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.
Display omitted
Korea imports all of its crude oil, and is the world's fifth largest oil importing country. We analyze the effects of oil prices, interest rates, consumer price indexes (CPIs), and industrial ...production indexes (IPIs) on the regime shift behavior of the Korean exchange rates against the USA from January 1991 to March 2019. We use the Markov regime switching model (MRSM) to detect the regime shift behavior of the movements of Korean exchange rates. In order to select the optimal MRSM, we fit a total of 30 models considering four explanatory variables. The selected model based on Akaike information criteria (AIC) and maximum log likelihood (MLL) includes the log-differentials of oil prices, the log-differentials of CPIs compared to those of the US, and its own auto-regressive terms. Based on the selected MRSM model, throughout all markets, we find evidence to support the existence of two distinct regimes: a stable regime with low-volatility, and an unstable regime with high-volatility. The regime with high-volatility includes the Asian financial crisis of 1997 and the global financial crisis of 2008–2009 in the Korean exchange rates market. In the regime with low-volatility, the Korean exchange rates are not significantly influenced by any of the explanatory variables, except for its own auto-regressive terms. In the regime with high-volatility, the Korean exchange rates are significantly influenced by the CPIs and oil prices. The transition probability from the regime with low-volatility to the regime with high-volatility is about ten times that of the opposite case.
The purpose of this study was twofold: (a) to examine and compare levels of parental self-efficacy (PSE) and parenting practices (PP) between parents of young children with and without disabilities ...regarding physical activity (PA) participation of their children and (b) to analyze and compare the relationship between PSE and PP. A total of 235 participants completed a survey measuring levels of PSE and PP related to the promotion of PA for their children. The results showed no differences in levels of PSE and PP between parents of children with and without disabilities (
p
> 0.05). A positive moderate relationship was found between PSE and PP from total participants (
r
= 0.497,
p
< 0.001) as well as parents of children with disabilities (
r
= 0.440,
p
< 0.001). Parents of children with disabilities had comparable levels of confidence (PSE) and competence (PP) in promoting PA to their children compared to those of parents of children without disabilities. The current study supports the mechanism of self-efficacy and behavior and the importance of early intervention for parents of children with disabilities to build higher PSE for their child’s future PA habit through improved PP.
Highlights
Parental self-efficacy (PSE) and parenting practices (PP) are important components promoting physical activity (PA) participation of young children.
Parents of children with and without disabilities may have comparable levels of PSE and PP related to PA promotion.
An intervention for parents is needed for quality PA participation of young children with disabilities.
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.
This clinical study aimed to predict the learning curve of wireless and wired intraoral scanners (IOSs) and to compare the reduction patterns of working time. Overall, 14 participants were enrolled ...in the study. The intraoral scanning procedure was repeated four times, each using wireless and wired IOSs (i700; MEDIT). The work time from the first to the 600th iterations was predicted using the Wright model. Regarding statistical analysis, the Mann-Whitney U-test was performed for comparison between wireless and wired IOSs and between groups with and without an IOS usage experience, and the Friedman test was performed to evaluate the time reduction (α = 0.05). There was a significant difference between wireless and wired IOSs in the first (P = 0.008) and the third (P = 0.035) iterations. Moreover, the time for 600 iterations was statistically significantly different between wireless and wired IOSs (P < 0.05); however, there was no significant difference after the sixth iteration (e.g., seventh iteration: P = 0.062). In wireless IOS, no significant difference was found between participants with and without an IOS usage experience after the 34th iteration (P = 0.053). The difference in the learning effect between wireless and wired IOSs can be overcome by initial learning; however, an IOS usage experience can affect the learning time of wireless IOSs.
Abstract
Recently, some studies have utilized silicon (Si) as an anode material of lithium ion battery by recycling Si from the slurry of wafer slicing dust. The filtration of Si particles condensed ...from Si vapors that were exhausted from the ingot growing furnace could propose another method of Si recycling. In this study, we investigated the possibility of using such collected silicon oxides (SiO
x
) particles as an anode material. After collecting SiO
x
particles, FE-SEM, TEM, EDS, XRD, XPS analysis, and charge/discharge test were carried out to investigate characteristics and usability of these particles. FE-SEM and FE-TEM images showed that these particles mainly consisted of spherical primary particles with a diameter of 10 nm or less. Agglomerates of these primary particles were larger than 300 nm in diameter. In TEM image and EDS analysis, crystalline particles were observed along with amorphous particles. As a result of XRD analysis, amorphous silica (SiO
2
) and crystalline Si were observed. Charge/discharge tests were carried out to determine the feasibility of using these particles as an anode material for lithium ion batteries. A cycle efficiency of 40.6% was obtained in the test in which the total number of charge/discharge cycle was 100 under the condition of C-rate 0.2 for the first three times and C-rate 1.0 for the remaining 97 times. Results showed that these collected particles could be used as an anode material for lithium ion batteries.
This study aimed to compare two methods of crosslinking collagen type I on implanted titanium surfaces, that is, using glutaraldehyde (GA) or gamma-rays (GRs), in a beagle dog model. For in vivo ...experiments, implants were allocated to three groups and applied to mandibular bone defects in beagle dogs; Group SLA; non-treated Sandblasted, large grit, acid-etched (SLA) implants, Group GA; SLA implants coated with GA crosslinked collagen type I, Group GR; SLA surface implants coated with collagen type I and crosslinked using 25 kGy of 60Co gamma radiation. New bone μCT volumes were obtained, and histologic and histometric analyses were performed in regions of interest. The GR group had significantly better new bone areas (NBAs) and bone to implant contact (BIC) results than the SLA group (p < 0.05), but the GA and GR groups were similar in this respect. New bone volumes and inter-thread bone densities (ITBD) were non-significantly different in the three groups (p > 0.05). Within the limits of this study, gamma-ray collagen crosslinking on titanium implants can be considered a substitute for glutaraldehyde crosslinking.
PDF
