Arsenic biomonitoring using a hyperaccumulator fern (Pteris vittata)

Samples of Pteris vittata L. (brake fern or ladder brake) collected in Genova and in areas outside urban centres, have been analysed for arsenic content in order to assess if hyper accumulating plants are suitable for monitoring purposes. Hyper accumulation ability of the Ligurian fern populations was evaluated by analysing specimens grown with hydroponic media added with As(v). Arsenic concentrations in the range 2-310 microg g(-1) dry weight have been measured in samples collected in different sites along the Ligurian coast. Arsenic concentrations in fern fronds correlate with the estimated arsenic emission in the area, verifying the applicability of P. vittata as an arsenic biomonitor.     

The importance of scientific literacy in fostering education for sustainability: Theoretical considerations and preliminary findings from a Brazilian experience

Scientific literacy can be considered as a new demand of post-industrial society. It seems necessary in order to foster education for sustainability throughout students' academic careers. Universities striving to teach sustainability are being challenged to integrate a holistic perspective into a traditional undergraduate curriculum, which aims at specialization. This new integrative, inter- and transdisciplinary epistemological approach is necessary to cultivate autonomous citizenship, i.e., that each citizen be prepared to understand and participate in discussions about the complex contemporary issues posed by post-industrial society. This paper presents an epistemological framework to show the role of scientific literacy in fostering education for sustainability. We present a set of 26 collaborative concept maps (CCmaps) in order to illustrate an instance of theory becoming practice. During a required course for first-year undergraduate students (ACH 0011, Natural Sciences), climate change was presented and discussed in broad perspective by using CCmaps. We present students' CCmaps to show how they use concepts from quantitative and literacy disciplines to deal with the challenges posed by the need of achieving a sustainable development.     

Plates made with solid waste from the recycled paper industry

The results of assays carried out on plates used in the construction industry, manufactured entirely with solid wastes of a recycled paper plant, are presented and compared with the results obtained using agglomerated wood and plywood plates. Previous results had shown that wastes are composed essentially of polymers when these wastes are generated by recycled paper produced with the “waved type II” shavings. These solid wastes were placed in a mold that was heated and pressed with a hydraulic press in order to obtain the plates. The waste-produced plates were submitted to tests for humidity, swelling, water absorption, density, modulus of rupture-static bending, modulus of elasticity and direct screw withdrawal. These same assays had been carried out on two types of commercial wood plates, agglomerated wood and plywood, in order to compare the results with those obtained with the waste plate. Waste plates had similar behavior to the agglomerated wood plate, but it was possible to distinguish greater flexibility in the waste-produced plate and a significant difference in the tests for swelling and water absorption which showed the waste plate had a better performance than the agglomerated wood and plywood plates.     

Improving food security and safety through use of edible by-products from wild game

Game harvesting in South Africa generally leaves behind edible by-products, which could be a low-cost source of protein for poor people in rural areas. Seven professional and nine recreational hunters were interviewed, a game harvest and trophy hunt attended and literature reviewed, in order to describe the food value chain for game and ways in which edible by-products could be legally channelled into the human food chain, rather than being left in the field for scavengers. Practices of informal vendors (n = 51) were assessed using structured interviews, observation and microbiological analysis. In an experiment, inspected game by-products (shinbones from impala and springbok) were provided to eight informal traders for cooking at an informal market and microbiological analysis was done before and after preparation. The results showed that providing edible by-products to poor consumers appears to be culturally acceptable, affordable, accessible and safe. A crossover from formal to informal marketing is recommended as it would enhance traceability and safety of the product and minimise the risk of poaching. It is suggested that methods should be developed which make the distribution of edible by-products to vulnerable rural communities feasible.     

Implication of organic acids in the long-distance transport and the accumulation of lead in Sesuvium portulacastrum and Brassica juncea

The implication of organic acids in Pb translocation was studied in two species varying in shoot lead accumulation, Sesuvium portulacastrum and Brassica juncea. Citric, fumaric, malic and α-cetoglutaric acids were separated and determined by HPLC technique in shoots, roots and xylem saps of the both species grown in nutrient solutions added with 200 and 400 μM of Pb(II). The lead content of the xylem saps was determined by ICP–MS. Results showed that S. portulacastrum is more tolerant to Pb than B. juncea. Lead concentration in xylem sap of the S. portulacastrum was significantly greater than in that of B. juncea. For both species, a positive correlation was established between lead and citrate concentrations in xylem sap. However minor relationship was observed for fumaric, malic and α-cetoglutaric acids. In the shoots lead treatment also induced a significant increase in citric acid concentration. Both observations suggest the implication of citric acid in lead translocation and shoot accumulation in S. portulacastrum and B. juncea. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could explain its high potential to translocate and accumulate this metal in shoot suggesting their possible use to remediate Pb polluted soils.     

Differential distribution of sperm subpopulations and incidence of pleiomorphisms in ejaculates of captive howling monkeys (Alouatta caraya)

The aim of this study was to develop an objective method to determine the incidence of pleiomorphisms and its influence on the distribution of sperm morphometric subpopulations in ejaculates of howling monkeys (Alouatta caraya) by using a combination of computerized analysis system (ASMA) and principal component analysis (PCA) methods. Ejaculates were collected by electroejaculation methods on a regular basis from five individuals maintained under identical captive environmental, nutritional, and management conditions. Each sperm head was measured for dimensional parameters (Area [A, (square micrometers)], Perimeter [P, (micrometers)], Length [L, (micrometers)], and Width [W, (micrometers)]) and shape-derived parameters (Ellipticity [(L/W)], Elongation [(L???W)/(L?+?W)], and Rugosity [(4лA/P ²)]). PCA revealed two principal components explaining more than the 96 % of the variance. Clustering methods and discriminant analyzes were performed and seven separate subpopulations were identified. There were differences (P?<?0.001) in the distribution of the seven subpopulations as well as in the incidence of abnormal pleiomorphisms (58.6 %, 49.8 %, 35.1 %, 66.4 %, and 55.1 %, P?<?0.05) among the five donors tested. Our results indicated that differences among individuals related to the incidence of pleiomorphisms, and sperm subpopulational structure was not related to the captivity conditions or the sperm collection method, since all individuals were studied under identical conditions. In conclusion, the combination of ASMA and PCA is a useful clinical diagnostic resource for detecting deficiencies in sperm morphology and sperm subpopulations in A. caraya ejaculates that could be used in ex situ conservation programs of threatened species in Alouatta genus or even other endangered neotropical primate species.     

The key role played by the Augusta basin (southern Italy) in the mercury contamination of the Mediterranean Sea

The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelled as a highly contaminated site. The release of mercury into the harbour seawater and its dispersion to the blue water, make the Augusta basin a potential source of anthropogenic pollution for the Mediterranean Sea. A mass balance was implemented to calculate the HgT budget in the Augusta basin. Results suggest that an average of ～0.073 kmol of HgT is released, by diffusion, on a yearly basis, from sediments to the seawater, with a consequent output of 0.162 kmol y(-1) to coastal and offshore waters; this makes the Augusta area an important contributor of mercury to the Mediterranean Sea. Owing to the geographical location of the Augusta basin, its outflowing shelf-waters are immediately intercepted by the surface Atlantic Ionian Stream (AIS) and mixed with the main gyres of the eastern Mediterranean Sea, thus representing a risk for the large-scale marine system.     

Soils and sediments of the Thua Thien-Hue Province (central Vietnam): recognizing trace element sources and the likely influence of natural events

Trace element concentrations have been measured in soil and sediment samples taken from the Thua Thien Hue (TT-H) Province and the Tam Giang-Cau Hai (TG-CH) Lagoon in 2002 and 2004. Results show that the lagoon is only slightly contaminated by elements such as Ag, Cd, Cr, Cu, Ni, Pb and Zn, whereas As, probably naturally enriched in this Asian region, reaches values above the lowest internationally accepted sediment quality guidelines. Concentrations in soils are ascribable to natural sources and distributions in the TG-CH Lagoon are mainly influenced by river inputs, with Ag and Cd undergoing estuarine desorption processes. However, concentration-depth profiles of most trace elements in sediments show a recent increasing trend that might be linked to the economic development of the area. The comparison of porosity and (210)Pb depth profiles (confirmed also by Cd and As) from repeated samplings of the same core locations in the TG-CH Lagoon seems to account for a loss of 5-10 cm of surficial sediment that took place during the time interval between the two samplings. It is hypothesized that extreme meteorological events (e.g. a major typhoon that hit the area in November 2003) could be responsible for such sediment displacement.