Analytical evaluation of mesoscale fluxes and pressure field

Terrain in natural areas is never homogeneous: there may be a variety of vegetation types and patches of vegetated and unvegetated areas which can modify the mesoscale atmospheric flow. Moreover, horizontal thermal inhomogeneities in the planetary boundary layer are a well known source of mesoscale circulation systems such as land and sea breezes, mountain-valley winds, and urban heat island circulations. Since those phenomena are not resolved in regional scale numerical models, therefore an analytic procedure able to evaluate the relative importance of mesoscale and turbulent heat fluxes associated with surface thermal heterogeneities is of crucial importance in the optic of developing a parameterization of mesoscale effects generated by these heterogeneities for use in larger scale models. In the present paper we analyze how small a horizontal variation in surface heating can be and still produce a significant mesoscale circulation, how the heat and momentum fluxes associated to mesoscale flows can penetrate deeply into the mid-troposphere, and how they modify tropospheric relevant climate parameters, such as the atmospheric static stability. In addition, we evaluate the terms of the pressure gradient force, nonlinear and linear, non-hydrostatic and hydrostatic, as function of time and space scales of the mesoscale flow. The present paper is mainly a review of analytical results, the numerical comparison and verification using RAMS is in progress.     

Analysis of air quality observations with the aid of the source-receptor relationship approach

In this study, an attempt was made to analyze time series of air quality measurements (O3, SO2, SO4(2-), NOx) conducted at a remote place in the eastern Mediterranean (Finokalia at Crete Island in 1999) to obtain concrete information on potential contributions from emission sources. For the definition of a source-receptor relationship, advanced meteorological and dispersion models appropriate to identify "areas of influence" have been used. The model tools used are the Regional Atmospheric Modeling System and the Lagrangian-type particle dispersion model (forward and backward in time), with capabilities to derive influence functions and definition of "areas of influence." When high levels of pollutants have been measured at the remote location of Finokalia, particles are released from this location (receptor) and traced backward in time. The influence function derived from particle distributions characterizes dispersion conditions in the atmosphere and also provides information on potential contributions from emission sources within the modeling domain to this high concentration. As was shown in the simulation results, the experimental site of Finokalia in Crete is influenced during the selected case studies, primarily by pollutants emitted from the urban conglomerate of Athens. Secondarily, it is influenced by polluted air masses arriving from Italy and/or the Black Sea Region. For some specific cases, air pollutants monitored at Finokalia were possibly related to war activities in the West Balkan Region (Kosovo).     

Study of the biodegradation process of polychlorinated biphenyls in liquid medium and soil by a new isolated aerobic bacterium (Janibacter sp.)

We have isolated and characterised a novel aerobic bacterial strain, designated MS3-02, belonging to the genus Janibacter sp. The capability of this new strain to degrade polychlorinated biphenyls (PCBs) in a commercial mixture (Aroclor 1242) in liquid medium and in soil (sterile and non sterile soil), under laboratory scale, has been evaluated. MS3-02 was isolated from the soil around of an incinerator, located in the east of Madrid (Spain). Gas-chromatographic analysis showed that MS3-02 was able to reduce most peaks observed in the chromatogram between 70% and 100% after seven days of incubation in a culture mineral medium containing yeast extract, but without the addition of biphenyl. The presence of biphenyl in the culture medium decreased the rate of PCB degradation by this bacterium. Comparing the performance of the MS3-02 in liquid culture medium and in soil, degradation was less efficient in sterile soil and still less efficient in non sterile soil. Under the best conditions (sterile soil and 20 weeks of incubation) MS3-02 was able to reduce, between 50% and 100%, nine of the main gas-chromatographic peaks in Aroclor 1242.     

Toxicity identification evaluation of leachates from municipal solid waste landfills: a multispecies approach

The toxicity of leachates from two municipal solid waste (MSW) landfills in Southern Italy was characterized using a toxicity identification evaluation procedure. The chemical and physical fractionation techniques were: pH adjustment, pH adjustment/filtration, pH adjustment/C(18) solid phase extraction, graduated pH and EDTA chelation. All the samples exhibited acute toxicity towards the bacterium Vibrio fischeri, the freshwater rotifer Brachionus calyciflorus and the freshwater crustaceans Thamnocephalus platyurus and Daphnia magna. Statistical techniques were used to determine the discriminatory power and the toxicity detection capacity of the different assays and to choose a minimal battery of tests for the toxicity identification of leachates. Toxicity was closely associated with pH, generally increasing at higher pH levels and decliming at lower ones. Furthermore, results showed that toxicants could be characterized as cations, basic chemicals, suspended solids and apolar compounds.     

In situ monitoring of urban air in Southern Italy with the Tradescantia micronucleus bioassay and semipermeable membrane devices (SPMDs)

This study was designed to assess toxic and genotoxic compounds in the urban air of Caserta, South Italy using cuttings from the plant Tradescantia #4430. In situ monitoring of gaseous pollutans was made at 17 sampling points in two seasons of the year. Genotoxicity was evaluated by recording the micronuclei in meiotic pollen mother cells (Trad-MCN assay). In addition, the passive sampler semipermeable membrane devices (SPMDs) were deployed at the sampling points with a significant increase in micronuclei frequency. SPMDs concentrated priority organic pollutants were identified by high performance liquid chromatography and gas chromatography, while toxicity and mutagenesis were assessed on the bacterium Vibrio fischeri using the Microtox and Mutatox systems respectively. Significant toxic and mutagenic effects were observed at different points on the town grid and SPMDs effectively concentrated trace contaminants. The relationship between what was present in the air sampled by SPMDs and the micronuclei frequency was also explored.     

A proteomic approach to the study of the marine mussels Mytilus edulis and M. galloprovincialis

In this study, a proteomic approach was applied for the generation of reference maps and subsequently to detect, quantify and compare the global protein expression between two related species of marine mussels, Mytilus edulis and Mytilus galloprovincialis, growing in their own geographical habitats. A comparative study of the protein profiles generated from analytical two-dimensional electrophoresis gels was performed, and changes in protein expression were analysed quantitatively by computer analysis. An average of 1,278 spots per gel was detected in 16 individuals (8 M. edulis and 8 M. galloprovincialis); however, not all spots were included in the study. Expression of 420 spots was compared, and significant differences in the intensity levels were detected in 37 protein spots (8.8%). Fifteen proteins showed higher expression in M. edulis, and 22 proteins, in M. galloprovincialis. The technique of peptide mass fingerprinting using MALDI-TOF (matrix-assisted laser desorption ionisation/time-of-flight) and/or nanoelectrospray double subfragmentation mass spectrometry enabled the unambiguous identification of 15 of these 37 differentially expressed proteins. Most of the identified proteins can be grouped basically into four broad functional classes: cytoskeletal and myofibrillar proteins, proteins associated with stress response, proteins associated with the storage or production of energy, and proteins related to rearrangement in the synthesis of native structures. These results expand our understanding of the molecular differentiation of the two mussel taxa and serve as a useful base for future ecological, physiological and genetic studies.     

Hydrogen peroxide photolysis, fenton reagent and photo-fenton for the degradation of nitrophenols: a comparative study

The kinetics of the degradation of seven nitrophenols (2-nitrophenol, 4-nitrophenol, 2,5-dinitrophenol, 2,6-dinitrophenol, 2,4-dinitrophenol, 2-methyl-4,6-dinitrophenol, 4-methyl-2,6-dinitrophenol) with the Fenton reagent, photo-Fenton, and hydrogen peroxide photolysis was investigated. The efficiency and operating costs for the studied treatments were evaluated and compared. The Fenton reagent was found to be the most efficient and the cheapest way for the nitrophenols (NPs) degradation. The formation of nitrate as a result of mineralisation of organically bounded nitrogen was observed during the treatment of NPs with studied treatment processes. The degrees of organically bounded nitrogen conversion to nitrate after 90% degradation of NPs with the Fenton, photo-Fenton and hydrogen peroxide photolysis were 51-67%, 85-90%, and 50-60%, respectively. According to Daphnia magna acute toxicity test, the Fenton treatment led to complete detoxification of NPs.     

Reproductive biology of <Emphasis Type="Italic">Cosmasterias lurida</Emphasis> (Echinodermata: Asteroidea) an anthropogenically influenced substratum from Golfo Nuevo,Northern Patagonia (Argentina)

The starfish Cosmasterias lurida was sampled from the pier piles of Almirante Storni in the Golfo Nuevo, northern Patagonia, from November 2001 to November 2003. In this anthropogenically modified site there is an unusually abundant food supply of mussels and large aggregations of starfishes. The reproductive cycle was studied by organ indices and histological examination of gonads. The highest gonad index (GI) values were found in the summer (February–March), followed by a drop in GI values, indicating spawning. Histological analyses indicated that gametogenesis takes place from June to January, sexual maturity occurred during the summer and spawning occurred in April. The GI and pyloric caeca index (PCI) tended to have an inverse relationship, but this was only statistically significant in males. However, biochemical analyses of the starfish indicated no transfer of nutrients between pyloric caeca and gonads in either sex. In fact, simultaneous accumulation of carbohydrates was found in the pyloric caeca and gonads of both sexes.     

Seasonal variation in feeding behavior, competition and female social relationships in a forest dwelling guenon, the blue monkey (Cercopithecus mitis stuhlmanni), in the Kakamega Forest, Kenya

Socioecological models relate differences in feeding strategies to variation in the nature of female social relationships. Among the African forest guenons, females consume large quantities of fruit and other plant reproductive parts, resources which are thought to promote contest competition, yet these monkeys have been characterized as having agonistically undifferentiated relationships in which rank, if discernible at all, does not correlate with fitness benefits. To determine whether female relationships become more hierarchical under relevant ecological conditions, we monitored the adult females of two blue monkey groups (Cercopithecus mitis stuhlmanni) over a complete annual cycle in the Kakamega Forest, Kenya. Females competed aggressively for plant reproductive parts more often than any other resource type, and in both groups we detected linear dominance hierarchies. Nonetheless, agonism rates remained low throughout our study, and did not vary with changes in ecological conditions. Rather, when plant reproductive parts were scarce, subordinate females spent more time feeding and less time resting in an apparent attempt to compensate for a reduced efficiency of food intake. The effects of rank and food abundance were not reflected, however, in the distribution of grooming. The use of alternative feeding strategies appeared to blunt competition – females of all ranks were unlikely to be near others while feeding and spent more time consuming alternative resources when plant reproductive parts were scarce. The diverse diet of this species may allow females to avoid conflict so that dominance has only subtle effects that are difficult to detect. While socioecological models often simplify the connection between resources and female interactions, our results emphasize that the behavior of animals consuming particular resources, and not the resources themselves, are critical predictors of social patterns.     

Characterisation of trace elements and methylmercury in an estuarine sediment reference material, IAEA-405

An estuarine sediment sample, IAEA-405, was recently characterised for trace elements and methylmercury (MeHg) for ultimate use as a marine reference material. The reference values were calculated using data sets from 120 laboratories that participated in a world-wide intercomparison exercise. The data evaluation is highlighted, and includes comparisons of different analytical methods, as well as the distribution of data. Overall laboratory performance for this exercise was encouraging: 86 laboratories (72%) reported data with <25% outliers. There was sufficient acceptable data to establish recommended values for 17 elements and information values for a further 15 elements. In addition, a recommended value was established for methylmercury. The estuarine sediment sample, IAEA-405, can be used as a reference material for quality control in the determination of trace elements and methylmercury in moderately polluted sediments.