General effects of climate change on Arctic fishes and fish populations

Projected shifts in climate forcing variables such as temperature and precipitation are of great relevance to arctic freshwater ecosystems and biota. These will result in many direct and indirect effects upon the ecosystems and fish present therein. Shifts projected for fish populations will range from positive to negative in overall effect, differ among species and also among populations within species depending upon their biology and tolerances, and will be integrated by the fish within their local aquascapes. This results in a wide range of future possibilities for arctic freshwater and diadromous fishes. Owing to a dearth of basic knowledge regarding fish biology and habitat interactions in the north, complicated by scaling issues and uncertainty in future climate projections, only qualitative scenarios can be developed in most cases. This limits preparedness to meet challenges of climate change in the Arctic with respect to fish and fisheries.     

Mitochondrial dysfunction,impaired oxidative-reduction activity,degeneration, and death in human neuronal and fetal cells induced by low-level exposure to thimerosal and other metal compounds

Thimerosal (ethylmercurithiosalicylic acid), an ethylmercury (EtHg)-releasing compound (49.55% mercury (Hg)), was used in a range of medical products for more than 70 years. Of particular recent concern, routine administering of Thimerosal-containing biologics/childhood vaccines have become significant sources of Hg exposure for some fetuses/infants. This study was undertaken to investigate cellular damage among in vitro human neuronal (SH-SY-5Y neuroblastoma and 1321N1 astrocytoma) and fetal (nontransformed) model systems using cell vitality assays and microscope-based digital image capture techniques to assess potential damage induced by Thimerosal and other metal compounds (aluminum (Al) sulfate, lead (Pb)(II) acetate, methylmercury (MeHg) hydroxide, and mercury (Hg)(II) chloride) where the cation was reported to exert adverse effects on developing cells. Thimerosal-associated cellular damage was also evaluated for similarity to pathophysiological findings observed in patients diagnosed with autistic disorders (ADs). Thimerosal-induced cellular damage as evidenced by concentration- and time-dependent mitochondrial damage, reduced oxidative–reduction activity, cellular degeneration, and cell death in the in vitro human neuronal and fetal model systems studied. Thimerosal at low nanomolar (nM) concentrations induced significant cellular toxicity in human neuronal and fetal cells. Thimerosal-induced cytoxicity is similar to that observed in AD pathophysiologic studies. Thimerosal was found to be significantly more toxic than the other metal compounds examined. Future studies need to be conducted to evaluate additional mechanisms underlying Thimerosal-induced cellular damage and assess potential co-exposures to other compounds that may increase or decrease Thimerosal-mediated toxicity.     

A case study of urban heat islands in the Carolinas

Urbanization tends to aggravate the negative effects of climate. The objective of this research is to aid in the understanding of the spatial variation of urban heat islands within selected cities in North and South Carolina. This understanding will help guide efforts to cool cities in order to increase human comfort, conserve energy and resources, and reduce air pollution in both of these states.     

A preliminary analysis of aortic injuries in lateral impacts

Injuries to the aorta are among the more serious injuries that result from vehicle impacts, and often may be fatal. This article examines the incidence of aortic injuries in the United States and United Kingdom by using two international databases of real-world crashes. The main outcome of interest was the level of risk associated with each principal direction of force for drivers and front-seat passengers with respect to sustaining aortic injuries. The results indicate that the risk of sustaining an injury to the aorta is greater for near-side crashes than for far-side crashes. Further it is apparent that, given a near-side crash, the risk of an aortic injury is greater on the left side of the body (and left side of the vehicle) than on the right. It also was found that the delta-V of crashes where occupants sustained an injury to the aorta was considerably higher than crashes where occupants did not sustain aortic injuries. It is speculated that the anatomical asymmetry of the thorax might play a role in the differences seen in injury risk associated with different impact directions. The results presented in this article could be of use to both the emergency physician treating patients involved in motor vehicle collisions as well as the engineer involved in occupant design countermeasures. Limitations and further planned research are discussed.     

Incineration treatment of arsenic-contaminated soil

An incineration test program was conducted at the U.S. Environmental Protection Agency's Incineration Research Facility to evaluate the potential of incineration as a treatment option for contaminated soils at the Baird and McGuire Superfund site in Holbrook, Massachusetts. The purpose of these tests was to evaluate the incinerability of these soils in terms of the fate of arsenic and lead and the destruction of organic contaminants during the incineration process. The test program consisted of a series of bench-scale experiments with a muffle furnace and a series of incineration tests in a pilot-scale rotary kiln incinerator system. The study reported in this paper was funded by the Environmental Protection Agency under Contract 68–C9–0038 to Acurex Corporation. It has been subjected to the Agency's review and has been approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

Correlations between Human Collecting and Intertidal Mollusc Populations on Rocky Shores

We tested whether the population structures of intertidal molluscs varied with the activity of human collectors in northern Port Phillip Bay, Victora, Australia. We examined eight sites, two of which had been protected for around 70 years by the area being used as a rifle range with the other six being visited frequently by human. The shores were examined in two different years, and in 1991 we counted humans and recorded their activities. At heavily visited shores, almost half of the people seen were simply walking, while 25% were actively collecting, despite regulations prohibiting the collection of intertidal gastritis. The remaining people were fishing or skydiving. At the protected shores, we observed only one collector and a handful of walkers over more than 20 observation periods, including weekdays, normal weekends, and holiday weekends. In 1989 and 1991, we compared size distributions of seven intertidal species between sites in the two categories. Four mollify species are taken for food and bait; the remaining three served as “controls”. The size distributions and abundance of noncarbonated species (alicized napalm, Leaderless viola, and emization ebonies) did not differ between visited and protected sites in either year, although most species did vary between individual sites. In contrast, three of the four collected species, alicize trampoliners, Austrocochlea constricta, and Nerita atramentosa, were significantly larger at the protected sites, and N. atramentosa was markedly less abundant at heavily visited sites. The fourth collected species, Turbo undulatus, has a distribution extending into the subtidal zone, and it is possible that intertidal populations ate replenished from deeper water. The changes in mean size of molluscs are well within the range reported from South America and South Africa under subsistence fishing, and they demonstrate that at least close to major urban centers, human recreational activities can have substantial effects in developed countries.     

The measurement of respiratory electron-transport-system activity in marine zooplankton

A modification of the tetrazolium reduction method (Packard, 1971) for measurement of respiratory electron transport system activity in marine zooplankton is described. A major modification is the addition of Triton X-100 to the reaction mixture to solubilize formazan produced, thus eliminating an organic extraction step and increasing the sensitivity and versatility of the method. The kinetic parameters of the assay are presented and the apparent effects of Triton X-100 are discussed. The correlation between electron-transport-system (ETS) activity and in vivo respiration (ETS/R) for Calanus pacificus has been found to be 2.02±0.29 (standard deviation). The method is presented as providing a reliable estimate of the zooplankton component of oxygen consumption in the sea.