Racial and ethnic differences in cognitive health appraisals: a comparison of non-Hispanic White, non-Hispanic Black, and Hispanic older adults

OBJECTIVES

To investigate the relationship between cognitive performance and cognitive health appraisals across non-Hispanic White, non-Hispanic Black, and Hispanic older adults in the United States and to explore within-group variations by examining interactions between cognitive performance and background and health variables.

METHOD

The sample (N = 3,099) included 2,260 non-Hispanic White, 498 non-Hispanic Black, and 341 Hispanic adults aged 65 or older, from the 2016-2017 Harmonized Cognitive Assessment Protocol. Regression models of cognitive health appraisals, indicated by self-rated cognitive health, were examined in the entire sample and in racial and ethnic subgroups to test direct and interactive effects of cognitive performance, indicated by the Mini-Mental State Examination (MMSE).

RESULTS

The regression model for the entire sample showed direct effects of cognitive performance and race/ethnicity on cognitive health appraisals, as well as a significant interaction between cognitive performance and being non-Hispanic Black. Cognitive performance and cognitive health appraisals were positively associated in non-Hispanic Whites but not significantly associated in non-Hispanic Blacks. Our subsequent analysis within each racial/ethnic group showed that the effect of cognitive performance in non-Hispanic Blacks and Hispanics became either reversed or nonsignificant when background and health variables were considered. Modification by age or chronic medical conditions in each racial and ethnic group was also observed.

CONCLUSION

Overall, these findings suggest that perceptions and appraisals of cognitive health vary by race and ethnicity and hold implications for how these differences should be considered in research and practice with diverse groups of older adults.

Older Korean Americans' concern about Alzheimer's disease: the role of immigration-related factors and objective and subjective cognitive status

Objectives: The present study examined the associations between immigration-related factors and objective and subjective cognitive status with older Korean Americans' concern about developing Alzheimer's Disease (AD). It was hypothesized that (1) AD concern would be associated with immigration-related factors and (2) self-rated cognitive status would mediate the relationship between cognitive performance (Mini Mental State Examination (MMSE) scores) and concern about AD.Method: Using data from the Study of Older Korean Americans (n = 2061, mean age = 73.2; 66.8% female), the direct and indirect effect models were tested.Results: Korean American immigrants with a higher level of acculturation had better cognitive performance, more positive self-ratings of cognitive status, and a lower level of concern about AD. Both poor cognitive performance and negative self-ratings of cognitive status were associated with increased concern about AD. Supporting the mediation hypothesis, the indirect effect of cognitive performance on AD concern through self-rated cognitive status was significant (bias corrected 95% confidence interval for the indirect effect = -.012, -.003).Conclusion: The mediation model not only helps us better understand the psychological mechanisms that underlie the link between cognitive status and AD concern but also highlights the potential importance of subjective perceptions about cognitive status as an avenue for interventions.

Associations of a social network typology with physical and mental health risks among older adults in South Korea

OBJECTIVES

The objectives of this study were to (1) develop an empirical typology of social networks in older Koreans; and (2) examine its effect on physical and mental health.

METHOD

A sample of 6900 community-dwelling older adults in South Korea was drawn from the 2014 Korean National Elderly Survey. Latent profile analysis (LPA) was conducted to derive social network types using eight common social network characteristics (marital status, living arrangement, the number and frequency of contact with close family/relatives, the number and frequency of contact with close friends, frequency of participation in social activities, and frequency of having visitors at home). The identified typologies were then regressed on self-rated health and depressive symptoms to explore the health risks posed by the group membership.

RESULTS

The LPA identified a model with five types of social network as being most optimal (BIC = 153,848.34, entropy = .90). The groups were named diverse/family (enriched networks with more engagement with family), diverse/friend (enriched networks with more engagement with friends), friend-focused (high engagement with friends), distant (structurally disengaged), and restricted (structurally engaged but disengaged in family/friends networks). A series of regression analyses showed that membership in the restricted type was associated with more health and mental health risks than all types of social networks except the distant type.

CONCLUSION

Findings demonstrate the importance of family and friends as a source of social network and call attention to not only structural but also non-structural aspects of social isolation. Findings and implications are discussed in cultural contexts.

Effects of longitudinal baffles on particles settling in a sedimentation basin

This study was conducted to evaluate the effects of longitudinal baffles on particles settling performance within a full-scale sedimentation basin with a flow rate of 1,000 m(3)/hr. Comparative experiments on turbidity removal efficiency and sludge deposit distribution were performed in longitudinally baffled and non-baffled sedimentation basins. The turbidity removal rate in the baffled sedimentation basin was observed to be higher than that in the non-baffled basin. In addition, the depth of the sludge deposit in the baffled sedimentation basin was approximately 20% less than that in the non-baffled sedimentation basin, and the sludge concentration was 10% higher. To explain these results and to further investigate the effects of longitudinal baffles, the authors performed computational fluid dynamics (CFD) simulation for both basin types. The results of this CFD simulation indicated that the flow, particularly near the outlet orifice, was more stable in the longitudinally baffled sedimentation basin. Moreover, it could be concluded that the longitudinal baffle enables a fully developed flow and is thus more effective for sedimentation.

An evaluation of preferred lip positions according to different age groups

The purpose of this study was to compare preferred facial profiles rated by different age groups. An average profile of each gender was constructed from subjects with normal occlusions. Each average profile was located in the centre, and then the lips were protruded or retruded in six 1mm increments in each direction. 70 lay people were divided into 3 groups: young adult (20-39 years); middle-aged (40-54 years); and senior (55-70 years). They were asked to rank their 3 most preferred profiles for each gender. The distribution of the most pleasing profile was compared according to age groups by the Kruskal-Wallis test and according to the rater's gender by the Mann-Whitney U-test. There was a significant difference between the three age groups regarding the preferred male and female profiles (P<0.001). Both the middle-aged and the senior groups tended to select a slightly more retruded lip/flat profile than the young adult group. There was no gender dimorphism in the selection of the preferred profile. The young adult group preferred the straight profile while the middle-aged and senior groups favoured the slightly retruded profile. This may provide useful information for treatment planning in orthodontics and orthognathic surgery.

Changes in intrapulpal temperature after Er:YAG laser irradiation

OBJECTIVE

This study was performed to investigate the changes in temperature induced by an Er:YAG laser irradiation and to find the means to minimize potential thermal damage due to temperature rise after irradiation.

BACKGROUND DATA

Intrapulpal temperature rise was found to last after irradiation at times, although the addition of appropriate water spray during tooth ablation by Er:YAG laser produced efficient ablation with little thermal damage.

METHODS

To investigate intrapulpal temperature change, each extracted tooth specimen was embedded into a resin block and temperature-measuring probes were placed on the irradiated and the opposite pulpal walls. An Er:YAG laser irradiation was performed at 300 mJ/pulse and 20 Hz, with a water flow rate of 1.6 mL/min for 3 sec. Each lasing was followed by (1) no application of post-irradiation water spray, (2) post-irradiation water spray for 1 sec and (3) for 2 sec.

RESULTS

No significant temperature change was found on the irradiated pulpal wall during Er:YAG laser, while there existed significant temperature rise on the irradiated pulpal wall after irradiation. However, the addition of water spray for 1 or 2 sec after irradiation significantly decreased intrapulpal temperature compared to no application of post-irradiation water spray. There were no significant differences between the 1- and 2-sec groups.

CONCLUSION

It is suggested that the addition of water spray for 1 or more seconds after irradiation reduces post-irradiation temperature rise, possibly leading to thermal damage on the dental pulp tissue.

Modeling of particle removal in the first coarse media of direct horizontal-flow roughing filtration

Horizontal-Flow Roughing Filtration (HRF) is an alternative pretreatment method e.g. prior to Slow Sand Filtration (SSF). However, some of its limitations are that the effluent quality drops drastically at higher turbidity (>200NTU) and at higher filtration rate (>1 m h(-1)). To overcome these drawbacks, we suggested Direct Horizontal-Flow Roughing Filtration (DHRF), which is a modified system of Horizontal-Flow Roughing Filtration (HRF) by addition of a low dose of coagulant prior to filtration. To optimize the DHRF configuration, a conceptual and mathematical model for the coarse compartment has been developed in analogy with multi-plate settler. Data from simple column settling test can be used in the model to predict the filter performance. Furthermore, the model developed herein has been validated by successive experiments. The conventional column settling test has been found to be handy and useful to predict the performance of DHRF for different raw water characteristics (e.g. coagulated or uncoagulated water, different amounts of organic matter, etc.) and different initial process conditions (e.g. coagulant dose, mixing time and intensity, etc.). An optimum filter design for the coarse compartment (grain size 20 mm) has been found to be of 3m h(-1) filtration rate with filter length of 4-4.5 m.

Examining the effect of length/width ratio on the hydro-dynamic behaviour in a DAF system using CFD and ADV techniques

Dissolved air flotation (DAF) is a solid-liquid separation system that uses fine bubbles rising from the bottom to remove particles in water. In this study, we investigated the effect of L/W(L; length, W; width) on the hydrodynamic behavior in a DAF system using CFD (computational fluid dynamics) and ADV (acoustic Doppler velocimetry) technique. The factual full-scale DAF system, L/W ratio of 1:1, was selected and various UW ratio conditions (2:1, 3:1,4:1 and 5:1) were simulated with CFD. For modelling, 2-phase (gas-liquid) flow equations for the conservation of mass, momentum and turbulence quantities were solved using a Eulerian-Eulerian approach based on the assumption that a very small particle is applied in the DAF system. Also, for verification of CFD simulation results, we measured the actual velocity at some points in the full-scale DAF system with the ADV technique. Both the simulation and the measurement results were in good accordance with each other. We concluded that the L/W ratio and outlet geometry play an important role for flow pattern and fine bubble distribution in the flotation zone. In the ratio of 1:1, the dead zone is less than those in other cases. On the other hand, in the ratio of 5:1, the fine bubbles were more evenly distributed.

Cytotoxic constituents from Solidago virga-aurea var. gigantea MIQ

Activity-guided fractionation of the whole plant of Solidago virga-aurea var. gigantea M(IQ). (Compositae) has led to the isolation of three cytotoxic compounds, erythrodiol-3-acetate (1), alpha-tocopherol-quinone (2), and trans-phytol (3) from the hexane soluble fraction. It is the first report of those compounds from the genus.

Bioisosterism: interchange of 4-OH to 4-NH2 in vanillin or homovanillin ring of capsaicinoids

A series of 4-amino Capsaicin analogs 15, 17 and 19 were prepared to investigate the bioisosteric effect of 4-amino group, and all these compounds exhibited moderate or weak potency from their analgesic test. From our previous results and others, 4-hydroxyl group as well as 3-methoxy substituent could be crucial for high analgesic activity. This biological result also shows that the activity is sensitive to alkyl chain length in hydrophobic region and the phenylacetic amides 19 are more active than the corresponding urea derivatives 17.

Molecular dynamics simulations of rubredoxin from Clostridium pasteurianum: changes in structure and electrostatic potential during redox reactions

Molecular dynamics simulations of Clostridium pasteurianum rubredoxin in the oxidized and reduced forms have been performed. Good agreement between both forms and crystal data has been obtained (rms deviation of backbone atoms of 1.06 and 1.42 A, respectively), which was due in part to the use of explicit solvent and counterions. The reduced form exhibits an unexpected structural change: the redox site becomes much more solvent-accessible, so that water enters a channel between the surface and the site, but with little actual structural rearrangement (the rms deviation of backbone atoms between the oxidized and reduced is 0.77 A). The increase in solvent accessibility is also seen, although to a much lesser extent, between the oxidized and reduced crystal structures of Pyrococcus furiosus rubredoxin, but no high resolution crystal or nuclear magnetic resonance solution data exist for reduced C. pasteurianum rubredoxin. The electrostatic potential at the iron site and fluctuations in the potential, which contribute to both the redox and electron transfer properties, have also been evaluated for both the oxidized and the reduced simulations. These results show that the backbone plays a significant role (62-70 kcal/mol/e) and the polar side chains contribute relatively little (0-4 kcal/mol/e) to the absolute electrostatic potential at the iron of rubredoxin for both forms. However, both groups contribute significantly to the change in redox state by becoming more polarized and more densely packed around the redox site upon reduction. Furthermore, these results show that the solvent becomes much more polarized in the reduced form than in the oxidized form, even excluding the penetrating water. Finally, the simulation indicates that the contribution of the charged side chains to the electrostatic potential is largely canceled by that of the counterions.

KR-25003, a potent analgesic capsaicinoid

The crystal structure of N-[3-(3,4-dimethylphenyl)propyl] (4-hydroxy-3-methoxyphenyl)acetamide, C20H25NO3, was determined to a final R value of 0.047. The vanilloid, amide and dimethylphenyl groups of the compound are nearly perpendicular with respect to one another. The overall conformation in the crystalline state is somewhat different from that of other capsaicinoids. The molecules are stabilized by intermolecular hydrogen bonds.