Dynamic Risk Perception in Two Communities: Risk Events and Changes in Perceived Risk

This paper examines the relationship between perceived risk and hazard events in two communities in terms of the perception and acceptability of risk. One community experienced an acute risk event comprised of a fire at a chemical plant that resulted in a large-scale evacuation (an acute hazard). The other community was involved in a seven-year controversy over the siting of a hazardous waste incinerator (a chronic risk). While the results are broadly consistent with a learning model of perceived risk, the support is more limited than envisioned; hence, the static forces of risk perception are stronger than anticipated.     

Maternal liver transplant: Another cause of discordant fetal sex determination using cell-free DNA

Noninvasive prenatal testing (NIPT) can very accurately determine fetal sex during pregnancy. We present an exceptional case where NIPT contradicts the ultrasound-based sex determination. The pregnant woman was recipient of a liver transplant from a male donor. Graft-derived cell-free DNA released into the maternal circulation clouded the NIPT-based sex determination. Hence, NIPT is not advisable when the pregnant mother underwent an organ transplant.     

Directional selection by fisheries and the timing of sockeye salmon (Oncorhynchus nerka) migrations.

The timing of migration from feeding to breeding areas is a critical link between the growth and survival of adult animals, their reproduction, and the fitness of their progeny. Commercial fisheries often catch a large fraction of the migrants (e.g., salmon), and exploitation rates can vary systematically over the fishing season. We examined daily records of sockeye salmon (Oncorhynchus nerka) in the Egegik and Ugashik management districts in Bristol Bay, Alaska (USA), for evidence of such temporally selective fishing. In recent years, the early migrants have experienced lower fishing rates than later migrants, especially in the Egegik district, and the median migration date of the fish escaping the fisheries has been getting progressively earlier in both districts. Moreover, the overall runs (catch and escapement) in the Egegik district and, to a lesser extent the Ugashik district, have been getting earlier, as predicted in response to the selection on timing. The trends in timing were not correlated with sea surface temperature in the region of the North Pacific Ocean where the salmon tend to concentrate, but the trends in the two districts were correlated with each other, indicating that there may be some common environmental influence in addition to the effect of selection. Despite the selection, both groups of salmon have remained productive. We hypothesize that this resilience may result from representation of all component populations among the early and late migrants, so that the fisheries have not eliminated entire populations, and from density-dependent processes that may have helped maintain the productivity of these salmon populations.     

A Value-Informed Framework for Interdisciplinary Analysis: Application to Recovery Planning for Snake River Salmon

Economic and social variables, in addition to biological variables, are often critical forces in directing recovery planning for threatened and endangered populations. Although including these variables in scientific analyses for recovery planning may be important, there is little agreement on how to integrate the relevant disciplines. The dilemma associated with interdisciplinary collaboration is that, while a diversity of values and perspectives is unavoidable, this diversity stands as a barrier to agreement on an integrative research approach. We describe a general framework for interdisciplinary analysis designed to support recovery planning that does not rely on choosing a single interdisciplinary approach. Rather, it uses value conflicts potentially arising in an interdisciplinary setting to select a diverse set of scientific approaches relevant to a particular conservation effort. We apply this framework to recovery planning for threatened Snake River chinook salmon ( Oncorhynchus tshawytscha ) and examine the implications of conflicts over the acceptability of institutional change, technological solutions, and transferability of recovery effort across groups responsible for the current status of the species.     

Sex ratio,monogamy and breeding success in the Midas cichlid (Cichlasoma citrinellum)

Summary The Midas cichlid (Cichlasoma citrinellum) is a large, aggressive monogamous fish from the Great Lakes of Nicaragua. It lives in an ecosystem where breeding sites are at a premium and where breeding success can be low. I tested the strength of the pair bond by manipulating the sex ratios in captive groups, using ratios of 1:1, 2:1, 4:1, 1:2 and 1:4 (:). No polygamy was seen at any of the ratios. Departure from a ratio of 1:1 decreased breeding success for those pairs that formed. Both sexes appeared to enforce the pair bond but did so in different ways: females attacked males and females equally but males attacked other males significantly more than they did females. These results, coupled with field observations, indicate the Midas cichlid is obligated to monogamy by the demands of competition for breeding sites, the need for two parents to protect the fry and by energetic constraints.     

The Triple Bottom Line for Sustainable Community Development

Rural communities in Australia are confronting a period of unprecedented change. They face declining commodity prices, the withdrawal of both public and private sector services, such as banks and hospitals, and the closure of small businesses. Their populations are in decline, with young people leaving for the larger regional centres. Many also face a declining resource base as soils become saline and water resources are sold to areas with higher unit returns. This paper presents a framework for sustainable community development based on emerging ideas of performance auditing and the development of progress indicators. The triple bottom line community audit approach is recast for the community level, measuring performance on improved community wellbeing, reduced environmental impact and increased economic vitality. Rural communities need to redefine their future. A sustainability focus offers a way forward. Las comunidades rurales en Australia estan afrontando un periodo de cambio sin precedente. Enfrentan disminución en los precios de los productos, retiro de servicios de ambos sectores, publico y privado, como bancos y hospitales y el cierre de pequeños negocios. Su población está disminuyendo, la gente joven emigra hacia centros regionales mas grandes. Muchos tambien enfrentan un deterioro en los recursos base ya que los suelos se tornan salinos, y los recursos de agua son vendidos a áreas con retorno de unidad mas alto. Este documento presenta una estructura para el desarrollo comunitario sostenible basado en el surgimiento de ideas de la revisión del desempeño y del desarrollo de indicadores de progreso. El enfoque de auditoria del triple resultado final esta rehecho para el nivel de la comunidad, midiendo el desempeño en el bienestar de la comunidad mejorada, el impacto ambiental reducido, y la vitalidad económica incrementada. Las comunidades rurales necesitan redefinir su futuro. Un enfoque sostenible ofrece una vía hacia adelante.     

Estimates of cloud water deposition at Mountain Acid Deposition Program sites in the Appalachian Mountains

Cloud water deposition was estimated at three high-elevation sites in the Appalachian Mountains of the eastern United States (Whiteface Mountain, NY; Whitetop Mountain, VA; and Clingman's Dome, TN) from 1994 through 1999 as part of the Mountain Acid Deposition Program (MADPro). This paper provides a summary of cloud water chemistry, cloud liquid water content, cloud frequency, estimates of cloud water deposition of sulfur and nitrogen species, and estimates of total deposition of sulfur and nitrogen at these sites. Other cloud studies in the Appalachians and their comparison to MADPro are also summarized. Whiteface Mountain exhibited the lowest mean and median concentrations of sulfur and nitrogen ions in cloud water, while Clingman's Dome exhibited the highest mean and median concentrations. This geographic gradient is partly an effect of the different meteorological conditions experienced at northern versus southern sites in addition to the difference in pollution content of air masses reaching the sites. All sites measured seasonal cloud water deposition rates of SO4(2-) greater than 50 kg/ha and NO3(-) rates of greater than 25 kg/ha. These high-elevation sites experienced additional deposition loading of SO4(2-) and NO3(-) on the order of 6-20 times greater compared with lower elevation Clean Air Status and Trends Network (CASTNet) sites. Approximately 80-90% of this extra loading is from cloud deposition.     

Microbial influenced degradation of solidified waste binder

Ordinary cement pastes with water/cement (w/c) ratios of 0.2, 0.4 and 0.5 were used to examine the chemical and physical effects of microbial influenced degradation (MID). Samples were exposed to an active culture of Thiobacillus thiooxidans or to sterile media containing sulphuric acid using an intermittent immersion technique. Acid consumption and Ca, Al and Fe releases are presented for an exposure period of 90 days. Exposed samples were also sectioned and analysed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). All cement paste samples were subject to significant degradation in either sterile acid media or the T. thiooxidans lixiviant. Corrosion depths observed from SEM examination of exposed samples were affected by the w/c ratio of the cement. The extent and rate of degradation were not apparent from the calculated rate of hydrogen ion consumption, or the leaching rates of Ca, Al and Fe. It was not possible to distinguish differences in corrosion due to the chemical and microbial influenced degradation from the results obtained to date and further work is focusing on modified procedures to address this.