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Fulltext Aqueous two-phase separation (ATPS) of polyphenol oxidase from lotus root (Nelumbo nucifera) and its characterisation

Wong, C. W, Ding, K. Y., Anggraeni, V. S.

International Food Research Journal, 2019;26(6):1699-1706.
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Polyphenol oxidase (PPO) was extracted from lotus (Nelumbo nucifera) root and partially
purified up to 11.51× with a 43.6% yield using aqueous two-phase separation system. The
optimum pH was at 8.0 for both substrates; 4-methylcatechol and pyrogallol. PPO activities
were maximally achieved at 50°C for pyrogallol, and 20°C for 4-methylcatechol. 84% and 71%
loss of relative PPO activities were obtained for pyrogallol and 4-methylcatechol, respectively
following heat inactivation at 90°C for 40 min. Inactivation rate constant (k) values ranged
between 0.88 × 10-2 min-1 to 2.97 × 10-2 min-1 for pyrogallol, and 0.69 × 10-2 min-1 to 2.44 × 10-2min-1 for 4-methylcatechol. The activation energy (Ea) were 75.32 kJ mol-1 and 73.14 kJ mol-1
for pyrogallol and 4-methylcatechol, respectively. PPO activity was strongly inhibited (> 79%)
by ascorbic acid. SDS exhibited the greatest efficiency in activating lotus root PPO.
Fulltext The evolution of Airbnb research: A systematic literature review using structural topic modeling

Ding K, Niu Y, Choo WC

Heliyon, 2023 Jun;9(6):e17090.
PMID: 37484274 DOI: 10.1016/j.heliyon.2023.e17090

This study employs advanced text-mining techniques to offer an in-depth and comprehensive overview of the extensive body of research on Airbnb. By analyzing 1021 articles published in 416 journals spanning the period from 2015 to 2022, this study aims at revealing Airbnb research topics and trends. The results show that the primary focus of academic inquiry regarding Airbnb revolves around two domains: the company's operational practices and its impacts on various domains. Within the realm of Airbnb's operational practices, four distinct research topics emerge as particularly prominent and extensively explored. These encompass the dynamics of 'trust in Airbnb,' the formulation and implementation of 'house rules,' the mechanisms of governing 'Airbnb pricing' strategies, and the critical examination of 'value creation in Airbnb' initiatives. Meanwhile, the most researched impacts of Airbnb are on urban tourism, rental housing markets, tourist destinations, and hotels. These spheres have received significant scholarly attention due to the profound implications and transformative effects engendered by Airbnb's disruptive presence in these areas. Moreover, the findings underscore that research pertaining to Airbnb's operational aspects has witnessed a significant increase in popularity over time, indicating a marked shift in the focal points of Airbnb research. Notably, the research topics that have experienced substantial growth include 'trust in Airbnb,' 'Airbnb pricing,' and 'impacts on tourist destinations.' Lastly, this study found that Airbnb-related research articles in hospitality and tourism journals tend to be more delving into industry-specific phenomena and challenges. Conversely, non-hospitality and tourism journals provide a broader coverage of topics related to Airbnb, encapsulating diverse areas of inquiry beyond the boundaries of the industry. This literature review provides valuable insights into existing research on Airbnb and highlights several critical areas for future research.
Fulltext Exploring Sources of Satisfaction and Dissatisfaction in Airbnb Accommodation Using Unsupervised and Supervised Topic Modeling

Ding K, Choo WC, Ng KY, Ng SI, Song P

Front Psychol, 2021;12:659481.
PMID: 33967922 DOI: 10.3389/fpsyg.2021.659481

This study aims to examine key attributes affecting Airbnb users' satisfaction and dissatisfaction through the analysis of online reviews. A corpus that comprises 59,766 Airbnb reviews form 27,980 listings located in 12 different cities is analyzed by using both Latent Dirichlet Allocation (LDA) and supervised LDA (sLDA) approach. Unlike previous LDA based Airbnb studies, this study examines positive and negative Airbnb reviews separately, and results reveal the heterogeneity of satisfaction and dissatisfaction attributes in Airbnb accommodation. In particular, the emergence of the topic "guest conflicts" in this study leads to a new direction in future sharing economy accommodation research, which is to study the interactions of different guests in a highly shared environment. The results of topic distribution analysis show that in different types of Airbnb properties, Airbnb users attach different importance to the same service attributes. The topic correlation analysis reveals that home like experience and help from the host are associated with Airbnb users' revisit intention. We determine attributes that have the strongest predictive power to Airbnb users' satisfaction and dissatisfaction through the sLDA analysis, which provides valuable managerial insights into priority setting when developing strategies to increase Airbnb users' satisfaction. Methodologically, this study contributes by illustrating how to employ novel approaches to transform social media data into useful knowledge about customer satisfaction, and the findings can provide valuable managerial implications for Airbnb practitioners.
Fulltext Revisiting SDG-7 under energy efficiency vision 2050: the role of new economic models and mass digitalization in OECD

Yu M, Kubiczek J, Ding K, Jahanzeb A, Iqbal N

Energy Effic, 2022;15(1):2.
PMID: 34980948 DOI: 10.1007/s12053-021-10010-z

Policies on reducing energy demand should incorporate the newly formed economic models, digitalization, and consumer awareness trends. Therefore, this study analyzes the interaction of the three trends with SDG7 under energy efficiency vision 2050, measuring the energy efficiency of OECD from 2005 to 2017 to enable this inclusion. In this context, four new trends expected to shape future energy demand are identified through extensive consultation with experts from South Asian countries by developing future power demand for the year of 2050. Consequently, the results show a crucial impact of such trends on a future power demand that exceeds the economic potential of techno. Hence, the best-case scenario, "New Trends Efficient," reduces final energy demand by 78% compared to the South Asian "Baseline" scenario in 2050, whereas the "Worst Case" scenario increases final energy demand by 35%. Therefore, Austria and Korea have the highest energy efficiency score of 0.76 and 0.75, whereas Canada and Chile have the lowest energy efficiency score of 0.41 and 0.42. This paper discusses the ability of digitalization and energy consumer awareness trends in shaping the future energy demand based on SDG 7, emphasizing the importance of energy efficiency vision 2050 in policymaking for effective acquisition.
Fulltext Exploring changes in guest preferences for Airbnb accommodation with different levels of sharing and prices: Using structural topic model

Ding K, Choo WC, Ng KY, Zhang Q

Front Psychol, 2023;14:1120845.
PMID: 36874802 DOI: 10.3389/fpsyg.2023.1120845

INTRODUCTION: Online reviews have become an important source of information for investigating customers' consumption experiences in academic studies. In the context of sharing economy-based accommodation, various studies have been conducted to investigate the user experience of Airbnb by analyzing online reviews; however, most previous Airbnb studies had focused on analyzing the user experience of Airbnb at a holistic level without distinguishing the accommodation attributes of Airbnb. Therefore, this article aimed to investigate how the preferences revealed by Airbnb users in online reviews vary across Airbnb listings with different levels of sharing and price ranges.
METHODS: This study analyzed 181,190 online reviews under Airbnb listings in Kuala Lumpur, Malaysia, using the structural topic model (STM).
RESULTS: This study identified 21 topics related to Airbnb service and product attributes.
DISCUSSION: The findings show that Airbnb users who stay at entire property are more concerned with the hedonic value of their stay, while those who stay at shared property are more concerned with the utilitarian value. The purposes of the host-guest interaction were also found to differ between these two types of Airbnb accommodations. Regarding the effect of listing prices on users' preferences, findings reveal that those staying at lower-priced rooms were more concerned about the convenience of exploring the surrounding area, while those who stayed at higher-priced rooms were more concerned about the surrounding environment and the interior facilities of the property.
Ultrasonic-assisted glycosylation with κ-carrageenan on the functional and structural properties of fish gelatin

Ding K, Geng H, Guo W, Sun W, Zhan S, Lou Q, et al.

J Sci Food Agric, 2023 Aug 30;103(11):5322-5331.
PMID: 37016806 DOI: 10.1002/jsfa.12600

BACKGROUND: Fish gelatin (FG) has multifunctional properties similar to mammalian gelatin (MG), and it has been recognized as the optimal alternative to MG. While its poor surface-active and gelling properties significantly limit its application values, glycosylation has been successfully used to increase surface-active properties of FG, but the influence of ultrasonic-associated glycosylation (UAG) on the gelling and structural characteristics of FG is still rarely reported. This article explores UAG (100-200 W, 0.5-1 h) with κ-carrageenan (κC) on the functional properties (emulsifying, gelling and rheological properties) and structural characteristics of FG.
RESULTS: The longer time and higher power of ultrasonics accelerated the glycosylation reaction with an increase in glycosylation degree and browning index values. Compared with original FG, FG-κC mixture and bovine gelatin, UAG-modified FG possessed higher emulsification activity index, emulsion stability index, gel strength, hardness and melting temperature values. Among them, gelatin modified by appropriate ultrasonic conditions (200 W, 0.5 h) had the highest emulsifying and gelling properties. Rheological results showed that UAG contributed to the gelation process of gelatin with advanced gelation time and endowed it with high viscosity. Structural analysis indicated that UAG promoted κC to link with FG by the formation of covalent and hydrogen bonds, restricting more bound and immobilized water in the gels, exhibiting higher gelling properties.
CONCLUSION: This work showed that UAG with κC is a promising method to produce high gelling and emulsifying properties of FG that could replace MG. © 2023 Society of Chemical Industry.
Human Expansion-Induced Biodiversity Crisis over Asia from 2000 to 2020

Yang C, Li Q, Wang X, Cui A, Chen J, Liu H, et al.

Research (Wash D C), 2023;6:0226.
PMID: 37746659 DOI: 10.34133/research.0226

Asia stands out as a priority for urgent biodiversity conservation due to its large protected areas (PAs) and threatened species. Since the 21st century, both the highlands and lowlands of Asia have been experiencing the dramatic human expansion. However, the threat degree of human expansion to biodiversity is poorly understood. Here, the threat degree of human expansion to biodiversity over 2000 to 2020 in Asia at the continental (Asia), national (48 Asian countries), and hotspot (6,502 Asian terrestrial PAs established before 2000) scales is investigated by integrating multiple large-scale data. The results show that human expansion poses widespread threat to biodiversity in Asia, especially in Southeast Asia, with Malaysia, Cambodia, and Vietnam having the largest threat degrees (∼1.5 to 1.7 times of the Asian average level). Human expansion in highlands induces higher threats to biodiversity than that in lowlands in one-third Asian countries (most Southeast Asian countries). The regions with threats to biodiversity are present in ∼75% terrestrial PAs (including 4,866 PAs in 26 countries), and human expansion in PAs triggers higher threat degrees to biodiversity than that in non-PAs. Our findings provide novel insight for the Sustainable Development Goal 15 (SDG-15 Life on Land) and suggest that human expansion in Southeast Asian countries and PAs might hinder the realization of SDG-15. To reduce the threat degree, Asian developing countries should accelerate economic transformation, and the developed countries in the world should reduce the demands for commodity trade in Southeast Asian countries (i.e., trade leading to the loss of wildlife habitats) to alleviate human expansion, especially in PAs and highlands.
Fulltext Mental Health among Adults during the COVID-19 Pandemic Lockdown: A Cross-Sectional Multi-Country Comparison

Ding K, Yang J, Chin MK, Sullivan L, Demirhan G, Violant-Holz V, et al.

Int J Environ Res Public Health, 2021 03 07;18(5).
PMID: 33800008 DOI: 10.3390/ijerph18052686

Despite the global impact of COVID-19, studies comparing the effects of COVID-19 on population mental health across countries are sparse. This study aimed to compare anxiety and depression symptoms during the COVID-19 lockdown among adults from 11 countries and to examine their associations with country-level COVID-19 factors and personal COVID-19 exposure. A cross-sectional survey was conducted among adults (≥18 years) in 11 countries (Brazil, Bulgaria, China, India, Ireland, North Macedonia, Malaysia, Singapore, Spain, Turkey, United States). Mental health (anxiety, depression, resilient coping, hope) and other study data were collected between June-August 2020. Of the 13,263 participants, 62.8% were female and 51.7% were 18-34 years old. Participants living in Brazil had the highest anxiety and depression symptoms while participants living in Singapore had the lowest. Greater personal COVID-19 exposure was associated with increased anxiety and depression symptoms, but country-level COVID-19 factors were not. Higher levels of hope were associated with reduced anxiety and depression; higher levels of resilient coping were associated with reduced anxiety but not depression. Substantial variations exist in anxiety and depression symptoms across countries during the COVID-19 lockdown, with personal COVID-19 exposure being a significant risk factor. Strategies that mitigate COVID-19 exposure and enhance hope and resilience may reduce anxiety and depression during global emergencies.
Fulltext Physical Activity among Adults Residing in 11 Countries during the COVID-19 Pandemic Lockdown

Ding K, Yang J, Chin MK, Sullivan L, Durstine JL, Violant-Holz V, et al.

Int J Environ Res Public Health, 2021 Jul 01;18(13).
PMID: 34280992 DOI: 10.3390/ijerph18137056

During the novel coronavirus (COVID-19) pandemic, physical activity (PA) behaviors were altered worldwide due to public health measures such as "lockdown." This study described PA among adults residing in 11 countries during COVID-19 lockdown and examined factors associated with PA engagement. We conducted a cross-sectional anonymous survey among adults (≥18 years old) in 11 countries (Brazil, Bulgaria, China, India, Ireland, Malaysia, North Macedonia, Singapore, Spain, Turkey, United States). Of 11,775 participants, 63.7% were female and 52.8% were 18-34 years old. More than 40% of participants were insufficiently active (43.9%) and reported a decrease in their PA during lockdown (44.8%). Statistically significant differences were observed in (1) proportions of participants being insufficiently active, (2) level of PA, and (3) decrease in PA across the 11 countries. More stringent governmental policy responses were associated with greater likelihood of being insufficiently active during lockdown (adjusted odds ratio = 1.22, 95% confidence interval = 1.03, 1.45). Higher depression or anxiety scores were associated with greater likelihood of decreased level of PA during lockdown.We found substantial reductions in PA levels during COVID-19 lockdown across countries. Country-specific PA promotion interventions are needed during this and similar global emergencies.