Neighborhood 'Disamenities': local barriers and cognitive function among Black and white aging adults.

BACKGROUND: This study examined the association between cognitive function and three neighborhood 'disamenities' that may pose local barriers to utilizing community resources and increase risk for cognitive decline. METHOD: Using national data from 21,165 urban- and suburban-dwelling Black and white adults (mean age: 67 years) in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study, we assessed global cognitive function through a factor score of five cognitive screening tests. General Additive Mixed Models (GAMM) tested whether residing in areas with more polluting sites, highways, and limited walkability was associated with worse cognitive function. RESULTS: Limited walkability and the presence of polluting sites had a significant negative association with cognitive function after controlling for individual and neighborhood factors. CONCLUSION: Neighborhood disamenities may be linked to cognitive function among aging residents. Identifying neighborhood factors that pose barriers to accessing community resources may inform upstream policy applications to reduce risk for cognitive decline.

Oxygen Impurity-Tuned Structure and Adhesion Properties of the Cu/SiO2 Interface.

The properties of the Cu/SiO2 interface usually deteriorate in the complex atmospheric environment, which may limit its performance and application in the engineering. Using the reactive molecular dynamics method, we investigate how the mechanical behaviors of the Cu/SiO2 interface change as it interacts with oxygen impurities. The interfacial oxidation degree could be enhanced as O2 penetrates into the interface area. This makes the interfacial structure disordered and is not conducive to the survival of Cu-O-Si bondings, which reduces the tensile and shear strengths of the interface. To improve the abrupt bonding property change at the interface and modify the interfacial adhesion properties, O impurities are introduced at the Cu interstitial sites near the interface. By doing so, the interface strength can be significantly enhanced due to the production of typical O-Cu-O bondings while the regular interfacial structure is retained. Meanwhile, the interfacial oxidation also changes the tensile failure site and shearing sliding mode of the interface, i.e., from inside the oxide to between oxide and Cu. The findings of this work may not only advance the understanding of interaction mechanism between oxygen impurities and the Cu/SiO2 interface but also provide new insights into optimizing the bonding properties of the metal/oxide interface.

Standard Deviation Effect of Average Structure Descriptor on Grain Boundary Energy Prediction.

The structural complexities of grain boundaries (GBs) result in their complicated property contributions to polycrystalline metals and alloys. In this study, we propose a GB structure descriptor by linearly combining the average two-point correlation function (PCF) and standard deviation of PCF via a weight parameter, to reveal the standard deviation effect of PCF on energy predictions of Cu, Al and Ni asymmetric tilt GBs (i.e., Σ3, Σ5, Σ9, Σ11, Σ13 and Σ17), using two machine learning (ML) methods; i.e., principal component analysis (PCA)-based linear regression and recurrent neural networks (RNN). It is found that the proposed structure descriptor is capable of improving GB energy prediction for both ML methods. This suggests the discriminatory power of average PCF for different GBs is lifted since the proposed descriptor contains the data dispersion information. Meanwhile, we also show that GB atom selection methods by which PCF is evaluated also affect predictions.

A superstable, flexible, and scalable nanofluidic ion regulation composite membrane.

Two-dimensional layered membranes with high and stable ion transport properties have various applications in nanofluidic devices; however, their construction remains a considerable challenge. Herein, we develop a superstable aramid nanofiber/graphite composite membrane with numerous one-dimensional and two-dimensional nano-confined interspaces for ultrafast ion transport. The fabricated flexible and scalable membrane exhibits high tensile strength (∼115.3 MPa) even after immersion in water for 90 days. Further, the aramid nanofiber/graphite conductor features the surface-charge-governed ion transport behavior. The ionic conductivity of the membrane at a low potassium chloride concentration of 10-4 mol/L can be enhanced by 16 times that of the bulk counterpart. More importantly, its structure and ionic conductivity remain unchanged even after immersion in different harsh solutions (e.g., acid, base, and ethanol) for over 30 days. Molecular dynamics simulations reveal that the superstability of the membrane is attributable to the robust interchain interactions within the aramid nanofibers and the strong interfacial interactions between the aramid nanofibers and graphite nanosheets. This study highlights the superior structural stability of the proposed flexible and scalable aramid nanofiber/graphite composite membrane, which could be employed in advanced nanofluidic devices for application under extreme working environments.

Developing a short screener for acquiescent respondents.

BACKGROUND: Acquiescent response style (ARS) refers to survey respondents' tendency to choose response categories agreeing to questions regardless of their content and is hypothesized as a stable respondent trait. While what underlies acquiescence is debatable, the effect of ARS on measurement is clear: bias through artificially increased agreement ratings. With certain population subgroups (e.g., racial/ethnic minorities in the U.S.) are associated with systemically higher ARS, it causes concerns for research involving those groups. For this reason, it may be necessary to classify respondents as acquiescers or a nonacquiescers, which allows independent analysis or accounting for this stylistic artifact. However, this classification is challenging, because ARS is latent, observed only as a by-product of collected data. OBJECTIVES: To propose a screener that identifies respondents as acquiescers. METHODS: With survey data collected for ARS research, various ARS classification methods were compared for validity as well as implementation practicality. RESULTS: The majority of respondents was classified consistently into acquiescers or nonacquiescers under various classification methods. CONCLUSIONS: We propose a method based on illogical responses given to two balanced, theoretically distant multi-item measurement scales as a screener.

Neighborhood cognitive amenities? A mixed-methods study of intellectually-stimulating places and cognitive function among older Americans.

Neighborhoods structure health and wellbeing in later life. Local spaces can encourage physically active and socially engaged aging in place, and may also nurture opportunities for cognitively-stimulating creative and complex activities such as reading; playing and listening to music; learning; and engagement in galleries, performing arts, and museums. These activities are associated with better cognitive health outcomes. In this exploratory sequential mixed-methods study, thematic analysis of interviews and ethnographic fieldwork with 125 diverse older adults in the Minneapolis (MN) metropolitan area (mean age 71 years) explored how and where older adults participated in intellectually-stimulating neighborhood activities. Thematic analysis indicated that libraries, higher education campuses, and sites of arts and culture were frequented intellectually-stimulating places, with racial differences in perception and usage. The qualitative findings informed quantitative investigation of associations between these amenities and cognitive function in a large national sample of aging Black and white Americans (n=21,165, mean age 67 years) in the Reasons for Geographic and Racial Differences in Stroke Study. We used multilevel linear regression models to examine whether living in a neighborhood with higher kernel densities of libraries, higher education campuses, and arts/cultural sites had a net positive effect on cognitive function. Analysis identified statistically significant positive associations between arts/cultural sites and cognitive function, with a significantly larger effect size for white versus Black participants. The study contributes new evidence to the emerging ecological model of cognitive health. It critically considers racial disparities in access to health-promoting neighborhood infrastructure and opportunities to age well in place.