The present paper investigates the effect of a mathematical model describing the aforementioned process in which the ambient nanofluid in the presence of suction/injection and magnetic field are taken into consideration. The flow is induced by an infinite elastic sheet which is stretched along its own plane. The stretching/shrinking of the sheet is assumed to be proportional to the distance from the slit. The governing equations are reduced to a nonlinear ordinary differential equation by means of similarity transformation. The consequential nonlinear equation is solved analytically. Consequences show that the flow field can be divided into a near-field region and a far-field region. Suction on the surface plays an important role in the flow development in the near-field whereas the far-field is responsible mainly by stretching. The electromagnetic effect plays exactly the same role as the MHD, which is to reduce the horizontal flow resulting from stretching. It is shown that the behavior of the fluid flow changes with the change of the nanoparticles type. The present study throws light on the analytical solution of a class of laminar boundary layer equations arising in the stretching/shrinking sheet problem.

PurposeIn this study, the spatial and temporal relationship of wind speed, atmospheric particles concentration, and the industrial-induced noise levels during different times of the day were examined, using sawmill industrial location around Ile-Ife in Osun of Nigeria as a case study.MethodsMobile devices were used to measure noise level and basic meteorological parameters were examined and their influences on the noise levels distribution were assessed. The maximum and minimum sound levels; Lmax and Lmin, the PM10 and PM1 particle concentrations, wind speeds and directions were measured in the morning (7–9 a.m.), afternoon (12–2) and evening (4–6 p.m.) over 14 consecutive days.ResultsThe results revealed that the noise level varies spatiotemporally, much more consistent spatial distribution along the vicinity of sawmill industries. A higher level of noise occurred during the weekday (WD), Leq > 70 dB(A), compared to weekends (WE). Extreme average noise levels are associated with the immediate neighbourhood of sawmill industrial areas during WD compared to streets and road annexes of the study area. The results also show a very weak relationship between noise and PM10 and PMcoarse for both WD and WE with r < 0.35 for PM1 and r < 0.20 for PMcoarse. There appears to be a moderate significant correlation between noise level and PM1 during some meteorological conditions with r > 0.51.ConclusionThe slight relationship between noise and PM1 is perhaps a result of wind movement that carries particles from the source region since booth noise and particles mostly originate from the sawmill. The study concludes that wind speeds and directions have a significant influence on both noise level and particle concentration within the study sites.

BackgroundWe evaluated the different climatic factors in urban and rural areas that may affect the incidence of urolithiasis. Nationwide data on urolithiasis were acquired from Health Insurance Review and Assessment Service between 2009 and 2013. Information on age, gender, date of diagnosis, geographic region and daily weather data from all weather stations was collected. The data were grouped by population density and substituted into the lag period model. The primary outcome was the incidence rate in each region. The secondary outcomes were differences between groups and relative risks (RRs) of climatic factors. The tertiary outcome was RRs of urolithiasis presentation cumulated over a 20-day lag period associated with the mean daily temperature.ResultsThe incidence rates of urolithiasis tended to increase annually in most regions from 2009 to 2013. The urban group showed a higher mean temperature, lower amount of rainfall, higher wind speed and lower mean relative humidity than the rural group (p < 0.001). The urban group showed significant RRs of temperature (1.013, 95% confidence interval [CI] 1.009–1.017, p < 0.001), wind speed (0.979, CI 0.973–0.986, p < 0.001), humidity (0.995, CI 0.994–0.996, p < 0.001), and sunshine (0.992, CI 0.988–0.996, p < 0.001). The rural group showed significant RRs of wind speed (0.980, CI 0.968–0.992, p = 0.002) and humidity (0.998, CI 0.996–0.999, p = 0.007). In the urban area, RRs increased gradually with increasing temperature.ConclusionsRegional differences in climatic factors, especially temperature, may provoke a gap in urolithiasis events between the urban and rural areas.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-3554-x) contains supplementary material, which is available to authorized users.

Leakage of underwater crude oil pipes causes severe pollution to soil and water, and results in great economic loss. To predict the diffusion area of spilled oil before it reaches the water’s surface and to reduce the time required for emergency response, numerical simulations were conducted on underwater spilled oil diffusion of bare crude oil pipes using FLUENT software. The influences of water-surface wind speed, leakage hole diameter, water velocity, and initial leakage velocity on oil diffusion were analyzed. The results revealed the following: (1) with wind blowing on the surface of the water, the vertical displacement of spilled oil jet-flow was affected by the combined action of water flow and wind, making it difficult for a high-speed jet-flow to form. A horizontal oil flow mostly moved in the direction of the bottom water, and frontier oil droplets dispersed quickly; (2) during the diffusion of spilled oil in water, the maximum horizontal displacement mostly increased linearly, while the maximum vertical displacement initially increased quickly and then slowed; (3) the greater the initial velocity and leakage hole diameter, the higher the oil jet-flow and the wider the diffusion area; the higher the water flow rate and water-surface wind speed, the smaller the vertical displacement of spilled oil. The existence of water-surface wind had no obvious influence on the horizontal displacement of underwater spilled oil.

BackgroundAs healthcare spending continues to increase, medical insurance is now under great pressure of growing economic burden. To control the excessive growth of medical expenditure, change of medical payment system was clearly put forward in China’s new healthcare reform. With this end, Tianjin, a large city in North China, is now exploring to replace traditional fee-for-service (FFS) with global budget payment system (GBPS), and actual effects of GBPS needs to be assessed.MethodsData of this study is from the 2013 National Health Services Utilization Survey among patients of Urban Basic Medical Insurance in China, containing 102,492 outpatient visits of 21,925 hypertensive patients to Tianjin’s primary hospitals in 2013. t test was used to compare the difference between continuous variables. A linear regression analysis was also done to identify possible risk factors of medical expenditure.ResultsOn the basis of expenditure per capital, GBPS, compared with FFS, has significantly reduced total medical expense (CNY 640.28 vs. CNY 700.64, p < 0.001), medical insurance (MI) fund expense (CNY 491.87 vs. CNY 532.37, p < 0.001) and out-of-pocket (OOP) expense (CNY 148.42 vs. CNY 168.27, p < 0.001). Results of generalized linear regression also show that younger people, female and GBPS independently predict less total medical expense, MI fund expense and OOP expense.ConclusionsCompared with FFS, GBPS can help reduce total medical expense, MI fund expense and OOP expense significantly. This study offers evidence for wider implementation of GBPS in China.

Large-scale network environments require effective detection and response methods against DDoS attacks. Depending on the advancement of IT infrastructure such as the server or network equipment, DDoS attack traffic arising from a few malware-infected systems capable of crippling the organization’s internal network has become a significant threat. This study calculates the frequency of network-based packet attributes and analyzes the anomalies of the attributes in order to detect IP-spoofed DDoS attacks. Also, a method is proposed for the effective detection of malware infection systems triggering IP-spoofed DDoS attacks on an edge network. Detection accuracy and performance of the collected real-time traffic on a core network is analyzed thru the use of the proposed algorithm, and a prototype was developed to evaluate the performance of the algorithm. As a result, DDoS attacks on the internal network were detected in real-time and whether or not IP addresses were spoofed was confirmed. Detecting hosts infected by malware in real-time allowed the execution of intrusion responses before stoppage of the internal network caused by large-scale attack traffic.

This paper investigates the l_p-regularization problems, which has a broad applications in compressive sensing, variable selection problems and sparse least squares fitting for high dimensional data. We derive the exact lower bounds for the absolute value of nonzero entries in each global optimal solution of the model, which clearly demonstrates the relation between the sparsity of the optimum solution and the choice of the regularization parameter and norm. We also establish the necessary condition for global optimum solutions of l_p-regularization problems, i.e., the global optimum solutions are fixed points of a vector thresholding operator. In addition, by selecting parameters carefully, a global minimizer which will have certain desired sparsity can be obtained. Finally, an iterative thresholding algorithm is designed for solving the l_p-regularization problems, and any accumulation point of the sequence generated by the designed algorithm is convergent to a fixed point of the vector thresholding operator.

The purpose of this study was to determine favorable physical activities, by intensity, type, and frequency that would serve to minimize the prevalence of metabolic syndrome. A total of 24,178 individuals participated in the Korean National Health and Nutrition Examination Survey that investigated the risk factors for metabolic syndrome and physical activity including the physical activity type (vigorous and moderate activity, walking, strength, and flexibility) and the frequency (numbers of days per weeks where physical activity lasted at least 10 min per session). Complex-samples analysis, descriptive statistics, Pearson’s Chi-square test, and multivariate logistic regression analyses were conducted to analyze the data. The results confirmed that physical activity had a favorable effect on reducing the occurrence of metabolic syndrome. The lowest prevalence of metabolic syndrome was observed when vigorous physical activity was conducted six times per week (OR 0.65, 95% CI 0.45–0.94). The associated beneficial effects included improvements in the risk factors of metabolic syndrome, depending on the specific physical activity type and frequency. Patients diagnosed, as having metabolic syndrome should be aware of the associated underling risk factors in order to determine a targeted physical activity intervention.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-3514-5) contains supplementary material, which is available to authorized users.

ObjectiveTo evaluate documentation of cardiovascular (CV) risk factors and obesity management by pediatric cardiologists.Study designReview of medical records of obese (≥95th body mass index percentile) 2–17 year-old children presenting to outpatient pediatric cardiology over 1 year. Subjects were categorized as: heart disease (HD) with increased risk for atherosclerosis; HD with average risk for atherosclerosis; or no HD. Data were evaluated on documentation of the assessment of seven CV risk factors [including recognition of elevated blood pressure (BP)] and management of obesity. Multivariable logistic regression (LR) examined physician documentation of obesity intervention by risk groups, including age and gender.ResultsData on 730 subjects were analyzed; 16 % had HD with increased risk for atherosclerosis, 41 % had HD with average risk for atherosclerosis, and 43 % had no HD. Documentation of risk factor assessment was highest for physical inactivity (53 %) and recognition of obesity (47 %). Other factors (child dyslipidemia, diet, dysglycemia, and cigarette exposure) were documented less frequently. Elevated BP was found in 144 patients (20 %); 53/144 (37 %) had documentation of elevated BP recognition. An obesity intervention was documented in 62 % of records and did not significantly differ between risk groups. In the multivariate LR, physician documentation of obesity intervention did not significantly differ between risk groups.ConclusionsComplete assessment of CV risk factors in obese patients is low. The number of risk factors assessed was similar among patients with HD with average risk of atherosclerosis and HD with increased risk of atherosclerosis. Increased care coordination between cardiologists and primary care providers may lead to uniform, comprehensive CV risk assessment.

Small giant clam, Tridacna maxima, widely distributed from French Polynesia to East Africa, has faced population declines due to over-exploitation. Comoros islands are an important biogeographic region due to potential richness of marine species, but no relevant information is available. In order to facilitate devising effective conservation management plan for T. maxima, nine microsatellite markers were used to survey genetic diversity and population differentiation of 72 specimens collected from three Comoros islands, Grande Comore, Moheli and Anjouan. A total of 51 alleles were detected ranged from 2 to 8 per locus. Observed and expected heterozygosity varied from 0.260 to 0.790 and from 0.542 to 0.830, respectively. All populations have high genetic diversity, especially the population in Moheli, a protected area, has higher genetic diversity than the others. Significant heterozygote deficiencies were recorded, and null alleles were probably the main factor leading to these deficits. FST value indicated medium genetic differentiation among the populations. Although significant, AMOVA revealed 48.9 % of genetic variation within individuals and only a small variation of 8.9 % was found between populations. Gene flow was high (Nm = 12.40) between Grande Comore and Moheli, while lower (Nm = 1.80) between Grande Comore and Anjouan, explaining geographic barriers to genetic exchanges might exist in these two islands. Global gene flow analysis (Nm = 5.50) showed that larval dispersal is enough to move between the islands. The high genetic diversity and medium population differentiation revealed in the present study offer useful information on genetic conservation of small giant clams.