Single Lag Research Articles

A Systematic Review on Lagged Association in Environmental Studies

The delayed association in environment-health studies has been acknowledged in recent years. However, the misspecification of lag dimension in time-series models, particularly distributed lag non-linear models (DLNM), would induce considerable deviation of effect estimate. This study reviewed the existing climate-health English literature with time-series and case-crossover design published during 2000-2019 to summarize the statistical methodologies used and the reported delays of association between meteorological variables and 14 common causes of morbidity and mortality. Generalized linear or additive model was the most widely employed method for regression analysis. Different types of lag design were adopted for infectious disease modeling, including cross-correlation analysis, single lag model, moving average lag model, unconstrained or polynomial distributed lag model, and DLNM, whereas studies on non-communicable diseases predominantly used DLNM to assess the delays of association. For infectious outcomes, the association of daily mean temperature was found to be lagged for one to two weeks for influenza, followed by two to five weeks for diarrhea, and eight to twelve weeks for dengue fever. Meanwhile, the association of both cardiovascular and respiratory diseases with hot temperatures lasted for less than five days, whereas the association of cardiovascular diseases with cold temperatures was observed for ten to twenty days. Additionally, rainfall, as a potential risk factor for infectious diseases, showed a four to eight weeks’ lagged association with diarrheal diseases, while the effect was further delayed to eight to twelve weeks for vector-borne diseases. This is the first systematic review that comprehensively provides epidemiological evidence on the delay of association of common meteorological parameters. Biologically plausible and reasonable definition of effect lag in the modeling process is warranted in further environmental epidemiological studies.

News Versus Market Sentiments

This paper investigates the impact of monetary policy announcements on the performance of the stock market in twenty countries (10 Developed and 10 developing). Exchange rate changes and changes in bond yield were taken as control. Daily basis Panel data was used with daily frequency for five (5) years (2014 – 2018). An impact of these selected independent variables on the stock market index is estimated using the regression model and Panel Least Square model. Monetary policy data has been run in three different lags i.e. lag (0), lag (-1, -2, -3, -4), and lag (1, 2, 3, 4) in order to check the availability of monetary policy impact in pre and post announcement dates also, while the other variables run on a single lag. It is observed that the stock market of developed countries has a significant relation with monetary policy announcements, however, these announcements showed an insignificance relation with the stock market index in the case of developing countries. Moreover, exchange rates seem to have a significant effect on markets of both developing and developed countries, whereas bond yield seems to have a significant effect on the stock market of Developing countries only.

A Mathematical Model on Heat Mass Transfer Including Relaxation Time for Different Geometries During Drying of Foods

Abstract In this paper, a single phase lag model on heat mass transfer in application of food drying has been developed. The present model is a generalization of the diffusion model. The whole analysis is presented in nondimensional form. The effects of shape parameter, relaxation time parameters, Luikov number, Kirpichev number, Biot number, Kossovich number, and Predvoditelev number on heat and mass transfer are discussed in detail. For experimental validation, we have taken examples of banana, mango, and cassava. Our simulations show that the present model is more suitable than diffusion model. The present model is in good agreement with experimental data. The moisture potential of slab food is higher than cylindrical food and moisture potential of cylindrical food is higher than spherical food for boundary condition of first, second, and third kinds. It has been observed that the moisture potential is highest in boundary condition of second kind and lowest in boundary condition of the third kind while in between in boundary condition of the first kind. We conclude that for complete drying, the spherical shape foods takes lesser time than cylindrical shape and cylindrical shape takes lesser time than slab shape.

Macroeconomic determinants of Long-term Sovereign bond yields in South Africa

Recent developments in South Africa warrant a complete understanding of the fiscal dynamics within the economy. The government budget deficit has soured to unprecedented levels pushing the debt to GDP ratio above 60%. We seek to reveal in this paper the impact this has on the South African long term bond yield, which represents the cost of borrowing to government. Our approach entails investigating the determinants of the long term bond yield for South Africa using linear and non-linear single equation Auto-regressive distributed lag (ARDL) approach. Our results show that the short-term interest rate is the major determinant of long term yields in South Africa, showing a persistent positive and statistically significant relationship with the long term yield. Furthermore, we find that government debt and the US long term yield are positively related to long term bond yields both in the short and long-run. Our tests for linearity reveal that the short-term interest rate has a non-linear relationship with the long-term bond yield. The rate of inflation, nominal exchange rate and bank credit all have negative impacts on the bond yield in the long-run. Economic growth has a positive impact in the short run but impact the long-term yield negatively in the long-run. We suggest a coordinated approach between monetary policy and fiscal policy authorities, a systematic program of deleveraging and implementation of structural strategies aimed at increasing production.

Research on the correlation between otorhinolaryngologic diseases and environmental meteorological factors in children

Objective:To explore the correlation between acute otitis media（AOM）, acute pharyngitis（AP） and allergic rhinitis（AR） and environmental-meteorological factors in children in Lanzhou. Method:Data were collected in 2015-2017 from the outpatient department and emergency department of Otolaryngology of one hospital in Lanzhou. The association between clinical data and the environmental meteorological factors during the same period, including the air quality index（AQI）, PM2.5, PM10, CO, NO₂, SO₂, O3, average temperature, average air pressure, average wind speed, average humidity in Lanzhou, was analyzed. Result:The incidence of AOM was positively correlated with AQI, PM2.5, PM10, CO, NO₂, SO₂, average air pressure, and was negatively correlated with O3, average wind speed and average air temperature, but not correlated with average humidity. The incidence of AP was positively correlated with average temperature and average humidity, and not correlated with other 9 factors. The incidence of AR was correlated with all 10 environmental meteorological factors except for O3.The number of children with AOM, AP and AR varied with different seasons. Environmental meteorological factors have single lag and cumulative lag effects on the incidence of children with AOM, AP and AR, and difference between the single lag and cumulative lag time was observed. Conclusion:There may be some correlation between the environmental meteorological factors and the incidence of AOM, AP, AR in children, and there is a lag effect. The incidence of pediatric AOM, AP and AR is affected by seasonal factors.

Computational study on constant and sinusoidal heating of skin tissue using radial basis functions

This paper concerns the study of heat distribution in skin tissue with constant and sinusoidal heat flux at the skin surface. Three types of heat transfer models, i.e., Pennes bioheat model, single-phase lag model, and dual-phase lag model based on Fourier and non-Fourier heat conduction, are taken into consideration. Also, Fourier, as well as non-Fourier boundary conditions, are considered at both the end of skin tissue for the single and dual-phase lag model of heat conduction. The resulting models are solved using finite difference and radial basis function (RBF) approximations for the temporal and spatial variables, respectively. The effects of these three models and other parameters involved in models on heat transfer in skin tissue are studied. The effects of Fourier and non-Fourier boundary conditions on heat transfer for single and dual-phase lag models are also studied.

News vs Sentiments: Impact of Monetary Policy Announcement on Developed and Developing Countries’ Market Performance

This paper investigates the impact of monetary policy announcements on the performance of the stock market in twenty countries (10 Developed and 10 developing). Exchange rate changes and changes in bond yield were taken as control. Daily basis Panel data was used with daily frequency for five (5) years (2014 – 2018). An impact of these selected independent variables on the stock market index is estimated using the regression model and Panel Least Square model. Monetary policy data has been run in three different lags i.e. lag (0), lag (-1, -2, -3, -4), and lag (1, 2, 3, 4) in order to check the availability of monetary policy impact in pre and post announcement dates also, while the other variables run on a single lag. It is observed that the stock market of developed countries has a significant relation with monetary policy announcements, however, these announcements showed an insignificance relation with the stock market index in the case of developing countries. Moreover, exchange rates seem to have a significant effect on markets of both developing and developed countries, whereas bond yield seems to have a significant effect on the stock market of Developing countries only Keywords: monetary policy announcements, stock market index, exchange rates, bond yields, cross country, news, sentiments DOI: 10.7176/JESD/11-7-05 Publication date: April 30 th 2020

Short-term exposure to desert dust and the risk of acute myocardial infarction in Japan: a time-stratified case-crossover study.

Particulate matter from natural sources such as desert dust causes harmful effects for health. Asian dust (AD) increases the risk of acute myocardial infarction (AMI). However, little is known about the risk of myocardial infarction with nonobstructive coronary arteries (MINOCA), compared to myocardial infarction with coronary artery disease (MI-CAD). Using a time-stratified case-crossover design and conditional logistic regression models, the association between short-term exposure to AD whereby decreased visibility (< 10km) observed at each monitoring station nearest to the hospitals was used for exposure measurements and admission for AMI in the spring was investigated using a nationwide administrative database between April 2012 and March 2016. According to presence of revascularization and coronary atherosclerosis, AMI patients (n = 30,435) were divided into 2 subtypes: MI-CAD (n = 27,202) or MINOCA (n = 3233). The single lag day-2 was used in AD exposure based on the lag effect analysis. The average level of meteorological variables and co-pollutants on the 3days prior to the case/control days were used as covariates. The occurrence of AD events 2days before the admission was associated with admission for MINOCA after adjustment for meteorological variables [odds ratio 1.65; 95% confidence interval (CI) 1.18-2.29], while the association was not observed in MI-CAD. The absolute risk difference of MINOCA admission was 1.79 (95% CI 1.21-2.38) per 100,000 person-year. These associations between AD exposure and the admission for MINOCA remained unchanged in two-pollutant models. This study provides evidence that short-term exposure to AD is associated with a higher risk of MINOCA, but not MI-CAD.

Short-term effects of particulate matter exposure on emergency room visits for cardiovascular disease in Lanzhou, China: a time series analysis.

Cardiovascular disease (CVD) has been the leading cause of death in China. Identifying the relationship between particulate matter (PM) and CVD in China is a significant challenge. In this study, daily CVD emergency room visit, environmental monitoring, and weather data from January 1, 2017, to December 31, 2018, in Lanzhou were collected. Generalized additive models (GAMs) were constructed to estimate the short-term effects of daily PM2.5, PMC, and PM10 concentrations on CVD emergency room visits with different lag structures after controlling for the influence of meteorological elements and gaseous pollutants. Stratified analyses were conducted according to age (≥ 65years and < 65years), sex (male and female), cold season (from November to April), and warm season (from May to October). The results showed that each 10μg/m3 increase in PM2.5 was associated with a 1.93% (95% CI 0.12-3.78%) increase in CVD emergency room visits at lag03, and no single lag model was statistically significant. The excess relative risks (ERRs) of PM10 and PMC were not statistically significant at any lag pattern. The exposure-response curves demonstrated a nonlinear upward trend for these three PM pollutants. When adjusting for other gaseous pollutants, such as NO2, SO2, CO, and O3, in the two-pollutant models, the associations between PM10 and PMC and CVD emergency room visits did not change compared with the single-pollutant models. The ERRs of PM2.5 were 1.67% (95% CI 0.03-3.34%) at lag02 after adjustment for NO2 and 1.65% (95% CI 0.02-3.30%) at lag02 after adjustment for SO2. The ERRs of PM2.5 were still statistically significant at lag03 when we adjusted for any one of the gaseous pollutants. Susceptibility to PM2.5 was increased in people aged < 65years, in males, and in the warm season. The findings are very important for local governments to develop environmental policies and strategies to reduce ambient PM2.5 levels.

News Vs Sentiments: Impact of Monetary Policy Announcement on Developed and Developing Countries’ Market Performance

This paper investigates the impact of monetary policy announcements on the performance of the stock market in twenty countries (10 Developed and 10 developing). Exchange rate changes and changes in bond yield were taken as control. Daily basis Panel data was used with daily frequency for five (5) years (2014 – 2018). An impact of these selected independent variables on the stock market index is estimated using the regression model and Panel Least Square model. Monetary policy data has been run in three different lags i.e. lag (0), lag (-1, -2, -3, -4), and lag (1, 2, 3, 4) in order to check the availability of monetary policy impact in pre and post announcement dates also, while the other variables run on a single lag. It is observed that the stock market of developed countries has a significant relation with monetary policy announcements, however, these announcements showed an insignificance relation with the stock market index in the case of developing countries. Moreover, exchange rates seem to have a significant effect on markets of both developing and developed countries, whereas bond yield seems to have a significant effect on the stock market of Developing countries only.

Study on the association between ambient air pollution and daily cardiovascular death in Hefei, China.

Cardiovascular disease has always been the most serious public health problem in China. Although many studies have found that the risk of death caused by cardiovascular disease is related to air pollutants, the existing results are still inconsistent. The aim of this study was to investigate the effects of air pollutants on the risk of daily cardiovascular deaths in Hefei, China. Daily data on cardiovascular deaths, daily air pollutants, and meteorological factors from 2007 to 2016 were collected in this study. A time-series study design using a distributed lag nonlinear model was employed to evaluate the association between air pollutants and cardiovascular deaths. First, a single air pollutant model was established based on the minimum value of Akaike information criterion (AIC), and the single day lag effects and multi-day lag effects were discussed separately. Then, two-pollutant models were fitted. Subgroup analyses were conducted by gender (male and female), age (< 65 age and ≥ 65 age), and disease type (ischemic heart disease and cerebral vascular disease). There were 34,500 cases of cardiovascular deaths during the period 2007-2016, and the average concentrations of air pollutants (PM10, SO2, NO2, PM2.5, CO, O3) were 106.11, 20.34, 30.49, 72.59, 958.7, and 67.88 μg/m3, respectively. An increase of interquartile range (IQR) in PM10, SO2, NO2, PM2.5, CO, and O3 were associated with an increase of 4.34% (95%CI 1.54~7.23%) at lag 0-6, 5.79% (95%CI 2.43~9.27%) at lag 0-5, 4.47% (95%CI 1.64~7.37%) at lag 0-5, 3.14% (95%CI 0.03~6.36%) at lag 0-4, 3.11% (95%CI 0.21~6.10%) at lag 0-3, and 8.17% (95%CI 1.89~14.84%) at lag 0-5 in cardiovascular deaths, respectively. Females, older group (≥ 65 years) and deaths from cerebral vascular disease were more vulnerable to air pollution than males, younger individuals (< 65 years) and deaths from ischemic heart disease. Our results suggest that air pollution increased the risk of cardiovascular deaths in Hefei. These findings can provide evidence for effective air quality interventions in Hefei.

Effect modifiers of lung function and daily air pollutant variability in a panel of schoolchildren

BackgroundAcute pollutant-related lung function changes among children varies across pollutants and lag periods. We examined whether short-term air pollutant fluctuations were related to daily lung function among a panel of...

Bone Anchor Suture Tape Fixation Technique for the Treatment of Calcaneal Avulsion Fractures

Category:Hindfoot, TraumaIntroduction/Purpose:Surgical treatment of avulsion fractures of the calcaneus has a reported fixation failure rate as high as 23%, and there is much controversy surrounding the best method of treatment for these fractures. We present a technique for fixation of calcaneal avulsion fractures utilizing a bone anchor suture tape fixation technique that can be utilized with or without additional standard internal fixation.Methods:Five patients (2 male, 3 female), with an average age of 73 years old, presenting with a closed extraarticular avulsion fracture of the calcaneus, are included in this case series. Patients underwent bone anchor and suture tape fixation of fracture by a single foot and ankle-fellowship trained orthopaedic surgeon. Patients were additionally assessed pre-operatively, using the contralateral uninjured limb, for gastrocnemius equinus; and if present, patients underwent a gastrocnemius recession. If appropriate, a single compression lag screw and washer inserted perpendicular to fracture line was utilized for additional fixation. Outcomes observed were time to radiographic consolidation, failure of fixation, reoperation rate, presence of post-operative infection, and return to previous function.Results:Of the included patient cohort, all fractures went on to union, and there were no failures of fixation. There was one removal of a compression screw and washer due to hardware pain, and one superficial infection, which resolved with local wound care. All patients went on to weight-bearing as tolerated within 8 weeks post-operatively. Radiographic consolidation was observed at approximately 12 weeks. 4 out of 5 patients returned to previous function, with 1 patient expiring due to unrelated causes prior to determination of final function.Conclusion:Use of a bone anchor suture tape fixation technique appears to hold promise and warrants further investigation for its potential utilization as a reliable technique for fixation for avulsion fractures of the calcaneus. Our technique increases the distribution of surface area forces over the cortical bone while incorporating multiple points of fixation, including through the Achilles tendon insertion, neutralizing the distraction forces of the tendon directly.

Dust storms and years of life lost in Seoul, South Korea

TPS 681: Short-term health effects of air pollutants 1, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Dust storms have been evaluated as a risk factor for human health. However, previous studies have estimated the effect of dust storms on absolute numbers of death without considering premature death. To set public health priorities and allocate resources within limited budgets, it is important to know the actual burden of an exposure-induced mortality. We aimed to estimate years of life lost (YLL) due to Asian dust storm (ADS) in Seoul, South Korea during 2002-2013. We performed a time-series analysis using a generalized additive model with Gaussian distribution to investigate the association between daily YLL and ADS. We assessed both single and cumulative lag effects of ADS by using a distributed lag model up to 5 days. In a main model, daily YLL was regressed on the ADS variable (ADS day:1) with a distributed lag parameterization. We adjusted for 2-day average of weather variables (temperature, relative humidity, barometric pressure, and wind speed), calendar time, influenza epidemic, holidays, and day of the week. We used a spline function for calendar time (6 df), temperature (6 df), and other weather variables (3 df). We identified 108 ADS events during study period. Exposure to ADS was significantly associated with increased YLL of non-accidental deaths. Specifically, daily YLL was increased by 48.5 years (95% CI: 3.0–94.1) at lag 2 and by 104.8 years (95% CI: 30.9–178.4) over lags 0–5. In disease-specific analyses, the association between ADS and YLL of cardiovascular mortality was significant at lag 2 (19.6 years [95% CI: 1.6–37.7]) and over lag 0–5 (34.5 years [95% CI: 4.1–64.8]), while that for respiratory mortality was significant at lag 3 (7.9 years [95% CI: 0.2–15.5]). Exposure to ADS occurrences was associated with an increased YLL of non-accidental death. These findings could help establish public health priorities.

Short-Term effects of fine particulate matter on respiratory disease in vulnerable population

OPS 50: Air pollution and health care utilization, Room 117, Floor 1, August 28, 2019, 10:30 AM - 12:00 PM An epidemiological research was conducted to establish the association between exposure to particular matter less than 2.5 diameters (PM2.5), and daily cases of respiratory disease (acute infection in the upper and lower respiratory tract) in vulnerable populations (under 5 years of age and 65 years and older) in the 10 municipalities of Aburra Valley region in Antioquia (Colombia) between 2008 and 2015. For each municipalities, the data was collected from the individual records of health service provision, time series analyzes were performed with generalized additive models (GAM) of Poisson regression. The findings were consolidated from meta-analysis supported in random effects models. In six of the 10 municipalities evidences of the shor-term effects of PM2.5 on the incidents of respiratory disease in the two age groups were found. In children under 5 years the consolidated effects show gradients for the single lag models and for the distributed lag models; the increase of the daily concentration of 10 µg/m3 of PM2.5 increased in 9.1% the cases of respiratory disease in Lag 1; the accumulated exposure during the first 3 days and during 15 days was related to respective increases of 12.6% and 19.4%. In adults aged 65 and over the effects were lower than those observed in the group of children, the increase of the daily concentration of 10 µg/m3 of PM2.5 increased in 4.2% the cases of respiratory disease. The accumulated exposure during 3-day was associated with increases of 2.9%, however the effect is reduced to 1.2% for accumulated lags of 7 days and diluted for cumulative exposure of 15 days, period for which the relative risk is not statistically significant. The results of this multicity analysis show the health effect of PM2.5 on respiratory morbidity of vulnerable population with greater association in children under 5 years.

Will We Ever Meet Again? The Relationship between Inter‐Firm Managerial Migration and the Circulation of Client Ties

AbstractA large body of research shows that the migration of managers from one professional service firm to another weakens the old employer’s relationship with its clients, because migrating managers remove their relationship‐specific knowledge and expertise – i.e., human and social capital – from their old employers, redeploying it to their new employers. This study extends this research by introducing a bi‐directional perspective of social capital in which both firms and managers may exploit these relationship‐specific resources. We use theory on social capital to build arguments about how one form of manager mobility, manager migration between two service providers in a single market, can both lead and lag the movement of client ties between those providers, and signaling theory to hypothesize the conditions under which this is likely to occur. Analyses using longitudinal data on New York City advertising agencies generally support our arguments. Our findings contribute to theory and research on manager migration, social capital, and signaling, and raise new questions for how the portability of relationship‐specific social capital shapes markets.

Learning from Errors While Forecasting Inflation: A Case for Intercept Correction

Structural changes are quite common in macroeconomic time series. Internal/external shock(s) may cause significant structural change in any economy. Simplest form of such change is observed as shift in constant of an underlying relationship between a pair of macroeconomic variables. Forecasting from such a model assuming no structural break is tantamount to ignoring the important aspects of underlying economy and mostly results in forecast failure. Intercept correction (adjustment for the realized forecast error) is a method for accommodating such ignored structural break(s). We use a simple model to forecast inflation (based upon single lag of money supply growth) for 25 countries and compare its performance with a) the same model with optimal intercept correction, b) the same model with half intercept correction, and c) a random walk model (with drift). Optimal intercept correction approach outperforms in forecasting next period inflation compared to one from a) the same model without intercept correction, b) the same model with half intercept correction, and c) random walk model. We also observe that higher correction is needed for countries with more volatile inflation.

Capacitance in Biochemical Networks: Sequential Reaction Delays

In an enzymatic reaction network there are four unavoidable, generally neglected, sources of delay: (1) diffusion of substrate S to the enzyme, (2) the rate k1 of binding S to the enzyme E, (3) the retention in the form of the ES complex as S is converted to product P, (4) “volume delay”, the transient delay for concentrations to reach the next steady state after each change in a flux, and (5)flux delay with reversible reactions. Michaelis‐Menten forward flux is the product of the maximal flux, Vmax, times the fractional occupancy of the active site, [S]/(Km +[S]), where Vmax= Etot • k2 , (Etot = enzyme concentration; k2 = rate of product release). This accounts for neither binding/unbinding nor the capacitance of the ES complex. We examine these delays for an unbranched unidirectional reaction sequence A→B→C→D→E, ignoring diffusion delay. The delays are nearly exponential single lags, each with time constant = exchanged mass/flux, e.g. t = ES/(k2 • ES) = 1/k2 . We consider four versions of this reaction set (available at www.physiome.org/Models): #423 forward first order reactions, #424 Michaelis‐Menten forward reaction, #425 M‐M coupled with a correcting time lag of 1/k2 , compensating virtually precisely for the lack of capacitance, and #426, the full enzyme binding and release kinetics. The programs include verification tests, and are open source, human readable differential equations in JSim's MML. Time constants for lags are: for binding substrate, 1/k1; for retention in ES complex 1/k2 ; for the “volume delay”, (Vol ml)/(Clearance in ml/sec) while going from one steady state to the next. A fifth model, #427, “flux reversal”, shows that with simultaneous forward and backward fluxes in an enzyme sequence such as A→B←→C←→D→E, there is increased capacitance or retention in the B←→D block of reactions that is dependent on the relative dissociation constants, Kd's, of the enzyme for binding substrate versus product. Such delays, and resultant flux limitations and increased susceptibility to system instabilities need to be accounted for in characterizing systems especially when branched or feedback‐controlled. Unidirectional M‐M models can be made temporally accurate by adding capacitance‐mimicking lags in series. In the full kinetic models the delays are fully accounted for by equations describing the kinetics directly, including the reversibility delays.Support or Funding Information(Supported by NIH/NHLBI U01‐HL122199)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Spatial variation in lag structure in the short-term effects of air pollution on mortality in seven major South Korean cities, 2006–2013

Lag is one of the major uncertainties in the heterogeneity of short-term effects of particulate matter with aerodynamic diameter <10 μm (PM10) on mortality. This study aimed to explore spatial variations in extended lag effects of PM10 on all-cause mortality, cardiovascular mortality and respiratory mortality in seven major South Korean cities over a period spanning 2006–2013. We did time-series analysis using generalized linear models and adjusted for temporal trend, day of the week, holiday, influenza epidemic, and weather. Single lag models and distributed lag models were extensively compared, specifically in terms of lag interval, and adjustment for temporal trend. We also conducted a time-stratified case-crossover analysis. Multivariate meta-regressions with city characteristic variables were conducted in order to assess spatial variation in the lag structure. When considering up to previous 45 days of exposure, we found longer lag associations between PM10 and mortality, particularly in all-cause mortality and respiratory mortality. SO2, the ratio of SO2 to PM10 and gross regional domestic product were all found to positively contribute towards the associations between PM10 and all-cause mortality and cardiovascular mortality. Ulsan (Korea's largest industrial city) was found to have the strongest cumulative percentage increases in all-cause mortality and cardiovascular mortality per 10 μg/m3 increase of PM10: 4.9% (95% CI: 2.5, 7.3) and 4.3% (95% CI: −0.9, 9.7) respectively. Busan (Korea's largest seaport city) was found to have the highest cumulative percentage increase in respiratory mortality with an 8.2% increase (95% CI: 2.8, 13.8). In summary, the short-term effects of PM10 on mortality may persist over a period of not just few weeks but longer than a month, and may differ according to regional economy. This study provides public health implication that, in order to minimize the health effects of PM, air quality interventions should focus on not only particulate pollution but also gaseous pollution, such as SO2.

Characteristics of Gas Permeation Behaviour in Multilayer Thin Film Composite Membranes for CO₂ Separation.

Porous, porous/gutter layer and porous/gutter layer/selective layer types of membranes were investigated for their gas transport properties in order to derive an improved description of the transport performance of thin film composite membranes (TFCM). A model describing the individual contributions of the different layers’ mass transfer resistances was developed. The proposed method allows for the prediction of permeation behaviour with standard deviations (SD) up to 10%. The porous support structures were described using the Dusty Gas Model (based on the Maxwell–Stefan multicomponent mass transfer approach) whilst the permeation in the dense gutter and separation layers was described by applicable models such as the Free-Volume model, using parameters derived from single gas time lag measurements. The model also accounts for the thermal expansion of the dense layers at pressure differences below 100 kPa. Using the model, the thickness of a silicone-based gutter layer was calculated from permeation measurements. The resulting value differed by a maximum of 30 nm to the thickness determined by scanning electron microscopy.