HPLC-MSn to investigate the oxidative destruction pathway of aromatic sulfonate wastes

The article concerns the problem of destruction and remediation of industrial wastes containing aromatic sulfonates. The effects of an oxidation process induced by thermally activated persulfate in the degradation of 1,5-naphthalenedisulfonate (NDS) are investigated by the use of UV-Vis spectrophotometry, high performance liquid chromatography-mass spectrometry (HPLC-MS) and HPLC-MS(n) techniques. The results obtained indicated that thermal activation (80 degrees C) of a solution containing NDS and sodium persulfate in a molar ratio equal to 1 leads to the cleavage of the naphthalene structure. Estimated chemical oxygen demand (COD) indicates that when the excess of persulfate is equal to 100, NDS undergoes a mineralization of the order of 90%. A degradation pathway undergone by NDS when thermally activated in the presence of persulfate is proposed.     

Chlorinated hydrocarbons in the tissues of South Polar Skuas (Catharacta maccormicki) and Adélie Penguins (Pygoscelis adeliea) from Ross Sea, Antarctica

High rates of egg infertility and embryo death in a colony of South Polar Skuas breeding in the Antarctic were similar to those in polluted North Atlantic populations of the Great Skua. Such loss could not be linked to factors such as organochlorine pollutants, as levels of DDE and PCBs in the contents of skua eggs from the population were only a small fraction of those in polluted skua populations from the Northern Hemisphere. Average eggshell thickness for skuas nesting on Ross Island has shown no significant change since the introduction of DDT. Concentrations of DDE and PCBs in South Polar Skuas were 13 and 22 times higher, respectively, than those in the eggs of sympatric Adélie Penguins, and this probably reflects the greater exposure of skuas to pollution when they migrate north of the Antarctic Convergence in winter. Residues in liver tissue showed a similar trend, and a higher rate of mixed function oxidase induction in skua liver compared to that of penguins is consistent with the trends seen in pollutant levels. The same PCB congener predominated in both skua and penguin samples. Comparisons with historical residue data suggest that global levels of DDT residues are declining.     

Gene flow among population of a teleost (painted greenling,Oxylebius pictus) from Puget Sound to southern California

Net photosynthetic oxygen evolution in Amphiroa anceps (Lamarck) Decaisne is inhibited at high oxygen concentrations. Photosynthesis is highest between pH 6.5 and 7.5. At pH 9 to 10 there is still a significant photosynthetic rate, suggesting that this alga can use HCO _- ³ as a substrate for photosynthesis. At pH 7.0 to 8.5, the photosynthetic rate saturates at a total inorganic carbon concentration (C_i) greater than 3 mM. At pH 8.5 and 8.8, calcification rate continues to increase with increasing concentration of C_i. Between pH 7 and 9, the calcification rate in the light in A. foliacea Lamouroux is proportional to the photosynthetic rate, whereas at higher pH where the photosynthetic rate is very low, the calcification rate is stimulated by the higher concentration of CO _2- ³ ion. At all pH values examined, the calcification rate of living plants in the dark and of dead plants is directly proportional to the CO _2- ³ ion concentration, suggesting little metabolic involvement in calcification processes in the dark, whereas calcification in live A. foliacea in the light is influenced both by the photosynthetic rate and the CO _2- ³ ion concentration in the medium.     

Suspended particulates in the Jamaican atmosphere

The results of a survey of air particulates at 23 sites across Jamaica for total suspended particulates (TSP), Al, Br, Cl, Na, Pb, and V, by instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF) are reported. The geometric mean of TSP values, 35 g m-3, is well within the World Health Organisation's standard of 60 g m-3 for TSP, but in areas of high vehicular traffic density the TSP values exceeded this limit. The correlation coefficient between Br and Pb concentrations in the particulates was 0.92 and the Br/Pb ratio of 0.38 compares well with a ratio of 0.39 found in commercial petrol indicating that the exhaust from vehicular traffic is the major source of Pb in atmospheric particulate matter in Jamaica.     

Sibling recognition in Richardson's ground squirrels (Spermophilus richardsonii)

Summary Young from 10 litters of Richardson's ground squirrels were crossfostered within 24 h of birth. Litters, composed then of uterine-sibs and fostered non-sibs, were caged together until 37 days of age (1 week after weaning), at which time the juveniles were separated and caged individually. At a mean age of 110 d squirrels were tested for recognition during 10-min trials in an arena using the following pair-types: sibs reared together (SRT), sibs reared apart (SRA), non-sibs reared together (NSRT), and non-sibs reared apart (NSRA). Juvenile S. richardsonii displayed an ability, determined prenatally or soon after birth, to recognize their biological siblings. Familiarity, based upon association before and at the time of weaning, also affected discrimination between conspecifics, although this effect was less apparent.     

Association among ascidians: facilitation of recruitment inPyura spinifera

Subtidal benthic communities on hard substrata are usually characterised by intense competition for space; neighbouring organisms are generally viewed as a threat to the maintenance of this limited resource. Here, I describe an association between two species of subtidal ascidians where the abundance of one appears to be wholly determined by the abundance of the other.Pyura spinifera is a large subtidal stalked ascidian that is common in south-eastern Australia and usually occurs in clumps. At the base of these clumps the unstalked ascidianCnemidocarpa pedata is often present. Between February and May 1992, I used a removal experiment to test the prediction that the recruitment ofP. spinifera was dependent on the presence ofC. pedata. There were three treatments at two sites: (i)C. pedata were totally removed, (ii)C. pedata densities were reduced by half, and (iii) ascidians were left untouched (control). The removal ofC. pedata significantly reducedP. spinifera recruitment relative to controls; recruitment ofP. spinifera was only observed onC. pedata. Results were consistent between sites. Furthermore, laboratory settlement trials indicated thatP. spinifera settle preferentially in response to cues with which recruits are normally associated, while settlement is poor or does not occur in the absence of such cues. Laboratory trials also indicate that these responses are mediated by water-borne compounds.