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Fresh embryos resulting from in vitro fertilization, including many of poor quality, can provide sources of human embryonic stem cell lines. We consider why some donate such embryos for this research, address relevant ethical and policy issues, and present core guidelines for fresh embryo donation based on those of Canada.  相似文献   

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The use of the Monsanto draft rice genome sequence in research   总被引:21,自引:0,他引:21  
Barry GF 《Plant physiology》2001,125(3):1164-1165
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Colin AM Semple 《Genome biology》2001,2(6):reviews2001.1-reviews20016
The volume of human genome sequence and the variety of web-based tools to access it continue to grow at an impressive rate, but a working knowledge of certain key resources can be sufficient to get the most from your genome. This article provides an update to Genome Biology 2000, 1(4):reviews2001.1-2001.5.  相似文献   

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A study designed to identify the principal determinants of use of inpatient facilities in NHS hospitals in England used the data and methods outlined in the previous paper. The model for the psychiatric sector contains mortality, self reported morbidity, and social variables indicating deprivation and the level of care at home. The non-acute model contains mortality and several socioeconomic variables. The models lay less weight on age than the current formula, and a national formula based on these models would, in the acute sector, redistribute resources to poorer areas compared with the current formula.  相似文献   

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The dramatic increase in yields of agricultural crops over the last 40 years in developed countries has been attributed equally to improved genetic components and improved agronomic practices. The success of plant breeding is based partly on an increased understanding of the parameters involved, to a great extent on improved and more efficient methods of selection, to greater use of available genetic diversity and also to advances in a number of related disciplines including plant pathology, biochemistry, agronomy and genetics. Successes and problems associated with using various genetic resources in plant breeding are illustrated with examples from some of the world's major crops, including potatoes, barley and cotton.  相似文献   

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Semple C 《Genome biology》2000,1(4):reviews2001.1-reviews20015
Much is expected of the draft human genome sequence, and yet there is no central resource to host the plethora of sequence and mapping information available. Consequently, finding the most useful and reliable human genome data and resources currently available on the web can be challenging, but is not impossible.  相似文献   

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Tax levels have important effects on cigarette prices and tax revenues. Over 70p of every pound spent on tobacco goes to the Chancellor of the Exchequer, yielding over 5 billion pounds. But the value of tobacco tax revenues have generally fallen--by 1986 they were 10% lower than at their peak in 1965, and tobacco revenue is becoming a smaller proportion of total tax receipts. The impact of a consistent increase in tobacco taxation is important in terms of reduced consumption (and harm to health) as well as in terms of reduced employment. Revenue may, however, increase in the short term. Finally, if the findings of Townsend and Atkinson et al (see above) still apply then the distributive effects of increased taxation on the poor might be less than is sometimes feared.  相似文献   

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The final article in the series considers the ways in which the methods described previously are used in the formation of policy. When health authorities are making decisions about how to spend their money they have to draw on several sources of information about priorities: diktats from policy makers, opinions of consumers and of the professional bodies involved, and evidence gained from research. They must also consider the various methods of costing and select the right one for their circumstances. Some of these methods are still in the early stages of development, but more are being developed all the time and they have a valuable role in helping decision making throughout the NHS.  相似文献   

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Aiming to estimate the rate of exploitation of the floral resources of Sparattosperma leucanthum (Vell.) K. Schum. as well as the interaction with their floral visitors in the pollination, the number of visits by flower was sampled, according to the type of visitation, the collected resource and the visitor's behavior during the forage for flowers. The floral visitors were grouped into seven guilds, organized in decreasing order of benefit to the S. leucanthum flower's pollination: effective pollinator, occasional pollinator, endogamic pollinator, generalist visitor, thievery visitor, thievery-pillager ant and pillager visitor. The total of 48.2 +/- 8.84 visits were recorded by flower. Nearly 50% of the visits resulted in nectar thief or pillage, which posed some problems to the reproduction of S. leucanthum, such as the drop in the attractiveness to pollinators and the harm to the flower's reproductive tissues. Trigona spinipes (Fabr.) (Hymenoptera: Apidae) was considered the most harmful species owing to the high frequency of pillage and forage. Bombus sp1, however, was probably the species that pollinated S. lecanthum flowers the most, making use of the crossed pollination.  相似文献   

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The nutritional and food safety characteristics of the foods customarily eaten by infants and mothers in The Gambia are discussed. Special emphasis is placed on their low energy and nutrient density and the consequent difficulty of meeting internationally recommended levels of intake. The consequences of an inadequate diet during pregnancy and lactation are considered in terms of their effect on the size of the baby at birth, the mother's lactational performance, and the growth and development of the baby. The microbiological contamination of locally introduced weaning foods is also highlighted. Suggestions are made concerning the desirable characteristics of new foods that need to be introduced to overcome these problems. Attention is paid to a more rational distribution and use for aid foods.  相似文献   

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Background

The tephritid fruit flies include a number of economically important pests of horticulture, with a large accumulated body of research on their biology and control. Amongst the Tephritidae, the genus Bactrocera, containing over 400 species, presents various species groups of potential utility for genetic studies of speciation, behaviour or pest control. In Australia, there exists a triad of closely-related, sympatric Bactrocera species which do not mate in the wild but which, despite distinct morphologies and behaviours, can be force-mated in the laboratory to produce fertile hybrid offspring. To exploit the opportunities offered by genomics, such as the efficient identification of genetic loci central to pest behaviour and to the earliest stages of speciation, investigators require genomic resources for future investigations.

Results

We produced a draft de novo genome assembly of Australia’s major tephritid pest species, Bactrocera tryoni. The male genome (650 -700 Mbp) includes approximately 150Mb of interspersed repetitive DNA sequences and 60Mb of satellite DNA. Assessment using conserved core eukaryotic sequences indicated 98% completeness. Over 16,000 MAKER-derived gene models showed a large degree of overlap with other Dipteran reference genomes. The sequence of the ribosomal RNA transcribed unit was also determined. Unscaffolded assemblies of B. neohumeralis and B. jarvisi were then produced; comparison with B. tryoni showed that the species are more closely related than any Drosophila species pair. The similarity of the genomes was exploited to identify 4924 potentially diagnostic indels between the species, all of which occur in non-coding regions.

Conclusions

This first draft B. tryoni genome resembles other dipteran genomes in terms of size and putative coding sequences. For all three species included in this study, we have identified a comprehensive set of non-redundant repetitive sequences, including the ribosomal RNA unit, and have quantified the major satellite DNA families. These genetic resources will facilitate the further investigations of genetic mechanisms responsible for the behavioural and morphological differences between these three species and other tephritids. We have also shown how whole genome sequence data can be used to generate simple diagnostic tests between very closely-related species where only one of the species is scaffolded.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1153) contains supplementary material, which is available to authorized users.  相似文献   

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