Objective
Along with rapid economic growth, the United Arab Emirates (UAE) has undergone enormous sociocultural changes. Consequently, sociocultural and psychological factors, along with malnutrition ...and physical inactivity, have contributed to the high obesity rate. The objective of this study is to assess the long‐term impact of these new emerging factors on obesity among women in the UAE via mathematical modeling.
Methods
A differential equation model was developed considering psychological/social factors in population dynamics. It predicts the long‐term prevalence of obesity among women in the UAE under these factors by 2070. Computer simulations and a sensitivity analysis of the model were conducted to measure the impact of these factors on obesity.
Results
The model predicts the following: 80.07% of female UAE nationals will become overweight or have obesity and 60.19% will have obesity by 2070, and the population with abnormal eating behavior will increase to 15% by 2070. Psychological/social factors aggravate the obesity problems and can cause abnormal eating behavior to develop with little effect on weight reduction.
Conclusions
The obesity rate of female UAE nationals will continue to rise by 2070. Rising abnormal eating behavior caused by psychological/social factors is an emerging issue and should be recognized as a sign of escalating obesity problems in the UAE.
Purpose
This paper aims to investigate the relationship between sustainability reporting and firm value, and subsequently, ascertains the moderating effect of assurance and the type of assurer on the ...sustainability reporting–firm value nexus.
Design/methodology/approach
The study is based on sample firms from the Johannesburg Stock Exchange (JSE) in South Africa. The fixed‐effect panel data analysis method is used to estimate the coefficients of the variables.
Findings
A significant positive relationship is found between sustainability reporting and firm value. The results also suggest that sustainability assurance has significant explanatory power on firm value. Furthermore, the authors found that the market is unable to distinguish between sustainability assurance services provided by Big 4 audit firms and specialist consultant firms.
Practical implications
The authors expect managers will see sustainability reporting and assurance as a business strategy with incremental market value. The study should also serve as a reference for stakeholders engaged in the advocacy for the adoption of sustainability assurance practices on the JSE and other emerging markets.
Social implications
The study finds that the South African market rewards firms that purchase third-party assurance to guarantee the integrity of their corporate social responsibility reports. This understanding could help encourage more firms to embrace the concept of sustainability assurance.
Originality/value
The study offers a first-hand information on how market participants in Johannesburg, an emerging economy, view sustainability assurance and the services provided by the different assurers.
We examined the effects of oil prices along with fundamental economic variables on exchange rate movements in the Korean and Japanese foreign exchange markets, using two-regime Markov Regime ...Switching Models (MRSMs) over the period from January 1991 to March 2019. We selected the best MRSMs explaining their exchange rate movements using the Maximum Log-Likelihood and Akaike Information Criteria, and analyze effects of oil prices on their exchange rates based on the selected best MRSMs. We consider two regimes, regime 1 with high-volatility and regime 2 with low-volatility. In Korea, two apparent regimes are observed, and unstable regime 1 consists of two distinct prolonged periods, the 1997 Asian Financial Crisis and the 2008 Global Financial Crisis. Meanwhile in Japan, no evident prolonged regimes are observed. Rather, the two regimes occasionally alternate. Oil prices influence exchange rate movements in regime 2 with low-volatility in Korea, while they do not influence exchange rate movements in either regimes in Japan. The Japanese foreign exchange market is more resistant to external oil price shocks because the Japanese industry and economy has less dependence on oil than Korea.
In the fabrication of safe, but powerful lithium ion batteries (LIBs), graphene-related materials are being actively examined in order to meet the demand for applications such as electric vehicles ...and smart grids. However, most of this work has focused on liquid-phase exfoliated graphene and reduced graphene oxide. Herein, we demonstrate a simple, but effective route for significantly improving the electrochemical performance of currently available LIBs by coupling current collector with catalytically grown large-area graphene. When coating current collectors with large-area three-layered graphene, a reduction in the internal resistance (or effective electron transfer) between the current collector and active materials was observed. The graphene also protected the underlying collector from corrosion, greatly improving the power capability and cyclability of LIBs. The three-layered graphene provided the best electrochemical performance and corrosion resistance because of its high electrical conductivity and mechanical stability during the transfer process. We believe that our approach using interfacial graphene coating can be used with all kinds of electrochemical energy-storage systems, in which high corrosion resistance, electrical conductivity, and flexibility are critical.
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Retinal pigment epithelium (RPE) cell dysfunction caused by excessive oxidative damage is partly involved in age-related macular degeneration, which is among the leading causes of visual impairment ...in elderly people. Here, we investigated the protective role of chrysoeriol against hydrogen peroxide (H
O
)-induced oxidative stress in RPE cells. The cellular viability, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were monitored under oxidative stress or pre-treatment with chrysoeriol. The expression levels of mitochondrial-related genes and associated transcription factors were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Moreover, the protein expression of antioxidant signal molecules was characterized by Western blot analysis. Chrysoeriol significantly increased cell viability, reduced ROS generation, and increased the occurrence of antioxidant molecules in H
O
-treated ARPE-19 cells. Additionally, mitochondrial dysfunction caused by H
O
-induced oxidative stress was also considerably diminished by chrysoeriol treatment, which reduced the mitochondrial membrane potential (MMP) and upregulated mitochondrial-associated genes and proteins. Chrysoeriol also markedly enhanced key transcription factors (Nrf2) and antioxidant-associated genes (particularly HO-1 and NQO-1). Therefore, our study confirms the protective effect of chrysoeriol against H
O
-induced oxidative stress in RPE cells, thus confirming that it may prevent mitochondrial dysfunction by upregulating antioxidant-related molecules.
A hybrid of silica decorated on porous activated carbon nanofibers (ACNFs) is fabricated in the form of a web via electrospinning and an activation process as an electrode material for ...electrochemical capacitors in an organic electrolyte. The introduction of PhSiH3 (PS) into the polyacrylonitrile (PAN) solution induces a porous ACNF structure containing silica nanoparticles (NPs) via the spontaneous sol-gel process of PS by steam in the subsequent physical activation process. These inorganic-organic hybrid composites of porous ACNF containing silica NPs show superior specific capacitance and energy density in electrochemical tests, along with good rate capability and excellent cycle life in an organic electrolyte, which is attributed to the combination of ACNF's high surface area and silica's hydrophilicity. The electrochemical performance decreases with increasing PS concentration, and this trend is consistent with the specific surface area results, which reveal the rapid formation of a double layer.
•ACNF-PSs are prepared by electrospinning and steam activation process.•ACNF-PSs at various PS contents are examined the morphological and textual structure.•ACNF-PS electrodes showed superior electrochemical performance.•Improved capacitance was related to ACNF's high surface area and SiO2's hydrophilicity.
PURPOSE By comparing and analyzing the sport safety policies in New Zealand, the USA, and the UK, this study sought to propose sport safety policies for people with disabilities in Korea. METHODS ...This study utilized a comparative research design in three steps. Policy documents were collected from the websites of institutions that directly or indirectly influence the sports safety policies for people with disabilities in each country, as well as academic articles from both domestic and international research databases. RESULTS The data analysis revealed each country’s legal basis, operating entities, and delivery systems. CONCLUSIONS Based on the results, the following implications for the development of sports safety policies for people with disabilities are presented. First, the current legislation system that serves as a foundation for the sports safety policy should be strengthened. Second, a cooperative system should be established among various operating entities related to sports for people with disabilities. Third, the delivery system of sports safety policies for people with disabilities needs to be diversified. To sustain the growing participation of such individuals in sports, developing sports safety policies and guidelines specific to people with disabilities at the national level is essential.
A novel anode material for lithium-ion batteries, graphene-wrapped Si nanoparticles (NPs) embedded in carbon composite nanofibers (CCNFs) with G/Si, is fabricated by electrospinning and subsequent ...thermal treatment. In CCNFs with G/Si, Si NPs are distributed and preserved inside the CNF surface because the graphene wrapping the Si NPs help prevent agglomeration and ensure a good dispersion of Si NPs inside the CNF matrix. 20-GSP prepared from a weight ratio of 20 wt% of G/Si to polyacrylonitrile exhibits stable capacity retention and a reversible capacity of above 600 mAh g sub(-1) up to 100 cycles. The high cycling performance and superior reversible capacity of the 20-GSP anode can be attributed to the onedimensional nanofibrous structure with non-agglomerated Si NPs in the CNF matrix, which promotes charge transfer, maintains a stable electrical contact, and buffers the Si volume expansion.
The purpose of this study was to evaluate the bone-generating ability of a new bovine-derived xenograft (S1-XB) containing hydrogel. For control purposes, we used Bio-Oss and Bone-XB bovine-derived ...xenografts. S1-XB was produced by mixing Bone-XB and hydrogel. Cell proliferation and differentiation studies were performed to assess cytotoxicities and cell responses. For in vivo study, 8 mm-sized cranial defects were formed in 16 rats, and then the bone substitutes were transplanted into defect sites in the four study groups, that is, a Bio-Oss group, a Bone-XB group, an S1-XB group, and a control (all n = 4); in the control group defects were left empty. Eight weeks after surgery, new bone formation areas were measured histomorphometrically. In the cell study, extracts of Bio-Oss, Bone-XB, and S1-XB showed good results in terms of the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and no cytotoxic reaction was evident. No significant difference was observed between mean new bone areas in the Bio-Oss (36.93 ± 4.27%), Bone-XB (35.07 ± 3.23%), and S1-XB (30.80 ± 6.41%) groups, but new bone area was significantly smaller in the control group (18.73 ± 5.59%) (p < 0.05). Bovine-derived bone graft material containing hydrogel (S1-XB) had a better cellular response and an osteogenic effect similar to Bio-Oss.
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