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61.
62.
壬基酚(NP)作为一种内分泌干扰物,越来越受到人们的关注。基于倏逝波光纤免疫传感器,利用间接竞争免疫反应原理,建立了一种NP的快速检测方法。通过对预反应时间、进样时间及抗体质量浓度等反应条件进行优化,提高了检测方法的灵敏度。结果表明,检测标准曲线符合Logistic模型,NP的定量检测区间为41.7~487μg/L,检出限为20μg/L,检测方法的半抑制质量浓度(IC50值)为143 μg/L。利用建立的检测方法对实际水样进行加标回收实验,回收率为86%~114%,表明该方法可用于较清洁水样中NP的快速检测。 相似文献
63.
Luke Holman 《Behavioral ecology and sociobiology》2009,63(11):1679-1688
The causes and consequences of variation in sperm quality, survival and ageing are active areas of research in ecology and
evolution. In order to address these topics, many recent studies have measured sperm viability using fluorescent staining.
Although sperm viability staining has produced a number of interesting results, it has some potential pitfalls that have rarely
been discussed. In the present paper, I review the major findings of ecology and evolution studies employing sperm viability
staining and outline the method’s principle limitations. The key problem is that the viability assay may itself kill sperm,
which is likely to confound many common experimental designs in addition to producing artificially low estimates of sperm
viability. I further suggest that sperm number should be routinely measured in sperm viability studies, as it may be an important
but overlooked source of spurious results. I provide methodological advice on sperm viability staining aimed at minimising
artefacts and producing robust conclusions, and discuss possible avenues for future research.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
64.
Parental care is a costly part of reproduction. Hence, natural selection should favor males which avoid caring for unrelated
young. However, the decision to abandon or reduce care requires cues which are evaluated to give information on potential
reproductive value of the offspring. The prediction that male sand gobies, Pomatoschistus minutus, care for foreign eggs as long as they were spawned in their own nest and at least some of such cues are fulfilled was tested.
Egg-guarding males that had recently taken part in a spawning event were given a clutch of eggs that was sired either by themselves
or another male, in either their own or another male’s aquarium. Males that had not taken part in a spawning event were used
as controls and were given eggs sired by another male. We measured the amount of filial cannibalism and nest building. Control
group males did not care for eggs and ate them all before rebuilding the nest. In the other treatments, there were no significant
effects of paternity, though males moved to another male’s aquarium increased their clutch area threshold and completely consumed
larger clutches than males that were not moved. There was no intermediate response in any treatment in the form of increased
partial filial cannibalism or less well-constructed nests. Our results suggest that egg-guarding males cannot distinguish
between eggs sired by themselves and those sired by other males but are able to react to cues indicating paternity state.
Males do not adopt eggs to attract females in P. minutus. 相似文献
65.
Carlos César Martínez-Rivera H. Carl Gerhardt 《Behavioral ecology and sociobiology》2008,63(2):195-208
Senders and receivers influence dynamic characteristics of the signals used for mate attraction over different time scales.
On a moment-to-moment basis, interactions among senders competing for a mate influence dynamic characteristics, whereas the
preferences of receivers of the opposite gender exert an influence over evolutionary time. We observed and recorded the calling
patterns of the bird-voiced treefrog Hyla avivoca to assess how the dynamic characters of calls vary during interactions among groups of males in a chorus. This question was
also addressed using playback experiments with males. Playback experiments with females showed how changes in dynamic call
properties are likely to affect male mating success. Frogs calling in pairs, groups, or in response to playbacks produced
longer calls than did isolated males. During call overlap, males often increased the duration of the silent interval (gaps)
between the pulses of their calls so that the pulses of the calls of two neighbors interdigitated. This change resulted in
increased variability of pulse rate, a traditionally static acoustic property; however, males also produced high proportions
of non-overlapped calls in which variability in pulse rate was low and had species-typical values. Females preferred long
calls to short- and average-duration calls, and non-overlapped calls to overlapped calls. Given a choice between pairs of
overlapped calls, females preferred pairs in which the proportion of overlap was low and pairs in which the pulses of such
calls interdigitated completely. The observed patterns of vocal competition thus reflect the preferences of conspecific females,
which have influenced the evolution of the calling behavior of H. avivoca.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
66.
Geir Rudolfsen Rudolf Müller Davnah Urbach Claus Wedekind 《Behavioral ecology and sociobiology》2008,62(4):561-567
The mating behavior and reproductive strategies of Alpine whitefish like Coregonus zugensis (Nüsslin) are poorly understood, probably because they spawn in deep water where direct observations are difficult. In this
study, we interpret life-history and sperm quality traits of fish that we caught from their spawning place. We found that
males invest heavily into gonadal tissue (up to 5.6% of their body weight), which is, in comparison to other fish, consistent
with external fertilization, distinct pairing and moderate to high communal spawning, or no pairing and low to moderate communal
spawning. Sperm competition theory and recent experimental studies on other salmonids predict that males optimize ejaculate
characteristics in relation to the costs of sperm and the level of competition they have to expect: dominant males are predicted
to invest less into ejaculate quality and to have slower spermatozoa than subdominant males. We found that spermatozoa of
older males are slower than those of younger males. Moreover, older males have larger breeding tubercles, a secondary sexual
trait that has, in some previous studies, been found to be linked to good condition and to good genetic quality. Our results
suggest that C. zugensis has age-linked reproductive strategies, that multimale spawning is common, i.e., that sperm competition plays a significant
role, and that older males are on average dominant over younger males at the spawning place. 相似文献
67.
In the meerkat (Suricata suricatta), a cooperative mongoose, pups follow potential feeders while the group is foraging and emit incessant calls when soliciting
food from them. In contrast to a ’stationary’ brood of chicks, in which nestlings are fed at a fixed location, meerkat pups
are ’mobile’ and become spread out. The question arises whether meerkat pups that experience different constraints to those
facing chicks have evolved similar begging strategies. This paper describes the vocalisations that meerkat pups emit in the
context of begging and investigates the influence of these calls on food allocation by older group members and on the behaviour
of littermates. Meerkat pups use two types of calls when soliciting food from a potential feeder. The most common is a ’repeat’
call, which pups emit continuously when following an older forager over several hours a day. In addition, when a potential
feeder finds a prey item, the pups next to it emit a bout of calls with increased calling rate, amplitude and fundamental
frequency, termed ’high-pitched’ calls. Observations, together with playback experiments, showed that more prey was allocated
to pups that called longer and more intensely. The pup closest to a feeder was almost always fed. The probability of emitting
high-pitched calls did not depend on the time since a pup had received food, and the change from repeat to high-pitched calls
occurred suddenly. The main function of the high-pitched call, therefore, does not appear to be to signal a pup’s hunger state.
More likely, the two calls, in the context of begging, may be an adaptation to energetic constraints in a mobile feeding system.
Pups, which are dispersed during foraging, may emit repeat calls over long periods to prevent potential feeders from eating
all the prey themselves. At the moment a potential feeder finds prey, pups may give the more intense high-pitched calls to
direct feeders to bring the food item to them and not to a littermate. Therefore, unlike the stationary feeding system where
chicks emit one type of begging call when the feeder approaches the nest, meerkats, with a mobile feeding system, have evolved
two discrete types of vocalisations in the context of begging.
Received: 22 November 1999 / Revised: 1 July 2000 / Accepted: 17 July 2000 相似文献
68.
温度、pH值和有机物对厌氧氨氧化污泥活性的影响 总被引:46,自引:16,他引:46
通过厌氧氨氧化速率的测定研究了温度、pH值和有机物对厌氧氨氧化污泥活性的影响.结果表明:温度和pH值对污泥的厌氧氨氧化活性有明显影响,最佳温度为30~35℃,在20~30℃之间,厌氧氨氧化速率与温度之间的关系可以用修正的Arrhenius方程式描述;最佳pH值为7.5~8.3,在pH值为7.0~9.0之间,厌氧氨氧化速率与pH值之间的关系可以用双底物双抑制剂模型描述;厌氧氨氧化污泥中存在着异养反硝化菌,有机物的存在会导致其与厌氧氨氧化菌之间的基质竞争. 相似文献
69.
滤池被广泛运用于饮用水厂中,前期研究发现某水厂生物滤池处理含砷地下水时,一方面三价砷可被生物氧化锰氧化为五价砷,另一方面滤池系统中存在的微生物砷还原酶可促使五价砷还原为三价砷,而滤池表面存在的这种微生物竞争关系会影响滤池的稳定性及处理效率.为探讨其内在机制,本研究选取1株锰氧化模式菌(Pseudomonas sp.QJX-1)和1株砷还原模式菌(Brevibacterium sp.LSJ-9),考察在Mn2+、As(As3+、As5+)共存时,两菌株对空间、营养物质以及对砷氧化/还原的竞争关系.结果表明,不同的反应时间,Mn、As质量浓度/价态不同,三价及五价砷体系中,Pseudomonas sp.QJX-1生成的锰氧化物在砷的氧化还原反应中占主导地位,即能迅速氧化本身存在的As3+(三价砷体系)和砷还原菌产生的As3+(五价砷体系),最终两体系中砷都主要以As5+的形式存在.PCR及RT-PCR结果表明,反应过程中锰氧化菌功能基因(cum A)抑制了砷还原酶(ars C)的表达,锰氧化菌16S rRNA表达量始终比砷还原菌高两个数量级,即锰氧化菌在生长竞争过程中占优势.实验结果表明滤池的水力停留时间是决定出水中砷价态的一个重要因素. 相似文献
70.
Haber W 《Environmental science and pollution research international》2007,14(6):359-365
Humans’ superiority over all other organisms on earth rests on five main foundations: command of fire requiring fuel; controlled
production of food and other biotic substances; utilization of metals and other non-living materials for construction and
appliances; technically determined, urban-oriented living standard; economically and culturally regulated societal organization.
The young discipline of ecology has revealed that the progress of civilization and technology attained, and being further
pursued by humankind, and generally taken for granted and permanent, is leading into ecological traps. This metaphor circumscribes
ecological situations where finite resources are being exhausted or rendered non-utilizable without a realistic prospect of
restitution. Energy, food and land are the principal, closely interrelated traps; but the absolutely decisive resource in
question is land whose increasing scarcity is totally underrated. Land is needed for fulfilling growing food demands, for
producing renewable energy in the post-fossil and post-nuclear era, for maintaining other ecosystem services, for urban-industrial
uses, transport, material extraction, refuse deposition, but also for leisure, recreation, and nature conservation. All these
needs compete for land, food and non-food biomass production moreover for good soils that are scarcer than ever. We are preoccupied
with fighting climate change and loss of biodiversity; but these are minor problems we could adapt to, albeit painfully, and
their solution will fail if we are caught in the interrelated traps of energy, food, and land scarcity. Land and soils, finite
and irreproducible resources, are the key issues we have to devote our work to, based on careful ecological information, planning
and design for proper uses and purposes. The article concludes with a short reflection on economy and competition as general
driving forces, and on the role and reputation of today’s ecology.
Updated version of the keynote lecture presented at the EcoSummit 2007 in Beijing, China, May 24. The article is gratefully
dedicated to the memory of my late colleague and friend Frank B. Golley. 相似文献