Screening of a potential probiotic Lactiplantibacillus plantarum NUC08 and its synergistic effects with yogurt starter.

This study aims to identify lactic acid bacteria (LAB) isolates possessing physiological characteristics suitable for use as probiotics in yogurt fermentation. Following acid and bile salt tolerance tests, Lactiplantibacillus plantarum (NUC08 and NUC101), Lacticaseibacillus rhamnosus (NUC55 and NUC201), and Lacticaseibacillus paracasei (NUC159, NUC216, and NUC351) were shortlisted based on intraspecies distribution for further evaluation. Their physiological probiotic properties, including transit tolerance, adhesion, autoaggregation, surface hydrophobicity, biofilm formation, and antibacterial activity, were assessed. Principal component analysis indicated that Lactiplantibacillus plantarum NUC08 was the preferred choice among the evaluated strains. Subsequent investigations revealed that co-culturing Lactiplantibacillus plantarum NUC08 with 2 yogurt starter strains resulted in a cooperative and synergistic effect, enhancing the growth of mixed strains and increasing their tolerance to simulated gastric and intestinal conditions. Additionally, when Vibrio harveyi bioluminescent reporter strain was used, the 3 cocultured strains cooperated to induce the activity of a quorum sensing (QS) molecule autoinducer-2 (AI-2), hinting a potential connection between phenotypic traits and QS in the cocultured strains. Importantly, LAB viable counts were significantly higher in yogurt co-fermented with Lactiplantibacillus plantarum NUC08, consistently throughout the storage period. In conclusion, the study demonstrates that the probiotic strain Lactiplantibacillus plantarum NUC08 can be employed in synergy with yogurt starter strains, affirming its potential for use in the development of functional fermented dairy products.

Built environment and loneliness in later life: productive engagement as the pathway.

OBJECTIVES: The built environment is increasingly recognized as being associated with late-life loneliness. However, the pathway remains understudied. This study investigated the mediating effects of productive engagement in relationships between the built environment and loneliness. METHODS: We conducted a cross-sectional analysis of data from 4,409 community-dwelling people aged 65 years and above in China. We employed the Chinese version of the De Jong Gierveld Loneliness Scale to assess loneliness. The built environment comprises residential density, street connectivity, park-based and vegetation-based green space, land use mix, and the number of and distance to the nearest recreational, health, shopping and community services within 300-meter and 500-meter buffer areas. Structural equation modeling was used. RESULTS: Only green space (parks) had a direct effect on loneliness. Residential density and green space (parks) had an indirect effect on loneliness through volunteering. The number of recreational services had an indirect effect on loneliness through recreational and sporting activities, although distance to the nearest recreational services did not. All the significant results were only found within 300-meter rather than 500-meter buffers. CONCLUSIONS: Our findings have implications for environmental gerontology theory and practice. Providing more green space and recreational services can significantly improve older adults' helping behavior, social activities and sporting activities, which can further reduce older adults' loneliness.

Objective and perceived service accessibility and mental health in older adults.

OBJECTIVES: Service accessibility plays a pivotal role in older adults' mental health. However, accessibility measures used in previous studies are either objective or perceived. This study aimed to integrate both objective and perceived measures of service accessibility to explore the relationship between environmental cognition on service accessibility and mental health in older adults and the pathways. METHODS: We used both questionnaire data collected from 2,317 older adults in Hong Kong and geographical data to explore the direct and indirect effect of environmental cognition (i.e. positive, negative, and matching evaluation) relating to service accessibility on mental health and two pathways (i.e. physical activity and sense of belonging) based on a structural equation model. RESULTS: Physical activity mediated the positive relationship between non-negative perceptions toward access to convenience stores, leisure facilities, clinics, community centers, places of worship and mental health. Sense of community can significantly mediate the positive relationships between non-negative perceptions toward all 10 types of services and mental health. CONCLUSION: This study provides an empirical contribution to environmental cognition theory and person-environment fit theory; its findings have implications for urban planning policy.

The findings from this study provide significant evidence that environmental cognition distortion, especially negative perception, can be significantly associated with lower mental health through physical activity and a sense of community. This suggests that policies focused on changing environmental cognitions could be a promising public health strategy. Environmental cognition theory suggests that improving awareness of setting could help improve the precision of cognitive mapping of environmental reality. This can be very important where it is difficult to change the objective environment due to the deep-rooted and long-standing urban structure.

Neighborhood built environments and cognition in later life.

Objectives: Maintaining good cognition is crucial in later life. However, most existing research has focused on individual factors impacting cognition, and few studies have investigated the association between neighborhood built environment and older adults' cognition. This study examined the association between neighborhood built environment and cognition among community-dwelling older adults and identified variations in this association between different age groups in the older population.Methods: Data were derived from a cross-sectional survey of 1873 people aged 65 years and above in Hong Kong. We merged individual data from the survey with neighborhood built environment data based on community auditing and geographical information system. After controlling for individual covariates, we used multivariable linear regression to examine the association between neighborhood built environment and cognition.Results: Residents aged 80 and younger in neighborhoods with a higher land-use mix and more public transport terminals exhibited better cognition. Only the number of community centers in a neighborhood was positively associated with cognition for people older than 80.Conclusion: The built environment creates diverse impacts on different age groups among older adults. Our findings provide useful information for urban planners and policymakers for planning community facilities and built environments that consider the needs of different age groups within the older population.

Tree Shrew Cells Transduced with Human CD4 and CCR5 Support Early Steps of HIV-1 Replication, but Viral Infectivity Is Restricted by APOBEC3.

The host range of human immunodeficiency virus type 1 (HIV-1) is narrow. Therefore, using ordinary animal models to study HIV-1 replication, pathogenesis, and therapy is impractical. The lack of applicable animal models for HIV-1 research spurred our investigation on whether tree shrews (Tupaia belangeri chinensis), which are susceptible to many types of human viruses, can act as an animal model for HIV-1. Here, we report that tree shrew primary cells are refractory to wild-type HIV-1 but support the early replication steps of HIV-1 pseudotyped with the vesicular stomatitis virus glycoprotein envelope (VSV-G), which can bypass entry receptors. The exogenous expression of human CD4 renders the tree shrew cell line infectible to X4-tropic HIV-1IIIB, suggesting that tree shrew CXCR4 is a functional HIV-1 coreceptor. However, tree shrew cells did not produce infectious HIV-1 progeny virions, even with the human CD4 receptor. Subsequently, we identified tree shrew (ts) apolipoprotein B editing catalytic polypeptide 3 (tsAPOBEC3) proteins as active inhibitors of HIV-1 particle infectivity, with virus infectivity reduced 10- to 1,000-fold. Unlike human APOBEC3G, the tsA3Z2c-Z1b protein was not degraded by the HIV-1 viral infectivity factor (Vif) but markedly restricted HIV-1 replication through mutagenicity and reverse transcription inhibition. The pooled knockout of tsA3Z2c-Z1b partially restored the infectivity of the HIV-1 progeny. This work suggests that tsAPOBEC3 proteins serve as an additional barrier to the development of HIV-1 tree shrew models, even when virus entry is overcome by exogenous expression of human CD4. IMPORTANCE The development of animal models is critical for studying human diseases and their pathogenesis and for evaluating drug and vaccine efficacy. For improved AIDS research, the ideal animal model of HIV-1 infection should be a small laboratory mammal that closely mimics virus replication in humans. Tree shrews exhibit considerable potential as animal models for the study of human diseases and therapeutic responses. Here, we report that human CD4-expressing tree shrew cells support the early steps of HIV-1 replication and that tree shrew CXCR4 is a functional coreceptor of HIV-1. However, tree shrew cells harbor additional restrictions that lead to the production of HIV-1 virions with low infectivity. Thus, the tsAPOBEC3 proteins are partial barriers to developing tree shrews as an HIV-1 model. Our results provide insight into the genetic basis of HIV inhibition in tree shrews and build a foundation for the establishment of gene-edited tree shrew HIV-1-infected models.

The geography of suicide in older adults in Hong Kong: An ecological study.

OBJECTIVES: The geography of suicide has been widely explored among the general population. However, little is known of the geographic variations in suicides among the older adults and their spatial correlates. This study aims to explore the spatial variations in the elderly suicide rates and their correlates in Hong Kong. METHODS: Bayesian hierarchical models have been used to estimate smoothed standardized mortality ratios (2006-2015) on suicide in people aged 65 years or older in each geographic unit in Hong Kong. Their associations with the Social Vulnerability Index and the accessibility of eight types of services (ie, recreational services, rehabilitation services, food services, daily necessity services, community services, and transportation services) were further analyzed. RESULTS: The results suggested that compared with the simple "inner-city high suicide rate and suburban low" pattern in the Western studies and the "central low suicide rate and peripheral high" pattern in the Asian studies, the spatial variations of elderly suicides in Hong Kong exhibit a much more complicated pattern. In Hong Kong, higher elderly suicide clusters were found in both the lower-density areas located in the New Territories and in some inner-city areas. The spatial variations of suicide in the older adults cannot be explained by the Social Vulnerability Index. Instead, service provision such as recreational services, daily necessity resources, and community centers played a more significant role in affecting suicides in the older adults. CONCLUSIONS: Strengthening public services, providing more public spaces and activities, and making good use of the community resources might be key and efficient strategies in elderly suicide prevention in Hong Kong. Key points The spatial variations of elderly suicides in Hong Kong show a much more complicated pattern compared with the simple "inner-city high suicide rate and suburban low" pattern in the Western countries and the "central low suicide rate and peripheral high" pattern in some of the Asian countries. In Hong Kong, suicide rates in the city centers were not higher than the average in the city. Clusters of higher suicide rates were mainly found in the New Territories, which is somewhat disconnected from the city and, in some inner-city neighborhoods, with high-density population. The spatial variations of suicide in the older adults in Hong Kong cannot be explained by the neighborhood Social Vulnerability Index as in the existing literature. Neighborhood service provision such as recreational services, daily necessity resources, and community centers played a significant role in affecting suicides in the older adults in Hong Kong.

University Students' Vaccination Intention after the Fifth Wave of the COVID-19 Outbreak in Hong Kong: Inspiration from a Health Belief Model.

The fifth wave of COVID-19, driven by the Omicron variant, started to surge in Hong Kong in December 2021. Previous studies have shown that younger adults, compared to older adults, are vulnerable to increased risks of side effects after vaccination. However, little is known about the COVID-19 vaccination behavior among younger adults, especially university students, in Hong Kong. Therefore, the present online survey study aimed to investigate the predictors of COVID-19 vaccination intention among university students in Hong Kong using the Health Belief Model (HBM) as a framework. Two other potential predictors, the previous influenza vaccine uptake frequency and the Hong Kong SAR government vaccination lottery program, were also examined. The intention to receive another dose of the COVID-19 vaccine was low (36.4%). Multivariate binomial logistic regression analysis showed that, after controlling for demographic and baseline characteristics, the perceived susceptibility (OR = 2.98, CI = 1.18-7.53) and previous influenza vaccine uptake frequency (OR = 1.54, CI = 1.08-2.19) significantly and positively predicted the COVID-19 vaccination intention. However, the government vaccination lottery program (i.e., wining prizes for being vaccinated) (OR = 0.87, CI = 0.34-2.26) was not a significant motivator of COVID-19 vaccination. Future public health campaigns should focus on the individual susceptibility to COVID-19 and past influenza vaccination history to promote increased vaccination uptake among university students.

Emodin Attenuates Hypoxic-Ischemic Brain Damage by Inhibiting Neuronal Apoptosis in Neonatal Mice.

Neonatal hypoxic-ischemic brain damage (HIBD) can lead to mortality and severe neurological dysfunction. Emodin is a natural anthraquinone derivative that is easy to obtain and has good neuroprotective effects. This study aimed to investigate the neuroprotective effect of emodin on neonatal mouse HIBD. The modified Rice-Vannucci method was used to induce HIBD in mouse pups. Eighty postnatal 7-day (P7) C57BL/6 neonatal mice were randomly divided into the sham group (sham), vehicle group (vehicle), and emodin group (emodin). TTC staining and whole-brain morphology were used to evaluate the infarct volume and morphology of the brain tissue. The condition of the neurons was observed through Nissl staining, HE staining, FJC staining, immunofluorescence and Western blot for NeuN, IBA-1, and GFAP. The physiological status of the mice was evaluated using weight measurements. The neural function of the mice was assessed using the negative geotaxis test, righting reflex test, and grip test. TUNEL staining was used to detect apoptosis in brain cells. Finally, Western blot and immunofluorescence were used to detect the expression levels of apoptosis-related proteins, such as P53, cleaved caspase-3, Bax and Bcl-2, in the brain. Experiments have shown that emodin can reduce the cerebral infarct volume, brain oedema, neuronal apoptosis, and degeneration and improve the reconstruction of brain tissue morphology, neuronal morphology, physiological conditions, and neural function. Additionally, emodin inhibited the expression of proapoptotic proteins such as P53, Bax and cleaved caspase-3 and promoted the expression of the antiapoptotic protein Bcl-2. Emodin attenuates HIBD by inhibiting neuronal apoptosis in neonatal mice.

Spatial-temporal analysis of suicide clusters for suicide prevention in Hong Kong: a territory-wide study using 2014-2018 Hong Kong Coroner's Court reports.

Background: This study aimed to (i) identify high-risk suicide-methods clusters, based on location of residence and suicide incidence; and (ii) compare the characteristics of cases and spatial units inside and outside clusters. Methods: Suicide data of 4672 cases was obtained from the Coroner's Court reports in Hong Kong (2014-2018). Monthly aggregated suicide numbers based on location of residence, and suicide incidence, were obtained in small tertiary planning units (STPUs). Community-level characteristics and population of STPUs were retrieved from 2016 Census. Retrospective space-time analyses were performed to identify locations with elevated suicide rates over specific time periods, i.e., spatial-temporal clusters. Clusters were evaluated for overall suicide (any method), as well as jumping, hanging, and charcoal burning methods, in location of residence and suicide incidence. Bi-variate analysis was performed to compare the characteristics of cases, and spatial units, inside and outside the clusters. Findings: Suicide clusters involving jumping and charcoal burning were identified, but no hanging clusters were found. The within-cluster distribution of types of housing was different from that of outside. For most of the overall suicide and suicide by jumping clusters, spatial units within the clusters were more socially disadvantaged compared to those outside. Interpretation: Clusters varied by suicide methods, location of residence and location of incidence. The findings highlighted the need for consistent and concerted support from different stakeholders within suicide clusters, to ensure appropriate design, implementation and sustainability of effective suicide prevention programs. Funding: General Research Fund (37000320) and seed fund from the University of Hong Kong (104006710).

The mechanism of action of Ophiocordyceps sinensis mycelia for prevention of acute lung injury based on non-targeted serum metabolomics.

Ophiocordyceps sinensis is a fungus with medicinal value in treating lung diseases, but no study has reported how to prevent acute lung injury using this fungus. The mice were divided into normal, model, positive control, and O. sinensis groups to observe lung histopathological sections and transmission electron microscopy, along with liquid chromatography-mass spectrometry and hematoxylin and eosin (H&E) staining to closely identify structural differences resulting from destruction between the groups. The results of the H&E staining showed that, compared with the normal group, the model group showed alveolar collapse. Compared with the model group, the infiltration of inflammatory cells in the alveolar cavity of the O. sinensis group was significantly reduced. Mitochondrial plate-like cristae were observed in type II alveolar cells of the normal group, with normal coloration of the mitochondrial matrix. Type II alveolar cells in the model group showed obvious edema. The statuses of type II alveolar cells in the O. sinensis and positive groups were similar to that in the normal group. Twenty-nine biomarkers and 10 related metabolic pathways were identified by serum metabolomics screening. The results showed that O. sinensis mycelia had a significant effect on the prevention of lipopolysaccharide-induced inflammation.

Neighborhood-Built Environment and Ageism in Later Life.

Ageism is a global challenge and a public health concern that the recent COVID-19 pandemic has further exacerbated. Existing research has mainly focused on individual factors, overlooking the association between the neighborhood-built environment and ageism. This study examined this association and whether its effect varied among areas possessing different socioeconomic characteristics. We conducted a cross-sectional survey of 1278 older people in Hong Kong and merged this with the built environment factors derived from geographical information system data. We used multivariable linear regression to examine the association. Findings revealed that more parks were significantly associated with a lower level of ageism, an impact that remained significant in low-income or low-education areas. Conversely, more libraries in high-income areas were associated with a lower level of ageism. Our findings provide urban planners and policymakers insight into planning for the built environment that reduces ageism enabling older people to achieve a better life.

Universities as Intermediary Organizations: Catalyzing the Construction of an Age-Friendly City in Hong Kong.

Background and Objectives: The construction of an Age-Friendly City (AFC) requires active contribution from relevant interest groups including older adults, nonprofit organizations, and policy-makers. However, given that relevant interest groups may have limited resources, knowledge, and skills, as well as unique contextual factors, they often require help from intermediary organizations-actors that aim to build interest groups' capabilities. Our objectives were to examine the functions of universities, as an example of intermediary organizations, in facilitating the construction of an AFC, and identify critical factors that enable intermediary organizations to perform their functions. Research Design and Methods: We conducted three focus groups and one individual interview with multiple interest groups including older adults and social workers from nonprofit organizations and local government involved in a 6-year citywide AFC project in Hong Kong. Participants were asked to share their views on the role of universities in relation to their own experiences and roles in the project. Data generated from the interviews were analyzed using thematic analysis. Results: Four themes pertinent to the functions of universities in facilitating development were identified: facilitating cross-sector collaborations, knowledge diffusion, interest-group building, and mediating divergent interests. We also found that neutrality and reputability are key characteristics for intermediary organizations to wield sufficient legitimacy to perform their functions efficiently. Discussion and Implications: Findings underscore the important yet overlooked role of intermediary organizations in bridging and mediating different interest groups to facilitate AFC development. We advance gerontological scholarship by providing insights into the theoretical mechanisms and practice implications for intermediary organizations in fostering an AFC.

Blood-brain barrier injury and neuroinflammation induced by SARS-CoV-2 in a lung-brain microphysiological system.

In some patients, COVID-19 can trigger neurological symptoms with unclear pathogenesis. Here we describe a microphysiological system integrating alveolus and blood-brain barrier (BBB) tissue chips that recapitulates neuropathogenesis associated with infection by SARS-CoV-2. Direct exposure of the BBB chip to SARS-CoV-2 caused mild changes to the BBB, and infusion of medium from the infected alveolus chip led to more severe injuries on the BBB chip, including endothelial dysfunction, pericyte detachment and neuroinflammation. Transcriptomic analyses indicated downregulated expression of the actin cytoskeleton in brain endothelium and upregulated expression of inflammatory genes in glial cells. We also observed early cerebral microvascular damage following lung infection with a low viral load in the brains of transgenic mice expressing human angiotensin-converting enzyme 2. Our findings suggest that systemic inflammation is probably contributing to neuropathogenesis following SARS-CoV-2 infection, and that direct viral neural invasion might not be a prerequisite for this neuropathogenesis. Lung-brain microphysiological systems should aid the further understanding of the systemic effects and neurological complications of viral infection.

Extracellular vesicles mediate antibody-resistant transmission of SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. Antibody resistance dampens neutralizing antibody therapy and threatens current global Coronavirus (COVID-19) vaccine campaigns. In addition to the emergence of resistant SARS-CoV-2 variants, little is known about how SARS-CoV-2 evades antibodies. Here, we report a novel mechanism of extracellular vesicle (EV)-mediated cell-to-cell transmission of SARS-CoV-2, which facilitates SARS-CoV-2 to escape from neutralizing antibodies. These EVs, initially observed in SARS-CoV-2 envelope protein-expressing cells, are secreted by various SARS-CoV-2-infected cells, including Vero E6, Calu-3, and HPAEpiC cells, undergoing infection-induced pyroptosis. Various SARS-CoV-2-infected cells produce similar EVs characterized by extra-large sizes (1.6-9.5 µm in diameter, average diameter > 4.2 µm) much larger than previously reported virus-generated vesicles. Transmission electron microscopy analysis and plaque assay reveal that these SARS-CoV-2-induced EVs contain large amounts of live virus particles. In particular, the vesicle-cloaked SARS-CoV-2 virus is resistant to neutralizing antibodies and able to reinfect naïve cells independent of the reported receptors and cofactors. Consistently, the constructed 3D images show that intact EVs could be taken up by recipient cells directly, supporting vesicle-mediated cell-to-cell transmission of SARS-CoV-2. Our findings reveal a novel mechanism of receptor-independent SARS-CoV-2 infection via cell-to-cell transmission, provide new insights into antibody resistance of SARS-CoV-2 and suggest potential targets for future antiviral therapeutics.

Community environment moderates the relationship between older adults' need for and utilisation of home- and community-based care services: The case of China.

This study explores the moderating influence of perceived and objective community environments on the relationship between older adults' home- and community-based care (HCBC) needs and their actual utilisation of such care. We selected 5,668 older adults in two cities in China and adopted latent class analysis to descriptively explore the patterns of their HCBC need and utilisation. Structural equation modelling was used to determine factors related to the patterns of need and utilisation of HCBC services, and to explore the moderating roles that the perceived and objective community environments had on the effect of long-term care need on its utilisation. The results descriptively showed that older adults' patterns of HCBC need and utilisation appear to be embedded within two broader latent categories: a high-need/use group and a low-need/use group. Among participants who were satisfied with their community or who lived in areas with high accessibility to HCBC services, HCBC need could predict HCBC use. Our integrated conceptual framework proved to be applicable, thus enriching the theoretical models in explaining HCBC-related behaviours. The results have strong implications for urban planners, policymakers, and programme managers who seek to support older people and provide elderly care services in communities.

Structure and Anti-Inflammation Potential of Lipoteichoic Acids Isolated from Lactobacillus Strains.

Lactobacillus are normal inhabitants of the gastrointestinal tract and confer a variety of health effects. Lipoteichoic acid (LTA), an amphiphilic substance located in the cell membrane, is a key molecule in probiotic-host crosstalk. Through the characterization of structural characteristics of LTA molecules derived from Lactobacillus plantarum A3, Lactobacillus reuteri DMSZ 8533, and Lactobacillus acidophilus CICC 6074, there exists some heterogeneity in LTA molecules, which perhaps contributes to the distinguishable adhesion properties of Lactobacillus strains based on fluorescence microscopy observations. In LPS-induced RAW 264.7 cells, LTAs derived from three Lactobacillus strains obviously alleviated inflammatory responses as evidenced by the altered inflammatory cytokine levels of TNF-α, IL-6, and IL-10. Western blotting demonstrated that L. reuteri LTA blocked LPS-triggered expression of the MAPK and NF-κB pathways. The findings further validated that LTA is an important effector molecule and deserves further consideration as an alternative therapeutic for ulcerative colitis treatment.

Amphiphysin AoRvs167-Mediated Membrane Curvature Facilitates Trap Formation, Endocytosis, and Stress Resistance in Arthrobotrys oligospora.

Bin1/Amphiphysin/Rvs (BAR) domain-containing proteins mediate fundamental cellular processes, including membrane remodeling and endocytosis. Nematode-trapping (NT) fungi can differentiate to form trapping structures through highly reorganized cell membranes and walls. In this study, we identified the NT fungus Arthrobotrys oligospora ortholog of yeast Rvs167 and documented its involvement in membrane bending and endocytosis. We further confirmed that the deletion of AoRvs167 makes the fungus more hypersensitive to osmotic salt (Nacl), higher temperatures (28 to 30 °C), and the cell wall perturbation agent Congo red. In addition, the disruption of AoRvs167 reduced the trap formation capacity. Hence, AoRvs167 may regulate fungal pathogenicity through the integrity of plasma membranes and cell walls.

Mobility Based on GPS Trajectory Data and Interviews: A Pilot Study to Understand the Differences between Lower- and Higher-Income Older Adults in Hong Kong.

Few studies have examined mobility from a social exclusion perspective. Limited mobility can restrict opportunities to interact with others and therefore may lead to social exclusion. This pilot study was designed to test the feasibility of integrating Global Positioning System (GPS) trajectory data and interview data to understand the different mobility patterns between lower- and higher-income older adults in Hong Kong and the potential reasons for and impacts of these differences. Lower- (n = 21) and higher- (n = 24) income adults aged 60 years of age or older in Hong Kong were recruited based on purposive sampling. They were asked to wear a GPS device for 7 days. Seven measures of mobility (four dimensions) were created based on GPS data and compared between lower- and higher-income older adults, including extensity (standard deviation ellipse, standard distance between all locations), intensity (time spent out of home, doing activities), diversity (number of locations), and non-exclusivity (time spent in public open spaces and places with higher public service provisions). It then administered semi-structured interviews to understand the determined differences. The activity spaces for lower-income older adults were, on average, smaller than those for higher-income older adults, but lower-income older adults spent significantly more time participating in out-of-home activities. They were more likely to be exposed to environments with similar socioeconomic characteristics as their own. The interviews showed that limited social networks and expenditure on transport were the two main factors associated with lower-income older adults having relatively fewer activity spaces, which may lead to further social exclusion. We recommend using GPS in daily life as a feasible way to capture the mobility patterns and using interviews to deeply understand the different patterns between lower- and higher-income older adults. Policy strategies aiming to improve the mobility of older might be helpful for further improving the social inclusion of lower-income older adults.

Spatial uncertainty and environment-health association: An empirical study of osteoporosis among "old residents" in public housing estates across a hilly environment.

BACKGROUND: Built environment can influence physical conditions of older adults (e.g. osteoporosis). However, traditional methods using 2-dimensional circular buffer as a spatial structure to measure neighbourhood effect may create bias in health estimation, especially for the hilly and compact environment across low-income neighbourhoods (e.g. public housing estates). METHODS: We evaluated the environmental influences on self-reported osteoporosis among "old residents" (age≥65) in Hong Kong (n = 2077). Twelve public housing estates across hilly neighbourhoods in Hong Kong were selected as study sites. A cross-validated approach was developed to evaluate four spatial structures (2D circular, 2D service area, 3D circular, 3D service area). To determine problems of spatial uncertainty, we compared odds ratios (OR) and differences in effect sizes from models using different spatial structures. When all adjusted models achieve significant results based on 95% confidence intervals (CI) and with all positive/negative ORs, this study reported to have reached "a result with consistency". Results from the 3D service area were then used to explain the environment-health relationship. RESULTS: Different spatial structures can yield different results. Particularly, circular buffers overestimated environmental effects on self-reported osteoporosis. Overestimated measures were related to walkability and accessibility but not greenery. Specifically, results from the 3D service area showed that more public space and health facilities within a walkable distance (500 m) from a location of subject's residence were negatively associated with self-reported osteoporosis (adjusted ORs: 0.44 [0.29, 0.66]; 0.94 [0.90, 0.99]). However, more major transport facilities at the immediate distance from residence (200 m) was positively associated with self-reported osteoporosis (adjusted OR: 1.11 [1.01, 1.23]). CONCLUSIONS: Physical conditions (e.g. osteoporosis) of older adults living in a hilly neighbourhood could be driven by walking behaviours. It is necessary to include local terrain and road network to define a walkable neighbourhood for environment-health estimations to minimize spatial bias.

Neighborhood Environment and Mental Well-Being Among Chinese Older Adults: The Mediating Role of Social Capital.

Background and Objectives: Neighborhood environments are increasingly recognized as associated with mental well-being among older adults. However, their underlying mechanisms remain unclear. This study investigated mediating effects of cognitive and structural social capital (SC) in relationships between neighborhood environments and mental well-being among older adults. Research Design and Methods: We conducted a cross-sectional analysis of 1,277 community-dwellers aged 60 years and older in Hong Kong in 2021. The Warwick-Edinburgh Mental Well-being Scale assessed mental well-being. Perceived age-friendly environment was assessed. Objective neighborhood environment was measured by the number of neighborhood facilities (e.g., transportation, community centers, leisure facilities) within 200-m and 500-m buffer areas from respondents' residences. Structural equational modeling was used. Results: Perceived age-friendly environment regarding community and health support had a protective role on mental well-being. More community centers were directly associated with better affective-emotional well-being, while more passive leisure facilities directly lowered psychological-functioning well-being. Cognitive SC outweighed structural SC in mediating relationships of neighborhood environment on mental well-being. Discussion and Implications: Our findings advance the ecological model of aging by providing evidence for cognitive and structural SC as mediators to explain the relationship between neighborhood environment and mental well-being. Policy implications for optimizing mental well-being in aging societies are discussed.