940 resultados para Wilhelmina, Queen of the Netherlands, 1880-1962.
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The shoot represents the basic body plan in land plants. It consists of a repeated structure composed of stems and leaves. Whereas vascular plants generate a shoot in their diploid phase, non-vascular plants such as mosses form a shoot (called the gametophore) in their haploid generation. The evolution of regulatory mechanisms or genetic networks used in the development of these two kinds of shoots is unclear. TERMINAL EAR1-like genes have been involved in diploid shoot development in vascular plants. Here, we show that disruption of PpTEL1 from the moss Physcomitrella patens, causes reduced protonema growth and gametophore initiation, as well as defects in gametophore development. Leafy shoots formed on ΔTEL1 mutants exhibit shorter stems with more leaves per shoot, suggesting an accelerated leaf initiation (shortened plastochron), a phenotype shared with the Poaceae vascular plants TE1 and PLA2/LHD2 mutants. Moreover, the positive correlation between plastochron length and leaf size observed in ΔTEL1 mutants suggests a conserved compensatory mechanism correlating leaf growth and leaf initiation rate that would minimize overall changes in plant biomass. The RNA-binding protein encoded by PpTEL1 contains two N-terminus RNA-recognition motifs, and a third C-terminus non-canonical RRM, specific to TEL proteins. Removal of the PpTEL1 C-terminus (including this third RRM) or only 16–18 amino acids within it seriously impairs PpTEL1 function, suggesting a critical role for this third RRM. These results show a conserved function of the RNA-binding PpTEL1 protein in the regulation of shoot development, from early ancestors to vascular plants, that depends on the third TEL-specific RRM.
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The Queensland Shark Control Program (QSCP) aims to protect swimmers at ten beach areas on the east coast of Queensland between Cairns (17°S) and the Gold coast (28°S). Since its inception in 1962 it has deployed shark nets and baited drumlines in a `mixed gear strategy' that adapts the type of gear to the characteristics of a site (e .g . extreme tidal range, high energy wave action, or proximity of turtle breeding areas) . The policy has provided swimmer protection, and the incidental capture of non-target species has been lower than that resulting from deployment of nets alone (Dudley 1997; Gribble et al. 1998b). The QSCP is the only major public-safety shark-control program to routinely use mixed gear. Both the New South Wales (Holt 1998) and KwaZulu-Natal (Dudley 1998) programs use nets exclusively, although the KwaZulu-Natal program has recently tested drumlines on an experimental basis (Dudley 1998; Dudley, personal communication).
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Most plant disease resistance (R) genes encode proteins with a nucleotide binding site and leucine-rich repeat structure (NBS-LRR). In this study, degenerate primers were used to amplify genomic NBS-type sequences from wild banana (Musa acuminata ssp. malaccensis) plants resistant to the fungal pathogen Fusarium oxysporum formae specialis (f. sp.) cubense (FOC) race 4. Five different classes of NBS-type sequences were identified and designated as resistance gene candidates (RGCs). The deduced amino acid sequences of the RGCs revealed the presence of motifs characteristic of the majority of known plant NBS-LRR resistance genes. Structural and phylogenetic analyses grouped the banana RGCs within the non-TIR (homology to Toll/interleukin-1 receptors) subclass of NBS sequences. Southern hybridization showed that each banana RGC is present in low copy number. The expression of the RGCs was assessed by RT-PCR in leaf and root tissues of plants resistant or susceptible to FOC race 4. RGC1, 3 and 5 showed a constitutive expression profile in both resistant and susceptible plants whereas no expression was detected for RGC4. Interestingly, RGC2 expression was found to be associated only to FOC race 4 resistant lines. This finding could assist in the identification of a FOC race 4 resistance gene.
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Bigeyed bugs (Geocoris spp., Hemiptera: Geocoridae) are common predators in Australian agricultural crops yet the development and reproductive biology of Australian geocorids has not been described before. Here we present the effects of diet, temperature and photoperiod on the development and survival of Geocoris lubra Kirkaldy from egg to adult. Nymphal survival of G. lubra reared on live aphids (Aphis gossypii Glover) was very low but improved slightly on a diet of Helicoverpa armigera (Hübner) eggs. Development was faster and nymphal survival improved significantly at 27°C compared with 25°C. Further investigation at 27°C showed photoperiod influenced development time, but not survival of immature G. lubra. Development time was significantly longer at 10L:14D. Fecundity of first generation G. lubra was not affected by photoperiod, although egg viability was greater at 12L:12D.
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Aconophora compressa (Hemiptera: Membracidae), a biological control agent introduced against the weed Lantana camara (Verbenaceae) in Australia, has since been observed on several non-target plant species, including native mangrove Avicennia marina (Acanthaceae). In this study we evaluated the suitability of two native mangroves, A. marina and Aegiceras corniculatum (Myrsinaceae), for the survival and development of A. compressa through no-choice field cage studies. The longevity of females was significantly higher on L. camara (57.7 ± 3.8 days) than on A. marina (43.3 ± 3.3 days) and A. corniculatum (45.7 ± 3.8 days). The proportion of females laying eggs was highest on L. camara (72%) followed by A. marina (36%) and A. corniculatum (17%). More egg batches per female were laid on L. camara than on A. marina and A. corniculatum. Though more nymphs per shoot emerged on L. camara (29.9 ± 2.8) than on A. marina (13 ± 4.8) and A. corniculatum (10 ± 5.3), the number of nymphs that developed through to adults was not significantly different. The duration of nymphal development was longer on A. marina (67 ± 5.8 days) than on L. camara (48 ± 4 days) and A. corniculatum (43 ± 4.6 days). The results, which are in contrast to those from previous glasshouse and quarantine trials, provide evidence that A. compressa adults can survive, lay eggs and complete nymphal development on the two non-target native mangroves in the field under no-choice condition.
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Reproduction of a painting of a meeting of the Joint Distribution Committee (representing the American Jewish Relief Committee, the Central Rellief Committee and the People's Relief Committee) and the Executive Committee of the American Jewish Relief Committee, with chairman Felix Warburg, secretary Albert Lucas, stenographer Mrs. F. Friedman, executive director Boris Bogen, comptroller Harriet Lowenstein, associate treasurer Paul Baerwald and treasurer Arthur Lehman; Office of Mr. Felix M. Warburg, 52 William Street, New York
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Laura (1878-1917) died during a flu epidemic. She married Sigmund Stiassny and had two children, Lisbeth (Gersuny) (1900-1986) and Walter (1902-1912) who died of a ruptured appendix.
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Autographed dedication: An Margot Einstein in innigem Gedenken an ihrem Vater, meinem grossen and teueren Freund Albert Einstein. Herzlichst Elisabeth April 1956
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A generalized Ginzburg-Landau approach is used to study the nonmonotonic temperature dependence of the upper critical field H c 2(T) in antiferromagnetic superconductors RE(Mo)6S8; RE = Dy, Tb, Gd. It is found that electrodynamic effects incorporated through screening and indirect coupling between the staggered magnetization M Q (T) and superconducting order parameter psgr cannot explain the observed nonmonotonicity. This suggests that the direct coupling between the two order parameters should be considered to understand the experimental results, a finding which is consistent with recent microscopic calculations.
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This study explores the decline of terrorism by conducting source-based case studies on two left-wing terrorist campaigns in the 1970s, those of the Rode Jeugd in the Netherlands and the Symbionese Liberation Army in the United States. The purpose of the case studies is to bring more light into the interplay of different external and internal factors in the development of terrorist campaigns. This is done by presenting the history of the two chosen campaigns as narratives from the participants’ points of view, based on interviews with participants and extensive archival material. Organizational resources and dynamics clearly influenced the course of the two campaigns, but in different ways. This divergence derives at least partly from dissimilarities in organizational design and the incentive structure. Comparison of even these two cases shows that organizations using terrorism as a strategy can differ significantly, even when they share ideological orientation, are of the same size and operate in the same time period. Theories on the dynamics of terrorist campaigns would benefit from being more sensitive to this. The study also highlights that the demise of a terrorist organization does not necessarily lead to the decline of the terrorist campaign. Therefore, research should look at the development of terrorist activity beyond the lifespan of a single organization. The collective ideological beliefs and goals functioned primarily as a sustaining force, a lens through which the participants interpreted all developments. On the other hand, it appears that the role of ideology should not be overstated. Namely, not all participants in the campaigns under study fully internalized the radical ideology. Rather, their participation was mainly based on their friendship with other participants. Instead of ideology per se, it is more instructive to look at how those involved described their organization, themselves and their role in the revolutionary struggle. In both cases under study, the choice of the terrorist strategy was not merely a result of a cost-benefit calculation, but an important part of the participants’ self-image. Indeed, the way the groups portrayed themselves corresponded closely with the forms of action that they got involved in. Countermeasures and the lack of support were major reasons for the decline of the campaigns. However, what is noteworthy is that the countermeasures would not have had the same kind of impact had it not been for certain weaknesses of the groups themselves. Moreover, besides the direct impact the countermeasures had on the campaign, equally important was how they affected the attitudes of the larger left-wing community and the public in general. In this context, both the attitudes towards the terrorist campaign and the authorities were relevant to the outcome of the campaigns.
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Background The obligate intracellular bacterium Chlamydia pneumoniae is a common respiratory pathogen, which has been found in a range of hosts including humans, marsupials and amphibians. Whole genome comparisons of human C. pneumoniae have previously highlighted a highly conserved nucleotide sequence, with minor but key polymorphisms and additional coding capacity when human and animal strains are compared. Results In this study, we sequenced three Australian human C. pneumoniae strains, two of which were isolated from patients in remote indigenous communities, and compared them to all available C. pneumoniae genomes. Our study demonstrated a phylogenetically distinct human C. pneumoniae clade containing the two indigenous Australian strains, with estimates that the most recent common ancestor of these strains predates the arrival of European settlers to Australia. We describe several polymorphisms characteristic to these strains, some of which are similar in sequence to animal C. pneumoniae strains, as well as evidence to suggest that several recombination events have shaped these distinct strains. Conclusions Our study reveals a greater sequence diversity amongst both human and animal C. pneumoniae strains, and suggests that a wider range of strains may be circulating in the human population than current sampling indicates.