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511.
Toni Lyn Morelli R. Andrew Hayes Helen F. Nahrung Thomas E. Goodwin Innocent H. Harelimana Laura J. MacDonald Patricia C. Wright 《Die Naturwissenschaften》2013,100(8):769-777
Lemurs are the most olfactory-oriented of primates, yet there is still only a basic level of understanding of what their scent marks communicate. We analyzed scent secretions from Milne-Edwards' sifakas (Propithecus edwardsi) collected in their natural habitat of Ranomafana National Park, Madagascar. We sought to test whether the scent mark could signal genetic relatedness in addition to species, sex, season, and individuality. We not only found correlations (r 2?=?0.38, P?=?0.017) between the total olfactory fingerprint and genetic relatedness but also between relatedness and specific components of the odor, despite the complex environmental signals from differences in diet and behavior in a natural setting. To the best of our knowledge, this is the first demonstration of an association between genetic relatedness and chemical communication in a wild primate population. Furthermore, we found a variety of compounds that were specific to each sex and each sampling period. This research shows that scent marks could act as a remote signal to avoid inbreeding, optimize mating opportunities, and potentially aid kin selection. 相似文献
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A new technique is described for observing the structures and mechanisms of suspension feeding in bivalves using endoscopic examination and video image analysis. This method permits direct in vivo observations of whole, intact structures of relatively undisturbed specimens. No surgical alterations of shell or tissue are required for most species. Pallial organ activity can be recorded for future observations and analysis. Using this technique we examined three bivalve species, each with different degrees of mantle fusion:Mya arenaria L.Mytilus edulis L., andPlacopecten magellanicus (Gmelin). The specimens were collected between April and September 1990 at various locations in Trinity Bay, Newfoundland, Canada. Particle retention by the gill and transport of material to the palps was observed, and velocity of particles moving on the gill was determined. We demonstrate that the endoscope-video-analysis system is an efficient and affordable technique suitable for studies of pallial organ function and mechanisms of feeding. 相似文献
515.
The transit mission wastewater may represent a future graywater, in which toilet waste is separated from other household waste streams, and dilution water is minimal. A loading rate study indicated that denitrification is stoichiometrically limited, and nitrification was kinetically limited. Denitrification stoichiometry was developed by deriving hypothetical molecular formulas of organic carbon inputs to be represented by the relative proportions of carbon, hydrogen, oxygen, and nitrogen. The derived stoichiometry was validated against experimental data by adjusting the values of fe and fs and multiplying the total dissolved organic carbon loss across the system by the overall R equation and then comparing the total nitrogen removed in the reaction to experimentally observed total nitrogen removal. The nitrification stoichiometry was similarly validated by multiplying the R equation by the ammonium-nitrogen removed and then comparing the NO(x)-N formed in the equation to actual NO(x)-N production values. The fs values for the denitrifying and nitrifying bacteria were 0.33 and 0.15, respectively. 相似文献
516.
Young (0-group) gadoid fish, which have been observed sheltering beneath jellyfish (Scyphozoa and Hydrozoa) umbrellas, may
find refugia from predation by retreating among medusan tentacles. The survival of juvenile gadoids may therefore be improved
by high abundances of medusae. Jellyfish (including Cyanea lamarckii and C. capillata) were caught in the North Sea during routine sampling for 0-group gadoids (cod Gadus
morhua, haddock Melanogrammus aeglefinus, Norway pout Trisopterus esmarkii and whiting Merlangius merlangus) between 1971 and 1986, and considerable overlaps have been shown between the spatial distributions of these fish and medusae.
Here correlations are made between the abundance of medusae in the North Sea and the residual survival of 0-group fish, as
quantified by the deviation in 1-group recruitment from the expected Ricker modelled estimate. Significant positive correlations
between the residual survival of whiting and medusa abundance are evident for each individual Cyanea sp. and for the combined Cyanea spp. ln(maximum) abundance (all R ≥ 0.60, P < 0.01, N = 15). The abundance of jellyfish may thus be an important factor influencing the mortality of whiting in the North Sea, and
as such should be considered in the development of ‘ecosystem-based’ management of whiting stocks. 相似文献
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Jean-Daniel M. Saphores Hilary Nixon Oladele A. Ogunseitan Andrew A. Shapiro 《Journal of Environmental Planning and Management》2007,50(1):113-133
Concerns about rapid increases in the volume of electronic waste (e-waste) and its potential toxicity have sharpened policy makers' interest for extended producer responsibility to encourage manufacturers of consumer electronic devices (CEDs) to ‘design for the environment’. This paper examines consumer willingness to pay for ‘green’ electronics based on a 2004 mail survey of California households. Using ordered logit models, it was found that significant predictors of willingness to pay for ‘greener’ computers and cell phones include age, income, education, beliefs about the role of government for improving environmental quality, as well as environmental attitudes and behaviors, but neither gender nor political affiliation. Although most respondents are willing to pay only a 1% premium for ‘greener’ CEDs, innovation and EU directives may soon make them competitive with conventional CEDs. 相似文献
520.
AndrewLayson 《电力环境保护》2007,23(1):7-11
讨论了一些为提高生产力和降低成本而发展起来的废水零排放或水回收循环利用前沿技术,并将这些技术的经济性与原有的水循环利用系统进行比较. 相似文献