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81.
The fragmentation of academic disciplines forces individuals to specialise. In doing so, they become experts over their narrow area of research. However, ambitious scientific projects, such as the search for gravitational waves, require them to come together and collaborate across disciplinary borders. How should scientists with expertise in different disciplines treat each others’ expert claims? An intuitive answer is that the collaboration should defer to the opinions of experts. In this paper we show that under certain seemingly innocuous assumptions, this intuitive answer gives rise to an impossibility result when it comes to aggregating the beliefs of experts to deliver the beliefs of a collaboration as a whole. We then argue that when experts’ beliefs come into conflict, they should waive their expert status.  相似文献   
82.

Human perceptions under unstructured forms contain valuable information for ecological restoration (ER). To aid in ER, this paper introduces a working process to analyze the unstructured information for the case study of black bear restoration (BBR) in East Texas where understanding of the perceptions of stakeholders at a community level is needed. We identified the current situation, revealed stakeholders and their interactions, and developed actions for change for BBR. Our techniques included recording discussions in meetings, Soft Systems Methodology, and stakeholder analysis. Results indicated the current situation of BBR with human-bear and human-human conflicts. We figured out that information exchange was interrupted in the public, a potential cause for conflicts. Through a systemization, results showed various roles of key stakeholders and constraints for BBR. We found that local state agencies and local residents (particularly landowners) are the key decision-makers for BBR success. Their collaboration can result in a small portion of success (1/9) that can be increased by more cooperation. The SSM framework introduced in this study can be used for modeling community perceptions in ecological restoration.

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83.
84.
The sequential timing of cell-cycle transitions is primarily governed by the availability and activity of key cell-cycle proteins. Recent studies in yeast have identified a class of ubiquitin ligases (E3 enzymes) called SCF complexes, which regulate the abundance of proteins that promote and inhibit cell-cycle progression at the G1-S phase transition. SCF complexes consist of three invariable components, Skp1, Cul-1 (Cdc53 in yeast) and Rbx1, and a variable F-box protein that recruits a specific cellular protein to the ubquitin pathway for degradation. To study the role of Cul-1 in mammalian development and cell-cycle regulation, we generated mice deficient for Cul1 and analysed null embryos and heterozygous cell lines. We show that Cul1 is required for early mouse development and that Cul1 mutants fail to regulate the abundance of the G1 cyclin, cyclin E (encoded by Ccne), during embryogenesis.  相似文献   
85.
V T Nguyen  T Kiss  A A Michels  O Bensaude 《Nature》2001,414(6861):322-325
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86.
87.
Dermal equivalents (DE), collagen lattices, were produced in vitro and used as a model for studying the possible role of a pure population of fibroblasts in post-radiotherapeutic dermal fibrosis. Single doses of gamma irradiation induced a partial inhibition of the collagen lattice retraction and of protein synthesis. The collagen production was less inhibited than was synthesis of non-collagen protein, which resulted in an increase of the relative amount of collagen synthesized by irradiated fibroblasts. These data suggest that gamma irradiation might be able to select some fibroblast clones able to produce increasing amounts of collagen. This selection process could be involved in the development of tissue fibrosis after therapeutic radiation.  相似文献   
88.
The genome of the flowering plant Arabidopsis thaliana has five chromosomes. Here we report the sequence of the largest, chromosome 1, in two contigs of around 14.2 and 14.6 megabases. The contigs extend from the telomeres to the centromeric borders, regions rich in transposons, retrotransposons and repetitive elements such as the 180-base-pair repeat. The chromosome represents 25% of the genome and contains about 6,850 open reading frames, 236 transfer RNAs (tRNAs) and 12 small nuclear RNAs. There are two clusters of tRNA genes at different places on the chromosome. One consists of 27 tRNA(Pro) genes and the other contains 27 tandem repeats of tRNA(Tyr)-tRNA(Tyr)-tRNA(Ser) genes. Chromosome 1 contains about 300 gene families with clustered duplications. There are also many repeat elements, representing 8% of the sequence.  相似文献   
89.
The laboratory rat (Rattus norvegicus) is an indispensable tool in experimental medicine and drug development, having made inestimable contributions to human health. We report here the genome sequence of the Brown Norway (BN) rat strain. The sequence represents a high-quality 'draft' covering over 90% of the genome. The BN rat sequence is the third complete mammalian genome to be deciphered, and three-way comparisons with the human and mouse genomes resolve details of mammalian evolution. This first comprehensive analysis includes genes and proteins and their relation to human disease, repeated sequences, comparative genome-wide studies of mammalian orthologous chromosomal regions and rearrangement breakpoints, reconstruction of ancestral karyotypes and the events leading to existing species, rates of variation, and lineage-specific and lineage-independent evolutionary events such as expansion of gene families, orthology relations and protein evolution.  相似文献   
90.
A highly pathogenic avian influenza virus, H5N1, caused disease outbreaks in poultry in China and seven other east Asian countries between late 2003 and early 2004; the same virus was fatal to humans in Thailand and Vietnam. Here we demonstrate a series of genetic reassortment events traceable to the precursor of the H5N1 viruses that caused the initial human outbreak in Hong Kong in 1997 (refs 2-4) and subsequent avian outbreaks in 2001 and 2002 (refs 5, 6). These events gave rise to a dominant H5N1 genotype (Z) in chickens and ducks that was responsible for the regional outbreak in 2003-04. Our findings indicate that domestic ducks in southern China had a central role in the generation and maintenance of this virus, and that wild birds may have contributed to the increasingly wide spread of the virus in Asia. Our results suggest that H5N1 viruses with pandemic potential have become endemic in the region and are not easily eradicable. These developments pose a threat to public and veterinary health in the region and potentially the world, and suggest that long-term control measures are required.  相似文献   
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