Accumulation of nitrogen and changes in assimilation pigments of lichens transplanted in an agricultural area

The results of a survey aimed at testing the hypothesis that the lichen Evernia prunastri, when transplanted in an agricultural area with high atmospheric NH₃ concentrations, would respond to NH₃ air pollution accumulating nitrogen in its thalli and showing changes in the concentration of assimilation pigments are presented. The results confirmed the hypothesis and showed that all lichen transplants accumulated nitrogen, suggesting that besides the release of atmospheric ammonia by animal stockfarms, the use of N-based fertilizers and the deposition of N-rich dust also may contribute to the high nitrogen availability to lichens in the study area. The result indicated that in the study area both the critical level of NH₃ and the critical load of N for lichens are exceeded and physiological damage is to be expected in sensitive species. The results of assimilation pigments in E. prunastri, with a decrease in the concentration of chlorophylls a and b and carotenoids, as well as chlorophyll degradation to phaeophytin, confirmed this hypothesis. However, owing to the limited data set and pending further studies, these conclusions should be considered as limited to the study area.     

Microplastics distribution and possible ingestion by fish in lacustrine waters (Lake Bracciano,Italy)

Understanding the spatial distribution patterns of microplastics (plastics?<?5 mm) contributes to the assessment of sources and sinks of pollution thus providing information for the management of biota safety and overall ecosystem functionality. We chose a semi-closed study area, Lake Bracciano (Italy), to assess the environmental variability of contamination, focusing on the water compartment and the exposure of biota, specifically fish, by analysing the ingestion of microplastics. The focus of this study is to evaluate the concentration of microplastics in water (surface and column) across the lake and the ingestion of microplastics by two fish species of economic interest: Atherina boyeri and Coregonus lavaretus, inhabiting demersal and pelagic habitats respectively. Results show a surface contamination of 392,000?±?417,000 items km^?2 and a column one of 0.76?±?1.00 items m^?3. Fragments were the most abundant in surface while fibres in the column. Microplastics were found in C. lavaretus specimens, corresponding to contamination frequency of 5% and concentration of 0.15 items/fish. The main polymer found in water was polyethylene (81%); of minor percentages, there were various other polymers, including polystyrene and acrylic, which were also found in fish. As scientific literature provides few research where water and fish are simultaneously sampled, this investigation wants to contribute filling this knowledge gap by investigating for the first time a volcanic lake.

     

Bioassay-guided isolation of allelochemicals from Avena sativa L.: allelopathic potential of flavone C-glycosides

The allelopathic potential of oat (Avena sativa L., var. Argentina, Poaceae, Cyperales) was investigated under field and laboratory conditions. In field trials, oat plants provided an effective control of weeds, showing a species-specific impact: the most abundant weed species, Picris echioides was reduced by 94% in number of individuals. Aerial parts of oat plants, harvested immediately before soil incorporation, were utilized in a bioassay-guided isolation, which was aimed at identifying the phytotoxic compounds in a methanol/water extract of the aerial parts of the plants. Further partitions of extract gave an active n-butanol portion composed of flavonoids and saponins. Phytotoxic activity was detected for the flavonoid fraction, whereas no activity was found for the saponin mixture. Germination of an indicator species, lettuce (Lactuca sativa L.), was completely inhibited at flavonoid concentrations of 6.7, 10.0, and 20.0 mg/mL, and conversely the number of abnormal seedlings was greatly increased from 2% of control to over 96% at concentrations equal to 6.7 and 10.0 mg/mL. Analysis of the flavonoid fraction by ESI-MS techniques identified two components of the mixture as isoorientin 2-O-glucoside and isovitexin 2″-O-arabinoside. Saponins were characterized as avenacoside A, avenacoside B, 26-desglucoavenacoside A, and 26-desglucoavenacoside B. Both flavone C-glycosides and saponins were isolated previously from oat.     

A model for estimation of potential generation of waste electrical and electronic equipment in Brazil

Sales of electrical and electronic equipment are increasing dramatically in developing countries. Usually, there are no reliable data about quantities of the waste generated. A new law for solid waste management was enacted in Brazil in 2010, and the infrastructure to treat this waste must be planned, considering the volumes of the different types of electrical and electronic equipment generated.This paper reviews the literature regarding estimation of waste electrical and electronic equipment (WEEE), focusing on developing countries, particularly in Latin America. It briefly describes the current WEEE system in Brazil and presents an updated estimate of generation of WEEE. Considering the limited available data in Brazil, a model for WEEE generation estimation is proposed in which different methods are used for mature and non-mature market products.The results showed that the most important variable is the equipment lifetime, which requires a thorough understanding of consumer behavior to estimate. Since Brazil is a rapidly expanding market, the “boom” in waste generation is still to come. In the near future, better data will provide more reliable estimation of waste generation and a clearer interpretation of the lifetime variable throughout the years.     

Variability of Water Column Transparency, Volume Flow and Suspended Solids Near San Diego Sewage Outfall (California): 15 Years of Data

The spatial and temporal variability of transparency measured for 15 years at 7 stations near the San Diego sewage outfall has been investigated and compared to the temporal variability of sewage suspended solid discharge and flow rate. the purpose of the time-series analyses was to distinguish natural from human (sewage discharge) causes of temporal changes in transparency. the results show that: 1) variations in transparency are highly correlated over the entire area, but there is a gradient in means and variability in the direction perpendicular to the coast; 2) there are no long term trends for increase or decrease in the water clarity at any of the stations; 3) most of the variance of transparency is contained in the seasonal frequency band; 4) over the same time period sewage discharge has significantly increased and suspended solids decreased; 5) most of the variance of these human-caused properties is in the interannual frequency band; (6) there is no correlation at any time-lag between water clarity and suspended solid discharge or flow. These results lead to the conclusion that these anthropogenic properties are not affecting transparency, while natural factors such as seasonality and distance from coast do.     

Kinetic and chemical assessment of the UV/H2O2 treatment of antiepileptic drug carbamazepine

The UV/H2O2-induced degradation of carbamazepine, a worldwide used antiepileptic drug, recently found as contaminant in many municipal sewage treatment plant (STP) effluents and other aquatic environments, is investigated. The oxidation treatment caused an effective removal of the drug. At complete abatement of the substrate after 4 min treatment, a 35% value of removed total organic carbon (TOC) was obtained. A kinetic constant of (2.05+/-0.14) x 10(9) lmol(-1)s(-1) was determined for OH radical attack to carbamazepine in the UV/H2O2 process. Preparative TLC of the reaction mixture led to the isolation of acridine-9-carboxaldehyde as a reaction intermediate. HPLC and GC/MS analysis indicated formation of small amounts of acridine, salicylic acid, catechol and anthranilic acid among the reaction products. Under the same reaction conditions, synthetically prepared 10,11-epoxycarbamazepine was easily degraded to acridine as main product, suggesting that this epoxide is a likely intermediate in the oxidative conversion of carbamazepine to acridine. Under sunlight irradiation, carbamazepine in water underwent slow degradation to afford likewise acridine as main product. In view of the mutagenic properties of acridine, these results would raise important issues concerning the possible environmental impact of carbamazepine release through domestic wastewaters and support the importance of prolonged oxidation treatments to ensure complete degradation of aromatic intermediates.     

Prenatal diagnosis of anatomical connections in conjoined twins by use of contrast magnetic resonance imaging

Omphalopagus conjoined twins were diagnosed by ultrasonography in a pregnant woman at 21 weeks' gestation. In order to clarify the anatomical connections, magnetic resonance imaging (MRI) was performed, having achieved fetal paralysis by intravascular injection of 100 mg of pancuronium into each twin. Prior to MRI, 2 ml of a 0.0001 mmol/ml solution of gadolinium DTPA was also injected into the stomach of one twin. The contrast agent opacified the bowel loops of both twins, indicating bowel to bowel anastomosis. Following pregnancy termination, autopsy confirmed the prenatal diagnosis.