Mirjana Perišić

Doppler assessment of splanchnic arterial flow in patients with liver cirrhosis: correlation with ammonia plasma levels and MELD score.

To assess the clinical significance of blood flow velocity and resistance index (RI) in the visceral arteries of patients with liver cirrhosis with respect to plasma ammonia (NH3) level and liver function.

Comprehensive analysis of PM10 in Belgrade urban area on the basis of long-term measurements

In this study, we investigated the impact of potential emission sources and transport pathways on annual and seasonal PM10 loadings in an urban area of Belgrade (Serbia). The analyzed dataset comprised PM10 mass concentrations for the period 2003–2015, as well as their chemical composition (organic/elemental carbon, benzo[a]pyrene, As, Cd, Cr, Mn, Ni, Pb, Cl−, Na+, Mg2+, Ca2+, K+, NO3−, SO42−, and NH4+), meteorological parameters, and concentrations of inorganic gaseous pollutants and soot for the period 2011–2015. The combination of different methods, such as source apportionment (Unmix), ensemble learning method (random forest), and multifractal and inverse multifractal analysis, was utilized in order to obtain a detailed description of the PM10 origin and spatio-temporal distribution and to determine their relationship with other pollutants and meteorological parameters. The contribution of long-range and regional transport was estimated by means of trajectory sector analysis, whereas the hybrid receptor models were applied to identify potential areas of concern.

Forecasting hourly particulate matter concentrations based on the advanced multivariate methods

In this study, several multivariate methods were used for forecasting hourly PM10 concentrations at four locations based on SO2 and meteorological data from the previous period. According to the results, boosted decision trees and multi-layer perceptrons yielded the best predictions. The forecasting performances were similar for all examined locations, despite the additional PM10 spatio-temporal analysis showed that the sites were affected by different emission sources, topographic and microclimatic conditions. The best prediction of PM10 concentrations was obtained for industrial sites, probably due to the simplicity and regularity of dominant pollutant emissions on a daily basis. Conversely, somewhat weaker forecast accuracy was achieved at urban canyon avenue, which can be attributed to the specific urban morphology and most diverse emission sources. In conclusion to this, the integration of advanced multivariate methods in air quality forecasting systems could enhance accuracy and provide the basis for efficient decision-making in environmental regulatory management.

Statistical Character and Transport Pathways of Atmospheric Aerosols in Belgrade

Clean air is considered to be a basic requirement for human health and well being. Various chemicals are emitted into the air from both, natural and anthropogenic sources. In spite of the introduction of cleaner technologies in industry, energy production and transport, air pollution remains a major health risk and tighter emission controls are being enforced by many governments. Atmospheric particles – aerosols – are some of the key components of the atmosphere. They influence the energy balance of the Earths surface, visibility, climate and environment as a whole [1-3]. According to World Health Organization (WHO), ozone, particulate matter (PM), heavy metals and some hydrocarbons present the priority pollutants in the troposphere [4]. Public health can also be indirectly affected by deposition of air pollutants in environmental media and uptake by plants and animals, what results in entering of chemicals into the food chain or drinking water, and thereby constituting additional sources of human exposure. A number of epidemiological studies have demonstrated that acute and chronic health effects are related to the inhalable PM10 (aerodynamic diameter less than 10 μm) exposure in the urban environment, and some data also seem to indicate possible seasonal effects of the particulate matter on human health [5-10]. This is especially important for urban aerosols, whose variety of size and composition make complete characterization a difficult task. Particulate matter pollution is nowadays one of the problems of the most concern in great cities, not only because of the adverse health effects, but also of the reducing atmospheric visibility and affect to the state of conservation of various cultural heritages [11]. Therefore, the measurement of the levels of atmospheric particulate matter is a key parameter in air quality monitoring throughout the world.

Characteristics and Application of Receptor Models to the Atmospheric Aerosols Research

Atmospheric aerosols can be defined as solid and liquid particles suspended in air. Due to their confirmed role in climate change (IPCC, 2001), impact on human health (Dockery and Pope, 1994; Schwartz et al., 1996; Schwartz et al., 2001; WHO, 2002, 2003; Dockery and Pope, 2006), role on the radiative budget (IPCC, 2007), effects on ecosystems (Niyogi et al., 2004; Bytnerowicz et al., 2007), and local visibility they are of major scientific interest. The human activities in various aspects cause a change in the natural air quality. This change is more marked in very inhabited areas with high industrialization. Epidemiological research over the past 15 years has revealed a consistent statistical correlation between levels of airborne particulate matter (PM) and adverse human health effects (Pope et al., 2004; Dockery and Stone, 2007). Airborne particulate matter contains a wide range of substances, such as heavy metals, organic compounds, acidic gases, etc. Chemical reactions occurring on aerosols in the atmosphere can transform hazardous components and increase or decrease their potential for adverse health effects. Especially organic compounds react readily with atmospheric oxidants, and since small particles have a high surface-to-volume ratio, their chemical composition can be efficiently changed by interaction with trace gases such as ozone and nitrogen oxides. The impact of atmospheric aerosols on the radiative balance of the Earth is of comparable magnitude to greenhouse gases effect (Anderson et al., 2003). Atmospheric aerosol in the troposphere influences climate in two ways: directly, through the reflection and absorption of solar radiation, and indirectly through the modification of the optical properties and lifetime of clouds. Estimation of the radiative forcing induced by atmospheric aerosols is much more complex and uncertain compared with the well-mixed greenhouse gases because of the complex physical and chemical processes involved with aerosols and because of their short lifetimes which make their distributions inherently more inhomogeneous. In order to protect public health and the environment i.e. to control and reduce particulate matter levels, air quality standards (AQS) were issued and target values for annual and daily mean PM10 (particles with aerodynamic diameter less than 10 m) and PM2.5 (particles with aerodynamic diameter less than 2.5 m) mass concentrations were established. For the first stage, the EU Directive (EC, 1999) required an annual limit of 40 g m-3 and a 24h limit 7