Toxic Effects of Copper, Cadmium, and Methoxychlor Shown by Neutral Red Retention Assay in Two Species of Freshwater Molluscs

We used neutral red retention assay in lysosomes of digestive gland cells as an indicator for stress effects by the environmental contaminants Cu, Cd, and the pesticide methoxychlor in two freshwater molluscs, the unionid mussel, Elliptio complanata (Lightfoot) and the ramshorn snail Helisoma trivolvis (Say). Mussels and snails were exposed for 7 and 14 days to Cu and Cd each at nominal concentrations of 2.5 μg/L, 5.0 μg/L, and 10.0 μg/L, and to methoxychlor concentrations of 1.0 μg/L, 10.0μg/L, and 100.0 μg/L. Both mussels and snails exposed to Cu showed a significant increase in the percent of destabilized lysosomes compared with lab control and freshly-collected (field control) mussels at both 7 and 14 days exposure for all concentrations. Cd-exposed mussels did not show a significant difference with either of the controls at 7 days, but at 14 days exposure, Cd significantly increased the percent of destabilized lysosomes at all concentrations compared to field control mussels. Compared to laboratory controls, Cd increased lysosomal destabilization at 5.0 μg/L and 10.0 μg/L. Snails exposed to Cd for 7 days had a significantly higher percentage of lysosomal destabilization than both lab and field controls but at 14 days, significant differences were only seen at the two highest Cd concentrations. Methoxychlor-exposed mussels showed no significant lysosomal destabilization at 7 days compared to controls. But at 14 days exposure, the pesticide increased the percentage of lysosomal destabilization at 10.0μg/L compared to lab controls, and increased at both 10.0μg/L and 100.0μg/L compared to field control mussels. Methoxychlor-exposed snails had a higher percentage of lysosomal destabilization at 7 and 14 days at all concentrations compared to both controls with the exception of the 1.0 μg/L -7 day exposure group. Snails were more sensitive to Cd and to methoxychlor than were mussels possibly because they lack an operculum and are thus completely exposed to the environment. The lowest observed effect concentration (LOEC) for Cd was 2.5 μg/L (14 days) for Elliptio and 2.5 μg/L (7 and 14 days) for Helisoma. For methoxychlor, the LOEC was 10.0 μg/L (14 days) for Elliptio and 10.0 and 1.0 μg/L (7 and 14 days, respectively) for Helisoma. The LOEC for Cu was 2.5 μg/L (7 and 14 day exposure) for both Elliptio and Helisoma. These results show that lysosomal destabilization as indicated by neutral red retention is a reliable indicator of stress from heavy metals and a pesticide in freshwater molluscs, including a taxon that is endangered or threatened in North America

Measuring WWZ and WWgamma coupling constants with Z-pole data

Triple gauge boson couplings between Z, gamma and the W boson are determined by exploiting their impact on radiative corrections to fermion-pair production in e+e- interactions at centre-of-mass energies near the Z-pole. Recent values of observables in the electroweak part of the Standard model are used to determine the four parameters epsilon_1, epsilon_2, epsilon_3 and epsilon_b. In a second step the results on the four epsilon parameters are used to determine the couplings Delta-g^1_Z and Delta-kappa_gamma. For a wide range of scales, these indirect coupling measurements are more precise than recent direct measurements at LEP 2 and at the TEVATRON. The Standard model predictions agree well with these measurements.Comment: 6 pages, 2 tables, 4 figure

Geophysical study of the structure and processes of the continental convergence zones: Alpine-Himalayan Belt

Intracontinental deformation occurrence and the processes and physical parameters that control the rates and styles of deformation were examined. Studies addressing specific mechanical aspects of deformation were reviewed and the studies of deformation and of the structure of specific areas were studied considering the strength of the material and the gravitational effect

Tropical Cooling and the Onset of North American Glaciation

We offer a test of the idea that gradual cooling in the eastern tropical Pacific led to cooling of North America and the initiation of glaciation ~3 Myr ago. Using modern climate data we estimate how warming of the eastern tropical Pacific affects North American temperature and ice-ablation. Assuming that the modern relationship holds over the past millions of years, a ~4°C warmer eastern tropical Pacific between 3–5 Ma would increase ablation in northern North America by approximately two meters per year. By comparison, a similar estimate of the ablation response to variations in Earth's obliquity gives less than half the magnitude of the tropically-induced change. Considering that variations in Earth's obliquity appear sufficient to initiate glaciations between ~1–3 Ma, we infer that the warmer eastern equatorial Pacific prior to 3 Ma suffices to preclude glaciation.Earth and Planetary Science

Climate Evolution in Central Asia during the Past Few Million Years: A Case Study from Issyk Kul

The lake Issyk Kul occupies a deep basin within the Earth’s most active intracontinental mountain belt, the Tien Shan, far from any oceanic influence. It offers a record of continental climate spanning millions of years that is likely unmatched by any other source.A three-day workshop, with the same title as this report and sponsored by the International Continental Drilling Project and German Science Foundation, was held on 12–17 June 2011 on the shore of Issyk Kul to discuss the scientific justification for and the logistical aspects of scientific drilling of the lake. A two-day geological field trip followed the workshop. Forty-five scientists from twelve countries discussed three obvious targets for paleoclimatic study, a related study of erosion, and a study of how microbial life has evolved within the basin. The conclusion was that these research topics justify further consideration of deep continental drilling at Issyk Kul