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81.
Rebecca Niemiec Megan S. Jones Stacy Lischka Veronica Champine 《Conservation biology》2021,35(4):1073-1085
Research suggests that encouraging motivated residents to reach out to others in their social network is an effective strategy for increasing the scale and speed of conservation action adoption. However, little is known about how to effectively encourage large numbers of residents to reach out to others about conservation causes. We examined the influence of normative and efficacy-based messaging at motivating residents to engage in and to encourage others to participate in native plant gardening in their community. To do so, we conducted a field experiment with messages on mailings and tracked native plant vouchers used. Efficacy messages tended to be more effective than normative messages at increasing residents’ willingness to reach out to others to encourage conservation action, as indicated by a several percentage point increase in native plant voucher use by residents’ friends and neighbors. Messages sometimes had different impacts on residents based on past behaviors and perceptions related to native plant gardening. Among these subgroups, efficacy and combined efficacy and norm messages most effectively encouraged individual and collective actions, as indicated by increased voucher usage. Our findings suggest that interventions that build residents’ efficacy for engaging in a conservation behavior and for reaching out to others may be a promising path forward for outreach. However, given our results were significant at a false discovery rate cutoff of 0.25 but not 0.05, more experimental trials are needed to determine the robustness of these trends. 相似文献
82.
83.
The extent to which exposure to environmental hypoxia (PO2=8, 6, and 4 kPa, approximately 40%, 30%, and 20% saturation, respectively) resulted in an increase in the concentration of the respiratory pigment haemocyanin ([Hc]) in individuals of the Norway lobster Nephrops norvegicus depended crucially on the initial [Hc] as well as the intensity of the hypoxia itself. While mean [Hc] did increase with decreasing PO2 (and the variation decreased), for individuals with relatively high initial [Hc] there was no change or even a decrease observed. The greatest hypoxia-related increases in [Hc] were observed in the individuals with the lowest initial [Hc]. Consequently the notion of an 'optimum' [Hc] for a given level of oxygenation was postulated. The changes in [Hc] recorded took place over a considerably shorter time scale (hours rather than days) than has been observed in previous studies. It was not possible to correlate environmental PO2 and median [Hc] in the field. However, it was interesting that the [Hc] frequency distribution curve for lobsters collected from a site that had been markedly hypoxic (PO2=8.0 kPa, approximately 40% saturation) until a few days before sampling was almost exactly the same shape (i.e. leptokurtic) and position (i.e. similar median) to that obtained when lobsters were exposed to PO2=8.0 kPa in the laboratory. Although it would have been desirable to investigate the effect of hypoxia on the frequency distribution of a physiological trait, in this case [Hc], it was not possible due to insufficient sample size, even though the sample sizes employed were considerably larger than those normally used in physiological investigations. 相似文献
84.
85.
The use of transparency as camouflage in the epipelagic realm is complicated by the presence of ultraviolet radiation, because
the presence of UV-protective pigments decreases UV transparency and may reveal transparent zooplankton to predators and prey
with UV vision. During July 1999, September 1999, and June 2000, transparency measurements (from 280 to 500 nm) were made
on living specimens of 15 epipelagic (collection depth: 0–20 m, average: 11 ± 1 m) and 19 mesopelagic (collection depth: 150–790 m,
average: 370 ± 40 m) species of transparent zooplankton from Oceanographer Canyon and Wilkinson Basin in the Northwest Atlantic
Ocean. In addition, measurements of downwelling irradiance (from 330 to 500 nm) versus depth were made. The tissues from epipelagic
zooplankton had lower UV transparency than those from mesopelagic zooplankton, while the average visible transparency (at
480 nm) of the two groups was not significantly different. Percent transparency was positively correlated with wavelength
over most of the measured range, with a rapid decrease below a certain cutoff wavelength. In mesopelagic tissues, the cutoff
wavelength was generally 300 nm. In epipelagic tissues, the cutoff wavelength was between 300 and 400 nm. Twelve out of 19
epipelagic tissues had transparencies at 320 nm that were half or less than their 480 nm transparency values, versus only
4 out of 21 mesopelagic tissues. The effects of UV absorption on UV visibility and minimum attainable depth were modeled using
contrast theory and the physics of light attenuation. Because UV absorption was generally significantly greater in the UVB
than in the UVA spectrum (where UV vision occurs), and because the highest UV absorption was often found in less transparent
individuals, its modeled effects on visibility were slight compared to its effects on minimum attainable depth.
Received: 14 April 2000 / Accepted: 16 November 2000 相似文献
86.
Relationship between Coefficient of Inbreeding and Parasite Burden in Endangered Gazelles 总被引:1,自引:0,他引:1
Jorge Cassinello Montserrat Gomendio Eduardo R. S. Roldan 《Conservation biology》2001,15(4):1171-1174
Abstract: We studied the effects of inbreeding depression on parasite infection in three species of endangered gazelles: Gazella cuvieri , G. dama, and G. dorcas . Coefficients of inbreeding were calculated for all individuals because complete genealogies were available. The levels of inbreeding differ both intra- and interspecifically. We collected samples of feces and determined nematode infection by counting nematode eggs in the samples. At the interspecific level, the species with the highest mean levels of inbreeding ( G. cuvieri ) had the highest levels of gastrointestinal parasites. Analyses done at the intraspecific level revealed a positive relationship between individual coefficient of inbreeding and parasite infection in G. cuvieri , but not in the species with the intermediate and lowest levels of inbreeding. Our findings suggest that high levels of inbreeding may make individuals more susceptible to parasitism, even under favorable environmental conditions, so this factor should be taken into account by those managing endangered species. 相似文献
87.
88.
S.D.Limaye 《生态毒理学报》2001,(2):36-37,38
在西印度的硬岩地层,地下水是城市和城市周围贫民区供水的主要来源.这些贫民区不是连接到城市供水和排水网上.一个可以提供200人用水的带手泵的自流井,通常是提供安全饮用水的成本最小的方法.完全地补救被污染的地下水可能是不可行的. 相似文献
89.
90.
Shredding is the common end-of-life treatment in Europe for dismantled car wrecks. It produces the so-called Automotive Shredded Residue (ASR), usually disposed of in landfill. This paper summarizes the outcome of a study carried out by Politecnico di Milano and LEAP with the support of Actelios SpA on the prospects of a technology based on sequential gasification and combustion of this specific waste stream. Its application to the treatment of ASR allows the recovery of large fractions of metals as non-oxidized, easily marketable secondary raw materials, the vitrification of most of the ash content and the production of power via a steam cycle. Results show that despite the unfavourable characteristics of ASR, the proposed technology can reach appealing energy performances. Three of four environmental impact indicators and the cumulative energy demand index are favourable, the main positive contributes being electricity production and metal recovery (mainly aluminium and copper). The only unfavourable indicator is the global warming index because, since most of the carbon in ASR comes from fossil sources, the carbon dioxide emissions at the stack of the thermal treatment plant are mainly non-renewable and, at the same time, the avoided biogas production from the alternative disposal route of landfilling is minor. 相似文献