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These findings highlight the dynamic nature of social relationships in late life. In addition, the findings both provide evidence of older adults managing their social ties to meet the challenges of aging and suggest the importance of the interplay between giving and receiving support.

This research examined the effects of giving and receiving assistance on psychological well-being while taking into account other salient dimensions of social support including negative interaction and anticipated support. Structural equation models were evaluated by using data derived from a national probability sample of 1,103 individuals aged 65 years or older. Results indicate that the major dimensions of social support are significantly interrelated, not only directly but also indirectly. Giving and receiving support have both positive and negative consequences on well-being. With reference to the role of reciprocity, the evidence provides some support for the hypothesis of esteem enhancement instead of social exchange and equity theories.

Fischer–Tropsch synthesis (FTS) is a process which converts syn-gas (H2 and CO) to synthetic liquid fuels and valuable chemicals. Thermal gasification of biomass represents a convenient route to produce syn-gas from intractable materials particularly those derived from waste that are not cost effective to process for use in biocatalytic or other milder catalytic processes. The development of novel catalysts with high activity and selectivity is desirable as it leads to improved quality and value of FTS products. This review paper summarises recent developments in FT-catalyst design with regards to optimising catalyst activity and selectivity towards synthetic fuels

Concern over the economics of accessing fossil fuel reserves, and widespread acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from combusting such carbon sources, is driving academic and commercial research into new routes to sustainable fuels to meet the demands of a rapidly rising global population. Here we discuss catalytic esterification and transesterification solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels to meet future societal demands.

Despite strong evidence for normal, age-related cognitive decline in this sample, older adults had sufficient cognitive function to manage medications. A busy lifestyle and middle age were more determinant of who was at risk of nonadherence than beliefs about medication or illness. Thus, practicing physicians should not assume that older adults have insufficient cognitive resources to manage medications and that they will be the most likely to make adherence errors. Very busy middle-aged adults seem to be at the greatest risk of managing medications improperly.

This research aims to identify distinct courses of depressive symptoms among middle aged and older Americans and to ascertain how these courses vary by race/ethnicity. Data came from the 1995-2006 Health and Retirement Study which involved a national sample of 17,196 Americans over 50 years of age with up to six repeated observations. Depressive symptoms were measured by an abbreviated version of the Center for Epidemiologic Studies Depression scale. Semi parametric group based mixture models (Proc Traj) were used for data analysis. Six major trajectories were identified: (a) minimal depressive symptoms (15.9%), (b) low depressive symptoms (36.3%), (c) moderate and stable depressive symptoms (29.2%), (d) high but decreasing depressive symptoms (6.6%), (e) moderate but increasing depressive symptoms (8.3%), and (f) persistently high depressive symptoms (3.6%). Adjustment of time-varying covariates (e.g., income and health conditions) resulted in a similar set of distinct trajectories. Relative to white Americans, black and Hispanic Americans were significantly more likely to be in trajectories of more elevated depressive symptoms. In addition, they were more likely to experience increasing and decreasing depressive symptoms. Racial and ethnic variations in trajectory groups were partially mediated by SES, marital status, and health conditions, particularly when both interpersonal and intrapersonal differences in these variables were taken into account.

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