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排序方式: 共有230条查询结果,搜索用时 15 毫秒
41.
Martin F. Breed Michael G. Stead Kym M. Ottewell Michael G. Gardner Andrew J. Lowe 《Conservation Genetics》2013,14(1):1-10
Revegetation is one practical application of science that should ideally aim to combine ecology with evolution to maximise biodiversity and ecosystem outcomes. The strict use of locally sourced seed in revegetation programs is widespread and is based on the expectation that populations are locally adapted. This practice does not fully integrate two global drivers of ecosystem change and biodiversity loss: habitat fragmentation and climate change. Here, we suggest amendments to existing strategies combined with a review of alternative seed-sourcing strategies that propose to mitigate against these drivers. We present a provenancing selection guide based on confidence surrounding climate change distribution modelling and data on population genetic and/or environmental differences between populations. Revegetation practices will benefit from greater integration of current scientific developments and establishment of more long-term experiments is key to improving the long-term success. The rapid growth in carbon and biodiversity markets creates a favourable economic climate to achieve these outcomes. 相似文献
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Plant Cell, Tissue and Organ Culture (PCTOC) - 相似文献
44.
Pollination-induced flower senescence: a review 总被引:11,自引:0,他引:11
A. D. Stead 《Plant Growth Regulation》1992,11(1):13-20
Ethylene has long been implicated in the control of the senescence of many cut flower species, but the control of senescence in relation to wild species has received much less attention. The longevity of individual flowers varies greatly from species to species; in some each flower is open for just a few hours, whilst in others the flower may persist for several weeks, or even months. The functional life of the flower may be terminated by petal wilting, abscission or a colour change of all, or part, of the perianth. In some species pollination appears to reduce floral longevity whilst in others, particularly those species having short-lived flowers, the pattern of flower development and senescence appears unaffected by pollination.Examples of the various pollination-induced strategies shown by plants are presented and the role of ethylene and other potential mediators of senescence in these processes discussed. 相似文献
45.
Mobility and emplacement in north coast Papua New Guinea: Worlding the Pacific Marine Industrial Zone
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Victoria Stead 《The Australian journal of anthropology》2016,27(1):30-48
On the north coast of Papua New Guinea, the construction of the Pacific Marine Industrial Zone is catalysing movements of people, capital and things, as well as of the ideas and imaginings which accompany and make them meaningful. Drawn from literary and postcolonial studies, the concept of worlding offers a narrative framework through which to think through these movements and the ways in which they complicate prevailing narratives of globalisation. At the Pacific Marine Industrial Zone, the neoliberal worldings that inform the project do not simply catalyse movements, but also act to impose barriers to movement. Local communities assert connection to place, but also generate new circuits of mobility, and rearticulate ideas of kastom (custom) that have movement at their core. An emphasis on worlding—drawing particularly on Heidegger's distinction between world and earth—allows for a more complex reflection on the relationship between mobility and emplacement, one that more fully illuminates the complexity of the relationship itself, and the way it is experienced at the PMIZ site. 相似文献
46.
The reaction of phosphoglycolipids and other lipids with hydrofluoric acid 总被引:1,自引:0,他引:1
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1. The use of HF as a dephosphorylating reagent for phospholipids was examined. 2. Hydrolysis of phosphatidylethanolamine at 0 degrees C for 24h with 60% HF gives a good yield of diglyceride. Under similar conditions phosphatidyldiglucosyl diglyceride gives diglyceride and diglucosyl diglyceride. 3. The glycolipid is also obtained from hydrolysis of glycerylphosphoryldiglucosyl diglyceride. No lyso derivative of the glycolipid could be detected and the glycosidic linkage was also stable. 4. Triglycerides, unsaturated and cyclopropane fatty acids were unaffected by the reagent. 5. 1,2-Diglycerides and 1,3-diglycerides were partially isomerized and also gave small amounts of free fatty acid and monoglyceride. 6. Monoglycerides underwent extensive rearrangement to form 1,2- and 1,3-diglycerides. 7. Lysophosphatidylethanolamine also gave 1,2- and 1,3-diglycerides as well as monoglycerides. 8. The application of this procedure to the structure determination of various phosphoglycolipids is discussed. 相似文献
47.
A major characteristic of cystic fibrosis (CF) is the progressive degeneration of acinar cells in the pancreas. It is now well established that the normal pancreas contains an abundant amount of an [3H]estradiol-binding protein. Although the physiological function of this protein is unknown, available evidence suggests that it modulates resting secretion from acinar cells. Analysis of pancreatic autopsy samples from 13 patients who had CF demonstrated a high degree of correlation between loss of acinar cells and loss of [3H]estradiol-binding activity. Autopsy samples taken from individuals unaffected by CF contained large amounts of the [3H]estradiol-binding protein that were significantly correlated with the tissue content of amylase. This biological model demonstrates that the [3H]estradiol-binding protein in pancreas is localized primarily within acinar cells. Based on the presumed regulatory role this protein has on pancreatic secretion, an hypothesis is offered to account for acinar cell degeneration in individuals suffering from cystic fibrosis. 相似文献
48.
C G Liddle J P Putnam O L Lewter J Y Lewis B Bell M W West A Stead 《Bioelectromagnetics》1986,7(1):101-105
Eight cross spiders (Araneus diadematus) were exposed overnight (16 h) during web-building activity to pulsed 9.6-GHz microwaves at average power densities of 10, 1, and 0.1 mW/cm2 (estimated SARs 40, 4, and 0.4 mW/g). Under these conditions, 9.6-GHz pulsed microwaves did not affect the web-spinning ability of the cross spider. 相似文献
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For a number of years, investigators have recognized that humans potentially are exposed to large numbers of genotoxicants. Many efforts have attempted to validate various short-term bioassays for use as rapid, inexpensive screens for genotoxicants--especially carcinogens. In this analysis, we examine Salmonella mutagenicity as an indicator of potential carcinogenicity by comparing published (and when possible, evaluated) Salmonella results with the evaluated Gene-Tox animal carcinogen data base. The Salmonella bioassay does especially well in those cases where the level of evidence for carcinogenicity is the strongest. Analysis shows that except for specific classes of compounds, the plate-incorporation protocol and the preincubation protocol are equally efficient at detecting mutagens. This paper also demonstrates how validation values (sensitivity, specificity, etc.) vary with chemical class. Overall, this analysis demonstrates that when used and interpreted in a meaningful chemical class context, the Salmonella bioassay remains extremely useful in identifying potential animal carcinogens. 相似文献