Metal concentration changes in growing Pacific oysters,Crassostrea gigas,cultivated in Tasmania,Australia

Pacific oyster spat (Crassostrea gigas Thunberg) transferred from the Tamar Estuary to two growing areas in southern Tasmania were monitored for their metal contents over one growing season (1974–1975). Oysters at Pipeclay Lagoon were grown with stick and tray culture while those at Dart Island were cultured with the longline technique. Metal content of the oysters increased with time and the trend was similar to the weight growth curves. Mean dry weights of oysters increased from 0.07 to 1.19 g at Pipeclay Lagoon and from 0.25 to 1.47 g at Dart Island. Metal contents (g) increased at each site, respectively: Fe 57 to 326; 91 to 446; Zn 259 to 6 555; 755 to 5 335; Cd 1.5 to 13.3; 1.9 to 16.3; Cu 26 to 142; 9 to 116; Pb 1.9 to 11.9; 0.6 to 3.8. Concentration curves generally showed a downward trend with time. The relationships of metal concentrations with weight did not differ from sample to sample at a site nor did they differ at one site compared with the other. The only exception was lead, which showed no relationship of concentration with weight at Pipeclay Lagoon and a negative one at Dart Island. It is postulated that higher winter concentrations of metals in the oysters were linked with greater solubility of metal ions in lower salinity water.     

Coelenterazine distribution and luciferase characteristics in oceanic decapod crustaceans

Coelenterazine biosynthesis has recently been demonstrated in the developing eggs of the decapod Systellaspis debilis. The cellular source of coelenterazine and the potential for biosynthesis in adult decapods, however, have not been fully investigated. We have conducted a systematic study of coelenterazine content in >230 individual decapods representing 19 species of Oplophoridae and 22 species from other families. We show for the first time that coelenterazine is responsible for both secretory and photophore luminescence in the same decapod. Tissues associated with secretory luminescence (hepatopancreas and stomach) in the Oplophoridae contained almost 3 orders of magnitude more coelenterazine (mean value=2154 pmol per specimen) than cuticular photophores (mean value=8 pmol per specimen). Coelenterazine content increases by 2 to 4 orders of magnitude during the development of three species of Oplophoridae. Species of Oplophoridae contain an order of magnitude more coelenterazine than those of other families (mean value=154 pmol per specimen). Coelenterazine was also detected in 11 apparently nonluminous decapod species (mean value=200 pmol per specimen). S. debilis luciferase characterisation enabled a luciferase assay to be developed to facilitate studies of the environmental control of bioluminescence. We hypothesise that the coelenterazine requirement in secretory bioluminescence exceeds that which could be assimilated from the food-chain. The significant increase of coelenterazine during the life cycle of secretory decapods supports this hypothesis. Putative evidence for environmental control of coelenterazine luminescence is also reported.     

Current uses of the EPA lead model to assess health risk and action levels for soil

The EPA lead model predicts mean blood lead levels and risk of elevated blood lead levels in children based on lead uptake from multiple sources. In the latest model versions, environmental data from individual homes within a community can be used to predict the overall blood lead distribution and percent risk of exceeding a specific blood lead level (i.e. 10 g dl^–1). Recent criteria used by the EPA to evaluate this information include no more than 5% of houses with a greater than 5% lead risk, and a community weighted-average risk below 5%. Environmental (primarily soil) and blood lead data from a residential community near a smelter were used to illustrate recent uses of the model. Scheduled remediation in the community will remove soil for approximately 60% of the houses (i.e. those with lead levels > 1000 mg kg^–1). After remediation, the model results indicate a relatively low community risk (0.5–1.9%), although the percentage of houses with lead risks above 5% ranged from 3 to as high as 13%, depending on the variation in blood lead and assuming the model's 7 g dl^–1 increase in blood lead with each 1000 mg kg^–1 increase in soil lead level. A comparison of the limited blood lead data with soil lead levels below 1000 mg kg^–1, however, indicated no apparent relationship. Given these uncertainties, less invasive actions than additional soil removal (e.g. exposure intervention, monitoring conditions, and follow-up as necessary) may be appropriate under the new EPA guidance for lead in soil.     

Substrate influence on epiphytic lichens

The origin of the presence of soil elements in the epiphytic lichen Lecanora conizaeoides was investigated in an area of heavily polluted soil (The Broekpolder The Netherlands). Analysis results of lichens, bark and tree rings of the supporting trees indicated that for As, Co, Cr, Cu, Fe, Hg, Sc and V the levels in lichens may be considered to originate from wet and dry deposition. The Cd, Mn and Zn levels in lichens might have originated from both wet and dry deposition and the substrate bark. For these three elements, in particular, accumulation characteristics in lichens should be further investigated.     

Contribution of sugar-cane harvesting season to atmospheric contamination by polycyclic aromatic hydrocarbons (PAHs) in Araraquara city,Southeast Brazil

In Brazil, sugar-cane crops are burned to facilitate harvesting, and this causes environmental pollution from the large amounts of smoke and soot that are released into the atmosphere. The smoke and soot contain numerous organic compounds such as PAHs. In this study, PM₁₀ and PAH concentrations in the air of Araraquara (SE Brazil, with around 200,000 inhabitants and surrounded by sugar-cane plantations) were determined during the harvest and non-harvest seasons. The sampling strategy included two campaigns in each season, with 20 samples per season. PM₁₀ was collected using a Hi-vol sampler with Teflon? – coated glass fiber filters. PM₁₀ ranged from 41 to 181 μg m^?3 during the harvest season, and from 12 to 47 μg m^?3 during the non-harvest season. The mean total concentration of PAHs was 2.5 ng m^?3 (non-harvest season) and 11.6 ng m^?3 (harvest season). In all sampling periods, the most abundant polycyclic aromatic hydrocarbons were phenanthrene and fluoranthrene, and the least abundant was anthracene. The cluster analysis of the total PAH concentrations for each day of sampling and the corresponding meteorological data suggested that the atmospheric concentration of PAHs was independent of the differences in the weather between the seasons. For both sampling seasons, the statistical treatment (PCA, Varimax rotation and HCA) indicated the presence of vehicle sources (diesel, gasoline, and natural-gas engines); but for the harvest season, the main source was attributed to sugar-cane burning. The data generated by this study indicated the burning of sugar-cane as the main contributor to the high levels of PAHs detected in samples during the sugar-cane harvest season.     

Satellite Rainfall Estimates Over South America – Possible Applicability to the Water Management of Large Watersheds1

Pereira Filho, Augusto J., Richard E. Carbone, John E. Janowiak, Phillip Arkin, Robert Joyce, Ricardo Hallak, and Camila G.M. Ramos, 2010. Satellite Rainfall Estimates Over South America – Possible Applicability to the Water Management of Large Watersheds. Journal of the American Water Resources Association (JAWRA) 46(2):344-360. DOI: 10.1111/j.1752-1688.2009.00406.x Abstract: This work analyzes high-resolution precipitation data from satellite-derived rainfall estimates over South America, especially over the Amazon Basin. The goal is to examine whether satellite-derived precipitation estimates can be used in hydrology and in the management of larger watersheds of South America. High spatial-temporal resolution precipitation estimates obtained with the CMORPH method serve this purpose while providing an additional hydrometeorological perspective on the convective regime over South America and its predictability. CMORPH rainfall estimates at 8-km spatial resolution for 2003 and 2004 were compared with available rain gauge measurements at daily, monthly, and yearly accumulation time scales. The results show the correlation between satellite-derived and gauge-measured precipitation increases with accumulation period from daily to monthly, especially during the rainy season. Time-longitude diagrams of CMORPH hourly rainfall show the genesis, strength, longevity, and phase speed of convective systems. Hourly rainfall analyses indicate that convection over the Amazon region is often more organized than previously thought, thus inferring that basin scale predictions of rainfall for hydrological and water management purposes have the potential to become more skillful. Flow estimates based on CMORPH and the rain gauge network are compared to long-term observed average flow. The results suggest this satellite-based rainfall estimation technique has considerable utility. Other statistics for monthly accumulations also suggest CMORPH can be an important source of rainfall information at smaller spatial scales where in situ observations are lacking.     

Preimplantation genetic diagnostic protocols for α- and β-thalassaemias using multiplex fluorescent PCR

Haemoglobinopathies including α- and β-thalassaemia are the world's most common class of single gene disorder. Prenatal diagnosis (PND) for β-thalassaemia has been proven to be an effective strategy for controlling the incidence of new cases and is widely used in several countries where the disease is common. Successful preimplantation genetic diagnosis (PGD) protocols for β-thalassaemia have been introduced using restriction fragment length polymorphism (RFLP), single-stranded conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE). However, contamination and allele dropout (ADO) remain an important concern for all of these strategies. In the present study two PGD protocols for detecting β-thalassaemia mutations (codon 41-42 and IVSI-110) and one for α-thalassaemia (SEA mutation) have been designed and tested. These methods contain failsafe mechanisms to reduce the risk of misdiagnosis due to ADO or contamination and utilise multiplex fluorescent PCR (F-PCR). Interestingly, amplification efficiency and ADO were significantly affected by the choice of DNA polymerase and the freshness of the single cells used. The close similarity between the DNA sequences of β-globin and δ-globin was also found to be an important issue that necessitated careful design of primers for the β-globin gene. Copyright © 2001 John Wiley & Sons, Ltd.     

Assessing the relation between the distribution of salt-marsh communities and the sediment budget of the North Norfolk coast

Very high resolution imagery from an airborne multi-spectrål scanner has been used to estimate the distribution of different salt-marsh communities along a 30-km stretch of the North Norfolk coast. Field observations have been used to develop a mathematical relationship between the vegetation, physical environment and sediment accumulation. This relationship has been used to produce provisional sediment accretion maps for the north Norfolk coast.     

A rare inherited euchromatic heteromorphism on chromosome 1

Extra genetic material that is euchromatic is generally regarded to be associated with phenotypic abnormalities. However, recent studies suggest that this is not always the case. Chromosome analysis was performed on amniotic fluid cells from a 37-year-old phenotypi-cally normal patient referred for advanced maternal age. All the cells analysed showed a karyotype of 46, XY, 1p-K The 1p+ chromosome had extra genetic material of uncertain origin in chromosome band region 1p21 →31. Chromosome analysis on the father revealed a normal 46, XY male karyotype. The mother's karyotype showed the same 1p+ chromosome. C and Q banding, as well as silver staining studies, in both the mother and the fetus support the interpretation that the extra chromosomal material was euchromatic in nature. This 1p + chromosome may be characterized as a euchromatic heteromorphism. Euchromatic hetero-morphisms not associated with phenotypic abnormalities have been reported for chromosomes 9 and 16. To the best of our knowledge, this is the first report involving this type of cytogenetic anomaly on chromosome number 1 in a phenotypically normal mother and infant.