in pine woodlands of the Ouachita Mountains

The use of prescribed fire is integral to the restoration of open woodlands and savannas, including shortleaf pine (Pinus echinata) woodlands in the Ouachita Mountains of Oklahoma and Arkansas. Fire offers many potential benefits to numerous wildlife; however, short-term implications for understory fruit production are not fully understood, especially in stands subjected to frequent, recurrent burns. We examined the effects of dormant season prescribed burns on woody fruit production (kg ha−1) and fruit producing vegetative cover in the understory of restored pine woodlands. We inventoried 32 stands during four temporal periods after dormant season prescribed fires: 1, 2, 3, and 5 growing seasons post-burn. We counted fruit (\u3c2 m above the ground) throughout the summer and visually estimated vegetative cover of fruit producing plants. Fruit production was greatest in the 3rd year (18.2 kg ha−1), followed by 5th (10.9 kg ha−1) and 2nd (9.8 kg ha−1) years after burns. Overall, 87% of total production consisted of three genera: American beautyberry (Callicarpa americana [38%]), Vitis spp. (summer grapes [Vitis aestivalis; 11%] and muscadine grape [V. rotundifolia; 10%]), and Rubus spp. (blackberry [20%] and dewberry [R. flagellaris; 8%]). Production was recorded in 13 of the 14 fruit producing species present during the 5th year post-burn, indicating that production diversity increased over time. Percent cover and species richness (26 taxa) of fruit producing taxa were greatest in the 3rd year post-burn. Taxa such as poison ivy (Toxicodendron radicans) and sumac (Rhus spp.) comprised a sizable percent of coverage (\u3e7% each), but this did not translate into substantial fruit production. American beautyberry and summer grape had both substantial coverage and production. Results suggest that burning on a 3-year rotation maximizes and prolongs fruit production; however, occasional burning on a 5-year rotation will promote a higher diversity of woody mast-producing understory species

Understory vegetative Diversity of Post-Thinned pine Plantations Treated with Fertilizer, Fire and Herbicide in East Texas

This study assessed biodiversity in the understory of two pine plantations where different management tools (fertilizer, prescribed burning, and herbicide application) were utilized. During three growing seasons, species, percent cover, and number of individuals, and physical characteristics were recorded. Responses to treatment were examined based on comparison of species richness, evenness, diversity, and importance. Two years after treatment, fertilized plots showed a decline in species richness, evenness, and diversity. Prescribed burning and herbicide treatments increased species richness but decreased species evenness, resulting in no change in diversity index. Herbicide treatment reduced the importance of dominant shrubs and increased the importance of disturbance-adapted species

Structural investigation and compression of a co-crystal of indomethacin and saccharin

The co-crystalline structure of the non-steroidal, anti-inflammatory indomethacin with the non-toxic, Generally Regarded As Safe (GRAS) sweetener component saccharin was investigated up to 6.33 GPa using a Diamond Anvil Cell (DAC). Single crystal X-ray diffraction measurements show that the co-crystal remains in the same triclinic, P-1, phase throughout the compression with a significant reduction in void space (155.69 to 55.61Å3). Information on the response of different types of intermolecular interactions to external force at the same time is enabled by the use of a co-crystal. We have rationalised that the length and compression rate of the saccharin amide dimer in the co-crystal is caused by the dimer sitting in a ‘pocket’ surrounded by the indomethacin framework. This framework reduces the effects of molecular packing on the dimer allowing for an ideal hydrogen bonding geometry

Non-isothermal model for the direct isotropic/smectic-A liquid crystalline transition

An extension to a high-order model for the direct isotropic/smectic-A liquid crystalline phase transition was derived to take into account thermal effects including anisotropic thermal diffusion and latent heat of phase-ordering. Multi-scale multi-transport simulations of the non-isothermal model were compared to isothermal simulation, showing that the presented model extension corrects the standard Landau-de Gennes prediction from constant growth to diffusion-limited growth, under shallow quench/undercooling conditions. Non-isothermal simulations, where meta-stable nematic pre-ordering precedes smectic-A growth, were also conducted and novel non-monotonic phase-transformation kinetics observed.Comment: First revision: 20 pages, 7 figure

Orientational order parameters of a de Vries–type ferroelectric liquid crystal obtained by polarized Raman spectroscopy and x-ray diffraction

The orientational order parameters 〈P2〉 and 〈P4〉 of the ferroelectric, de Vries–type liquid crystal 9HL have been determined in the SmA* and SmC* phases by means of polarized Raman spectroscopy, and in the SmA* phase using x-ray diffraction. Quantum density functional theory predicts Raman spectra for 9HL that are in good agreement with the observations and indicates that the strong Raman band probed in the experiment corresponds to the uniaxial, coupled vibration of the three phenyl rings along the molecular long axis. The magnitudes of the orientational order parameters obtained in the Raman and x-ray experiments differ dramatically from each other, a discrepancy that is resolved by considering that the two techniques probe the orientational distributions of different molecular axes. We have developed a systematic procedure in which we calculate the angle between these axes and rescale the orientational order parameters obtained from x-ray scattering with results that are then in good agreement with the Raman data. At least in the case of 9HL, the results obtained by both techniques support a “sugar loaf” orientational distribution in the SmA* phase with no qualitative difference to conventional smectics A. The role of individual molecular fragments in promoting de Vries–type behavior is considered

Mental Health of Parents and Life Satisfaction of Children: A Within-Family Analysis of Intergenerational Transmission of Well-Being

This paper addresses the extent to which there is an intergenerational transmission of mental health and subjective well-being within families. Specifically it asks whether parents’ own mental distress influences their child’s life satisfaction, and vice versa. Whilst the evidence on daily contagion of stress and strain between members of the same family is substantial, the evidence on the transmission between parental distress and children’s well-being over a longer period of time is sparse. We tested this idea by examining the within-family transmission of mental distress from parent to child’s life satisfaction, and vice versa, using rich longitudinal data on 1,175 British youths. Results show that parental distress at year t-1 is an important determinant of child’s life satisfaction in the current year. This is true for boys and girls, although boys do not appear to be affected by maternal distress levels. The results also indicated that the child’s own life satisfaction is related with their father’s distress levels in the following year, regardless of the gender of the child. Finally, we examined whether the underlying transmission correlation is due to shared social environment, empathic reactions, or transmission via parent-child interaction