Heinherg and Thompson (I 995) demonstrated that females exposed to a compila tion of media images (commercials) reflecting the current societally sanctioned standards of thinness and attractiveness experienced greater mood and body image disturbance than females who viewed a neutral, nonappearance-related control video Social comparison has been offered as one mechanism for the negative out comes of such media-based exposures. In the current study, social comparison was manipulated by creating three instructional conditions: comparison, distraction, and neutral. Instructional set did not differentially affect recall ot appearance or nonappearance aspects of either an appearance-related collection of commercials or a nonappearance video (e.g., Heinberg & . However, partici pants in the comparison condition self-reported a greater degree of self-to-model comparison than participants in the distraction or neutral conditions. A marginally signifii ant three-way interaction between condition, tape, and time emerged for a measure of appearance dissatisfaction, suggesting that comparison participants' body images were more negatively affected than the other groups. Tape by Time in teractions also emerged for measures of anger, anxiety, and depression, revealing that greater distress was associated with the viewing ot media images reflecting the c urrent societal bias towards thinness and attractiveness. Dispositional level of in ternalization of societal values regarding attractiveness moderated women's reac tions to the two video presentations. The findings are discussed with regard to sociocultural models of body image and possible implications for interventions for appeal a nee-re la ted distress A large number of survey and correlational studies have supported the notion that sociocultural factors play a role in the development of body image disturbance (Fallon, f 990; Heinberg, 1996). Recent findings from contn illed laboratory studies provide even stronger support for a socio-

No abstract

Trifluoroacetate (TFA, CF3COO-) is a stable and mildly phytotoxic breakdown product of several fluorinated organic compounds including the hydro(chloro)fluorocarbons (HFC/HCFCs) that have largely replaced the stratospheric ozone-depleting chlorofluorocarbons (CFCs). TFA enters aquatic ecosystems primarily through precipitation and has the potential to accumulate in water bodies with little or no outflow to the point where toxic concentrations could be achieved. This study demonstrated that seasonal wetlands lacking outflow concentrated TFA as they evaporated during the dry season. In addition, the TFA within the pools was retained between years, which may result in long-term TFA accumulation. Since plants acquire TFA from their growing media, the plants exposed to high aqueous concentrations of TFA within the pools had elevated TFA concentrations with a median concentration of 279 ng/g dry weight in their tissues as compared to 33 ng/g for species growing outside the pools. The highest TFA concentrations in water, which occurred just prior to the pools drying up, were in the 2-10 micrograms/L range. These concentrations are approximately 190 or less than reported toxic concentrations for the most sensitive species tested, but our evidence suggests that these concentrations will increase with continued TFA deposition into the pools.

The bull trout Salvelinus confluentus, a stream-living salmonid distributed in drainages of the northwestern United States, is listed as threatened under the Endangered Species Act because of rangewide declines. One proposed recovery action is the reconnection of tributaries in the Lemhi Basin. Past water use policies in this core area disconnected headwater spawning sites from downstream habitat and have led to the loss of migratory life history forms. We developed an adaptive management framework to analyze which types of streams should be prioritized for reconnection under a proposed Habitat Conservation Plan. We developed a Stochastic Dynamic Program that identified optimal policies over time under four different assumptions about the nature of the migratory behavior and the effects of brook trout Salvelinus fontinalis on subpopulations of bull trout. In general, given the current state of the system and the uncertainties about the dynamics, the optimal policy would be to connect streams that are currently occupied by bull trout. We also estimated the value of information as the difference between absolute certainty about which of our four assumptions were correct, and a model averaged optimization assuming no knowledge. Overall there is little to be gained by learning about the dynamics of the system in its current state, although in other parts of the state space reducing uncertainties about the system would be very valuable. We also conducted a sensitivity analysis; the optimal decision at the current state does not change even when parameter values are changed up to 75% of the baseline values. Overall, the exercise demonstrates that it is possible to apply adaptive management principles to threatened and endangered species, but logistical and data availability constraints make detailed analyses difficult.

Great blue heron (Ardea herodias) eggs and prey items were collected from six colonies in Oregon and Washington, USA, during 1994 to 1995. Contaminant concentrations, reproductive success, and biomagnification factors were determined and effects of residue levels were measured by H4IIE rat hepatoma bioassays. Mean residue concentrations in heron eggs and prey items were generally low. However, elevated concentrations of polychlorinated biphenyls (PCBs) were detected in eggs and prey from Ross Island on the Willamette River. Biomagnification factors varied among sites. Sites were not significantly different in H4IIE tetrachlorodibenzo‐p‐dioxin equivalents (TCDD‐EQs), although the TCDD‐EQ for Karlson Island was 9 to 20 times greater than that of any other site. Large differences existed between toxic equivalents calculated from egg residue concentrations and TCDD‐EQs, which indicated nonadditive interactions among the compounds. Tetrachlorodibenzo‐p‐dioxin equivalents and nest failure were positively correlated with TCDD concentration. Fledging and reproductive rates were similar to those determined for healthy heron populations, however, indicating that any adverse effects were occurring at the individual level and not at the colony level. Our results support the use of great blue herons as a biomonitor for contamination in aquatic ecosystems. Their relatively low sensitivity to organochlorine contaminants and high trophic position allows contaminant accumulation and biomagnification without immediate adverse effects that are often seen in other, more sensitive species.