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Elvis G. Ngwenya Maud Walsh Caroline A. Metosh‐Dickey Ralph J. Portier 《补救:环境净化治理成本、技术与工艺杂志》2006,16(2):79-90
Biological and physicochemical approaches were utilized in a treatment train for acid mine dis charge (AMD) waters. Anaerobic bioreactors, chemical precipitation reactors, and biopolymer chelation reactors, operated in static, semicontinuous, and continuous flow modes, removed significant quantities of metals and sulfates associated with AMD water. Static tests indicated accept able copper removal via precipitation by generation of hydrogen sulfide in anaerobic reactors. However, low pH affected the biopolymer coating in the chelation reactor, resulting in loss of bed surface. Corrections of AMD to pH > 7 resulted in some metal precipitationprior to biopolymer treatment. A series of static semicontinuous tests at pH 5.0 provided improved metal and sulfate removal. Copper (Cu+) was reduced to trace concentrations, while manganese (Mn+), although reduced, proved to be the most recalcitrant of the metals. © 2006 Wiley Periodicals, Inc. 相似文献
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Jason Collodi Mark Pelling Arabella Fraser Maud Borie Simone Di Vicenz 《Disasters》2021,45(1):202-223
The Sendai Framework for Disaster Risk Reduction 2015–2030 and the United Nations’ Sustainable Development Goals call for action to build back better in ways that leave no one behind. At the same time, ensuring a local voice is increasingly central to humanitarian engagement. These aims contrast with limited analysis of how local actors might be supported in these respects during response and recovery, and how far recommendations are specific or generalisable across richer and poorer national contexts. The paper begins by comparing lessons learnt by survivors and community organisations in Sint Maarten, Dutch Caribbean, following a high‐income state‐led response to Hurricane Irma in 2017 with the priorities of lower income, humanitarian‐led endeavours. The differences reveal the importance of economic resources as the basis for individual self‐reliance and a fragmented civil society with limited leadership ambitions in Sint Maarten. Strong cross‐cultural alignment nevertheless allows for a globally‐relevant and yet contextually‐sensitive framework for survivor‐led action and reconstruction. 相似文献
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Maud Bonato Matthew R. Evans Dennis Hasselquist Richard B. Sherley Schalk W. P. Cloete Michael I. Cherry 《Behavioral ecology and sociobiology》2013,67(12):1891-1901
One of the most important measures of offspring performance is growth rate, which is often traded off against another important survival trait, immune function. A particular feature of ostrich chicks maintained in farmed environments is that cohorts of chicks vary widely in size. As parents can have a profound effect on the phenotype and fitness of their offspring, we investigated whether chick growth and immune defence were related to variation in levels of immune defence in their genetic parents. As secondary sexual traits of sires could serve as indicators of male quality, and be used in female mating decisions, we also investigated whether chick growth rate and immune defence were related to male plumage and integumentary colouration. We found that offspring growth rates and humoral responses were related to the humoral responses of their parents, suggesting that at least some components of humoral immune capacity are heritable. The white colour of male ostrich feathers was correlated to the humoral response and growth rate of their offspring, suggesting that this visual cue involved in the male courtship display could serve as an important signal to females of male quality, thereby forming the basis of mate choice in this species. 相似文献
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Maud C. O. Ferrari Myles R. Brown Michael S. Pollock Douglas P. Chivers 《Chemoecology》2007,17(3):157-161
Summary. Many aquatic prey are known to use chemical alarm cues to assess their risk of predation. In fishes, such alarm cues can be
released either through damage of the epidermis during a predatory attack (capture-released) or through release from the predator
feces (diet-released). In our study, we compared the importance of capture- versus diet-released alarm cues in risk assessment
by fathead minnows (Pimephales promelas) that were na?ve to fish predators. We utilized two different fish predators: a specialized piscivore, the northern pike
(Esox lucius) and a generalist predator, the brook trout (Salvelinus fontinalis). Handling time of pike consuming minnows was much shorter than for trout consuming minnows, likely resulting in less epidermal
damage to the minnows during attacks by pike. In accordance with this, minnows showed a less intense antipredator response
to capture-released cues from pike than capture-released cues from trout. This represents a paradox in risk assessment for
the minnows as they respond to the specialized piscivore, the more dangerous predator, with a less intense antipredator response.
In contrast, the minnows showed a stronger antipredator response to the specialized piscivore than to the generalist when
given diet cues. This work highlights the need for researchers to carefully consider the nature of the information available
to prey in risk assessment. 相似文献
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Antoine?O.H.C.?Leduc Maud?C.O.?Ferrari Jocelyn?M.?Kelly Grant?E.?BrownEmail author 《Chemoecology》2004,14(2):107-112
Summary. Recent studies have demonstrated that under
weakly acidic conditions (pH 6.0), many prey fishes, including
juvenile rainbow trout (Onchorhynchus mykiss), do not
exhibit overt antipredator responses to conspecific chemical
alarm cues. In laboratory trials, we investigated the potential
effects of reduced pH on the ability of hatchery reared, predator
naïve juvenile rainbow trout to acquire the recognition of
a novel predator (yellow perch, Perca flavenscens). Initially,
we exposed trout to the odour of a predatory yellow perch,
buffered to pH 6.0 (weakly acidic) or pH 7.0 (neutral) paired
with conspecific skin extracts (also buffered to pH 6.0 or 7.0)
or a distilled water control. Juvenile trout exhibited significant
increase in antipredator behaviour when exposed to neutral
skin extract (pH 7.0). When retested 48 hours later to perch
odour alone (pH 7.0), only trout initially conditioned with
neutral skin extracts (pairs with either neutral or acidic perch
odour) exhibited a learned recognition of perch odour as a
predator risk. Those initially exposed to weakly acidic skin
extract or the distilled water control did not show a learned
response to predator odour. These results demonstrate that the
ability to acquire the recognition of novel predators is
impaired under weakly acidic conditions, as would occur in
natural waterways affected by acidic precipitation. 相似文献
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Glucocorticosteroids (GCs) of the hypothalam–pituitary–adrenal axis play a role in association with both stressful events
and daily life processes. However, relatively little is known about the role of GCs in relation to daily and seasonal life
processes in animals in the wild. In this paper, we present data on basal levels of plasma corticosterone CORT in chicks of
a pelagic seabird, the thin-billed prion, Pachyptila belcheri, during two predictable changes in demands, the daily activity pattern and the preparation for fledging. By comparing chicks
fed recently with unfed chicks, we test how GC levels are modified according to nutritional condition. In accordance with
their nocturnal feeding rhythm, chicks had a clear daily rhythm with increased CORT secretion at night, but CORT levels during
the active phase were also highly elevated in unfed chicks compared with fed chicks. Close to fledging, chicks rapidly increased
basal CORT levels, and again unfed chicks had higher levels than fed chicks, although the age effect here was stronger than
the effect of recent feeding. The present data thus support the hypothesis that GC levels are adjusted to life stages with
predictable changes in demands, but food availability and/or internal energy stores also affect the level to which GCs increase. 相似文献
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Maud Bonato Matthew R. Evans Dennis Hasselquist Schalk W. P. Cloete Michael I. Cherry 《Behavioral ecology and sociobiology》2009,64(2):183-191
A tradeoff between immune response and life history traits, in particular growth rate, has been documented in various bird
species. Ostriches are fast-growing birds and a typical feature of cohorts is that offspring often differ greatly in size.
We investigated the relationship between hatching date and growth rate of chicks and both cell-mediated (measured using a
phytohaemagglutinin (PHA) injection) and humoral immune responses in ostrich chicks maintained on a research farm. Chicks
with higher growth rates had intermediate responses to both diphtheria and tetanus toxoids. By contrast, no relation between
growth rates and responses to PHA injection were found. We conclude that chick growth rate variation may be explained beyond
a certain threshold by a tradeoff between the humoral response and growth. Both responses to PHA injection and humoral responses
in chicks were found to decrease with chick hatching date. Within the context of ostrich farming, these results could partially
explain size variations observed in cohorts of chicks, as well as high mortality rates during their first 3 months of age. 相似文献
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Amphibians are able to learn to recognize their future predators during their embryonic development (the ghost of predation
future). Here, we investigate whether amphibian embryos can also acquire additional information about their future predators,
such as the level of threat associated with them and the time of day at which they would be the most dangerous. We exposed
woodfrog embryos (Rana sylvatica) to different concentrations of injured tadpole cues paired with the odor of a tiger salamander (Ambystoma tigrinum) between 1500 and 1700 hours for five consecutive days and raised them for 9 days after hatching. First, we showed that embryos
exposed to predator odor paired with increasing concentrations of injured cues during their embryonic development subsequently
display stronger antipredator responses to the salamander as tadpoles, thereby demonstrating threat-sensitive learning by
embryonic amphibians. Second, we showed that the learned responses of tadpoles were stronger when the tadpoles were exposed
to salamander odor between 1500 and 1700 hours, the time at which the embryos were exposed to the salamander, than during
earlier (1100–1300 hours) or later (1900–2100 hours) periods. Our results highlight the amazing sophistication of learned
predator recognition by prey and emphasize the importance of temporal considerations in experiments examining risk assessment
by prey. 相似文献