Bayesian analysis of Jolly-Seber type models

We propose the use of finite mixtures of continuous distributions in modelling the process by which new individuals, that arrive in groups, become part of a wildlife population. We demonstrate this approach using a data set of migrating semipalmated sandpipers (Calidris pussila) for which we extend existing stopover models to allow for individuals to have different behaviour in terms of their stopover duration at the site. We demonstrate the use of reversible jump MCMC methods to derive posterior distributions for the model parameters and the models, simultaneously. The algorithm moves between models with different numbers of arrival groups as well as between models with different numbers of behavioural groups. The approach is shown to provide new ecological insights about the stopover behaviour of semipalmated sandpipers but is generally applicable to any population in which animals arrive in groups and potentially exhibit heterogeneity in terms of one or more other processes.     

Distribution of persistent organic pollutants, polycyclic aromatic hydrocarbons and trace elements in soil and vegetation following a large scale landfill fire in northern Greece

Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), including hexaclorocyclohexanes (HCHs) and DDTs, as well as trace elements were determined in soil and vegetation samples collected from the surrounding area of the landfill "Tagarades", the biggest in northern Greece, following a large scale fire involving approximately 50,000 tons of municipal waste. High concentrations of total PAHs, PCBs and heavy metals were found inside the landfill (1475 microg kg(-1) dw, 399 microg kg(-1) dw and 29.8 mg kg(-1) dw, respectively), whereas concentrations in the surrounding soils were by far lower ranging between 11.2-28.1 microg kg(-1) dw for PAHs, 4.02-11.2 microg kg(-1) dw for PCBs and 575-1207 mg kg(-1) dw for heavy metals. The distribution of HCHs and DDTs were quite different since certain soils exhibited equal or higher concentrations than the landfill. In vegetation, the concentrations of PAHs, PCBs, HCHs and DDTs ranged from 14.1-34.7, 3.64-25.9, 1.41-32.1 and 0.61-4.03 microg kg(-1) dw, respectively, while those of heavy metals from 81 to 159 mg kg(-1) dw. The results of the study indicated soil and vegetation pollution levels in the surroundings of the landfill comparable to those reported for other Greek locations. The impact from the landfill fire was not evident partially due to the presence of recent and past inputs from other activities (agriculture, vehicular transport, earlier landfill fires).     

Cx43 regulates mechanotransduction mechanisms in human preterm amniotic membrane defects

Objective

The effects of mechanical stimulation in preterm amniotic membrane (AM) defects were explored.

Methods

Preterm AM was collected from women undergoing planned preterm caesarean section (CS) due to fetal growth restriction or emergency CS after spontaneous preterm prelabour rupture of the membranes (sPPROM). AM explants near the cervix or placenta were subjected to trauma and/or mechanical stimulation with the Cx43 antisense. Markers for nuclear morphology (DAPI), myofibroblasts (αSMA), migration (Cx43), inflammation (PGE₂) and repair (collagen, elastin and transforming growth factor β [TGFβ₁]) were examined by confocal microscopy, second harmonic generation, qPCR and biochemical assays.

Results

In preterm AM defects, myofibroblast nuclei were highly deformed and contractile and expressed αSMA and Cx43. Mechanical stimulation increased collagen fibre polarisation and the effects on matrix markers were dependent on tissue region, disease state, gestational age and the number of fetuses. PGE₂ levels were broadly similar but reduced after co-treatment with Cx43 antisense in late sPPROM AM defects. TGFβ₁ and Cx43 gene expression were significantly increased after trauma and mechanical stimulation but this response dependent on gestational age.

Conclusion

Mechanical stimulation affects Cx43 signalling and cell/collagen mechanics in preterm AM defects. Establishing how Cx43 regulates mechanosignalling could be an approach to repair tissue integrity after trauma.     

Primary and secondary organic aerosol in an urban/industrial site: Sources, health implications and the role of plastic enriched waste burning

PM10 samples were collected from an urban/industrial site nearby Athens, where uncontrolled burning activities occur. PAHs, monocarboxylic, dicarboxylic, hydroxycarboxylic and aromatic acids, tracers from BVOC oxidation, biomass burning tracers and bisphenol A were determined. PAH, monocarboxylic acids, biomass burning tracers and bisphenol A were increased during autumn/winter, while BSOA tracers, dicarboxylic- and hydroxycarboxylic acids during summer. Regarding aromatic acids, different sources and formation mechanisms were indicated as benzoic, phthalic and trimellitic acids were peaked during summer whereas p-toluic, isophthalic and terephthalic were more abundant during autumn/winter. The Benzo[a]pyrene-equivalent carcinogenic power, carcinogenic and mutagenic activities were calculated showing significant (p < 0.05) increases during the colder months. Palmitic, succinic and malic acids were the most abundant monocarboxylic, dicarboxylic and hydrocarboxylic acids during the entire sampling period. Isoprene oxidation was the most significant contributor to BSOA as the isoprene-SOA compounds were two times more abundant than the pinene-SOA (13.4 ± 12.3 and 6.1 ± 2.9 ng/m³, respectively). Ozone has significant impact on the formation of many studied compounds showing significant correlations with: isoprene-SOA (r = 0.77), hydrocarboxylic acids (r = 0.69), pinene-SOA (r = 0.63),dicarboxylic acids (r = 0.58), and the sum of phthalic, benzoic and trimellitic acids (r = 0.44). PCA demonstrated five factors that could explain sources including plastic enriched waste burning (30.8%), oxidation of unsaturated fatty acids (23.0%), vehicle missions and cooking (9.2%), biomass burning (7.7%) and oxidation of VOCs (5.8%). The results highlight the significant contribution of plastic waste uncontrolled burning to the overall air quality degradation.     

Impact of shipping emissions on ozone levels over Europe: assessing the relative importance of the Standard Nomenclature for Air Pollution (SNAP) categories

Environmental Science and Pollution Research - The impact of shipping emissions on ozone mixing ratio over Europe is assessed for July 2006 using the Community Multiscale Air Quality modeling...     

Interrelationships of pollution load index, transfer factor, and concentration factor under the effect of sludge

A greenhouse experiment was conducted during 2010–2011. A complete randomized blocks design was used including seven treatment levels of sludge(tons per hectare), i.e., 0, 6, 12, 18, 24, 30, and “30+ treated wastewater”, in four replications. Lettuce (Lactuca sativa L var longifolia) was chosen as a test plant. The purpose of the experiment was to study the relationships between soil Pollution Load Index, heavy metal transfer factor, and concentration factor and to determine optimum concentration factor values. The following were found: several mathematical relationships were established between the above parameters that could be used for the study of heavy metal accumulation in soils and plants under the effect of the applied sludge. They can be also used for the calculation of one of the above parameters as a function of the others. Based on the experimental data, the optimum concentration factor for several heavy metals were determined by multiple linear regression analysis, expressing the concentration factor as a function of the maximum dry lettuce matter yield, and of optimum/minimum heavy metal content of plant dry matter. The mean value of the calculated concentration factor obtained for each separate metal was: Zn, 2.93; Cd, 0.39; Co, 1.47; and Ni, 0.52.     

MOSESS: A New Emission Model for the Compilation of Model-Ready Emission Inventories—Application in a Coal Mining Area in Northern Greece

Over the last years, the capabilities of chemical transport models have been greatly improved and the need for more accurate emission data has increased as well. In the past, a number of emission models have been developed and present different functionalities and applications. The majority of these though cover very specific needs. This paper describes the development of a new emission model namely computer model for the construction of model-ready emission inventories (MOSESS) which is used to compile high-resolution emission inventories or improve existing ones, utilizing complex GIS techniques. The model aims in helping chemical modelers to obtain a better overview of their modeling application by having a comprehensive understanding of the emission input. MOSESS incorporates more than 70 different emission calculation methodologies, and it is capable of handling external emission databases (such as EMEP and EPER) from which emissions can be extracted. The temporal variation (annual/daily and diurnal processing), chemical speciation of NMVOCs and particles, vertical distribution and point source treatment, as well as the spatial disaggregation of emissions (utilizing numerous spatial proxies including high-resolution landuses) can help create model-ready emission inventories which can be used for contemporary modeling applications.     

Evaluating contamination of dredges and disposal criteria in Greek coastal areas

Sediments were collected from areas that were going to be dredged located at six small Greek ports, as well as from possible disposal areas. In order to assess the contamination level of dredged material, the samples were analysed for pH, organic matter, the metals Cd, Pb, Hg, Cr, Ni, Cu, Zn and major organic compounds (PAHs, PCBs). The sediments' quality was evaluated by two approaches: (i) by classifying each area according to two sets of Sediment Quality Guidelines (SQGs) and (ii) by calculating the contamination factors and degree for each area. The results showed that organic compounds were detected in trace amounts in 14% of the port samples belonging to the PAHs group. The characterization of the sediment samples was based on the metals' concentration showing that the majority of the areas to be dredged (80%) are classified as of medium-low contamination according to the SQGs. However, according to the contamination degree, only 30% of the areas are classified as of low contamination, while 40% as of moderate contamination and 30% of the areas as of considerable contamination. From the point of view of "no disturbance" of the ecosystem, decisions about dumping should be taken only after evaluating the material to be dredged. If the SQGs are exceeded, dumping must be forbidden. Otherwise, further evaluation is needed based on the comparison with the receiving area, i.e. by estimating the contamination degree. Dumping could be allowed if the contamination degree is found to be below moderate.