BackgroundLife's Simple 7 is a new metric based on modifiable health behaviors and factors that the American Heart Association uses to promote improvements to cardiovascular health (CVH). We hypothesized that better Life's Simple 7 scores are associated with lower incidence of cognitive impairment.Methods and ResultsFor this prospective cohort study, we included REasons for Geographic And Racial Differences in Stroke (REGARDS) participants aged 45+ who had normal global cognitive status at baseline and no history of stroke (N=17 761). We calculated baseline Life's Simple 7 score (range, 0 to 14) based on smoking, diet, physical activity, body mass index, blood pressure, total cholesterol, and fasting glucose. We identified incident cognitive impairment using a 3‐test measure of verbal learning, memory, and fluency obtained a mean of 4 years after baseline. Relative to the lowest tertile of Life's Simple 7 score (0 to 6 points), odds ratios of incident cognitive impairment were 0.65 (0.52, 0.81) in the middle tertile (7 to 8 points) and 0.63 (0.51, 0.79) in the highest tertile (9 to 14 points). The association was similar in blacks and whites, as well as outside and within the Southeastern stroke belt region of the United States.ConclusionsCompared with low CVH, intermediate and high CVH were both associated with substantially lower incidence of cognitive impairment. We did not observe a dose‐response pattern; people with intermediate and high levels of CVH had similar incidence of cognitive impairment. This suggests that even when high CVH is not achieved, intermediate levels of CVH are preferable to low CVH.

Micrometeorological data collected from an automatic weather station over a total of 85 days during the summer of 2007/2008 in the ablation zone (1770 m a.s.l.) of the Brewster Glacier, New Zealand, were used to determine the main atmospheric processes controlling the magnitude and variability of daily ablation. During the field season, ablation was measured and modelled using an energy balance model (EBM) and a degree-day model (DDM). Calculation of the energy balance over the glacier using the EBM revealed that net radiation provided the largest source of energy for ablation (52%). The turbulent sensible heat flux was the next largest energy source (25%), followed by the turbulent latent heat flux (20%) and the rain heat flux (3%). While daily measured and modelled (EBM) ablation were both equal to approximately 40 mm w.e. d −1 , the EBM was used to demonstrate that rates were highly variable, ranging from less than 10 mm w.e. d accounted for almost 25% of total ablation, despite such events occurring on only 11 of the 85 days monitored. The contribution of the individual terms of the energy balance to observed air temperature is complex on Brewster Glacier, leading to a larger uncertainty in DDM ablation estimates (under prediction of total ablation by 11%). Advection of warm and moisture-laden air over Brewster Glacier, which is not uncommon given its close proximity to the ocean, is not well accounted for by the DDM. This is because the turbulent latent heat flux and the rain heat flux are poorly correlated to air temperature but are, nonetheless, important sources of energy during large ablation events.

Objectives The REasons for Geographic and Racial Differences in Stroke (REGARDS) study is a prospective cohort of 30,239 Americans in the contiguous United States; the first of this scale to use home visits to obtain, process, and ship biologic samples to a core laboratory. Pre-analytical factors resulting from this study design may affect the results of some laboratory assays. We investigated the impact of REGARDS processing on a variety of analytes. Design and methods In REGARDS, blood samples were processed in the field by technicians who were trained on standardized methods for phlebotomy and sample processing. Field processing included centrifugation using varying non-uniform equipment and shipping overnight on ice to the University of Vermont, where samples were re-centrifuged for 30,000 ×g-minutes and stored at −80 °C. We assessed the effects of REGARDS sample handling by processing split samples from 20 volunteers using either ideal procedures or simulated REGARDS procedures. Assays for 19 analytes for potential study in REGARDS were then run on both samples and results compared. Results Spearman correlation coefficients for analytes measured in ideal versus REGARDS processed samples ranged from 0.11 to 1.0. Thirteen of 19 analytes were highly correlated (>0.75), but platelet proteins were more variable. Conclusions Simulation of non-optimal field processing and shipment to a central laboratory showed high variability in analytes released by platelets. The majority of other analytes produced valid results, but platelet contamination in REGARDS samples makes measurement of platelet proteins unadvisable in these samples. Future analytes considered by REGARDS or similar studies should undergo similar pilot testing.

How does the brain encode, store, and retrieve an entire lifetime of experiences? Biological memory capacity has been extensively studied with regard to the short-term retention of recent information (Miller, 1956;Nelson, 2001), and a system with a limited capacity in the single digits has consistently been suggested. Such findings suggest that the brain may have multiple memory systems, and numerous longer term stores (e.g., procedural, episodic, long-term, semantic, associative, and reference memory) have been proposed to capture the extensive knowledge and memories stored beyond those of the recent past. One challenging issue concerns the storage capacity and information retrieval of these longer term memory mechanisms. Attempts to examine the capacity of such longer term memory stores have been limited and mainly computational (Dudai, 1997;Landauer, 1986;Standing, 1973). Although there is general agreement that the human capacity for recognizing pictorial information is considerable (Shepard, 1967;Standing, 1973) and the storage needs for language use substantial, the empirical study of long-term memory capacity has been virtually absent because of the impractical requirements of testing humans over extended periods.Nonhuman animals are similarly guided by a combination of acquired knowledge and recent experiences, but here as well, little effort has been directed at understanding the capacity of their longer term memory systems. Vaughan and Greene (1984) conducted the most extensive study of animal memory capacity. They showed that pigeons could discriminate among 320 randomly assigned pictorial stimuli (160 positive and 160 negative) in a successive go/no-go discrimination. On the basis of a smaller stimulus set (160), they further demonstrated that some of these memories endure for at least 2 years. There are some important limitations, however, to these findings. Their rate-based discrimination procedure and rankorder measure of performance were not designed to yield a measure of how many stimuli were retained, for example. Thus, their pigeons' above-chance discrimination could have been accomplished with considerably fewer than the 320 pictures being memorized. Furthermore, the testing of all 320 stimuli was quite brief, making it impossible to judge the long-term effects of high memory load. Since then, the capacity of pigeons to remember large numbers of pictures has been confirmed. Von Fersen and Delius (1989) used a two-alternative choice proceThis research was supported by a grant from the Animal Behavior program of the National Science Foundation to R.G.C., who thanks everyone in the Cook lab for assistance in conducting these experiments over the last 3 years and Taylor Johnson and Angie Koban for their comments on earlier drafts. Correspondence concerning this article should be addressed to R. G. Cook, Department of Psychology, Tufts University, 530 Bacon Hall, Medford, MA 02155 (e-mail: robert.cook@tufts.edu; home page, www.pigeon.psy.tufts.edu). How much information can a brain store over a li...

Objective: To assess the relationships among ABO group, factor VIII (FVIII), and incident cognitive impairment in a large, prospective cohort study of black and white adults in the United States using a nested case-control design.Methods: Incident cognitive impairment was defined using cognitive domain tests over a mean follow-up of 3.4 years. ABO blood group was measured by genotyping in a nested case-control sample of 495 cases with cognitive impairment and 587 controls.Results: Those with blood group AB and those with higher FVIII had an increased risk of cognitive impairment, adjusting for age, race, region, and sex (respective odds ratios 1.82, 95% confidence interval [CI] 1.15-2.90; and 1.24, 95% CI 1.10-1.38 for 40 IU/dL higher FVIII). Mean FVIII was higher in those with blood type AB (142 IU/dL; 95% CI 119-165) compared with O (104 IU/dL; 95% CI 101-107), and FVIII mediated 18% of the association between AB group and incident cognitive impairment (95% CI for mediation 230% to 68%).Conclusions: Blood group AB and higher FVIII were associated with increased incidence of cognitive impairment in this prospective study. The association of blood group AB with incident cognitive impairment was not significantly mediated by FVIII levels. There is a growing understanding that cardiovascular disease (CVD) and cognitive impairment share many common risk factors. Hypertension, 1,2 elevated cholesterol, 3 hyperglycemia, 2,4 and obesity 4,5 are all associated with longitudinal declines in cognitive function and dementia. Higher levels of the hemostatic markers von Willebrand factor (vWF), coagulation factor VIII (FVIII), and D-dimer have also been related to risk of cognitive impairment and dementia. [6][7][8][9] ABO blood group is associated with many forms of CVD, including coronary heart disease (CHD), stroke, and venous thromboembolism. [10][11][12] In general, individuals with blood group O have a reduced risk of CVD.13,14 Non-O blood types are associated with higher levels of vWF and FVIII, procoagulant proteins that circulate as a complex in blood, 11,12 because the ABO antigen affects clearance of vWF.15 Levels of both vWF and FVIII are associated with thrombosis, 16 and were recently linked to dementia risk. 17 A recent report demonstrating an association between blood type AB and stroke risk found that 60% of that association was mediated by differences in FVIII level. 18Although ABO blood group is a CVD risk factor, we are not aware of studies on its relationship with cognitive impairment. In this study, we examined the relationships among ABO group, FVIII, and incident cognitive impairment in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. We hypothesized that blood group A, B, or AB would be associated with an increased risk of cognitive impairment relative to group O.