Combined application of Triton X-100 and Sinorhizobium sp. Pb002 inoculum for the improvement of lead phytoextraction by Brassica juncea in EDTA amended soil

The process of EDTA-assisted lead phytoextraction from the Bovisa (Milan, Italy) brownfield soil was optimized in microcosms vegetated with Brassica juncea. An autochthonous plant growth-promoting rhizobacterium (PGPR), Sinorhizobium sp. Pb002, was isolated from the rhizosphere of B. juncea grown on the Pb-contaminated soil in presence of 2 mM EDTA. The strain was augmented (10(8) CFU g(-1) soil) in vegetated microcosms to stimulate B. juncea biomass production and, hence, its phytoextraction potential. Triton X-100 was also added to microcosms at 5 and 10 times the critical micelle concentration (cmc) to increase the permeability of root barriers to the EDTA-Pb complexes. Triton X-100 amendment determined an increase in Pb concentration within plant tissues. However it contextually exerted a phytotoxic effect. Sinorhizobium sp. Pb002 augmentation was crucial to plant survival in presence of both bioavailable lead and Triton X-100. The combination of the two treatments produced up to 56% increase in the efficiency of lead phytoextraction by B. juncea. The effects of these treatments on the structure of the soil bacterial community were evaluated by 16S rDNA denaturing gradient gel electrophoresis (DGGE).     

Working and Health Conditions of Italian Air Traffic Controllers

The paper summarises some studies carried out in recent years on Italian air traffic controllers. Work stress appeared related mainly to mental charge, aggravated by time pressure and high responsibility. Shiftwork was not considered highly stressful, thanks to the good shift schedules adopted. The disorders most frequently complained of had a prevalent psychosomatic component, concerning the digestive, neuropsychic, and cardiovascular systems. However, their prevalence was lower than, or similar to, that recorded in general population. The controllers engaged in regional centres showed slightly worse health conditions than those engaged in airport towers; the same was found in the radar controllers compared to those working in non-radar positions.     

Matching biodiversity indicators to policy needs

At the global scale, biodiversity indicators are typically used to monitor general trends, but are rarely implemented with specific purpose or linked directly to decision making. Some indicators are better suited to predicting future change, others are more appropriate for evaluating past actions, but this is seldom made explicit. We developed a conceptual model for assigning biodiversity indicators to appropriate functions based on a common approach used in economics. Using the model, indicators can be classified as leading (indicators that change before the subject of interest, informing preventative actions), coincident (indicators that measure the subject of interest), or lagging (indicators that change after the subject of interest has changed and thus can be used to evaluate past actions). We classified indicators based on ecological theory on biodiversity response times and management objectives in 2 case studies: global species extinction and marine ecosystem collapse. For global species extinctions, indicators of abundance (e.g., the Living Planet Index or biodiversity intactness index) were most likely to respond first, as leading indicators that inform preventative action, while extinction indicators were expected to respond slowly, acting as lagging indicators flagging the need for evaluation. For marine ecosystem collapse, indicators of direct responses to fishing were expected to be leading, while those measuring ecosystem collapse could be lagging. Classification defines an active role for indicators within the policy cycle, creates an explicit link to preventative decision-making, and supports preventative action.     

Side effects of the herbicide triasulfuron on collembola under laboratory conditions

Triasulfuron, a member of the sulfonylureas class of herbicides, was tested under laboratory conditions on the collembolan Onychiurus pseudogranulosus. Pure triasulfuron and commercial formulations at different rates (starting from a dose about 5 times the recommended agricultural rate) were tested separately on one-week old juveniles and adults reared in the laboratory. The persistence of the herbicide at the end of the trials lasting 30 and 60 days was verified by HPLC analysis. Laboratory tests indicated that only the rates exceeding 500 times the soil concentration expected soon after field application of the herbicide directly affected the tested species.     

A review of plant-based coagulants for turbidity and cyanobacteria blooms removal

Environmental Science and Pollution Research - In recent years, the proliferation of Harmful Cyanobacterial Blooms (CyanoHABs) has increased with water eutrophication and climate change, impairing...     

Effects of copper on Sambucus nigra L. seedlings studied by electron paramagnetic resonance and atomic absorption spectroscopies

We present in this work preliminary results on the translocation of copper, manganese and iron from soil to leaves of Sambucus nigra L. seedlings in the presence of increasing copper concentrations in the growth medium. The use of electron spin resonance spectroscopy and the comparison with atomic absorption spectroscopy is not presently common in the study of metal absorption in plants. This approach gave promising results both on the detection of some metal ions, as well as of radical species related to the presence of Cu2+ in plant tissues. Copper was found to act synergistically in manganese uptake.     

Multiple regression analysis of the sources of variation in orientation of two sympatric sandhoppers, <Emphasis Type="Italic">Talitrus saltator</Emphasis> and <Emphasis Type="Italic">Talorchestia brito</Emphasis>, from an exposed Mediterranean beach

Two sympatric species from an exposed sandy beach in north-western Tunisia, the sandhoppers Talitrus saltator (Montagu) and Talorchestia brito Stebbing, were compared as regards orientation under natural conditions. Sets of experiments were carried out on the beach using two experimental arenas, one permitting the view of both the sky and landscape and the other of the sky only. Replicates were made at different hours of the day, in different days and period of the year and with various climatic conditions. Multiple regression models were fitted to the angular data obtained. These models allow an estimate of the trends of variation depending on a combination of factors. The simultaneous effects of environmental factors influencing orientation were quantified for each species. The sun was confirmed as the major orientation cue in these populations, but the concentration of directional choices was enhanced by the landscape vision. The climatic factors affected orientation in different ways depending on the time of day and year. When the two species were compared, Talitrus saltator showed a higher flexibility of response than Talorchestia brito under the same environmental conditions, supporting the hypothesis of a higher level of terrestrialization of the former species.     

Assessment of Iodine Direct Titration in Sea Water by Constant Current Potentiometry

Dissolved iodine in sea water, about 60 μg L^-1, usually exists in equal proportions as iodate and iodide ions. For their determination several techniques have been proposed (Riley, 1975); among them the volumetric one which depends upon the release of elementary iodine by the addition of acid and iodide ions to the iodate present in the sample. The liberated iodine is titrated with thiosulphate the equivalence point being detected photometrically (Matthews and Riley, 1970; Wong and Brewer, 1974) or it can also be reduced with an excess of thiosulphate and the residual thiosulphate back-titrated with iodate amperometrically (Barkley and Thompson, 1960; Truesdale and Spencer, 1974; Tsonkova and Kulev, 1981). To titrate total iodine in the sample the iodide must be previously oxidized to iodate with bromine (Barkley and Thompson, 1960; Tsonkova and Kulev, 1981) or permanganate (Schnepfe, 1972). In the amperometric procedure Truesdale and Spencer (1974) observed that platinum electrodes often do not respond reliably.