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1.
Summary The defensive mechanisms which protect ladybird beetles (Coccinellidae) against predators are reviewed. Besides behavioural mechanisms, such as thanatosis and reflex bleeding, chemical defence mechanisms are playing a prevalent role. Indeed, ladybirds are protected not only by their smell, but also by repulsive alkaloids, most of which are considered to be of autogenous origin. In a few cases, dietarily-acquired substances are also involved. Particular emphasis is laid on the repellent alkaloids which are contained in the haemolymph of many species. The structures of 34 nitrogen-containing compounds isolated so far are presented, and their distribution within the family is discussed in the light of the most widely accepted classification of these beetles. To conclude, the mode of release of the alkaloids, their variation through the life cycle and their repellent and toxic properties are discussed, as well as the few biosynthetic data yet available.  相似文献   

2.
恶臭污染评价分级方法   总被引:2,自引:0,他引:2  
恶臭污染的定量评价分级是评价恶臭污染状况的重要依据,但目前我国还没有成熟的恶臭污染分级标准.在分析了国外臭气强度标准的基础上,结合韦伯-费希纳公式,计算臭气浓度与臭气强度的对应值,以臭气强度的嗅觉感觉和丰富的实验经验为依据,将恶臭污染程度初步划分为5级,并对分级结果的科学性和合理性进行实验验证.  相似文献   

3.
城市生活垃圾焚烧炉渣的性质及其环境影响评价   总被引:1,自引:0,他引:1  
通过对上海市江桥生活垃圾焚烧发电厂的炉渣性质分析,测定其气味分子为喹啉基及异硫氰基衍生物,炉渣的镉、锌、镍等3种重金属含量分别为8.0,2 432.9,216.7 mg/kg,不能达到国家土壤环境质量标准,其重金属溶出浓度不能达到国家地表水环境质量标准;据此对炉渣进行环境影响评价,并分析了炉渣资源化的可行性。  相似文献   

4.
Food toxins are produced as defense tools by microorganisms that use nutrients for their growth. Microorganisms thus spoil food, taste and can infect humans, sometimes leading to death. Food adulteration and brand protection are also major issues in the food industry. Here we review the use of nanomaterials for sensing food quality. Nanosensors can detect pathogenic bacteria, food-contaminating toxins, adulterant, vitamins, dyes, fertilizers, pesticides, taste and smell. Food freshness can be monitored using time–temperature and oxygen indicators. Product authenticity and brand protection can be assessed using invisible nanobarcodes. Overall, nanosensors with unique properties are improving food security.  相似文献   

5.
Studies involving health status of bicycle manufacturing industrial workers exposed to chemicals and unexposed workers of the same industry who formed control were conducted at Sonepatin Haryana State, India. Negligence of industrial hygiene and personal protection affected the health of exposed workers adversely Epidemiological spectrum of exposed subjects showed much variation from control. Some unique disorders, such as nail impairments, nasal septum perforation and metal fume fever were observed in exposed workers against their absence in unexposed workers. Data showed occurrence of following diseases in the order of asthma>skin disorders>allergic disorders>bronchitis>all other respiratory diseases>nail disorders and acute pharyngitis>pulmonary tuberculosis and loss of smell and hearing>nasal septum perforation showing high risk factor for 'all other respiratory diseases' and skin disorders. Importance of occupational health surveillance has been highlighted.  相似文献   

6.
The increasing alienation of people from nature is profoundly concerning because people's interactions with nature affect well-being, affinity for nature, and support of biodiversity conservation. Efforts to restore or enhance people's interactions with nature are, therefore, important to ensure sustainable human and wildlife communities, but little is known about how this can be achieved. A key factor that shapes the way people interact with nature is their affinity for nature (often measured as nature relatedness [NR]). We explored how using cues to experience nature as a means to induce NR situationally can influence the quality of people's nature interactions on visits to green spaces and their positive affect after the visit. Cues to experience are cues that guide individuals on how to interact with nature. We surveyed 1023 visitors to a nature reserve to examine the relationships between trait (i.e., stable and long-lasting) and state (i.e., temporary, brief) NR, the quality of nature interactions, and positive affect. We also conducted a controlled experiment in which 303 participants spent 30 min outdoors on campus and reported the quality of their nature interactions and positive affect. Participants were randomly assigned to 1 of 9 cues-to-experience experimental groups (e.g., smell flowers, observe wildlife, turn off your phone) that differed in the psychological distance from nature that they prompted. Participants who received cues of close psychological distance from nature (e.g., smell and touch natural elements) interacted 3 to 4 times more with nature and reported 0.2 more positive affect than other participants. Our results demonstrate that providing cues to experience nature, which bring people closer to nature and potentially induce state NR, can enhance the quality of people's nature interactions and their positive affect. These results highlight the role of NR in high-quality nature interactions and suggest the use of cues to experience as a promising avenue for inducing state NR and promoting meaningful interactions with biodiversity, thus, reconciling conservation and well-being objectives.  相似文献   

7.
Swimming pools are considered to be the prime source for public exposure to trihalomethanes (THMs), mainly chloroform, because of their use for hygienic purposes. High doses of chlorine are easily perceptible by smell. The aim of this study was to measure simultaneously the THM levels in urine and blood of swimmers and in pool water itself (from city and university swimming pool), in order to investigate further the relationship between substances in different matrices at known environmental levels with uptake of these substances in indoor swimming pools. Volatile analytes were isolated and preconcentrated from the samples by thin layer headspace analysis (TLHS) with autogenous generation of the liquid sorbent. Chloroform, bromodichloromethane and dibromochloromethane were detected in the urine of all persons attending a swimming pool. Concentrations of THM compounds varied in the case of each swimmer. The research confirmed that approximately 10% of the volatile haloorganic compounds are excreted in urine in the unchanged form.  相似文献   

8.
酵母生物转化生产2-苯乙醇的研究进展   总被引:3,自引:0,他引:3  
主要论述了利用酵母菌生物转化合成天然2苯乙醇的研究进展,从应用微生物学的角度介绍了2苯乙醇生产菌株的筛选,分析了2苯乙醇合成过程中几方面因素的影响和培养条件的选择,并对产物原位转移技术作了简要说明.并从分子生物学的角度出发,对生物转化的重点途径———艾利希途径在基因水平上作了诠释,且例举了利用从头合成途径进行的基因工程育种,旨在为利用微生物生产2苯乙醇的研究开发提供参考.图1参40  相似文献   

9.
Marine sponges of the Genus Plakortis are typically unfouled; they can have a distinctive pleasant smell and an oily surface. A significant quantity of fragrant oil was obtained from a Jamaican Plakortis sp. by cryo-trap. The oil was determined to be exclusively 2-decanone. The antifouling character of the oil was evaluated by its effects on surface attachment of a gram negative bacterial model using confocal fluorescence microscopy as well as its effects on the attachment of Dreissena polymorpha (zebra mussel). The ketone dramatically inhibited attachment of the bacteria and zebra mussels. The results suggest that the oil impacts establishment of related epifauna on the Plakortis sponge in nature. Although the aliphatic ketone alone is not a potential commercial alternative for antifouling coatings, incorporating the functionality into coating design should be considered in future studies.  相似文献   

10.
Unless sensory control is coupled with developmental flexibility, organisms are unable to produce adaptive phenotypes in response to environmental risk cues. However, empirical examples of adaptive phenotypic plasticity focus largely on development and rarely on sensory control. Here, I ask whether past exposure to predation cues affects an intertidal whelk’s (Nucella lamellosa) sensitivity to the scent of a known predatory crab (Cancer productus). I pre-conditioned whelks for 30 days with the smell of crabs eating other whelks and then, after a period of rest (14 days in fresh seawater free of predator effluent), re-introduced them to different concentrations of waterborne crab scent. Relative to controls, pre-conditioned whelks expressed crab-defences at significantly lower concentrations of crab effluent, suggesting the pre-conditioning reduced their risk–response threshold. Results remind us that the full scope of factors controlling adaptive phenotypic plasticity in natural populations remains underappreciated.  相似文献   

11.
In numerous laboratory experiments involving the incubation of reptile eggs, both the maternal origin of eggs and the incubating environment (nest effect) have been demonstrated to influence hatchling phenotype. Although different hatchling phenotypes have been reported from natural nests, the separate effects of maternal origin and nest on hatchling phenotype in natural nests have not been demonstrated because in natural nests the two effects are confounded with each other. Here, we use a split clutch design to experimentally separate nest effects from maternal origin effects in field nests of green turtles (Chelonia mydas). We found both maternal origin and nest to influence hatchling morphology and locomotor performance in some but not all field nests. By using egg mass (maternal origin effect) and nest temperature (nest effect) in multiple regression analysis, we found maternal origin had a greater influence than nest temperature on the morphological attributes of hatchling mass and carapace size, but nest temperature had a greater influence than maternal origin on the performance attributes of self-righting time, self-righting propensity, swim thrust during the first 30 min of swimming, and power stroke rate during the first 30 min of swimming.  相似文献   

12.
Using four dynamic criteria, the following environmental changes were evaluated: Global warming; destruction, of the stratospheric ozone layer; eutrophication and acidification of aquatic ecosystems; photochemical smog; reduction of the available area of agricultural soils; loss of species diversity; consumption of resources; reduction of crop yield; forest decline; noise, and smell. These ecosystem changes, or negative effects, were characterized by four dynamic criteria: 1) Regional importance, 2) extent of alteration, 3) resilience and 4) irreversibility. A multi-criteria assessment, accounting simultaneously for all four criteria, requires a generalized concept of order. Here, the concept of partially ordered sets, visualized by Hasse diagrams, was used to derive a priority list of environmental changes. Highest priority was equally assigned to the loss of species diversity, the consumption of resources and the destruction of the ozone layer. However, these ecosystem changes are incomparable to each other concerning the four criteria used and thus require different management strategies.  相似文献   

13.
We estimated for the first time the growth rates of loggerhead sea turtles of Mediterranean and of Atlantic origin found in the Mediterranean Sea, combining both skeletochronological and genetic analyses. Our growth models suggested that the growth rate of loggerhead sea turtles of Mediterranean origin was faster than that of their conspecifics with an Atlantic origin exploiting the feeding grounds in the Mediterranean Sea. The age at maturity for Mediterranean origin loggerhead sea turtles, estimated using our best fitting model, was 24 years, which suggests that loggerhead sea turtles nesting in the Mediterranean are not only smaller than those nesting in the western North Atlantic but also younger.  相似文献   

14.
Summary The research addressed two questions: (1) doIguana iguana hatchlings recognize their kin, and (2) what are the recognition mechanisms? Eggs were collected from wild and captive-raised females and hatched in semi-natural incubators. In the first experiment we used eggs from two females. One of the clutches was subdivided to be placed in different incubators. Immediately after emergence one of these hatchling groups was introduced into a 10 m x 10 m enclosure. At the same time we introduced hatchlings from another female. The remaining hatchling group was kept separate for 3 weeks and was then introduced into the same cage. Unrelated hatchlings separated from each other. Related but separated hatchlings grouped according to introduction date. In the second experiment we maintained eight kin groups in individual cages and two hatchlings per kin group in an additonal cage. Hatchlings from the mixed group showed no preference for their kin before physical contact with pure kin groups had occurred. After physical contact hatchling recognized their kin by feces smell. Body odor is likely to be also involved.  相似文献   

15.
Amphipods are analysed as one of the main food components of the flatfishes: Verecundum rasile, Etropus longimanus and Simphurus jenynsi. The fish were caught on the continental shelf of south Brazil and north Uruguay. V. rasile, E. longimanus and S. jenynsi ingested respectively: 19, 17 and 8 species from a total of 29 species. Only Ampelisca panamensis, Liljeborgia quinquedentata and Pseudharpinia dentata were common prey for the three fishes. Amphipoda species were consumed in a different way by the fishes in terms of percent composition. V. rasile is an infaunal feeder, while E. longimanus is epifaunal. An equal percentage of epifaunal and infaunal species found in S. jenynsi revealed a non-preference, probably due to its characteristics of smell and touch feeders.Contribution no. 506 of the Instituto Oceanográfico, Universidade de São Paulo, Brazil  相似文献   

16.
Summary Homing pigeons were displaced and kept until they were released in airtight containers ventilated with environmental air that could be passed through: (a) a filter made of fiberglass paper retaining large portions of the solid and liquid aerosol particles, (b) an additional filter consisting of activated charcoal, or (c) no filter (controls). Before its release, each bird was taken out of the container, and its olfactory epithelium was immediately anesthetized by lidocaine (Xylocaine). Thus, neither experimentals nor controls were able to smell while their initial orientation behavior was being observed.The controls' initial bearings were better homeward-oriented than those of pigeons ventilated with charcoal-filtered air in 14 of 17 releases conducted in Italy and Germany, at distances of 24–155 km. In the final analysis, the bearings of the charcoal-filter birds did not show any relation to the direction toward home, whereas those of the controls did. Pigeons ventilated with air that had passed through only the paper filter did not behave noticeably differently from control pigeons.It is concluded that the material bases of olfactory navigation in pigeons are substances dispersed in the atmosphere, most probably in a molecular state.  相似文献   

17.
The phenotype of social animals can be influenced by genetic, maternal and environmental effects, which include social interactions during development. In social insects, the social environment and genetic origin of brood can each influence a whole suite of traits, from individual size to caste differentiation. Here, we investigate to which degree the social environment during development affects the survival and fungal resistance of ant brood of known maternal origin. We manipulated one component of the social environment, the worker/brood ratio, of brood originating from single queens of Formica selysi. We monitored the survival of brood and measured the head size and ability to resist the entomopathogenic fungus Beauveria bassiana of the resulting callow workers. The worker/brood ratio and origin of eggs affected the survival and maturation time of the brood and the size of the resulting callow workers. The survival of the callow workers varied greatly according to their origin, both in controls and when challenged with B. bassiana. However, there was no interaction between the fungal challenge and either the worker/brood ratio or origin of eggs, suggesting that these factors did not affect parasite resistance in the conditions tested. Overall, the social conditions during brood rearing and the origin of eggs had a strong impact on brood traits that are important for fitness. We detected a surprisingly large amount of variation among queens in the survival of their brood reared in standard queenless conditions, which calls for further studies on genetic, maternal and social effects influencing brood development in the social insects.  相似文献   

18.
Summary By means of training flights (mostly flock releases), two groups of young homing pigeons were made familar with a larger area asymmetrically extending from the loft toward SW and NE, respectively. Thereafter, birds of both groups were released within each of the training areas with which one sort of birds was familiar (F+), the other unfamiliar (F-). Even the F+ pigeons had never been released at the test site itself (nearest previous release 10 km apart). Half of each group was allowed to smell environmental odors (O+); the other half breathed charcoal-filtered air during transportation and at the release site until a few minutes before release when they were deprived of olfaction by intranasal application of Xylocain (O-). The two test sites were 53 km distant from home. There was little difference in initial orientation as well as in homing performance between pigeons that were allowed to smell natural air and were familiar with the area (F+O+) and those that were privileged in only one respect (F+O- and F-O+). Yet if none of the preconditions was met (F-O-), performances were drastically reduced. The findings show that pigeons make use of two independent homing methods, olfactory navigation (presumably based on a navigational map) and non-olfactory pilotage (presumably based on a topographical map). The latter method is restricted to a more or less familiar area determined by individual experience. Its boundaries are poorly defined and can be estimated by the experimenter only in rough approximation. Within this area, the homing system takes advantage of more or less redundant inputs. Outside of it, olfactory information seems indispensable.  相似文献   

19.
Petrels and albatrosses evolved well-developed olfactory anatomical structures comparable to those of mammals. To date it has been demonstrated that petrels are attracted by food-related odours, and that some hypogean species have decreased homing performances if anosmic. The ability to distinguish between familiar and unfamiliar odours had not been demonstrated. Here we show that the Antarctic prion, Pachyptila desolata, is able to distinguish between its own nest and that of a conspecific, relying on olfactory cues only. When tested in a maze, only prions with an intact sense of smell made a choice and recognized their own burrow whereas anosmic birds did not. In the absence of leading odours in the maze prions behaved similarly to anosmic birds. These results suggest the mechanism used in the short-range homing process of this species as an olfactory beaconing and suggest the skill of recognising individually distinctive odours. Evolving an efficient identification system in the dark allowed these hypogean petrels to return to their colony at night and recognise their own burrow without singing. This behaviour protects them from predation by skuas, Catharacta skua lönnbergi, that hunt petrels by vision and hearing.  相似文献   

20.
居民点地名起源分类法——以茂名市各个镇为例   总被引:1,自引:0,他引:1  
地名是人们日常提及最多、使用最多的词语之一,对我们的日常生活、社会活动和经济活动都重要的影响.每个地名都有它产生的过程,认识地名的起源,对研究一个地区的文化有重要的意义.地名起源是地名研究的重要部分,以往的地名起源分类多以概括性为主,缺少系统的分类方法.该研究从地理要素的角度,将居民点地名起源其分化为自然环境、人文和经济社会三个一级类,二十七个二级分类,自然环境分类又划分了三级和四级分类.根据这一分类方法,以茂名市各个镇的地名为例,将居民点地名分类法运用到区域地名的研究中,并阐述其分类过程中的一些基本原则.  相似文献   

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