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蛋白质组学是旨在研究蛋白质表达谱和蛋白质与蛋白质之间相互作用的新的领域。蛋白质组学的研究必须依赖高通量、自动化程度很高的技术。双向电泳、液相色谱和生物质谱技术的发展推动了蛋白质组学的研究。蛋白质组学为疾病发病机制的研究提供了新的思路和方法 ,本文重点介绍了蛋白质组学技术在心血管疾病研究中的应用 相似文献
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蛋白质组学是以基因组编码的所有蛋白为研究对象,高通量地从细胞及整体水平上研究蛋白质的组成及其功能的新兴学科。在后基因组时代的今天,蛋白质组学的研究正逐渐深入到生命科学的各个领域,21世纪蛋白质组学将成为生命科学中最热门的学科。蛋白质组分析已成为鉴定植物功能的有力工具之一,叶绿体作为比较重要的细胞器,在植物蛋白质组学中已有较多的研究,,随着双向电泳技术的改进和质谱法的出现,并与不断增多的拟南芥、水稻、玉米等植物的序列数据相结合,叶绿体蛋白质组可以被快速鉴定。本文主要介绍了植物蛋白质组学、叶绿体及其蛋白质组学研究技术和研究进展,并对蛋白质组学的研究趋势进行了展望。 相似文献
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MICROBIAL COLONIZATION ON NATURAL AND ARTIFICIAL MACROPHYTES IN A PHOSPHORUS-LIMITED,HARDWATER LAKE1
Epiphyte communities in a phosphorus-limited hard-water lake were compared over a 14-week period from Potamogeton illinoensis and structurally similar artificial plants of different leaf ages. Artificial plants were serially incubated in the lake to simulate the age of natural leaves. The physiognomy of loosely attached epiphytes appeared similar on the two substrata. Algal cell number and biovolume were 15-fold and 17-fold higher, respectively, on artificial leaves early in the growing season, but total algal density gradually became similar on natural and artificial plants. In contrast, the taxonomic composition of loosely attached algae became increasingly distinct, and mean cell biovolume on natural leaves was twice that on artificial leaves. Adnate epiphytes on both substrata developed from sparse populations of bacteria on new leaves to a community of diatoms, blue-green algae and numerous bacteria on mature and senescent leaves. Adnate community succession on natural leaves in late senescence/death differed from that on artificial leaves colonized for comparable periods in having (1) a marked increase in filamentous blue-green algae, (2) a subsequent decrease in all algae, and (3) a final fungi-dominated stage. The trends in colonization indicate that macrophytes in this oligotrophic lake provided a distinct habitat from that of artificial substrata for epiphytes throughout the growing season. 相似文献
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1. We describe a generalized mainland-island metapopulation model which includes migration among the island populations. We test model predictions with quantitative data on more than 200 species of moths in two contrasting networks of small islands. The data include a direct measure of migration rate, based on trapping of moths on rocky skerries with no local populations of the vast majority of species.
2. We predicted that moths which are strong fliers but uncommon on the islands have a higher incidence on scattered islands than on islands in a group, because the latter 'compete' for immigrants from the mainland. In contrast, we predicted that weakly flying species with potentially large local populations on the islands occur more frequently on islands in a group due to enhanced colonization rate.
3. Both predicted patterns were observed. Island occupancy increased significantly with the number of individuals caught on the rocky skerries, which is our measure of migration rate from the mainland, supporting the basic assumption that the species occur on the islands in a balance between colonizations and extinctions.
4. These results demonstrate that the moth metapopulations on islands represent a mixture of Levins's and mainland-island metapopulations, and that the mixture is different for different species in the same landscape. 相似文献
2. We predicted that moths which are strong fliers but uncommon on the islands have a higher incidence on scattered islands than on islands in a group, because the latter 'compete' for immigrants from the mainland. In contrast, we predicted that weakly flying species with potentially large local populations on the islands occur more frequently on islands in a group due to enhanced colonization rate.
3. Both predicted patterns were observed. Island occupancy increased significantly with the number of individuals caught on the rocky skerries, which is our measure of migration rate from the mainland, supporting the basic assumption that the species occur on the islands in a balance between colonizations and extinctions.
4. These results demonstrate that the moth metapopulations on islands represent a mixture of Levins's and mainland-island metapopulations, and that the mixture is different for different species in the same landscape. 相似文献
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Plant cues influence searching behaviour and parasitism in the egg parasitoid Trichogramma nr. brassicae 总被引:1,自引:0,他引:1
Abstract. 1. The effect of experience of plant cues at emergence on searching behaviour and parasitism was investigated in two strains of Trichogramma nr. brassicae (Hymenoptera: Trichogrammatidae).
2. Wasps reared on Sitotroga cereallela were allowed to emerge on a tomato plant or in a vial, with or without food. For one of the strains, females emerging on tomato searched significantly longer on a tomato seedling than females emerging in a vial.
3. The experience effect lasted between 1 and 2 days. It involves associating plant stimuli with the remains of the host, because females emerging from their host on a tomato plant had an increased searching response to tomato, but females transferred to the plant immediately after emergence did not.
4. The effect of emergence environment on parasitism of the host Helicoverpa punctigera on tomato and lettuce seedlings was tested. Wasps were allowed to emerge on seedlings of tomato or lettuce, or in an empty vial. For one strain, females experienced with tomato at emergence parasitized significantly more hosts on tomato than did females emerging on lettuce or in a vial. Parasitism on lettuce was not influenced by the treatments. 相似文献
2. Wasps reared on Sitotroga cereallela were allowed to emerge on a tomato plant or in a vial, with or without food. For one of the strains, females emerging on tomato searched significantly longer on a tomato seedling than females emerging in a vial.
3. The experience effect lasted between 1 and 2 days. It involves associating plant stimuli with the remains of the host, because females emerging from their host on a tomato plant had an increased searching response to tomato, but females transferred to the plant immediately after emergence did not.
4. The effect of emergence environment on parasitism of the host Helicoverpa punctigera on tomato and lettuce seedlings was tested. Wasps were allowed to emerge on seedlings of tomato or lettuce, or in an empty vial. For one strain, females experienced with tomato at emergence parasitized significantly more hosts on tomato than did females emerging on lettuce or in a vial. Parasitism on lettuce was not influenced by the treatments. 相似文献
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Harold N. Bryant 《Biological journal of the Linnean Society. Linnean Society of London》1997,62(4):495-503
A phylogenetic definition of a taxon name associates that name with a clade through its reference to a particular ancestor and all of its descendants. Depending on one's perspective, phylogenetic definitions name either clades on the one true, but unknown, phylogeny, or components on cladograms (clades on hypotheses regarding the true phylogeny). Phylogenetic definitions do not contain enough information to identify components without a reference cladogram. As a result, (1) if clades are equated with components on cladograms, a phylogenetic definition may associate a taxon name with different clades on different cladograms, and (2) the inclusiveness, diagnostic synapomorphies, and distribution in time and space of the clade with a particular name can differ markedly depending on the phylogenetic hypothesis one chooses to adopt. This potentially unacceptable lability in the clade to which a name refers can be avoided by using a taxon name in conjunction with only phylogenetic hypotheses on which specific taxa are related in a particular fashion. This designated phylogenetic context can be described in an n-taxon statement that would be appended to the phylogenetic definition. Use of the taxon name would be considered inappropriate in conjunction with cladograms on which the relationships contradict those in the n-taxon statement. Whereas phylogenetic definitions stabilize the meaning of taxon names, designated phylogenetic contexts would stabilize the usage of those names. 相似文献
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Even though specific adjustments of the multi-joint control of posture have been observed when posture is challenged, multi-joint coordination on a seesaw device has never been accurately assessed. The current study was conducted in order to investigate the multi-joint coordination when subjects were standing on either a seesaw device or on a stable surface, with the eyes open or closed. Eighteen healthy active subjects were recruited. A principal component analysis and a Self-Organizing Maps analysis were performed on the joint angles in order to detect and characterize dominant coordination patterns. Intermuscular EMG coherence was analysed in order to assess the neurophysiological mechanisms associated with these coordination patterns. The results illustrated a multi-joint organization of posture on both stable ground and on the seesaw, with a higher variability among the individual postural responses observed when standing on the seesaw. These findings challenge the classical assumption of ankle mechanisms as dominating control on seesaw devices and confirm that inter-joint coordination in postural control is strongly modulated by stance conditions. When standing on the seesaw without vision, a decrease in intermuscular coherence was observed without any impact on the joint coordination patterns, likely due to an increase dependence on proprioceptive information. 相似文献
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Casey P. terHorst Steve R. Dudgeon 《Journal of experimental marine biology and ecology》2009,370(1-2):120-126
The role of disturbance in community ecology has been studied extensively and is thought to free resources and reset successional sequences at the local scale and create heterogeneity at the regional scale. Most studies have investigated effects on either the disturbed patch or on the entire community, but have generally ignored any effect of or on the community surrounding disturbed patches. We used marine fouling communities to examine the effect of a surrounding community on species abundance within a disturbed patch and the effect of a disturbance on species abundance in the surrounding community. We varied both the magnitude and pattern of disturbance on experimental settlement plates. Settlement plates were dominated by a non-native bryozoan, which may have established because of the large amount of initial space available on plates. Percent covers of species within the patch were affected by the surrounding community, confirming previous studies' predictions about edge effects from the surrounding community on dynamics within a patch. Disturbance resulted in lower percent cover in the surrounding community, but there were no differences between magnitudes or spatial patterns of disturbance. Disturbance lowered population growth rates in the surrounding community, possibly by altering the abiotic environment or species interactions. Following disturbance, the recovery of species within a patch may be affected by species in the surrounding community, but the effects of a disturbance can extend beyond the patch and alter abundances in the surrounding community. The dependence of patch dynamics on the surrounding community and the extended effects of disturbance on the surrounding community, suggest an important feedback of disturbance on patch dynamics indirectly via the surrounding community. 相似文献
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Andrew S. Pullin 《Journal of Insect Conservation》1997,1(3):177-185
This paper reports on studies of the habitat requirements of Lycaena dispar batavus in its largest remaining site, the Weerribben National Park in the Netherlands. Observations and experiments were carried out to assess requirements for male territories, egg-laying sites and larval survival. The management of the fenland was also assessed on a landscape scale. Male territories were all situated in summer cut fen meadow. Eggs were laid on Rumex hydrolapathum in a range of habitat situations, although a preference was shown for plants on fen edges. Larval survival was highest on plants on watersides and fen edges, with no survival on plants in summer cut fen meadow. The findings are discussed in relation to whether the Broadland area in eastern England is suitable as a re-establishment site. Although many elements of the habitat mosaic are present, at the landscape scale there is insufficient open fenland and areas suitable for male territories are probably too isolated; however, a fen restoration strategy is in place which may restore suitable habitat and make re-establishment feasible in the future. 相似文献
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Jan H. Mol 《Studies on Neotropical Fauna and Environment》2013,48(3):189-195
Piranhas have a reputation of being man‐eating fishes, notwithstanding the absence of well‐documented records of piranha attacks on human beings. Three sites in Suriname where piranha attacks on bathers have taken place are discussed. In two isolated villages on the Wayombo River, most victims were children. In one village, 30 piranha attacks occurred in a period of 12 years, bites were mostly on the feet, and injuries were relatively harmless. In the second village, attacks occurred in a period of 7 years, and injuries were more serious, including the loss of digits and large and deep wounds in legs, arms and trunk. Two victims were attacked by several piranhas simultaneously. At the third site, a recreation park on the Suriname River, most attacks involved a single bite on the feet and victims were able to walk back to the beach without being attacked by other piranhas. Piranha attacks on humans did not result in deaths. The recovery of a toe phalange (Wayombo River) and a piece of flesh including a nail (Suriname River) from the stomach of two piranhas identified the fish responsible for the attacks as Serrasalmus rhombeus. Attacks on humans by S. rhombeus were associated with high age 0+ piranha densities in the dry season, high human prey densities, commotion in the water by humans, and spillage of food, fish offal or blood in the water. 相似文献
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We discuss the strengths and weaknesses of the meta-analytic approach to estimating the effect of a new treatment on a true clinical outcome measure, T, from the effect of treatment on a surrogate response, S. The meta-analytic approach (see Daniels and Hughes (1997) 16, 1965-1982) uses data from a series of previous studies of interventions similar to the new treatment. The data are used to estimate relationships between summary measures of treatment effects on T and S that can be used to infer the magnitude of the effect of the new treatment on T from its effects on S. We extend the class of models to cover a broad range of applications in which the parameters define features of the marginal distribution of (T, S). We present a new bootstrap procedure to allow for the variability in estimating the distribution that governs the between-study variation. Ignoring this variability can lead to confidence intervals that are much too narrow. The meta-analytic approach relies on quite different data and assumptions than procedures that depend, for example, on the conditional independence, at the individual level, of treatment and T, given S (see Prentice (1989) 8, 431-440). Meta-analytic calculations in this paper can be used to determine whether a new study, based only on S, will yield estimates of the treatment effect on T that are precise enough to be useful. Compared to direct measurement on T, the meta-analytic approach has a number of limitations, including likely serious loss of precision and difficulties in defining the class of previous studies to be used to predict the effects on T for a new intervention. 相似文献
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Judgement post-stratification, which is based on ideas similar to those in ranked set sampling, relies on the ability of a ranker to forecast the ranks of potential observations on a set of units. In practice, the authors sometimes find it difficult to assign these ranks. This note shows how one can borrow techniques from the literature on finite population sampling to allow a probabilistic ranking of the units in a set, thus facilitating use of these sampling plans and improving estimation. The same techniques provide one approach to estimation using a judgement post-stratified sample with multiple rankers. The technique is illustrated on allometric data relating brain weight to body weight in different species of mammals, and on a study of student performance in graduate school. 相似文献