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Conservation In vitro of threatened plants—Progress in the past decade   总被引:1,自引:0,他引:1  
Summary In vitro techniques have found increasing use in the conservation of threatened plants in recent years and this trend is likely to continue as more species face risk of extinction. The Micropropagation Unit at Royal Botanic Gardens, Kew, UK (RBG Kew) has an extensive collection of in vitro plants including many threatened species from throughout the world. The long history of the unit and the range of plants cultured have enabled considerable expertise to be amassed in identifying the problems and developing experimental strategies for propagation and conservation of threatened plants. While a large body of knowledge is available on the in vitro culture of plants, there are limited publications relating to threatened plant conservation. This review highlights the progress in in vitro culture and conservation of threatened plants in the past decade (1995–2005) and suggests future research directions. Works on non-threatened plants are also included wherever methods have applications in rare plant conservation. Recalcitrant plant materials collected from the wild or ex situ collections are difficult to grow in culture. Different methods of sterilization and other treatments to establish clean material for culture initiation are reviewed. Application of different culture methods for multiplication, and use of unconventional materials for rooting and transplantation are reviewed. As the available plant material for culture initiation is scarce and in many cases associated with inherent problems such as low viability and endogenous contamination, reliable protocols on multiplication, rooting, and storage methods are very important. In this context, photoautotrophic micropropagation has the potential for development as a routine method for the in vitro conservation of endangered plants. Long-term storage of material in culture is challenging and the potential applications of cryopreservation are significant in this area. Future conservation biotechnology research and its applications must be aimed at conserving highly threatened, mainly endemic, plants from conservation hotspots.  相似文献   

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Tourism accounts for 9% of global GDP and comprises 1.1 billion tourist arrivals per annum. Visits to wildlife tourist attractions (WTAs) may account for 20–40% of global tourism, but no studies have audited the diversity of WTAs and their impacts on the conservation status and welfare of subject animals. We scored these impacts for 24 types of WTA, visited by 3.6–6 million tourists per year, and compared our scores to tourists’ feedback on TripAdvisor. Six WTA types (impacting 1,500–13,000 individual animals) had net positive conservation/welfare impacts, but 14 (120,000–340,000 individuals) had negative conservation impacts and 18 (230,000–550,000 individuals) had negative welfare impacts. Despite these figures only 7.8% of all tourist feedback on these WTAs was negative due to conservation/welfare concerns. We demonstrate that WTAs have substantial negative effects that are unrecognised by the majority of tourists, suggesting an urgent need for tourist education and regulation of WTAs worldwide.  相似文献   

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Background

The emerging submucosal tunneling and endoscopic resection (STER) technique provides definitive histological diagnosis as well as a therapeutic method for the gastric submucosal tumors (SMTs). We aim to present our experience and discuss key technical issues of STER.

Methods

45 patients with gastric SMTs arising from MP received STER. First, a mucosal incision was made 3cm proximal to the tumour, a submucosal tunnel was subsequently built from the incision to the tumor. The tumor was gradually exposed and dissected from surrounding tissue and retrieved from the tunnel. The initial mucosal incision was closed by metal clips. For SMTs in the gastric fundus near cardia, the submucosal tunnel was built from lower esophagus, through the angle of His, to the tumor for resection.

Results

STER was successfully performed in 43 patients; the other two were converted to surgery. Mean operating time was 79.3min (range 45–150min). Mean tumor size was 1.4cm (range 0.5–5cm). Of the total 47 resected SMTs, 36 were GISTs, 10 were leiomyomas and 1 was schwannoma. Complete resection was achieved in all patients. Intra-procedural peumoperitoneum occurred in 3 cases because of iatrogenic perforation, no special treatment was given. 7 patients presented with mild abdominal pain/distention and fever were given antibotics. No severe post-operative complication happened. No tumor recurrence occurred in the median 11 month follow-up period.

Conclusion

Based on short-term follow-up observation, STER is a feasible, safe and minimally invasive method for the diagnosis and treatment of small (<3cm) SMTs in gastric body, antrum and proximal cardia.  相似文献   

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The uniformitarian principle is one of the most important foundations of all dendro- and paleo-sciences. Without it, no inferences about the past can be made. However, the use of this principle in our community is not consistent and partially incorrect, with the main confusion relating to the understanding of the “uniformitarian principle” as somehow implying a stable relationship between climate and tree growth. To solve this, we look briefly at the history of the term, show how we teach this principle in our textbooks, give some examples of incorrect applications of this principle in the recent literature and close with a simple, logical and straightforward interpretation of this principle to the dendro-community. Applying the principle of aggregate tree growth we show that instable climate-growth relationships and the “no-analogue problem” are not a violation of the uniformitarian principle, but rather reflect our incomplete understanding of tree growth processes. Simply stated: The “uniformitarian principle” is an a priori assumption of spatial and temporal invariance of law’s describing nature’s processes. Applied to the dendro-sciences it means that the principle of aggregate tree growth is valid in time and space.  相似文献   

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Tools for Living is a concept which regards a technical aid for a disabled individual as being no different in principle from a tool which allows a normal individual to carry out a task for which his intrinsic biological equipment is inadequate.Acceptance of this concept would change the status, mechanism for provision and attitude towards technical aids, in a direction which would lower the barriers against personal acceptance, particularly in the elderly. It is forecast that the production of ‘tools’ specifically devised to compensate for the performance decrements in the elderly could become an important new branch of industry.  相似文献   

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Effective task switching is supported by the inhibition of the just executed task, so that potential interference from previously executed tasks is adaptively counteracted. This inhibitory mechanism, named Backward Inhibition (BI), has been inferred from the finding that switching back to a recently executed task (A-B-A task sequence) is harder than switching back to a less recently executed task (C-B-A task sequence). Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material. To address this issue, a group of individuals with Williams syndrome (WS) characterized by specific difficulties in maintaining and processing visuo-spatial, but not verbal, information, and a mental age- and gender-matched group of typically developing (TD) children were subjected to three task-switching experiments requiring verbal or visuo-spatial material to be processed. Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching. Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture.  相似文献   

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This Fifth Progress Report is to be printed in three parts in California Medicine. Following the appearance of Part III the report will be bound in a pamphlet which may be ordered at $1 a copy from 693 Sutter Publications, Inc., 693 Sutter Street, San Francisco, California 94102.  相似文献   

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This Fifth Progress Report is being printed in three parts in California Medicine. Following the appearance of Part III the report will be bound in a pamphlet which may be ordered at $1 a copy from 693 Sutter Publications, Inc., 693 Sutter Street, San Francisco, California 94102.  相似文献   

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Melipona capixaba, popularly known as “uruçu preta”, is a stingless bee restricted to the mountainous Atlantic Rainforest areas of Espírito Santo State, Brazil. Due to the endemism and small population size, this species discovered in 1994 is now considered “vulnerable to extinction”. Using ISSR, PCR–RFLP and microsatellites markers, we studied the genetic variability and structure of M. capixaba from 88 colonies collected throughout the distribution area of the species within Espírito Santo State. The microsatellite, ISSR and mitochondrial haplotype analyses showed that M. capixaba has low genetic variability compared to other insect species. The molecular analyses also indicated a high genetic similarity among the M. capixaba samples, with no clear pattern of structuring. The analyses of molecular variance results indicated that most of the total genetic variation in M. capixaba was explained by the genetic diversity within local populations. Results suggest that the analyzed samples could be treated as a single population for preservation purposes. Thus, given its endemism, local adaptation and low number of natural colonies, efforts for the conservation of M. capixaba should focus on preservation and increasing the number of colonies in the wild, so that M. capixaba can support constant captures and the effects of habitat deforestation in Espírito Santo State.  相似文献   

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<正>On the day of Oct.6,2014,John O’Keefe and a Norwegian couple May-Britt Moser and Edvard Moser won the Nobel Prize in Physiology or Medicine for discovering the"inner GPS"that functions in the brain when the animals navigate through the world.The prize was awarded for their work in identifying the cells that make up the positioning system in the mammalian brain.  相似文献   

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Fourier Transform Infrared Radiation (FTIR) spectroscopy is one of the most powerful methods for the detection of gaseous constituents, aerosols, and dust in planetary atmospheres. Infrared spectroscopy plays an important role in searching for biomarkers, organics and biological substances in the Universe. The possibility of detection and identifications with FTIR spectrometer of bio-aerosol spores (Bacillus atrophaeus var. globigii=BG) in the atmosphere is discussed in this paper. We describe the results of initial spectral measurements performed in the laboratory and in the field. The purpose of these experiments was to detect and to identify bio-aerosol spores in two conditions: 1) In a closed chamber where the thermal contrast between the background and aerosols was large, and 2) In open air where the thermal contrast between the background and aerosols was small. The extinction spectrum of BG spores was deduced by comparing our measurements with models, and other measurements known from the literature. Our theoretical and experimental studies indicate that, during passive remote sensing measurements, it is difficult-but possible to detect and to identify bio-aerosol clouds by their spectral signatures. The simple spectral analysis described in the paper can be useful for the detection of various kinds of trace aerosols-not only in the Earth's atmosphere, but also during planetary missions in the environments of other astronomical objects such as planets, comets etc. We expect that the interpretation of data from spectrometric sounding of Venus and Mars during the current missions Mars and Venus Express, and later during the Rosetta mission will benefit from our experimental work and numerical modelling.  相似文献   

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Myelography using pantopaque in greater than usual amount with a variation in technique, which is described, is believed to provide increased accuracy in differential diagnosis and precise localization of lesions in the lumbar spine. The need for multiple space exploration is eliminated and more detailed information concerning the size and shape of lesions is provided as compared to that secured by the use of 3 or 6 cc. of opaque medium and fluoroscopic examination alone. In 53 cases in which lumbar myelography was performed and the diagnosis verified or disproved at operation, there was a 5 per cent diagnostic error in 41 instances in which the method outlined was used, as compared with 17 per cent error in 12 cases in which only 3 or 6 cc. of radiopaque material and fluoroscopy alone were used. The accuracy of the procedure would appear to warrant its use in the evaluation of patients suspected of having abnormalities of the lumbar discs associated with nerve root compression.  相似文献   

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This Fifth Progress Report is being printed in three parts in California Medicine. Following the appearance of Part III the report will be bound in a pamphlet which may be ordered at $1 a copy from 693 Sutter Publications, Inc., 693 Sutter Street, San Francisco, California 94102.  相似文献   

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