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We study how the public changes their mobility and retail spending patterns as precautionary responses to the disclosed location of COVID-19 cases. To look into the underlying mechanisms, we investigate how such change varies spatially and whether there is any spatial spillover or substitution. We use the daily data of cell phone?based mobility and credit card transactions between February 10 and May 31 in both 2019 and 2020 in Seoul, South Korea, and employ the empirical approach analyzing the year-over-year percent change for the mobility and consumption outcomes. Results report that one additional COVID-19 case within the last 14 days decreased non-resident inflow and retail spending by 0.40 and 0.65 percentage points, respectively. Then, we also find evidence of spatial heterogeneity: the mobility and retail performances of neighborhoods with higher residential population density were more resilient to COVID-19 case information while neighborhoods with higher levels of land use diversity and retail agglomeration experienced a greater localized demand shock. This heterogeneity is not negligible. For example, one additional COVID-19 case in neighborhoods in the bottom 20% for population density led to a decline of 1.2 percentage points in retail spending, while other neighborhoods experienced a less negative impact. Finally, we find a significant spatial spillover effect of disclosed COVID-19 information instead of spatial substitution. One additional COVID-19 case in geographically adjacent areas within the last 14 days reduced non-resident inflow and retail spending in the subject neighborhood by 0.06 and 0.09 percentage points, respectively. This article is protected by copyright. All rights reserved.

This study aimed to understand school nurses' perceptions regarding barriers to and facilitators for health care services for children with chronic diseases in school settings. Using the PubMed, Cumulative Index to Nursing and Allied Health Literature, Embase, and Web of Science databases, a mixed studies review was conducted for literature published between January 2011 and June 2020. We performed a mixed-methods systematic review using a convergent integrated approach. A quality appraisal of the included studies was conducted using a mixed-methods appraisal tool. Twenty-seven articles (10 qualitative, 10 quantitative, and seven mixed-methods) that met the inclusion criteria were analyzed. Integrated findings that emerged from data synthesis were categorized into four levels (intrapersonal level, interpersonal level, institutional level, and community and public policy level) based on a socio-ecological model framework. This mixed systematic review provides a comprehensive understanding of school nurses' perceived barriers and facilitators when providing school health care for students with chronic diseases and how these barriers and facilitators interact across multiple systems. Further policies and strategies should be developed to provide effective school health services considering this study's findings.

Fog computing is a paradigm which brings computing, storage, and networking closer to end users and end devices for better service provisioning. One of the crucial factors in the success of fog computing is on how to incentivize the individual users’ edge resources and provide them to end users such that fog computing is economically beneficial to all involved economic players. In this paper, we model and analyze a market of fog computing, from which we aim at drawing practical implications to uncover how the fog computing market should operate. To this end, we conduct an economic analysis of such user-oriented fog computing by modeling a market consisting of Infrastructure and Service Provider (ISP), end Service Users (SUs), and Edge Resource Owners (EROs) as a non-cooperative game. In this market, ISP, which provides a platform for fog computing, behaves as a mediator or a broker which leases EROs’ edge resources and provides various services to SUs. In our model, a two-stage dynamic game is used where in each stage, there exists a dynamic game, one for between ISP and EROs and another for between ISP and SUs, to model the market more practically. Despite this complex game structure, we provide a closed-form equilibrium analysis which gives an insight on how much economic benefit is obtained by ISP, SUs, and EROs from user-oriented fog computing under what conditions, and we figure out the economic factors that have a significant impact on the success of fog computing.

This study examines the effectiveness of the Community Reinvestment Act (CRA) in facilitating small business lending to lower-income neighborhoods. Taking advantage of an exogenous policy shock tha...

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease and can lead to multiple complications, including non-alcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma. The fibrotic liver is characterized by the pathological accumulation of extracellular matrix (ECM) proteins. Type VI collagen alpha3 (Col6a3) is a biomarker of hepatic fibrosis, and its cleaved form, endotrophin (ETP), plays a critical role in adipose tissue dysfunction, insulin resistance, and breast cancer development. Here, we studied the effects of the Col6a3-derived peptide ETP on the progression of chronic liver diseases, such as NASH and liver cancer. We used a doxycycline (Dox)-inducible liver-specific ETP-overexpressing mouse model on a NAFLD-prone (liver-specific SREBP1a transgenic) background. For this, we evaluated the consequences of local ETP expression in the liver and its effect on hepatic inflammation, fibrosis, and insulin resistance. Accumulation of ETP in the liver induced hepatic inflammation and the development of fibrosis with associated insulin resistance. Surprisingly, ETP overexpression also led to the emergence of liver cancer within 10 months in the SREBP1a transgenic background. Our data revealed that ETP can act as a “second hit” during the progression of NAFLD and can play an important role in the development of NASH and hepatocellular carcinoma (HCC). These observations firmly link elevated levels of ETP to chronic liver disease., Liver disease: Collagen fragment spurs liver inflammation and fibrosis Localized buildup in the liver of a collagen-derived cleavage fragment plays a critical role in accelerating the development of tissue scarring and liver cancer in mice. Using a transgenic mouse model of fatty liver disease, a team led by Philipp Scherer from the University of Texas Southwestern Medical Center, Dallas, USA, and Jiyoung Park of Ulsan National Institute of Science and Technology, South Korea, showed that liver-specific accumulation of a collagen fragment known as endotrophin leads to activation of inflammatory and fibrotic pathways. The mice subsequently develop metabolic dysfunction, insulin resistance and, with time, cancerous nodules in the liver. The findings suggest that endotrophin accumulation, when it occurs in liver tissue that already contains large depositions of fat, can overwhelm normal liver physiology and accelerate organ damage.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease in China, Japan, and Korea. This study aimed to estimate the monthly SFTS occurrence and the monthly number of SFTS cases in the geographical area in Korea using epidemiological data including demographic, geographic, and meteorological factors. Important features were chosen through univariate feature selection. Two models using machine learning methods were analyzed: the classification model in machine learning (CMML) and regression model in machine learning (RMML). We developed a novel model incorporating the CMML results into RMML, defined as modified-RMML. Feature importance was computed to assess the contribution of estimating the number of SFTS cases using modified-RMML. Aspect to the accuracy of the novel model, the performance of modified-RMML was improved by reducing the MSE for the test data as 12.6–52.2%, compared to the RMML using five machine learning methods. During the period of increasing the SFTS cases from May to October, the modified-RMML could give more accurate estimation. Computing the feature importance, it is clearly observed that climate factors such as average maximum temperature, precipitation as well as mountain visitors, and the estimation of SFTS occurrence obtained from CMML had high Gini importance. The novel model incorporating CMML and RMML models improves the accuracy of the estimation of SFTS cases. Using the model, climate factors, including temperature, relative humidity, and mountain visitors play important roles in transmitting SFTS in Korea. Our findings highlighted that the guidelines for mountain visitors to prevent SFTS transmissions should be addressed. Moreover, it provides important insights for establishing control interventions that predict early identification of SFTS cases.

Objectives: A rubella epidemic has been ongoing in Japan since August 2018. In the present study, we aimed to predict the likely size of a congenital rubella syndrome (CRS) epidemic during 2018–19. Methods: The expected number of CRS cases was estimated using an integral equation based on age-specific incidence of rubella among adult women, the time delay from gestational age of infection to diagnosis of CRS, and distribution of the mothers’ age at delivery. We used epidemic data during 2012–14 to parameterize the model and applied this in the prediction for 2018–19. Results: In analyzing the 2012–14 epidemic data, the mean delay from the mother’s infection to diagnosis was estimated at 24.2 weeks (95% confidence interval (CI): 20.7, 28.1). Applying the parameterized model, together with the more than 480 rubella cases in women in 2018 as well as delayed mother’s age at delivery in 2017, we determined that the expected number of CRS cases would be 9.7 (95% CI: 6.5, 12.5) cases. As the epidemic is ongoing, the cumulative number of CRS cases could potentially reach 96.8 (95% CI: 65.3, 125.5) cases, if rubella cases in adult women rose to 10 times the number by week 49 in 2018. Conclusions: CRS is expected to occur an average of 24 weeks following the mother’s infection with rubella virus. Accounting for an increase to 650 cases in women by week 5 in 2019, the expected number of CRS cases during 2018–19 has already exceeded 13 cases, as of week 5 in 2019. Keywords: Rubella virus, Statistical model, Forecasting, Outbreak, Epidemiology, Prediction, Japan

The international spread of Zika virus (ZIKV) began in Brazil in 2015. To estimate the riskof observing imported ZIKV cases, we calculated effective distance, typically an excellent predictorof arrival time, from airline network data. However, we eventually concluded that, for ZIKV, effectivedistance alone is not an adequate predictor of arrival time, which we partly attributed to the difficultyof diagnosing and ascertaining ZIKV infections. Herein, we explored the mechanisms behind theobserved time delay of ZIKV importation by country, statistically decomposing the delay into twoparts: the actual time to importation from Brazil and the reporting delay. The latter was modeled as afunction of the gross domestic product (GDP) and other variables that influence underlying diagnosticcapacity in a given country. We showed that a high GDP per capita is a good predictor of shortreporting delay. ZIKV infection is generally mild and, without substantial laboratory capacity, casescan be underestimated. This study successfully demonstrates this phenomenon and emphasizes theimportance of accounting for reporting delays as part of the data generating process for estimatingtime to importation.

While the coronavirus disease 2019 (COVID-19) outbreak has been ongoing in Korea since January 2020, there were limited transmissions during the early stages of the outbreak. In the present study, we aimed to provide a statistical characterization of COVID-19 transmissions that led to this small outbreak. We collated the individual data of the first 28 confirmed cases reported from 20 January to 10 February 2020. We estimated key epidemiological parameters such as reporting delay (i.e., time from symptom onset to confirmation), incubation period, and serial interval by fitting probability distributions to the data based on the maximum likelihood estimation. We also estimated the basic reproduction number (R0) using the renewal equation, which allows for the transmissibility to differ between imported and locally transmitted cases. There were 16 imported and 12 locally transmitted cases, and secondary transmissions per case were higher for the imported cases than the locally transmitted cases (nine vs. three cases). The mean reporting delays were estimated to be 6.76 days (95% CI: 4.53, 9.28) and 2.57 days (95% CI: 1.57, 4.23) for imported and locally transmitted cases, respectively. The mean incubation period was estimated to be 5.53 days (95% CI: 3.98, 8.09) and was shorter than the mean serial interval of 6.45 days (95% CI: 4.32, 9.65). The R0 was estimated to be 0.40 (95% CI: 0.16, 0.99), accounting for the local and imported cases. The fewer secondary cases and shorter reporting delays for the locally transmitted cases suggest that contact tracing of imported cases was effective at reducing further transmissions, which helped to keep R0 below one and the overall transmissions small.

Blockchain technology has been regarded as a paradigm that enables enterprises to deploy decentralized Internet of things (IoT) applications, which require security, mutual truthfulness, privacy, and data reliability. However, the adoption of blockchain technology on IoT applications has been limited due to the lack of blockchain's capability to process a huge amount of transaction requests from IoT devices. In this paper, we propose a new transaction processing mechanism, called Accelerator, which improves the performance of blockchain-based IoT applications in terms of transaction throughput and latency. Two key design ideas of Accelerator lie in: (i) independent modular structure that can be implemented without changing the incumbent blockchain network and (ii) adaptive multi-batch scheduling engine for robust performance. We first provide a mathematical analysis that is used to choose the parameters of Accelerator to maximize the performance. Moreover, we implement Accelerator on a decentralized blockchain network using Hyperledger Fabric and perform the extensive test using Hyperledger Caliper. We show that Accelerator achieves 8x transaction throughput improvement without sacrificing latency.

This paper shows that a negative shock to agricultural productivity may increase food prices, and labor and capital can move away from manufacturing into agriculture to meet the subsistence requirement for food. This effect depends on income levels and openness to trade. Using annual manufacturing data and rainfall shocks as the instrument for crop yields (proxy for agricultural productivity), I find that an exogenous decline in yield decreases manufacturing output as well as employment and capital investment in manufacturing. Overall, crop yield variation can explain up to 44% of industrial output fluctuations in developing countries (rainfall shocks cause 31% of the fluctuations). Lastly, this paper shows that such perverse phenomena, in which resources move toward the sector with declining productivity, can lead to a significant reduction in aggregate productivity.

To unravel metabolic determinats of insulin resistance, we performed a targeted metabolomics analysis in Korean Children-Adolescent Cohort Study (KoCAS, n = 430). Sixty-seven metabolites were associated with insulin resistance in adolescents and the association also found in an adult population (KoGES, n = 2,485). Functional interactions of metabolites with gene/proteins using biological pathway with insulin resistance were not identified biological significance and regulatory effects of asymmetric dimethylarginine (ADMA). However, ADMA showed a higher association with adolescent obesity (P

Objectives The characteristics of disease in North Korea, including severe malnutrition and infectious disease risks, have not been openly and widely analyzed. This study was performed to estimate the risks of infectious diseases among refugees from North Korea. Methods A literature review of clinical studies among North Korean defectors was conducted to statistically estimate the risks of infectious diseases among North Korean subjects. Results A total of six groups of data from five publications covering the years 2004 to 2014 were identified. Tuberculosis and viral hepatitis appeared to be the two most common infectious diseases, especially among adult refugees. When comparing the risks of infectious diseases between North Korean and Syrian refugees, it is critical to remember that Plasmodium vivax malaria has been endemic in North Korea, while cutaneous leishmaniasis has frequently been seen among Syrian migrants. Conclusions Valuable datasets from health surveys of defectors were reviewed. In addition to tuberculosis and viral hepatitis, which were found to be the two most common infectious diseases, a special characteristic of North Korean defectors was Plasmodium vivax malaria. This needs to be added to the list of differential diagnoses for pyretic patients.

The Internet consists of economically selfish players in terms of access/transit connection and content distribution. Such selfish behaviors often lead to techno-economic inefficiencies, such as unstable peering and revenue imbalance. Recent research results suggest that cooperation-based fair revenue sharing, i.e., multi-level Internet service provider (ISP) settlements, can be a candidate solution to avoid unfair revenue share. However, it has been under-explored whether selfish ISPs actually cooperate or not (often referred to as the stability of coalition), because they may partially cooperate or even do not cooperate, depending on how much revenue is distributed to each individual ISP. In this paper, we study this stability of coalition in the Internet, where our aim is to investigate the conditions under which ISPs cooperate under different regimes on the traffic demand and network bandwidth. We first consider the under-demanded regime, i.e., network bandwidth exceeds traffic demand, where revenue sharing based on Shapley value leads ISPs to entirely cooperate, i.e., stability of the grand coalition. Next, we consider the over-demanded regime, i.e., traffic demand exceeds network bandwidth, where there may exist some ISPs who deviate from the grand coalition. In particular, this deviation depends on how users’ traffic is handled inside the network, for which we consider three traffic scheduling policies having various degrees of content-value preference. We analytically compare those three scheduling policies in terms of network neutrality, and stability of cooperation that provides useful implications on when and how multi-level ISP settlements help and how the Internet should be operated for stable peering and revenue balance among ISPs.

Glutamate is a major excitatory neurotransmitter and is involved in the ER stress and β-cell dysfunction, which are important clinical features of diabetes mellitus. However, metabolic studies of diabetes in relation to glutamate are not well understood. In this regard, we tried to search for the function of glutamate in type 2 diabetes. We found that glutamate levels were significantly increased in both prediabetic and diabetic participants in 10 years follow-up study (Korean Genome and Epidemiology Study: Ansan-Ansung cohort). And also, we observed that glutamate is associated with FERM domain-containing protein 4B (FRMD4B), plasminogen (PLG) and partitioning-defective 3 (PARD3) by genome-wide association studies (GWAS). Among them, PLG levels were not only significantly increased by palmitate treatment, which is general model for induction of insulin resistance, but also increased by glutamate treatment. To demonstrate the association between PLG and type 2 diabetes, we treated thapsigargin (ER stress) or oligomysin (mitochondrial dysfunction) in Sk-Hep I cells, and observed that PLG levels were significantly increased in these conditions. Consistently, PLG overexpression increased expression of ER stress-related factors; however, repression of PLG expression by plg siRNA attenuated these changes. Our results demonstrate that high levels of glutamate are associated with development of diabetes, and are assumedly regulated by PLG. Disclosure H. Lee: None. J. Yun: None. H. Kim: None. H. Jang: None. S. Park: None. H. Lee: None. Funding Korea National Institute of Health (2017-NG64001-02)

Epidemiological models are routinely used to predict the effects of interventions aimed at reducing the impacts of Ebola epidemics. Most models of interventions targeting symptomatic hosts, such as isolation or treatment, assume that all symptomatic hosts are equally likely to be detected. In other words, following an incubation period, the level of symptoms displayed by an individual host is assumed to remain constant throughout an infection. In reality, however, symptoms vary between different stages of infection. During an Ebola infection, individuals progress from initial non-specific symptoms through to more severe phases of infection. Here we compare predictions of a model in which a constant symptoms level is assumed to those generated by a more epidemiologically realistic model that accounts for varying symptoms during infection. Both models can reproduce observed epidemic data, as we show by fitting the models to data from the ongoing epidemic in the Democratic Republic of Congo and the 2014-16 epidemic in Liberia. However, for both of these epidemics, when interventions are altered identically in the models with and without levels of symptoms that depend on the time since first infection, predictions from the models differ. Our work highlights the need to consider whether or not varying symptoms should be accounted for in models used by decision makers to assess the likely efficacy of Ebola interventions.

This study provides new evidence on the effectiveness of the Community Reinvestment Act (CRA) on small business lending by focusing on a sample of neighborhoods with changed CRA eligibility status across the country because of an exogenous policy shock in 2013. The results of difference-in-differences analysis provide consistent evidence that the CRA promotes small business lending, especially in terms of number of loan originations, in lower-income neighborhoods. The generally positive effects of the CRA are sensitive to the types of CRA treatment. Losing CRA eligibility status has a relatively larger effect on small business lending activities, while the effects of newly gaining CRA eligibility are less pronounced. The results are fairly robust when alternative sample periods and control groups are used.

Background It is plausible that the routine immunization among infants using pneumococcal conjugate vaccine 13 (PCV13) from 2013 and among the elderly using pneumococcal polysaccharide vaccine 23 (PPV23) from 2014 contributed to reducing the pneumonia mortality among the elderly in Japan. The present study aimed to estimate the causal effect of this vaccination on pneumonia mortality, using the available cause-of-death data and employing a difference-in-difference (DID) design. Methods Two types of mortality data, that is, prefecture-dependent and age- and gender-specific mortality data, from 2003 to 2017 were retrieved. We used mortality due to malignant neoplasm and heart disease as control groups and employed a DID design with an assumed parallel mortality trend between pneumonia and control group mortality since 2013 to estimate the causal effect of pneumococcal vaccination from 2014. Results Our estimation based on malignant neoplasm and heart disease as controls indicated that the reduced pneumonia mortality in 2017 owing to pneumococcal vaccination was as large as 41.9 (33.2, 50.6) and 31.2 (23.8, 38.6) per 100,000 individuals, respectively. The largest mortality reduction was observed for the oldest group (aged ≥90 years), especially among men. Discussion The pneumococcal vaccination program, perhaps mainly represented by high vaccination coverage of PCV13 among children and partly by PPV23 administration with low coverage among the elderly in Japan, was shown to have reduced the pneumonia mortality in the elderly at the population level.

The United States is aging, and many baby boomers are reaching or will soon reach the retirement age of sixty-five. On the other hand, the Millennials, the biggest generation in the U.S. history, has been experiencing the issues of rental affordability and uncertainty in housing market. Given the shifts, we are again seeing growing debates about how these changes in age structure will affect our housing and labor market.To address the concerns, we revisit Green and Hendershott (1996) and analyze the links between the willingness to pay for a constant-quality house and demographics using the Census 2000 and 2005-2011 American Community Survey 1-Year Public Use Microdata Sample data. The results generally reconfirm what Green and Hendershott (1996) found: The massive demographic shift will not result in another housing crisis. This is because the educational and income levels of the current and future seniors are relatively higher than before, leading them to consume more than previous generations. Also, the size of the Millennial generation will drive the growth of aggregate housing demand, although the growth of per household housing demand may be relatively modest.

Highlights • There have been errors in determining the end of the Ebola virus disease epidemic from 2014 to 2016. • Of the total five cases of recrudescence, three were caused by sexual contact with survivors. • Recognition of the sexual transmission risk among survivors could potentially involve discrimination., Objectives There have been errors in determining the end of the Ebola virus disease (EVD) epidemic when adhering to the criteria of the World Health Organization. The present study aimed to review and learn from all known recrudescence events in West Africa occurring in 2014–2016. Methods Background mechanisms of five erroneous declarations in Guinea, Liberia, and Sierra Leone during 2014–2016 were reviewed. Results Three cases of recrudescence were suspected to have been caused by sexual contact with survivors, one to be due to international migration, and one was linked to a potentially immunocompromised mother. The three sexual transmission events involving survivors—the first two in Liberia and one in Sierra Leone—required 164 days, >150 days, and approximately 180 days, respectively, from discharge of the survivors to confirmation of the recrudescent case. Conclusions The events of recrudescence were associated with relatively uncommon routes of transmission other than close contact during burial or care-giving, including sexual transmission, possible immunocompromise, and migration. Recognition of the sexual transmission risk among survivors could potentially involve discrimination, which may lead to under-ascertainment.

Background To estimate the causal impact of a change in the national health insurance policy to cover the cost of respiratory syncytial virus (RSV) antigen testing on the incidence of RSV infection by age-groups, we analyzed the sentinel datasets of RSV infection in Japan from 2009-2017. Methods The causal effect of introducing RSV antigen testing on increasing the reported incidence of RSV infection was quantified using a quasi-experimental difference-in-differences (DID) design and influenza as a control group. Results Examining sentinel and virus surveillance datasets, only clinically mild cases have selectively increased from 2012/13. The median estimated incidences of influenza and RSV infection among children aged 0-4 years, the age group that dominates cases of both diseases, were estimated at 5,607 and 1,761 per 100,000 individuals, respectively. Exploring sentinel datasets, only the incidence of RSV infection abruptly increased from 2012/13. Using an age-dependent model, the estimated causal effect on the increase in RSV annual incidence was greatest among children aged 5-9 years, with an estimated additional 1,912 cases per 100,000 individuals (95% CI: 418-3,406). Conclusions Owing to financial support of bedside RSV antigen testing from 2012/13, the incidence of RSV infection has been elevated. The recent increasing trend in RSV infection incidence should not be directly perceived as an increase in natural infections with RSV.

This research explores whether banks strategically leverage regulatory rules for the Community Reinvestment Act that fix a neighborhood's eligibility status over a decade based on a neighborhood's economic trajectory over that decade. Using 2004–2011 Home Mortgage Disclosure Act (HMDA) data, we find that banks approve loans more frequently in those neighborhoods that are most rapidly improving, and that this effect is stronger if the neighborhoods are CRA-eligible low- and moderate-income (LMI) tracts. We find the “moving up” CRA premium ranges in magnitude from a 2 to 13 percent reduction in the likelihood an application is not approved. These results suggest that banks learn which neighborhoods are most rapidly improving and funnel activity to those places to reduce default risk while complying with the fair lending regulation. The results imply a potential unanticipated consequence of the regulation is that it changes the distribution of resources within the target population.

This study examines the role of direct parental assistance in their adult children's home buying, net of other resources. Past research has cited the importance of down payment constraints, but often has not included data on parental wealth and direct transfers. Using both the Health and Retirement Survey (HRS) and Panel Study of Income Dynamics (PSID), we first confirm other research that children whose parents have more resources are more likely to buy homes themselves. In addition, we find that financial transfers increase the probability of home buying among adult children, net of parental wealth and other characteristics of parents and children. Results from the HRS suggest that receiving a transfer greater than $5000 for any purpose increases the probability of transitioning to homeownership by 15.1%. Results from the PSID suggest that this effect was magnified after the recession.

Successful operation of User-Provided Networks (UPN) requires that both of Internet Service Provider (ISP) and self network-operating users (hosts) cooperate appropriately in terms of resource sharing and pricing strategy since ISP and hosts have a multilateral reliance on each other with respect to virtual infrastructure expansion and Internet connectivity. However, it has been underexplored whether such cooperation provides sufficient incentive to ISP and hosts under a setup where ISP and hosts are fully included, having a high dependence on how to cooperate and how to distribute the resulting cooperation worth. In this paper, we model a market of UPN, consisting of ISP, hosts, and clients via game theory, where we model various heterogeneities in terms of (i) willingness to pay and mobility pattern of clients, (ii) hosts' QoS, and (iii) type of cooperation among ISP and hosts. The key technical challenges lie in the natural mixture of cooperative and non-cooperative game theoretic angles, where the worth function---one of the crucial components in coalitional game theory---comes from the equilibrium of an embedded, non-cooperative two-stage dynamic game. We consider the Shapley value as a mechanism of revenue sharing and overcome its hardness in characterization by taking the fluid limit when the number of hosts and clients is large. Our analytical studies reveal useful implications that in UPN when and how much economic benefits can be given to the players and when they maintain their grand coalition under what conditions, referred to as stability.

Fog computing is a paradigm which brings computing, storage, and networking closer to end users and devices for better service provisioning. One of the crucial factors towards the success of fog computing is how to incentivize the individual users' edge resources, thereby opening the era of user- participated fog computing. In this paper, we provide an economic analysis of such user-oriented fog computing by modeling a market consisting of ISP (Infrastructure and Service Provider), SUs (end Service Users), and EROs (Edge Resource Owners) as a noncooperative game. In this market, ISP, which provides a platform of fog computing, behaves as a mediator or a broker to lease the edge resources from EROs and provide various services to SUs. In our game formulation, a two-stage dynamic game is used, where in each stage there exists another dynamic game, one for between ISP and EROs and another for between ISP and SUs, to model the market more practically. Despite this complex game structure, we provide a closed- form equilibrium analysis, which gives an insight of how much economic benefits are obtained by ISP, SUs, and EROs under what conditions.

Background DA-1229 is a novel, potent and selective dipeptidyl peptidase-4 (DPP-IV) inhibitor that is orally bioavailable. We aimed to evaluate the optimal dose, efficacy and safety of DA-1229, in Korean subjects with type 2 diabetes mellitus suboptimally controlled with diet and exercise. Methods We enrolled 158 patients (mean age, 53 years and a mean BMI, 25.6 kg/m2). The mean baseline fasting plasma glucose level, HbA1c and duration of diabetes were 8.28 mmol/L, 7.6% (60 mmol/mol) and 3.9 years, respectively. After 2 or 6 weeks of an exercise and diet program followed by 2 weeks of a placebo period, the subjects were randomized into one of four groups for a 12-week active treatment period: placebo, 2.5, 5 or 10 mg of DA-1229. Results All three doses of DA-1229 significantly reduced HbA1c from baseline compared to the placebo group (−0.09 in the placebo group vs. −0.56, −0.66 and −0.61% in 2.5, 5 and 10-mg groups, respectively) but without any significant differences between the doses. Insulin secretory function, as assessed by homeostasis model assessment β-cell, the insulinogenic index, 2-h oral glucose tolerance test (OGTT) C-peptide and post-OGTT C-peptide area under the curve (AUC)0–2h, significantly improved with DA-1229 treatment. The incidence of adverse events was similar between the treatment groups and DA-1229 did not affect body weight or induce hypoglycaemic events. Conclusions DA-1229 monotherapy (5 mg for 12 weeks) improved HbA1c, fasting plasma glucose level, OGTT results and β-cell function. This drug was well tolerated in Korean subjects with type 2 diabetes mellitus. © 2014 The Authors. Diabetes/Metabolism Research and Reviews published by John Wiley & Sons, Ltd. DA-1229 is a novel, potent and selective DPP-IV inhibitor that is orally bioavailable. In a pharmacodynamic study, more than 80% of DPP-IV was inhibited by a single dose of 5 mg or higher of DA-1229, and this level of inhibition was maintained for at least 24 h after a single dose of 10 mg or higher of DA-1229. This phase II clinical trial was designed to evaluate the efficacy and safety of oral DA-1229 and to determine the optimal dose to use for a phase III clinical study in Korean subjects with type 2 diabetes.

From 2012&ndash, 2013, Japan experienced a major epidemic of rubella, involving a total of 12,614 rubella cases and 45 confirmed cases of congenital rubella syndrome (CRS). One of the contributory factors in this outbreak may have been that the majority of adult males remained unvaccinated. To plan for a supplementary immunization program (SIP) to elevate the herd immunity level, it is critical to determine the required amount of vaccine and identify the target age groups among males for the SIP. The present study aimed to answer these policy questions, employing a mathematical model and analyzing epidemiological datasets from 2012&ndash, 2013. Our model allowed us to reconstruct the age- and sex-dependent transmission patterns, and the effective reproduction number during the exponential growth phase in 2013 was estimated to be 1.5. The computed next-generation matrix indicated that vaccinating adult males aged from 20&ndash, 49 years in 2013, using at least 17 million doses, was considered essential to prevent a major epidemic in the future. The proposed model also indicated that, even with smaller doses of vaccine, the SIP in adult males could lead to a substantial reduction in the incidence of rubella, as well as CRS. Importantly, the present study endorses a substantial background risk of observing another major epidemic from 2018&ndash, 2019, in which cases may be dominated by adult males aged from 25&ndash, 54 years, that is, our identified age groups plus a five-year time lag from 2013 to 2018.

To cope with consumers' ever-increasing demand of high-quality contents in the Internet, content providers (e.g., YouTube) mainly pay to global pure-play CDN companies (e.g., Akamai) instead of ISPs for content delivery. This motivates ISPs to offer their own regional CDN services as Telco-CDNs that compete with the pure-play CDNs for CPs in the CDN market. Unlike the pure-play CDNs with global consumer coverage geographically, Telco-CDNs have the strength of better QoS due to integration of traffic engineering with content delivery. In this paper, we study their competition for CPs by using dynamic game theory, where Telco-CDNs can choose to federate with each other and to which extent. We first analyze the traditional case when Telco-CDNs do not federate and independently operate to locally compete with a typical pure-play CDN. We next study the case when Telco-CDNs form a federation by (i) physically pooling their resources and/or further (ii) economically sharing the total revenue. Depending on the degree of their cooperation (with only (i), called partial federation, or with both (i) and (ii), called full federation), we study how strongly and successfully Telco-CDNs are able to penetrate into the CDN market. Perhaps surprisingly, we show that Telco-CDNs' federation may not help themselves due to the threat of perfect competition with the pure-play CDN.

Dengue fever is a major international public health concern, with more than 55% of the world population at risk of infection. Recent climate changes related to global warming have increased the potential risk of domestic outbreaks of dengue in Korea. In this study, we develop a two-strain dengue model associated with climate-dependent parameters based on Representative Concentration Pathway (RCP) scenarios provided by the Korea Meteorological Administration. We assess the potential risks of dengue outbreaks by means of the vector capacity and intensity under various RCP scenarios. A sensitivity analysis of the temperature-dependent parameters is performed to explore the effects of climate change on dengue transmission dynamics. Our results demonstrate that a higher temperature significantly enhances the potential threat of domestic dengue outbreaks in Korea. Furthermore, we investigate the effects of countermeasures on the cumulative incidence of humans and vectors. The current main control measures (comprising only travel restrictions) for infected humans in Korea are not as effective as combined control measures (travel restrictions and vector control), dramatically reducing the possibilities of dengue outbreaks.

Vascular inflammation induced by the proinflammatory cytokine/NF-kappaB pathway is one of the key mechanisms in the development of neointimal hyperplasia. Accumulating evidence suggests that a recently identified chemokine, fractalkine, is involved in arterial inflammation and atherogenesis. However, no study has examined the expression of neointimal fractalkine and the effects of pharmacological agents on this process. The purposes of this study were to measure neointimal fractalkine expression in the rat carotid artery following balloon injury and to determine if alpha-lipoic acid (ALA) inhibits fractalkine expression and neointimal hyperplasia. Balloon injury of the rat carotid artery induced fractalkine expression in the medial as well as neointimal regions. ALA inhibited this expression and consequently prevented neoinitmal hyperplasia in a balloon-injured rat carotid artery. Additionally, ALA inhibited TNF-alpha-stimulated fractalkine expression in cultured vascular smooth muscle cells (VSMCs), a process which is mediated through the NF-kappaB pathway. In addition to fractalkine, ALA successfully inhibited TNF-alpha-stimulated expression of vascular cell adhesion molecule-1 and monocyte chemotactic protein-1 in cultured VSMCs. These data suggest that the cytokine-fractalkine system is involved in the pathogenesis of restenosis. The present study supports the possibility that ALA, which inhibits the NF-kappaB/fractalkine pathway, may be used to prevent neointimal hyperplasia after angioplasty or stenting.

Sensor networks have emerged as an interesting and important research area in the last few years. These networks require that time be synchronized more precisely than in traditional Internet applications. In this paper, we compared and analyzed the performance of the RBS and TDP mechanisms in the view of the number of generated messages and the synchronization accuracy. The reason that we chose be RBS ad the TDP mechanism to be compared is because the RES is an innovative method to achieve the high accurate synchronization. And TDP is a new method taking over the NTP method which has been used widely in the Internet. We simulated the performance of two methods assuming the IEEE 802.11 CSMA/CA MAC. As for the number of nodes in the sensor networks, two situations of 25 (for the small size network) and 100 (for the large size network) nodes are used. In the aspect of the number of messages generated for the synchronization, TDP is far better than RBS. But, the synchronization accuracy of RBS is far higher than that of TDP. We cm conclude that in a small size sensor networks requiring very high accuracy, such as an application of very high speed objects tracking in a confined space, the RBS is more proper than TDP even though the RBS may generate more traffic than TDP. But, in a wide range sensor networks with a large number of nodes, TDP is more realistic though the accuracy is somewhat worse than RBS because RBS may make so many synchronization messages, and then consume more energies at each node. So, two mechanisms may be used selectively according to the required environments, without saying that the one method is always better than the other.

Location Positioning is a major technology for ubiquitous computing. A research on Location Positioning using UWB is ongoing. In order to construct an indoor location network, synchronization of base stations is very important. NTP is popularly used as a clock synchronization protocol ranging from LAN to WAN. The Master-Slave scheme, however, is the simplest method for synchronizing an indoor network that uses UWB. In this paper, we compare and analyze the NTP and Master-Slave schemes according to the statistical channel model for an indoor multi-path propagation environment. Error ranges are calculated at various circumstances such as when the indoor network expands from one primary base station to several base stations. In particular, we compare the correctness of the NTP and Master-Slave synchronization methods. We have found that NTP is a more reasonable synchronization protocol in UWB positioning.

The CDN (Content Delivery Network) market consists of content providers (CPs), Internet service providers (ISPs), and CDN providers and evolves based on their complex cooperation and competition. Recently, the rapid growth of content-oriented traffic has brought forth a new entity called Telco CDNs in the content delivery supply chain, where Telco CDNs are the ISP-operated CDN providers, vertically integrating content delivery service with traffic engineering, so as to provide better reliability and QoS to users and reduce infrastructure investments. Telco CDNs and traditional CDNs would compete for their market shares with their unique advantages: Telco CDNs are capable of jointly optimizing network costs and user-perceived QoS, but possibly with their geographical limitation in service areas, whereas traditional CDNs operate a network of servers worldwide, with the advantages of performing global, sophisticated analytics or providing better security solutions. Telco CDNs may form an alliance (e.g., cache server sharing) to compete with traditional CDNs, but with some alliance cost. With this CDN market evolution, this paper conducts a game-theoretic study of when and how traditional CDNs survive in the competition with Telco CDNs. In particular, our study answers the questions about the impact of Telco CDNs' unique characteristics on the long-term competition against traditional CDNs, and the impact of Telco CDNs' alliance. Our analysis provides useful implications on the economics of the future CDN market, e.g., what factors can be Achilles' heel and thus what features should be more focused for Telco and traditional CDNs.

The Internet is a complex system, consisting of different economic players in terms of access/transit connection and content distribution, which are typically selfish and try to maximize their own profits. Due to this different perspective of economic interest as well as dynamic changes of the Internet market, a certain degree of techno-economic inefficiency has naturally been observed, e.g., unstable peering and revenue imbalance among content, eyeball, and transit ISPs (Internet Service Providers). At the center of this issue is “good” revenue sharing among them. Recently, revenue sharing based on the notion of Shapley Value (SV) from cooperative game theory has been applied to address the afore-mentioned issue, shedding light upon many nice properties which have been used not only to understand the current Internet eco-system but also to predict its future. However, the positive features from the SV based revenue sharing can be practically feasible only when the providers agree to form a grand coalition, which may not hold in practice. In this paper, we first investigate the conditions under which the grand coalition is stable under SV by classifying the network into two cases: under-demanded and over-demanded. We then study the gap between the conditions of the grand coalition's stability and optimal coalition structures (i.e., coalition structures that maximize the aggregate revenue of ISPs).

Flows typically pass through multiple networks owned and managed by different ISPs (Internet Service Providers). Users pay usage fee to the traversed networks, and each ISP typically applies different charging rules, depending on their own economic interests and business policies. The revenue sharing rule among ISPs, i.e., how users' fee is shared among them has been known to have large impacts on evolution of the networks, e.g., incentives to upgrade the networks. Related to revenue sharing is network neutrality, where we are particularly interested in the way of sharing the network operation cost between EUs (End-User) and CPs (Content-Providers). This paper studies the interaction between ISP revenue sharing and neutrality-compatible pricing between EU and CP. We study the cases (i) when ISPs charge users/CPs selfishly and (ii) when they coordinate towards fairness of ROI (Return-On Investment). We discuss different engineering and economic implications using the analytical results for two revenue sharing policies coupled with neutrality in the network.

Sensor networks have emerged as an interesting and important research area in the last few years. In order to construct a wireless sensor network, synchronization of base stations is very important. As the synchronization mechanisms based on the purpose of the sensor network, the RBS (reference broadcast synchronization) and TDP (time-diffusion synchronization protocol) have been proposed. This paper compared and analyzed the performance of the RBS and TDP mechanisms according to the number of generated messages, the elapsed time for overall synchronization, the number of nodes to be synchronized from a reference node and the number of reference nodes in the wireless sensor network. In the simulation results based on the number of generated messages and the elapsed time in overall synchronization, TDP is far better than RBS. But, in the environments with small number of nodes, RBS is far more accurate than TDP. So, if it requires only few base nodes in the network and the more high synchronization accuracy is necessary, RBS mechanism is more preferable. However, the RBS has a disadvantage that does not consider energy requirement of sensor nodes and a new E-RBS (Efficient RBS) is proposed. E-RBS decreases the number of messages to be processed and saves the energy consumption, with a range of an acceptable accuracy. So, E-RBS can be used efficiently in such an environment as small home/office sensor networks with small base nodes

Background Germline mutations in the BRCA1 and BRCA2 genes account for 20–25 % of inherited breast cancers and about 10 % of all breast cancer cases. Detection of BRCA mutation carriers can lead to therapeutic interventions such as mastectomy, oophorectomy, hormonal prevention therapy, improved screening, and targeted therapies such as PARP-inhibition. We estimate that African Americans and Hispanics are 4–5 times less likely to receive BRCA screening, despite having similar mutation frequencies as non-Jewish Caucasians, who have higher breast cancer mortality. To begin addressing this health disparity, we initiated a nationwide trial of BRCA testing of Latin American women with breast cancer. Patients were recruited through community organizations, clinics, public events, and by mail and Internet. Subjects completed the consent process and questionnaire, and provided a saliva sample by mail or in person. DNA from 120 subjects was used to sequence the entirety of BRCA1 and BRCA2 coding regions and splice sites, and validate pathogenic mutations, with a total material cost of $85/subject. Subjects ranged in age from 23 to 81 years (mean age, 51 years), 6 % had bilateral disease, 57 % were ER/PR+, 23 % HER2+, and 17 % had triple-negative disease. Results A total of seven different predicted deleterious mutations were identified, one newly described and the rest rare. In addition, four variants of unknown effect were found. Conclusions Application of this strategy on a larger scale could lead to improved cancer care of minority and underserved populations. Electronic supplementary material The online version of this article (doi:10.1186/s13742-015-0088-z) contains supplementary material, which is available to authorized users.