首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
美国与欧盟的转基因食品安全性政策演变比对   总被引:2,自引:0,他引:2  
随着转基因食品的研究与发展,人们对待转基因食品的态度表现为主要以美国和欧盟为主的两种代表性政策.美国采取遵循可靠科学原则,坚决反对预防原则,即对转基因食品采取积极支持,自愿标识的宽松政策;欧盟采取谨慎预防原则,必须标识和可追溯.从管理原则出发,结合相应采取的监管措施和相关条例,对两国从开始颁布转基因食品政策到当下态势的发展,并结合最新出台的政策进行跟踪分析,比对美国及欧盟对这些指令和条例的执行情况.  相似文献   

2.
This note summarizes the results of a consultation of scientific and regulatory experts in July 2005 on the potential of transgenic crops in Bangladesh. We find that Bangladeshi experts are optimistic on the potential of agricultural biotechnology to respond to biotic and abiotic stresses in their country in the future. Public research is constrained by human capacities, infrastructure and capital investment, and transgenic crop development will require the active involvement of outside partners, such as international organizations or collaboration with private companies. We also find that social acceptance of genetic engineering is not considered a major issue, but could become one, and prompted experts to call for a wider awareness campaign on the technology.This research project was conducted as part of the South Asia Biosafety Program (SABP), a project funded by the US Agency for International Development (USAID) and jointly managed by the International Food Policy Research Institute and AGBIOS Canada. The authors would like to thank the Bangladesh Agricultural Research Council and all the participants to the meetings in Dhaka and Mymensingh for their help.  相似文献   

3.
Safety Evaluation of Transgenic Tilapia with Accelerated Growth   总被引:2,自引:0,他引:2  
Recent advances in modern marine biotechnology have permitted the generation of new strains of economically important fish species through the transfer of growth hormone genes. These transgenic fish strains show improved growth performance and therefore constitute a better alternative for aquaculture programs. Recently, we have obtained a transgenic tilapia line with accelerated growth. However, before introducing this line into Cuban aquaculture, environmental and food safety assessment was required by national authorities. Experiments were performed to evaluate the behavior of transgenic tilapia in comparison to wild tilapia as a way to assess the environmental impact of introducing transgenic tilapia into Cuban aquaculture. Studies were also conducted to evaluate, according to the principle of substantial equivalence, the safety of consuming transgenic tilapia as food. Behavior studies showed that transgenic tilapia had a lower feeding motivation and dominance status than controls. Food safety assessment indicated that tilapia growth hormone has no biological activity when administered to nonhuman primates. Furthermore, no effects were detected in human healthy volunteers after the consumption of transgenic tilapia. These results showed, at least under the conditions found in Cuba, no environmental implications for the introduction of this transgenic tilapia line and the safety in the consumption of tiGH-transgenic tilapia as an alternative feeding source for humans. These results support the culture and consumption of these transgenic tilapia. Received: March 9, 1998; accepted June 25, 1998.  相似文献   

4.
The ‘precautionary principle’, as formulated in the 1992 Rio Declaration on Environ ment and Development, calls for regulatory action in the face of serious environmental risks even in the absence of full scientific certainty. This paper traces negotiation of the principle at the Rio Conference, and its history in Europe from 1969 Swedish legislation to the latest directives of the European Union. As illustrated by recent court cases from Germany and France, in particular (on nuclear power plants, electro magnetic fields, and genetically modified organisms), judicial interpretation of the principle has tended to be restrictive. Future law making in this field is likely to focus on public access to environmental risk information, and on the development of new ‘right to know’ instru ments such as mandatory product labelling and transnational pollutant release inven tories, an area where Europe can still learn from North American experience.  相似文献   

5.
In the French debate over genetically modified organisms (GMOs), actors present divergent definitions of food quality located between poles of technoscience and techne. Although scientists often define food quality in terms of technoscience, assessing food safety, small farmers often appeal to technes of production, positing GMOs as a rupture with artisanal culture. Whereas small farmers (from the union the Confédération Paysanne [CP]) deploy notions of "techne" to promote their anti-GMO campaign, they often define quality in an ambiguous way, vacillating between ideas of agricultural method (technique) or production scale. Despite this ambiguity, the CP successfully designates GMOs as la malbouffe , or "bad" food, establishing themselves as protectors of artisanal technés such as Roquefort. Finally, unlike many cultures that cast GMOs as "unnatural," the CP tends to frame GMOs as "uncultural." In the French debate, the CP posits culture against a "culturelessness" associated with technoscience and industry-driven foods such as GMOs and McDonald's.  相似文献   

6.
As an alternative to traditional semantic analysis using class-product logic ("Componential analysis"), it is proposed that the possibilities of analysis in terms of relative products be explored in appropriate lexical-taxonomic domains, particularly kinship. In such analyses the order of components is intrinsic to meaning. The process is illustrated by an analysis of American kinship terminology.  相似文献   

7.
Bacterial biofilms are notorious for their ability to protect bacteria from environmental challenges, most importantly the action of antibiotics. Bacillus subtilis is an extensively studied model organism used to understand the process of biofilm formation. A complex network of principal regulatory proteins including Spo0A, AbrB, AbbA, Abh, SinR, SinI, SlrR, and RemA, work in concert to transition B. subtilis from the free-swimming planktonic state to the biofilm state. In this review, we explore, connect, and summarize decades worth of structural and biochemical studies that have elucidated this protein signaling network. Since structure dictates function, unraveling aspects of protein molecular mechanisms will allow us to devise ways to exploit critical features of the biofilm regulatory pathway, such as possible therapeutic intervention. This review pools our current knowledge base of B. subtilis biofilm regulatory proteins and highlights potential therapeutic intervention points.  相似文献   

8.
Global, comparative gene expression analysis is potentially a very powerful tool in the safety assessment of transgenic plants since it allows for the detection of differences in gene expression patterns between a transgenic line and the mother variety. In the present study, we compared the gene expression profile in developing seeds of wild type wheat and wheat transformed for endosperm-specific expression of an Aspergillus fumigatus phytase. High-level expression of the phytase gene was ensured by codon modification towards the prevalent codon usage of wheat genes and by using the wheat 1DX5HMW glutenin promoter for driving transgene expression. A 9K wheat unigene cDNA microarray was produced from cDNA libraries prepared mainly from developing wheat seed. The arrays were hybridised to flourescently labelled cDNA prepared from developing seeds of the transgenic wheat line and the mother variety, Bobwhite, at three developmental stages. Comparisons and statistical analyses of the gene expression profiles of the transgenic line vs. that of the mother line revealed only slight differences at the three developmental stages. In the few cases where differential expression was indicated by the statistical analysis it was primarily genes that were strongly expressed over a shorter interval of seed development such as genes encoding storage proteins. Accordingly, we interpret these differences in gene expression levels to result from minor asynchrony in seed development between the transgenic line and the mother line. In support of this, real time PCR validation of results from selected genes at the late developmental stage could not confirm differential expression of these genes. We conclude that the expression of the codon-modified A.␣fumigatus phytase gene in the wheat seed had no significant effects on the overall gene expression patterns in the developing seed.  相似文献   

9.
This paper considers the workings of various kinds of 'capital' in the early lives of one cohort, the Class of '58 of a U.S. High School. Bourdieu's valuable concept of capital as both material and cultural/symbolic is augmented with the idea of 'psychological' capital, a concept meant to begin to fill a gap in Bourdieu's framework concerning the complexity of desires, intentions, and 'personalities' in acting subjects. The paper also tackles some problems of ethnographic and ethnohistorical representation, suggesting the value of an analogy with several sub-genres of documentary films.  相似文献   

10.
A full genome analysis of differences between the gene expression in the human and chimpanzee brains revealed that the gene for transthyretin, the carrier of thyroid hormones, is differently transcribed in the cerebella of these species. A 7-kbp DNA fragment of chimpanzee was sequenced to identify possible regulatory sequences responsible for the differences in expression. One hundred and thirteen substitutions were found in the chimpanzee sequence in comparison with the human sequence. About 40% of the substitutions were revealed within the repeating elements of the genome; their location and sizes did not differ from those in the corresponding fragments of the human genome, and the nucleotide sequences had a high degree of identity. A comparison of nucleotide sequences of the transthyretin region of human, chimpanzee, and mouse genes revealed substantial differences in the distribution of G + C content along the examined fragment in the human (chimpanzee) and mouse genes and allowed us to localize three sequence tracts with a higher degree of identity in the three species. One of these tracts was located in the promoter region of the gene, and the other two probably determine the specificity of transthyretin gene expression in the liver and brain. One of the conserved tracts of the chimpanzee genome was found to have a single and a triple nucleotide substitution. The triple substitution distinguishes chimpanzees from humans and mice, which have identical sequences of this site. It is likely that these substitutions are responsible for the differences in the expression levels of the transthyretin gene in the human and chimpanzee brains.  相似文献   

11.
12.
Zhu X  Cheng J  Huang L  Gao J  Zhang ZT  Pak J  Wu XR 《Transgenic research》2003,12(2):155-162
Tissue-specific expression of human genes and secretion of human proteins into the body fluids in transgenic animals provides an important means of manufacturing large-quantity and high-quality pharmaceuticals. The present study demonstrates using transgenic mice that a 3.0 kb promoter of the mouse Tamm-Horsfall protein (THP, or uromodulin) gene directs the specific expression of human growth hormone (hGH) gene in the kidney followed by the secretion of hGH protein into the urine. hGH expression was detected in renal tubules that actively produce the THP, that is, the ascending limb of Henle's loop and distal convoluted tubules. Up to 500 ng/ml of hGH was detected in the urine, and this level remained constant throughout the 10-month observation period. hGH was also detectable in the stomach epithelium and serum in two of the transgenic lines, suggesting position-dependent effects of the transgene and leakage of hGH from the site of synthesis into the bloodstream, respectively. These results indicate that the 3.0 kb mouse THP promoter is primarily kidney-specific and can be used to convert kidney into a bioreactor in transgenic animals to produce recombinant proteins. Given the capacity of urine production independent of age, sex and lactation, the ease of urinary protein purification, and the potentially distinct machinery for post-translational modifications in the kidney epithelial cells, the kidney-based transgenic bioreactor may offer unique opportunities for producing certain complex pharmaceuticals.  相似文献   

13.
14.
All adequately known post-Paleozoic asteroids are either assignable to surviving families or closely related families whereas no Paleozoic species assignable to a surviving order has been recognized. The Mississippian speciesCompsaster formosus is similar enough to various Recent taxa in overall form as well as in the form and arrangement of body wall ossicles to raise the issue of affinities: IsC. formosus nested within a phylogenetic branch hitherto known only from post-Paleozoic strata or is it only homeomorphic?The nature of the ambulacral system is critical to interpretation of echinoderms, and post-Paleozoic asteroids share three fundamental ambulacral characters or character suites: dorsal podial pores, staggered positioning of ambulacrals and adambulacrals, and complex articular structures between these two ossicular types.Calliasterella americana, a Carboniferous asteroid, shares the three ambulacral features, although it is distinctive from post-Paleozoic asteroids in other ways.Compsaster formosus exhibits at least two of the three ambulacral characters, although presence of staggering has not been finally established. LikeC. americana, C. formosus differs from post-Paleozoic species in details of ambulacral anatomy as well as aspects of ventral body surface ossicular arrangement. Although approaching crown-group organization,C. formosus nevertheless represents a branch basal to the crown group.Because asteroids are generalists, understanding of life habits ofCompsaster is sketchy in spite of morphological similarities between it and younger genera.Compsaster probably was epifaunal and its overall form is strongly reminiscent of that of Recent predatory asteriids but it is also similar to small-particle feeding echinasterids.  相似文献   

15.
Factors related to geography such as climate, natural resources or waterways often affect human activities. However, traditional approaches such as ordinary least squares (OLS) have limitations in investigating such patterns. Unlike OLS regression, geographically weighted regression (GWR) allows the coefficients of explanatory variables to differ by locality by giving relatively more weight to geographically close observations. GWR depicts spatial patterns. This paper examines the pattern of height and crude death rate in the United States prior to the Civil War by this method. The GWR results show that access to water transportation increased mortality and decreased stature in the food exporting areas of the Midwest, and the opposite pattern appeared in the food importing areas of the Northeast.  相似文献   

16.
The main objective of this work is the evaluation, by means of the finite element method (FEM) of the mechanical stability and long-term microstructural modifications in bone induced to three different kinds of fractures of the distal femur by three types of implants: the Condyle Plate, the less invasive stabilization system plate (LISS) and the distal femur nail (DFN). The displacement and the stress distributions both in bone and implants and the internal bone remodelling process after fracture and fixation are obtained and analysed by computational simulation. The main conclusions of this work are that distal femoral fractures can be treated correctly with the Condyle Plate, the LISS plate and the DFN. The stresses both in LISS and DFN implant are high especially around the screws. When respect to remodelling, the LISS produces an important resorption in the fractured region, while the other two implants do not strongly modify bone tissue microstructure.  相似文献   

17.
This paper suggests correlation characteristics for marked point processes with two marks for each point and describes statistical methods for their estimation. Its use is demonstrated by means of an example, where the points are locations of pine saplings, and the marks are their heights and ages. Furthermore, a soft-core point process model is presented. It is shown that a pattern of sites of beadlet anemones on a rock has a pair-correlation function and intensity which can be very well approximated by the model.  相似文献   

18.
In 2004, IUCN listed 20% of all mammals, 12% of birds and 4% of reptiles as threatened with extinction. Why are these species, but not the others in their clades, at risk? Most comparative studies of Red List status to date have investigated the relationship between status and life history or ecology, either at a local level where species face a given situation which may be known in detail, or at a global level where threats are much more heterogeneous. The use of data at a sub-global level raises several issues, including the need to assess populations across geopolitical borders and how best to treat non-breeding phases of populations. However, regional-level data provide the opportunity to look in more detail at how threatening processes operate. We employ comparative analysis using phylogenetically independent contrasts and multiple regression to control for inter-related and confounding independent variables, to evaluate correlates of regional threat for three groups of central Asian vertebrates. We find that aspects of dispersal, area of occupancy, body mass and generation time are important in predicting the perceived risk of regional extinction.  相似文献   

19.
Arabidopsis PsbQ, encoding a 16 kDa protein of the oxygen-evolving complex, is regulated by light and is expressed preferentially in leaf tissues. To analyze the components required for light-regulated and organ-specific expression of PsbQA, several promoter constructs were generated and expressed in tobacco. The 2.2 kb promoter could confer organ-specific expression of the reporter gene, whereas regulatory elements for light-dependent induction could not be located within this promoter and the transcribed region extending up to a second exon, represented by a genomic fragment encompassing the gene. The genomic fragment representing the transcribed region, however, could confer light regulation even on a constitutive promoter, as observed by steady-state mRNA analysis in T0 and T1 tobacco plants. The results obtained have led to the conclusion that regulatory elements for organ-specificity mainly reside in the promoter region whereas the transcribed region of the gene has an important role in light regulation.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号