Self-reported sensory impairment and social participation among Korean older adults: mediating roles of cognitive function and digital technology use.

OBJECTIVES: This study investigates the correlation between self-reported sensory impairment, cognitive function, digital technology use, and social participation among older adults in South Korea. METHOD: Data from the 2020 National Survey of Older Koreans, comprising a nationally representative sample of 7849 individuals aged 65 years or older, were analyzed. A serial mediation analysis (Model = 6) was conducted using the PROCESS macro for SPSS. RESULTS: Following adjustment for covariates, cognitive function and digital technology use serially mediated the relationship between self-reported sensory impairment and social participation among older adults (B = -0.0020, SE = 0.0005, 95% confidence interval [CI] = [-0.0030, -0.0010]). Specifically, self-reported sensory impairment exhibited a negative correlation with cognitive function (B = -0.3277, SE = 0.0753, p < .001), which was positively associated with digital technology use (B = 0.0763, SE = 0.0056, p < .001), subsequently linking to enhanced social participation (B = 0.0784, SE = 0.0037, p < .001). CONCLUSION: Through cross-sectional analysis, this study confirms that self-reported sensory impairment in older adults may precede cognitive decline, hindering digital technology use and reducing social participation. Early diagnosis and treatment are crucial in preventing cognitive decline, while age-friendly digital devices may alleviate cognitive burden and promote social engagement.

Evaluation of changes in lacrimal canaliculi width depending on temperature and viscosity of eye drops using spectral-domain optical coherence tomography in dogs.

OBJECTIVE: To evaluate the changes in the width of the lower lacrimal canaliculi (LC) upon instillation of artificial tears (AT) at different temperatures and viscosities using spectral-domain optical coherence tomography (SD-OCT). ANIMAL STUDIED: Eight eyes of four client-owned adult dogs. PROCEDURES: Imaging of lower LC was performed under general anesthesia. AT at temperatures of 2°C, 20°C, and 38°C, and a high-viscosity tear gel of 20°C, were topically instilled in 100 µL volumes. SD-OCT tracked LC width changes following each instillation. RESULTS: The average baseline width of the LC was 96.38 ± 30.18 µm. The 2°C AT expanded LC width to 183.50 ± 44.11 µm, returning to baseline in 5.00 ± 1.31 min. The 20°C AT resulted in a width of 155.25 ± 35.79 µm, with a 3.88 ± 1.25 min return. The 38°C AT expanded LC width to 131.75 ± 29.49 µm, with a 2.25 ± 0.89 min return. The high-viscosity tear gel expanded LC width to 208.57 ± 56.31 µm, with remained expanded for 10 or more minutes. In temperature comparisons, the 2°C and 20°C AT significantly expanded the LC width more and had longer return times than the 38°C AT (p < .05). Viscosity comparisons showed higher viscosity eye drops significantly expanded LC width more than lower viscosity eye drops (p < .05). CONCLUSIONS: This study found that lower temperature and higher viscosity of eye drops had tendency to result in a wider expansion of the LC width. Additionally, the return time to baseline for LC width tended to be longer with eye drops of lower temperature and higher viscosity. This finding could be helpful in advancing future research on tear dynamics.

Types of bereavement and depressive symptoms among older adults: Does race/ethnicity matter?

AIM: To explore racial/ethnic differences in relation between types of bereavement and depressive symptoms among older adults in the USA. METHODS: The sample limited to racially/ethnically diverse adults aged ≥55 (n = 879) was drawn from the third wave of the National Social Life, Health, and Aging Project (NSHAP). The NSHAP provides self-identified racial/ethnic categories (non-Hispanic Whites, Blacks, and Hispanics) of respondents who were categorized into three groups by experience of bereavement: non-loss, spousal loss, and parental loss. Using the weights, a two-way analysis of covariance with Bonferroni post-test was conducted to explore the main effect of types of loss and race/ethnicity and their interaction effects on depressive symptoms. RESULTS: Spousal loss reported higher levels of depressive symptoms than non-loss or parental loss. Based on the interaction between types of loss and race/ethnicity; however, distinctive patterns were observed. Blacks and Hispanics who lose a parent reported significantly higher levels of depressive symptoms than non-Hispanic Whites did. CONCLUSIONS: An increase in depressive symptoms after bereavement manifested distinctively based on racial/ethnic background and the relationship with the deceased. This implies that it is necessary to develop coping strategies concerning race/ethnicity and whom they lose. Geriatr Gerontol Int 2024; 24: 266-272.

The dark side of social capital: Geographic differences in COVID-19 preventive behaviors among older adults in South Korea.

AIM: The present study examined whether geographic location (i.e., rural vs. urban areas) moderated the relationship between social capital and COVID-19 preventive behaviors among older adults in South Korea. METHODS: Participants were a nationally representative sample of 61 075 Korean adults aged 65 years or older from the 2021 Community Health Survey by the Korea Disease Control and Prevention Agency. The moderation analysis was conducted with PROCESS. RESULTS: After adjusting for covariates, the moderation analysis showed a significant moderation effect of geographic location on the relationship between social capital and COVID-19 preventive behaviors among older adults in South Korea. Specifically, in urban areas, older adults with higher social capital were more likely to adhere to COVID-19 preventive behaviors. However, social capital negatively impacted older adults' COVID-19 preventive behaviors in rural areas. CONCLUSIONS: Findings suggest that social capital is not always helpful for maintaining COVID-19 preventive behaviors among older adults in South Korea. The social characteristics of geographic location need to be considered when initiating COVID-19 prevention campaigns in South Korea. Geriatr Gerontol Int 2024; 24: 377-384.

Is living alone beneficial to older adults during the COVID-19 pandemic? Examining associations between living arrangements and life satisfaction by gender in Korea.

OBJECTIVES: This study examines associations between living arrangements and life satisfaction and the associated effects of gender among Korean older adults during the pandemic. METHOD: Data were drawn from the 2020 National Survey of Older Koreans-a nationally representative survey. Living arrangements were categorized into four groups: living alone; living with spouse only; living with family and spouse; and living with family without spouse. Logistic regression analyses were used to examine associations between living arrangements and life satisfaction measured as a binary outcome. RESULTS: Older adults living alone were more likely to be satisfied with life compared with those who lived with a spouse only. However, living alone became nonsignificant after controlling for social contact with friends or neighbors and social participation. Interestingly, there was a significant interaction between living arrangements and gender, showing that living alone was beneficial to older women but not to men. Subsample analysis by gender confirmed that older women living alone had a greater likelihood of being satisfied with life than those living with a spouse only, whereas men living alone had lower life satisfaction. CONCLUSION: Findings suggest that living alone is not always deleterious to older adults, particularly women. During the pandemic, older Korean women living with their spouse and/or family might be less satisfied with life due to the dual burden of family care and housework, associated with traditional gendered norms and social context.

A longitudinal examination of psychosocial mechanisms linking discrimination with objective and subjective sleep.

OBJECTIVE: Although chronic discrimination negatively impacts sleep, the cross-sectional nature of most research limits the understanding of how changes in discrimination over time are associated with sleep health. Therefore, the aims of this study were to explore the: (1) longitudinal association between daily discrimination and subjective and objective sleep; (2) mediating roles of anxiety and social well-being; and (3) moderating role of change in discrimination over time. METHODS: An archival analysis was completed using data from the Midlife in the United States study across 3 timepoints. Participants were primarily female-identifying, white, and college-educated. Measures included Pittsburgh Sleep Quality Index (N = 958), sleep diaries (N = 307), and actigraphy (N = 304). Daily discrimination, the Social Well-Being Scale, and the Mood and Anxiety Symptom Questionnaire were also administered. Moderated parallel mediations were performed using the PROCESS macro controlling for depressive symptoms. RESULTS: More discrimination at time 1 was associated with worse global sleep quality (b = 0.10 and p = .001) and daily sleep quality (b = 0.03 and p = .02) and worse objective sleep-onset latency (b = 0.93 and p = .02), wake after sleep onset (b = 1.09 and p = .002), and sleep efficiency (b = -0.52 and p < .001) at time 3. Social well-being mediated the associations between discrimination and subjective global sleep quality 95% CI [0.00, 0.03] and daily sleep quality 95% CI [0.00, 0.01] and objective TST 95% CI [0.00, 0.96] when discrimination was increasing or chronic. Anxiety mediated the discrimination-global sleep quality association regardless of changes in discrimination. CONCLUSIONS: Discrimination showed durable associations with a broad array of sleep outcomes across a 10-year period. Anxiety and social well-being linked discrimination to subjective sleep outcomes, illustrating the importance of psychosocial well-being for sleep health in those experiencing discrimination.

The Role of Purpose in Life in the Relationship Between Widowhood and Cognitive Decline Among Older Adults in the U.S.

OBJECTIVES: The objective of this study was to examine the role of purpose in life in the relationship between widowhood and cognitive decline. METHODS: This study used a sample of 12,856 respondents (20,408 observations) collected from a national panel survey, the 2006-2014 waves of the Health and Retirement Study (HRS), that sampled older adults aged 50 or older. The study estimated growth-curve models with years since spousal death, purpose in life, and interaction between the two to predict cognition using three measures-total cognition, fluid, and crystallized intelligence scores. We also estimated growth-curve models by sex, race/ethnicity, and education. RESULTS: While years since spousal death negatively correlated with cognition, purpose in life positively correlated with cognition. Furthermore, purpose in life had a moderating effect on the relationship between years since spousal death and cognition. This effect was found by using total cognition (coef. = 0.0515; z = 2.64; p < 0.01) and fluid intelligence scores (coef. = 0.0576; z = 3.23; p < 0.05). The same effects were salient among females (coef. = 0.0556; z = 2.19; p < 0.05), Whites (coef. = 0.0526; z = 2.52; p < 0.05), and older adults with more education (coef. = 0.0635; z = 2.10; p < 0.05). CONCLUSION: Higher purpose in life relates to the negative correlations between widowhood and cognition of older adults. Educational programs improving purpose in life are a possible avenue for reducing the adverse effect of widowhood on cognition and warrant future exploration.

Multi-group frailty trajectories among older Koreans: Results from the Korean Longitudinal Study of Aging.

BACKGROUND: Studies that examined changes in frailty in older populations have been increasing. However, frailty patterns are often portrayed as having single trajectories corresponding to age, and different courses of change in frailty and related factors remain unexplored. OBJECTIVES: We aimed to identify distinct frailty trajectories over time and examine the relationship of frailty trajectories with the sociodemographic and lifestyle-related factors among older Koreans. METHODS: We used data of 3160 community-dwelling Korean adults aged ≥65 years from the Korean Longitudinal Study of Aging (2006-2016). We conducted the analyses using group-based trajectory modeling, analysis of variance or chi-square tests, and multinomial logistic regression. RESULTS: We identified three frailty trajectory groups among older Koreans: no frailty, increasing frailty, and high frailty based on a deficit-related frailty measure. Each frailty trajectory group showed unique sociodemographic and lifestyle characteristics. Compared to individuals in the no frailty group, those in the increasing frailty group were more likely to be older, less educated, unemployed, current smokers, and current drinkers. Compared to those in the no frailty group, individuals in the high frailty group were more likely to be older, unemployed, current drinkers, and without regular exercise. CONCLUSIONS: Using longitudinal data over a 10-year period, we identified multiple frailty trajectories in a cohort of older Koreans, which highlights a significant heterogeneity in frailty development. Our findings suggest the importance of socioeconomic status in determining different patterns of frailty change and the role of lifestyle factors in delaying frailty.

Racial/Ethnic Differences in the Longitudinal Effects of Fear of Falling on Falls.

INTRODUCTION: Recent evidence suggests that the effects of fear of falling on falls may differ by race/ethnicity. This study investigated whether race/ethnicity (white, black, and Hispanic) moderated the longitudinal effects of fear of falling on the incidence of falling and having a repeated fall among community-dwelling older adults. METHODS: We used data from 2011 to 2018 of the National Health and Aging Trends Study (NHATS). These included a total of 19,516 person-intervals from 5,113 respondents. Any self-reported fall in the past year was the outcome variable with baseline fear of falling as the predictor and race/ethnicity as the moderator. Covariates included self-reported sociodemographic information, probable depression, chronic conditions, functional impairment, pain, insomnia symptoms, the Clock Drawing Test, the Short Physical Performance Battery, and grip strength. RESULTS: Among respondents who had no experience of falling at baseline, baseline fear of falling increased the odds of having a new onset of fall at 1-year follow-up significantly among blacks, compared to whites (odds ratio [OR] = 1.85, 95% confidence interval [CI] = 1.44-2.38). No significant difference was found for Hispanics. Among respondents who already fell at baseline, baseline fear of falling increased the odds of having a repeated fall at 1-year follow-up significantly among Hispanics, compared to whites (OR = 1.91, 95% CI = 1.06-3.44). No significant difference was found for blacks. CONCLUSIONS: Clear evidence of racial/ethnic differences was found in the relationship between fear of falling and falls among community-dwelling older adults in the USA. Special attention should be paid to black older adults with a fear of falling but have not fallen down recently and Hispanics with fear of falling and have fallen in the past year. Readily available educational programs should be actively advertised to older adults to reduce the fear of falling, and at the same time, culturally tailored educational programs should be developed for older adults from racial/ethnic minority backgrounds.

The Role of Polygenic Score and Cognitive Activity in Cognitive Functioning Among Older Adults.

BACKGROUND AND OBJECTIVES: This study explored whether the intensity of cognitive activities could moderate the relationship between a genetic predisposition for developing Alzheimer's disease (AD) and cognitive functioning among older adults in the United States. Furthermore, we examined whether the same moderating effects were dependent on different measures of cognition. RESEARCH DESIGN AND METHODS: We used a data set from the 2000-2014 waves of the Health and Retirement Study and the Consumption and Activities Mail Survey. Our sample included 3,793 individuals aged 50 or older. We used the polygenic score (PGS) for AD as a genetic trait for cognitive functioning. Reading, listening to music, using a computer, playing cards/games/solving puzzles, singing/playing musical instruments, and creating art and crafts were included as cognitive activities, and TV viewing as passive activities. We used total cognition, fluid intelligence, and crystallized intelligence as proxies for cognitive functioning. Growth-curve models were conducted. RESULTS: After controlling for covariates, we found that reading books, using a computer, and playing cards/games/solving puzzles had a positive effect on cognitive functioning. An additional hour spent reading books moderated the negative effect of AD PGS on cognition. The measure of fluid, when compared with crystallized intelligence, appeared to drive these results. DISCUSSION AND IMPLICATIONS: Reading could be a protective factor against cognitive decline among older adults who are genetically predisposed to developing AD. Implications for individuals, caregivers, clinicians, and policymakers are suggested. Furthermore, the onset of AD in those at greater genetic risk may be delayed with this intervention.

Associations Between Perceived Environmental Pollution and Mental Health in Middle-Aged and Older Adults in East Asia.

Given the widely used objective measures of environmental pollution in previous research, this study investigated subjective measures in relation to mental health among middle-aged and older adults in three East Asian countries-China, Japan, and South Korea. The samples from the 2010 East Asian Social Survey included 2502 Chinese, 1794 Japanese, and 871 South Korean adults aged 40 and older. Linear regression models were used to examine the associations between mental health measure (SF-12) and 4 perceived environmental pollution indicators (ie, air, water, noise, and pollution index). Greater perceived pollution indicators, as well as the perceived pollution index, were associated with poorer mental health, even after adjusting for covariates in all three countries. Although results need to be further verified in future research, national-level efforts to improve perceptions of environmental pollution may be useful to enhance the mental health of East Asian middle-aged and older adults.

Digital technology use and depressive symptoms among older adults in Korea: beneficial for those who have fewer social interactions?

OBJECTIVES: Our study examines the relationship between digital technology use and depressive symptoms among older Koreans and whether social interaction moderates the relationship. METHODS: The data were drawn from the 2017 Survey of Living Conditions and Welfare Needs of Korean Older Persons, a nationally representative survey. Digital technology use was measured by the number of digital functions that respondents perform with their electronic devices. Social interactions were measured by the frequencies of face-to-face and remote connections with friends or neighbors. Relationships were estimated with multiple regression analyses. RESULTS: Digital technology use was inversely associated with depressive symptoms even after adjusting for covariates including cognitive function. Both remote and face-to-face connections with friends or neighbors were associated with fewer depressive symptoms. An interaction between digital technology use and remote contact also was detected: the effect of digital technology use on depressive symptoms was more beneficial for older adults with infrequent remote contact with friends or neighbors than for those with frequent remote contact. CONCLUSION: Findings suggest that digital technology use can reduce depressive symptoms of older adults, especially those who have fewer social interactions. Educating older adults to increase their digital literacy level and use of remote interactions may improve their psychological wellbeing, perhaps even during times of a viral pandemic.

Mental Health of Asian American Older Adults: Contemporary Issues and Future Directions.

Given the increased attention to older Asian Americans due to their increasing numbers in the United States, this article aims to provide a collective appraisal of older Asian American mental health issues by reviewing trends in older Asian American mental health research over the past 2 decades. This review article provides an overview of the current state of mental health and care research on older Asian Americans and vital factors associated with older Asian American mental health and care. We also identify gaps in current research on Asian American mental health issues and propose 5 potential areas for future research into which gerontologists need to put more effort during the next decade. Ways to reduce disparities in mental health and improve the quality of mental health of older Asian Americans are also discussed.

Erratum to: Mental Health of Asian American Older Adults: Contemporary Issues and Future Directions.

[This corrects the article DOI: 10.1093/geroni/igaa037.].

Age Discrimination and Suicidal Ideation Among Korean Older Adults.

OBJECTIVE: We examined the role of age discrimination in suicidal ideation among community-dwelling older adults in South Korea. METHODS: We analyzed adults aged 65 or older residing in Korea drawn from the 2014 Survey of Living Conditions and Welfare Needs of Korean Older Persons (total unweighted n = 10,279; total weighted N = 6,280,588). Data were analyzed using chi-square, t tests, and logistic regression analyses. RESULTS: Results from logistic regression analysis showed that after adjusting for covariates, Korean elders who experienced age discrimination had 2.26 times higher odds of having suicidal ideation than those who did not. CONCLUSIONS: The experience of age discrimination increased the risk of suicidal ideation among Korean elders. Identifying ways to reduce age discrimination may be an effective means of reducing suicidal ideation, which would, in turn, potentially decrease suicide rates among older adults. There may be cross-cultural clinical implications and variations due to belief systems surrounding respect for older adults.

The association between the number of chronic health conditions and advance care planning varies by race/ethnicity.

Objectives: Although a national consensus exists on the need to increase the rates of advance care planning (ACP) for all adults, racial/ethnic differences in ACP have been consistently observed. This study investigated the intersection of racial/ethnic differences and the number of chronic health conditions on ACP among middle-aged and older adults in the United States.Method: Responses from 8,926 adults from the 2014 wave of the Health and Retirement Study were entered into multilevel hierarchical logistic regression analyses with generalized linear mixed models to predict ACP focused on assigning a durable power of attorney for healthcare (DPOAHC) and having a written living will after adjusting for covariates.Results: We found a significant positive relationship between the number of chronic health conditions and ACP. Non-Hispanic Blacks/African Americans and Hispanics were less likely to engage in ACP than non-Hispanic Whites/Caucasians. Racial/ethnic disparities were even starker for completing a living will. The number of chronic health conditions had a greater effect for Hispanics than non-Hispanic Whites/Caucasians on ACP through assigning a DPOAHC and having a living will. The initial disparity in ACP among Hispanics with no chronic health conditions decreased as the number of chronic health conditions increased.Conclusion: Our findings suggest that more chronic health conditions increase the likelihood that Hispanics will complete ACP documents. These ACP differences should be highlighted to researchers, policymakers, and healthcare professionals to reduce stark racial/ethnic disparities in ACP. A comprehensive and culturally caring decision-making approach should be considered when individuals and families engage in ACP.

Body mass index and trajectories of cognitive decline among older Korean adults.

Objectives: This study examined the relationship between body mass index (BMI) and trajectories of cognitive decline among older Korean adults.Methods: Participants were a nationally representative sample of 5126 Korean adults aged 60 or older from the Korean Longitudinal Study of Aging (KLoSA: 2006-2014). The main outcome variable, cognitive function, was measured with the Korean Mini-Mental State Examination (K-MMSE). According to the BMI values, respondents were divided into four groups at each wave: underweight (<18.5 kg/m2), healthy weight (18.5-22.9 kg/m2), overweight (23.0-24.9 kg/m2), and obese (≥25.0 kg/m2). Growth curve modeling was used to analyze the relationship of interest.Results: The growth curve modeling revealed that, regardless of BMI values, cognitive functioning declined as participants aged, and the rate of cognitive decline accelerated with age. After adjusting for all covariates, older Korean adults who were underweight displayed steeper declines in cognitive functioning, compared to those with a healthy weight. Conversely, overweight or obese older adults showed a much slower cognitive decline as they aged, after adjusting for covariates.Conclusion: Compared to people with a healthy BMI, people with a low BMI may be at risk for cognitive dysfunction, whereas a high BMI could function as a protective factor for cognitive dysfunction in older adulthood. Future research examining the mechanism for these trajectories are needed. Implications for research and clinical practice are discussed.

Measurement Equivalence of the Subjective Well-Being Scale Among Racially/Ethnically Diverse Older Adults.

OBJECTIVES: The present study examined differences by race/ethnicity in the measurement equivalence of the Subjective Well-Being Scale (SWBS) among older adults in the United States. METHOD: Drawn from the National Health and Aging Trends Study (NHATS), adults aged 65 years and older from three racial/ethnic groups (n = 1,200) were selected for the analyses from a total of 8,245: 400 non-Hispanic Whites, 400 African Americans, and 400 Hispanics/Latinos. We tested measurement equivalence of the SWBS that is categorized into three domains: positive and negative affect (four items), self-realization (four items), and self-efficacy and resilience (three items). Multiple-group confirmatory factor analyses were conducted to test measurement invariance. RESULTS: After adjusting for age, gender, and education, the underlying construct of the SWBS was noninvariant across three racial/ethnic elderly groups. DISCUSSION: Findings suggest that the comparison of latent means (especially for positive and negative affect and self-realization) across racial/ethnic groups is highly questionable. The SWBS should be used with extreme caution when it is applied to diverse racial/ethnic elderly groups for comparison purposes. Implications are discussed in cultural and methodological contexts.

The Relationship between Physical-Mental Comorbidity and Subjective Well-Being among Older Adults.

OBJECTIVES: The present study examined the relationship between types and severity of physical-mental comorbidity and subjective well-being (SWB) among older adults. METHODS: The sample was drawn from the National Health and Aging Trends Study (NHATS) collected in 2011. A total of 6,945 older adults aged 65 to 105 were categorized into four groups using 16 common physical health conditions and two mental health problems: no chronic health condition (n = 562, referent), physical health condition (n = 4,946), mental health problem (n = 56), and physical-mental comorbidity (n = 1,380). Outcome variable was self-reported SWB measured with 11 items. Analyses of covariance (ANCOVAs) were used to assess the relationship between types and severity of physical-mental comorbidity and SWB. RESULTS: After adjusting for covariates, older adults with a mental health problem or physical-mental comorbidity reported lower SWB compared to the no chronic health condition group. Physical-mental comorbidity was associated with lower SWB compared to the physical health condition group. Higher severity level of physical-mental comorbidity was associated with decreased SWB. DISCUSSION: Findings suggest that mental health problem and physical-mental comorbidity negatively associated with SWB among older adults. CLINICAL IMPLICATIONS: Integrative interventions should be developed to target mental health issues and comorbid physical-mental health conditions in the older populations.

Factor Structures of Reasons for Immigration Among Older Asian and Latino Immigrants in the United States.

BACKGROUNDS AND OBJECTIVES: Although reasons for immigration are significant predictors of immigrants' health, factor structures of reasons for immigration are still unclear among older immigrants. The present study examined the factor structure of reasons for immigration among older Asian and Latino immigrants in the United States. RESEARCH DESIGN AND METHODS: Drawn from the National Latino and Asian American Study, 396 Latino and 298 Asian immigrants over 55 years of age were selected for analysis. Exploratory factor analysis was conducted for nine items concerning reasons for immigration in each immigrant group. RESULTS: Three factors were extracted from both Asian and Latino immigrant elders: (a) "voluntary reasons" to pursue development, (b) "involuntary reasons" due to uncontrollable situations, and (c) "semivoluntary reasons" regarding family/medical duties. While immigration to join family members was located in the "semivoluntary reasons" factor among older Asian immigrants, it was located in the "voluntary reasons" factor among older Latino immigrants. DISCUSSION AND IMPLICATIONS: These findings suggest that three underlying factors of reasons for immigration should be understood considering the different characteristics of two racial/ethnic groups of immigrants. In addition, a migratory reason to join the family should be considered differently for elderly Asian and Latino immigrants. This three-factor framework of reasons for immigration can help clinicians provide more culturally sensitive interventions for older minority immigrants.