6,651 research outputs found
Childhood reading problems and cognitive ageing across mid to later life
BACKGROUND: Little research has investigated long-term associations of childhood reading with cognitive ageing. The aim of this study was to test longitudinal associations between childhood reading problems and cognitive function from mid-adulthood (age 43) to early old age (age 69), and whether associations were mediated by education. METHODS: Data were from the MRC National Survey of Health and Development, a prospective population-based birth cohort. Reading problems were measured at age 11 using a reading test. Verbal memory and processing speed were measured at ages 43, 53, 60-64 and 69 and Addenbrooke's Cognitive Examination (ACE) was administered at age 69. Linear mixed models and path analyses were used to test: (1) associations between reading problems and verbal memory and processing speed trajectories; (2) associations between reading problems and ACE-III scores; (3) whether associations were mediated by education. RESULTS: Reading problems were associated with poorer verbal memory at intercept but not rate of decline (N=1726), and were not associated with processing speed intercept or decline (N=1730). There were higher rates of scores below ACE-III clinical thresholds (<82 and <88) in people with reading problems compared with those without. Reading problems were associated with poorer total ACE-III scores and all domain scores at age 69 (N=1699). Associations were partly mediated by education. CONCLUSION: Reading problems in childhood were associated with poorer cognitive function in early old age, and associations were partly mediated by education
The interaction between exchange rates and stock princes: An Australian context.
The aim of this paper is to examine the interaction between stock prices and exchange rates in Australia. During the period of the study, the value of the stock market increased by two-thirds and the Australian dollar exchange rate appreciated by almost one-third. The empirical analysis employed provides evidence of a positive co-integrating relationship between these variables, with Granger causality found to run from stock prices to the exchange rate during the sample period. Although commodity prices have not been included, the significance of the results lends support to the notion that these two key financial variables interacted in a manner consistent with the portfolio balance model, that is, stock price movements cause changes in the exchange rate. This challenges the traditional view of the Australian economy as export-dependent, and also suggests that the Australian stock market has the depth annd liquidity to adequately compete for both domestic and international capital against other larger markets
Long-range electron transfer in structurally engineered pentaammineruthenium (histidine-62) cytochrome c
In many biological processes, long-range electron transfer (ET) plays a key role. When the three-dimensional structures of proteins are accurately known, use of modified proteins and protein-protein complexes provides an experimental approach to study ET rates between two metal centers. For Ru(His)- modified proteins, the introduction of histidine residues at any desired surface location by site-directed mutagenesis opens the way for systematic investigations of ET pathways
High Performance Human Resource Practices And Corporate Entrepreneurship: The Mediating Effect Of Middle Managers Knowledge Collecting And Donating Behaviour
This study develops a mediation model in which high-performance human resource
practices affect corporate entrepreneurship through two dimensions of knowledge
sharing: knowledge collecting and knowledge donating. In a sample of 292 middle
managers from Malaysia, we find that high-performance human resource practices relate
positively to corporate entrepreneurship, and this relation is mediated by knowledge
sharing. The results suggest that the willingness of middle managers to engage in
knowledge sharing serves as a partial mediator to attenuate this positive relationship.
However, an interesting outcome from this study is that although high-performance
human resource practices are positively related to the willingness of middle managers to
collect and donate knowledge, only middle managers' willingness to donate knowledge
was found to partially mediate the relationship between high-performance human
resource practices and corporate entrepreneurship. We discuss the theoretical and
managerial implications for human resource management research and practice
Bidirectional relation between affective symptoms and cognitive function from middle to late adulthood: a population-based birth cohort study
Objectives: There is an association between affective symptoms and cognition. However, the direction of this association remains unclear. This study aimed to test bidirectional relationships between affective symptoms and cognition from middle to late adulthood.Method: Data were available from the MRC National Survey of Health and Development (NSHD), a prospective birth cohort of 5362 people born in 1946. Affective symptoms and cognition were measured at ages 53, 60-64, and 69. Latent scores of affective symptoms were derived and cross-lagged models were fitted for affective symptoms with verbal memory and processing speed. Results: Results revealed an inverse cross-sectional association between affective symptoms and verbal memory (β=-0.18, SE=0.04, p<.001) and processing speed (β=-0.13, SE=0.06, p=.05) at age 53, but not at ages 60-64 or 69. Affective symptoms at age 53 predicted lower verbal memory at age 60-64 (β=-0.58, SE=0.27, p=.03), and affective symptoms at age 60-64 predicted lower verbal memory (β=-0.64, SE=0.29, p=.03) and processing speed (β=-1.27, SE=0.41, p=.002) at age 69. Verbal memory and processing speed did not predict subsequent affective symptoms.Conclusion: Affective symptoms predict poorer verbal memory and processing speed over a period of 16 years, but not vice versa
Effect of an agri-environmental measure on nitrate leaching from a beef farming system in Ireland
peer-reviewedAgricultural nitrogen (N) management remains a key environmental challenge. Improving N management is a matter of urgency to reduce the serious ecological consequences of the reactive N. Nitrate (NO3−–N) leaching was measured under suckler beef production systems stocked at two intensities: (1) intensive, 210 kg organic N ha−1 with two cut silage harvests; and (2) rural environmental protection scheme (REPS), 170 kg organic N ha−1 with one cut silage harvest. Three replicate plots of each treatment were instrumented with ceramic cups (8 per plot), randomly placed within each plot at a depth of 1 m to collect soil solution for NO3−–N at 50 kPa suction to collecting vessels one week prior to sampling. Samples were taken on a total of 53 sampling dates over 3 winter drainage periods (2002/03, 2003/04 and 2004/05). Over the course of the experiment the mean annual soil solution NO3−–N concentration exceeded the MAC twice out of 15 means (5 treatments over 3 years). The REPS grazing and silage sub treatments had significantly lower mean annual soil solution total oxidized N (TON) concentrations than the respective intensive treatments in years 2 and 3. Annual total NO3−–N losses over the three years in intensive and REPS systems ranged from 55 to 71 and 15 to 20 kg N ha−1, respectively. Mean N surpluses in intensive and REPS systems were 210 and 95 kg ha−1, respectively with the corresponding mean N inputs of 272 and 124 kg N ha−1. The reduction in N inputs under the REPS system results in lower N leaching losses and contributed to a significant reduction in pressures on water quality
Electron Transfer Reactivity of Type Zero Pseudomonas aeruginosa Azurin
Type zero copper is a hard-ligand analogue of the classical type 1 or blue site in copper proteins that function as electron transfer (ET) agents in photosynthesis and other biological processes. The EPR spectroscopic features of type zero Cu^(II) are very similar to those of blue copper, although lacking the deep blue color, due to the absence of thiolate ligation. We have measured the rates of intramolecular ET from the pulse radiolytically generated C3−C26 disulfide radical anion to the Cu^(II) in both type zero C112D/M121L and type 2 C112D Pseudomonas aeruginosa azurins in pH 7.0 aqueous solutions between 8 and 45 °C. We also have obtained rate/temperature (10−30 °C) profiles for ET reactions between these mutants and the wild-type azurin. Analysis of the rates and activation parameters for both intramolecular and intermolecular ET reactions indicates that the type zero copper reorganization energy falls in a range (0.9−1.1 eV) slightly above that for type 1 (0.7−0.8 eV), but substantially smaller than that for type 2 (>2 eV), consistent with XAS and EXAFS data that reveal minimal type zero site reorientation during redox cycling
Affective problems and decline in cognitive state in older adults: a systematic review and meta-analysis
Evidence suggests that affective problems, such as depression and anxiety, increase risk for late-life dementia. However, the extent to which affective problems influence cognitive decline, even many years prior to clinical diagnosis of dementia, is not clear. The present study systematically reviews and synthesises the evidence for the association between affective problems and decline in cognitive state (i.e. decline in non-specific cognitive function) in older adults. An electronic search of PubMed, PsycInfo and ScienceDirect was conducted to identify studies of the association between depression and anxiety separately and decline in cognitive state. Key inclusion criteria were prospective, longitudinal designs with a minimum follow-up period of one year. Data extraction and methodological quality assessment using the STROBE checklist were conducted independently by two raters. A total of 34 studies (n=71,244) met eligibility criteria, with 32 studies measuring depression (n=68,793), and 5 measuring anxiety (n=4,698). A multi-level meta-analysis revealed that depression assessed as a binary predictor (OR=1.36, 95% CIs: 1.05-1.76, p=.02) or a continuous predictor (B=-0.008, 95% CIs: -0.015, -0.002, p=.012; OR=0.992, 95% CIs: 0.985-0.998) was significantly associated with decline in cognitive state. The number of anxiety studies were insufficient for meta-analysis and are instead described in a narrative review. Results of the present study improve current understanding of the temporal nature of the association between affective problems and decline in cognitive state. They also suggest that cognitive function need to be monitored closely in individuals with affective disorders, as these individuals may be at a particular risk of greater cognitive decline
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