Validation of the Korean version of the Summated Xerostomia Inventory among older adults residing in nursing homes.

BACKGROUND: Xerostomia is commonly experienced by older individuals. We sought to develop and evaluate the reliability and validity of the Korean version of the Summated Xerostomia Inventory (K-SXI) among older adults residing in long-term care facilities (LTCFs) in Korea. METHODS: In this secondary data analysis study using cross-sectional data, a cross-cultural adaptation process was conducted for the Korean version before data collection. Data collection was conducted from July 2021 to January 2022, targeting 544 older adults in 16 LTCFs. Data analysis included intraclass correlation coefficient (ICC) for test-retest reliability, and Cronbach's α for internal consistency reliability. Exploratory and confirmatory factor analyses were used to verify construct and convergent validity. Test-retest analysis was performed 6 weeks after baseline. Convergent and concurrent validities were assessed with age group and the xerostomia standard single question, respectively. RESULTS: A total of 544 older adults participated in this study. The mean of total K-SXI score was 11.70 (standard deviation, 4.96) points. The ICC value was calculated to be 0.90, and Cronbach's α of K-SXI was 0.92. Exploratory factor analysis revealed a single factor, explaining 74.8% of the total variance, however, some goodness-of-fit indices of the single factor model were found to be unsuitable in confirmatory factor analysis. The convergent and concurrent validity were supported. CONCLUSION: The present study provides evidence supporting the validity and reliability of the K-SXI for measuring xerostomia in institutionalized older adults in Korea.

Longitudinal changes in frailty prevalence and related factors in older adults living in long-term care facilities.

AIMS: To investigate longitudinal changes in the prevalence of frailty and related factors in older adults residing in long-term care facilities (LTCFs) in Korea. DESIGN: A longitudinal cohort study design. METHODS: Three hundred and fifty adults (aged 65 and older) residing in 10 LTCFs between January 2014 and January 2016 in Korea were initially investigated. Among these, 182 participants were included in the final analysis. Fried's Cardiovascular Health Study index was used to assess frailty based on Freiheit and colleagues. Data analysed included descriptive statistics and repeated-measures multivariate analysis of variance. RESULTS: The prevalence of frailty was 25.8%, 33.5% and 35.2% in 2014, 2015 and 2016, respectively. Differences in dependence of activities of daily living, number of chronic diseases, nutritional status and depression were statistically significant among the normal, pre-frail and frail groups at each year. Overall, from 2014-2016, the percentage of older adults decreased from 9.4-6.0% in the normal group and from 64.8%-58.8% in the pre-frail group, while increasing in the frail group from 25.8%-35.2%. CONCLUSION: The prevalence rate of frailty among older adults living in LTCFs was high and the rate of frail older adults gradually increased over time. IMPACT: Frailty is a comprehensive health condition and a dynamic, changeable state. This longitudinal study showed a high rate of frailty and dynamic change in frailty level over time among residents. Because frailty is dynamic in every older adult over time, management should be tailored according to the individual's state of frailty to prevent functional decline. Development of a comprehensive frailty assessment tool that can easily measure not only physical frailty but also the comprehensive aspects of frailty would be useful for older adults in LTCFs.

Application of the remote microphone method to active noise control in a mobile phone.

Mobile phones are used in a variety of situations where environmental noise may interfere with the ability of the near-end user to communicate with the far-end user. To overcome this problem, it might be possible to use active noise control technology to reduce the noise experienced by the near-end user. This paper initially demonstrates that when an active noise control system is used in a practical mobile phone configuration to minimise the noise measured by an error microphone mounted on the mobile phone, the attenuation achieved at the user's ear depends strongly on the position of the source generating the acoustic interference. To help overcome this problem, a remote microphone processing strategy is investigated that estimates the pressure at the user's ear from the pressure measured by the microphone on the mobile phone. Through an experimental implementation, it is demonstrated that this arrangement achieves a significant improvement in the attenuation measured at the ear of the user, compared to the standard active control strategy. The robustness of the active control system to changes in both the interfering sound field and the position of the mobile device relative to the ear of the user is also investigated experimentally.

Fear of falling and its predictors among community-living older adults in Korea.

OBJECTIVES: To explore the prevalence and predicting factors of fear of falling (FOF) among community-living older adults in Korea. METHODS: Secondary data analysis of the 2011 Korean National Elderly Living Conditions and Welfare Desire Survey was used. Logistic regression analysis was conducted to examine the predictors of FOF. RESULTS: In total, 75.6% of older adults with normal cognition have FOF. Factors associated with an increased risk of FOF in older adults are previous experience with falling (OR = 3.734, 95% CI = 2.996-4.655), limitations in the performance of exercise involving lower extremities (OR = 2.428, 95% CI = 2.063-2.858), being female (OR = 2.335, 95% CI = 2.023-2.694), having more than three chronic diseases (OR = 1.994, 95% CI = 1.625-2.446), limitations in instrumental activities of daily living (IADLs) (OR = 1.745, 95% CI = 1.230-2.477), limitations in the performance of exercise involving upper extremities (OR = 1.646, 95% CI = 1.357-1.997), living without a spouse (OR = 1.626, 95% CI = 1.357-1.948), having poor self-rated health (OR = 1.571, 95% CI = 1.356-1.821), limitations in muscle strength (OR = 1.455, 95% CI = 1.150-1.841), age (≥75 years) (OR = 1.320, 95% CI = 1.150-1.516), lower levels of education (0-6 years) (OR = 1.231, 95% CI = 1.075-1.409), and life satisfaction (OR = 1.104, 95% CI = 1.065-1.114). CONCLUSION: A multidimensional construct of general characteristics, physical, and psychosocial variables act as risk factors for FOF. Preventive intervention should be developed to decrease the FOF among Korean older adults.

Changes in instrumental activities daily living limitations and their associated factors according to gender in community-residing older adults: A longitudinal cohort study.

BACKGROUND: Increases in dependence among older adults cause increases in care needs and social care burden. Instrumental activities of daily living (IADL) are often used to assess the independence of older adults residing in communities. Various factors affect IADL limitations, but few studies confirm gender differences in IADL limitations in older adults. This study explored the changes in incidence of IADL limitations across 14 years and identified the factors associated with IADL limitations according to gender among older adults in Korea. METHOD: This study uses secondary data analysis with 2006-2020 data from the Korean Longitudinal Study of Aging (KLoSA), a longitudinal cohort study. Among the total 10,254 participants, 1,230 adults aged 65 years and over who met the criteria were included in the final analysis. For each IADL item, a limitation was defined when the response was partial or complete dependence. Multivariate logistic regression was performed to identify the factors (in 2006) associated with IADL limitations in 2020. RESULTS: The mean age of the participants at baseline was 69.64 years (SD 3.93), and 61.0% of participants were female. Total scores for IADL limitations increased gradually across 14 years in all participants, and observed changes were statistically significant. The top three ranked items of IADL limitations differed according to gender in 2020: the top limitations in men were preparing meals, laundry, and using public transportation, and the top limitations in women were using public transportation, going out, and handling money. Factors associated with total IADL limitations were grip strength in men and age, dementia, fear of fall, and grip strength in women. Factors associated with the top three ranked items of IADL limitations differed according to gender. CONCLUSION: The incidence of IADL limitations gradually increased in all participants over a 14-year period. In older adults in Korea, gender differences were confirmed in the factors associated with IADL limitations, as well as in the main limited activities. To minimize IADL limitations in community-residing older adults, it is necessary to plan tailored interventions.

The moderating effect of care time on care-related characteristics and caregiver burden: differences between formal and informal caregivers of dependent older adults.

Objective: This study examined differences in care burden between formal and informal caregivers of dependent older adults according to care-related characteristics, and whether care time had a moderating effect on the relationship between care-related characteristics and caregiver burden. Methods: Participants were formal (n = 520) and informal caregivers (n = 142) of dependent older adults in South Korea. Caregiver burden was measured using the Korean version of the Zarit Burden Interview. Data were analyzed using hierarchical regression with interaction terms and moderation analysis. Results: Caregiver burden was higher for informal caregivers than formal caregivers. Factors associated with an increased risk of caregiver burden in both formal and informal caregiver of dependent older adults were caregivers' stress, physical strain, and care time. Care time significantly moderated the relationship between care attitude and care burden only among formal caregivers. When formal caregivers' care time was 1 standard deviation higher than the mean value, care attitude was significantly associated with care burden (bsimple = -0.903, SE = 0.106, p < 0.001). Conclusion: The caregiver burden of dependent older adults can be reduced by providing interventions to attenuate the effects of modifiable risk factors that were identified in this study. And to weaken the relationship between care attitude and burden of formal caregivers who have long care hours, a positive social atmosphere for care should be provided in addition to education. To realize sustainable care, policy considerations that reflect the results of this study will help solve the problem of formal and informal caregiver burden of dependent older adults.

Malnutrition as a major related factor of frailty among older adults residing in long-term care facilities in Korea.

OBJECTIVES: The objectives of this study were 1) to investigate the prevalence and co-existence of frailty and malnutrition and 2) to identify factors related to frailty (including malnutrition) according to the level of frailty. METHODS: Data collection was conducted from July 11, 2021, to January 23, 2022, in 558 older adults residing in 16 long-term care facilities (LTCFs) in Korea. The FRAIL-NH and Mini-Nutritional Assessment short form were used to measure frailty and nutrition, respectively. The data analysis included descriptive statistics and a multivariate logistic regression. RESULTS: The mean age of the participants was 83.68 (± 7.39) years. Among 558 participants, 37 (6.6%), 274 (49.1%), and 247 (44.3%) were robust, prefrail, and frail, respectively. At the same time, 75.8% were categorized as having malnutrition status (malnourished: 18.1%; risk of malnutrition: 57.7%), and 40.9% had co-existing malnutrition and frailty. In the multivariate analysis, malnutrition was identified as the major frailty-related factor. Compared with a normal nutritional status, the incidence of frailty in the malnutrition group was 10.35 times (95% CI: 3.78-28.36) higher than the incidence of robustness and 4.80 times (95% CI: 2.69-8.59) higher than the incidence of prefrail. CONCLUSION: The prevalence of frailty and malnutrition, and their co-existence, among older adults residing in LTCFs was high. Malnutrition is a major factor that increases the incidence of frailty. Therefore, active interventions are needed to improve the nutritional status of this population.

Factors Associated With Functional Limitations in Daily Living Among Older Adults in Korea: A Cross-Sectional Study.

Objective: This paper assesses the relationship between demographics, health parameters, and functional limitations among older adults in Korea, including limitations in activities of daily living (ADLs) and instrumental activities of daily living (IADLs). Methods: We analyzed data from the Korean Longitudinal Study of Aging survey in 2020 and included only participants aged 65 and older. Multinomial logistic regression models were conducted to evaluate the factors that predicted functional limitations. Results: The prevalence of at least one ADL and IADL limitations were 6.14% (severe 1.94% and moderate 4.20%) and 15.49% (severe 3.11% and moderate 12.38%), respectively. People aged 85 and older had high rates of severe disability with 7.37% for ADLs and 12.06% for IADLs. High rates also occurred among people with low education, underweight, physical inactivity, depression, and three or more chronic diseases. Conclusion: Factors associated with functional limitations were age, educational status, body mass index, physical activity, depression, and chronic diseases. To prevent and improve functional limitations in the older populations, active and applicable interventions should be considered for modifiable factors such as physical activity, depression, and abnormal weight.

Comparison of Beef Palatability Characteristics between Longissimus Thoracis and Vastus Lateralis Muscles from Different Grades during Postmortem Aging.

The objectives of this study was to compare palatability changes of the longissimus thoracis (LT) and vastus lateralis (VL) muscles of Hanwoo steers from different beef quality grades (1+ and 1) during 28 d of wet-aging in order to improve the utilization of the VL muscle as a steak. The VL muscle showed a higher collagen content and a lower intramuscular fat content than the LT muscle (p<0.05). As expected, the Warner-Bratzler shear force value was greater in the LT 1 grade (LT-1) muscle than the LT-1+ muscle (p<0.05); whereas no difference was observed between the grades in the VL muscle at 24 h postmortem. Compared to 0 d of aging, tenderness scores significantly increased after 14 and 21 d of aging in the LT and VL muscles, respectively (p<0.05). Additionally, there was no difference in tenderness score between the VL-1+ aged for 21 d and the LT-1 at 24 h postmortem, although tenderness score was greater in the LT than the VL at each period (p<0.05). Moreover, the VL-1+ steak exhibited a higher tenderness score than the VL-1 steak at 21 and 28 d of aging (p<0.05). On the other hand, the effect of aging time on juiciness and flavor in the VL muscle was somewhat limited unlike the LT muscle. Taken together, the VL muscle requires a longer aging time than the LT muscle to improve consumer preference. Considering the tenderness, using a higher quality grade for aging is more useful in the VL muscle.

Associations of Heat-Shock Protein Expression with Meat Quality and Sensory Quality Characteristics in Highly Marbled Longissimus Thoracis Muscle from Hanwoo Steers Categorized by Warner-Bratzler Shear Force Value.

The influence of heat-shock protein (HSP) concentrations at 45 min and 24 h postmortem on meat quality and sensory quality characteristics of longissimus thoracis muscle from highly marbled Hanwoo steers (beef marbling standard grade 6-8) was investigated. Muscle samples were segregated into three groups based on Warner-Bratzler shear force (WBSF) value. The low group exhibited a lower WBSF value compared to the medium and high groups (37.8 vs. 48.9 and 64.3 N, p < 0.001). Muscle pH at 45 min and 24 h postmortem was not different (p > 0.05), and all groups exhibited low ultimate pH value (pH < 5.8). Beef steaks from the low group were significantly easier to pierce and chew, and they left less perceptible residue than the high group (p < 0.05). These differences in tenderness attributes were associated with differences in small HSPs at 45 min postmortem, with the low group exhibiting a lower level of αß-crystallin and higher levels of HSP20 and HSP27 compared with the high group (p < 0.05). No differences were observed for small HSPs, HSP70, and HSP90 at 24 h postmortem (p > 0.05). Therefore, the expression levels of small HSPs at 45 min postmortem seems to have the potential to be an indicator of tenderness in highly marbled Hanwoo beef with low ultimate pH.

Comparison of Factors Associated with Fear of Falling between Older Adults with and without a Fall History.

Background: Although fear of falling (FOF) has been studied since FOF has negative consequences for the elderly, there is limited information about the risk factors of FOF, including the environment. The purpose of this study was to describe individual and environmental factors of FOF between those with and without a fall history from an ecological aspect and to examine whether individual and environmental factors differently affect the FOF according to the state of fall history in community-dwelling older adults in Korea. Methods: Data from the 2014 Survey of Living Conditions and Welfare Needs of Korean Older Adults were used. Participants were 7730 older adults. Hierarchical logistic regression analysis was conducted to examine the predictors of FOF. Results: According to the ecological model, female and discomfort with the neighborhood environment were significantly associated with greater odds of reporting FOF in both older adults with fall history and those without. A significant interaction was not observed between any variable of FOF in participants with and without a fall history. Conclusions: An ecological model including individual and environmental factors should be considered when conducting research and designing programs and decision policies related to FOF for older adults with and without a history of falling.

Comparison of Marbling Fleck Characteristics and Objective Tenderness Parameters with Different Marbling Coarseness within Longissimus thoracis Muscle of High-marbled Hanwoo Steer.

It is important to understand how marbling traits and tenderness differ among beef steaks from the carcass grading site and other regions within the longissimus thoracis (LT) muscle, as these characteristics are closely associated with consumer acceptability and willingness to purchase. Thus, the aim of this study was to compare the marbling fleck traits and objective tenderness parameters in the groups classified by the coarseness index (CI) of marbling fleck (high and low groups) at the carcass grading site (13th thoracic vertebra; 13T) and three different locations (13T, 9T, and 6T) within the LT muscle from well-marbled (marbling score 7 to 9) Hanwoo steer. Image analysis showed that the longitudinal locations had a significant effect on marbling fleck traits. The total area of large marbling fleck divided by the total marbling area (coarseness) was higher at the central region (13T to 12T) compared to the front thoracic region (6T to 5T) in the high CI group (0.23 vs. 0.17, p<0.05), whereas no significant differences were observed in the total number of marbling fleck within the LT muscle in the high or low CI groups (p>0.05). Location effect on objective tenderness parameters within the LT muscle was somewhat limited, although the high CI group had a lower Warner-Bratzler shear force (WBS) value than did the low group (p<0.05). Taken together, the degree of coarseness of marbling fleck decreased from the carcass grading site to the front thoracic site, whereas the objective tenderness parameters, including WBS and hardness, of the grading site did not differ from the other regions within the LT muscle.

Reliability and Validity of the Korean Version of the Perceived Stress Scale-10 (K-PSS-10) in Older Adults.

The purpose of the current study was to examine the reliability and validity of the Korean version of the Perceived Stress Scale-10 (K-PSS-10). After translation and back-translation of the original PSS-10, a convenience sample of 342 community-dwelling older adults was recruited from senior community centers. Data were analyzed using factor analysis, Pearson's correlation coefficient, and Cronbach's alpha. Using factor analysis with principal axis factoring with oblimin rotation, two factors were extracted. The two-factor solution explained 49.71% of the total variance. Internal consistency values for negative and positive subdomains were 0.87 and 0.71, respectively. Moderate relationships were found between a negative response to stress and depression (r = 0.42, p < 0.001) and quality of life (r = -0.45, p < 0.001). A positive response to stress had moderate significant correlations with depression (r = 0.30, p < 0.001) and quality of life (r = -0.36, p < 0.001). Overall, the K-PSS-10 had good reliability, with a Cronbach's alpha of 0.75. The K-PSS-10 demonstrated the desired psychometric properties and was easy to use to assess the stress of community-dwelling older adults in Korea.

Comparative analysis of cognitive tasks for modeling mental workload with electroencephalogram.

Previous electroencephalogram (EEG) studies have shown that cognitive workload can be estimated by using several types of cognitive tasks. In this study, we attempted to characterize cognitive tasks that have been used to manipulate workload for generating classification models. We carried out a comparative analysis between two representative types of working memory tasks: the n-back task and the mental arithmetic task. Based on experiments with 7 healthy subjects using Emotiv EPOC, we compared the consistency, robustness, and efficiency of each task in determining cognitive workload in a short training session. The mental arithmetic task seems consistent and robust in manipulating clearly separable high and low levels of cognitive workload with less training. In addition, the mental arithmetic task shows consistency despite repeated usage over time and without notable task adaptation in users. The current study successfully quantifies the quality and efficiency of cognitive workload modeling depending on the type and configuration of training tasks.

A review on the computational methods for emotional state estimation from the human EEG.

A growing number of affective computing researches recently developed a computer system that can recognize an emotional state of the human user to establish affective human-computer interactions. Various measures have been used to estimate emotional states, including self-report, startle response, behavioral response, autonomic measurement, and neurophysiologic measurement. Among them, inferring emotional states from electroencephalography (EEG) has received considerable attention as EEG could directly reflect emotional states with relatively low costs and simplicity. Yet, EEG-based emotional state estimation requires well-designed computational methods to extract information from complex and noisy multichannel EEG data. In this paper, we review the computational methods that have been developed to deduct EEG indices of emotion, to extract emotion-related features, or to classify EEG signals into one of many emotional states. We also propose using sequential Bayesian inference to estimate the continuous emotional state in real time. We present current challenges for building an EEG-based emotion recognition system and suggest some future directions.

Classification and identification of recorded and synthesized impact sounds by practiced listeners, musicians, and nonmusicians.

Three experiments were conducted to test the viability of a low-parameter modal model for synthesizing impact sounds to be used in commercial and psychoacoustic research. The model was constrained to have four physically based parameters dictating the amplitude, frequency, and decay of modes. The values of these parameters were selected by ear to roughly match the recordings of ten different resonant objects suspended by hand and struck with different mallets. In experiment 1, neither 35 professional musicians nor 187 college undergraduates could identify which of the two matched sounds was the real recording with better than chance accuracy, though significantly better than chance performance was obtained when modal parameters were selected without the previously imposed physical constraints. In experiment 2, the undergraduates identified the source corresponding to the recorded and synthesized sounds with the same level of accuracy and largely the same pattern of errors. Finally, experiment 3 showed highly practiced listeners to be largely insensitive to changes in the acoustic waveform resulting from an increase in the number of free parameters used in the modal model beyond 3. The results suggest that low-parameter, modal models might be exploited meaningfully in many commercial and research applications involving human perception of impact sounds.

Children's detection of pure-tone signals: informational masking with contralateral maskers.

When normal-hearing adults and children are required to detect a 1000-Hz tone in a random-frequency multitone masker, masking is often observed in excess of that predicted by traditional auditory filter models. The excess masking is called informational masking. Though individual differences in the effect are large, the amount of informational masking is typically much greater in young children than in adults [Oh et al., J. Acoust. Soc. Am. 109, 2888-2895 (2001)]. One factor that reduces informational masking in adults is spatial separation of the target tone and masker. The present study was undertaken to determine whether or not a similar effect of spatial separation is observed in children. An extreme case of spatial separation was used in which the target tone was presented to one ear and the random multitone masker to the other ear. This condition resulted in nearly complete elimination of masking in adults. In young children, however, presenting the masker to the nontarget ear typically produced only a slight decrease in overall masking and no change in informational masking. The results for children are interpreted in terms of a model that gives equal weight to the auditory filter outputs from each ear.

One factor underlies individual differences in auditory informational masking within and across age groups.

Masked threshold for a pure-tone signal can be substantially elevated whenever the listener is uncertain about the spectral or temporal properties of the masker, an effect referred to as auditory informational masking. Individual differences in the effect are large, with young children being most susceptible. When masker uncertainty is introduced by randomizing the frequencies of a multitone masker on each presentation, the function relating a child's pure-tone signal threshold to the number of masker components is found to be substantially elevated above that of most adults. The age effect and the individual differences among adults are not well understood, though a difference in the shapes of the masking functions suggests that different detection strategies may be involved. The present study reports results from a principal components analysis of informational masking functions obtained from 38 normal-hearing children ranging in age from 4 to 16 years and 46 normal-hearing adults ranging in age from 19 to 38 years. The premise underlying the analysis is that if different detection strategies are involved, they should add independent sources of variance to the masking functions. Hence, more than one principal component (PC) should be required to account for a substantial proportion of the variance in these functions. The results, instead, supported the operation of a single underlying strategy with all but 17% of the variance accounted for by the first PC within and across age groups. An analysis of variance on the first two PCs showed that only the first changed with age, and a cluster analysis of the masking functions showed complete separation of clusters along this PC for all but 1 listener. The results are taken to suggest that large individual differences informational masking at all ages reflect differences in the extent to which masker uncertainty adds variance to the decision variable of an otherwise optimal decision strategy.