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• 2002  (23)
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• 2000-2004  (23)
• 1995-1999
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• 1
Electronic Resource
Springer
The European physical journal 23 (2002), S. 675-689
ISSN: 1434-6052
Source: Springer Online Journal Archives 1860-2000
Topics: Physics
Notes: Abstract. We investigate the exclusive photoproduction of a heavy timelike photon which decays into a lepton pair, $\gamma p\to \ell^+\!\ell^- p$ . This can be seen as the analog of deeply virtual Compton scattering, and we argue that the two processes are complementary for studying generalized parton distributions in the nucleon. In an unpolarized experiment the angular distribution of the leptons readily provides access to the real part of the Compton amplitude. We estimate the possible size of this effect in kinematics where the Compton process should be dominated by quark exchange.
Type of Medium: Electronic Resource
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• 2
Electronic Resource
Springer
The European physical journal 29 (2002), S. 71-77
ISSN: 1434-6036
Keywords: PACS. 71.45.Lr Charge-density-wave systems – 65.40.Ba Heat capacity – 64.70.Kb Solid solid transitions – 64.70.Pf Glass transitions
Source: Springer Online Journal Archives 1860-2000
Topics: Physics
Notes: Abstract: Specific heats of the charge-density-wave compounds o-TaS3 and (TaSe4)2I have been measured over the wide temperature interval 10 K-300 K. Both systems exhibit strong non-Debye behavior. Very weak and broad anomalies are observed at the Peierls transition temperatures. For o-TaS3, the change in the curvature of the specific heat occurs at temperature of 40 K where glass transition has been deduced from dielectric measurements, and an extended scaling analysis suggests that the glass transition is associated with a dynamical cross over in length scales. We briefly discuss the characteristics and physical origins of the anomalies at both the Peierls and glass transitions.
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• 3
Electronic Resource
[s.l.] : Nature Publishing Group
Nature genetics 31 (2002), S. 379-384
ISSN: 1546-1718
Source: Nature Archives 1869 - 2009
Topics: Biology , Medicine
Notes: [Auszug] Impaired insulin action is a key feature of type 2 diabetes and is also found, to a more extreme degree, in familial syndromes of insulin resistance. Although inherited susceptibility to insulin resistance may involve the interplay of several genetic loci, no clear examples of interactions among ...
Type of Medium: Electronic Resource
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• 4
Electronic Resource
Oxford, UK : Blackwell Publishing Ltd
Journal of sensory studies 17 (2002), S. 0
ISSN: 1745-459X
Source: Blackwell Publishing Journal Backfiles 1879-2005
Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
Notes: Relationships between odor properties and volatile chemical composition were explored on 39 cocultures of three different yeasts, three Geotrichum candidum and five bacteria, commonly used in bacteria and mold surface ripened cheese. Sensory profiling was performed by ten trained judges by scoring the intensity of 14 odor attributes. At the same time, the volatile compounds of the cocultures were extracted and analyzed by dynamic headspace gas chromatography and mass spectrometry. Sensory and instrumental data were compared and correlated using correlation analysis and partial least squares regression analysis. The sample plot including the whole set of samples evidenced a clustering of the associations containing the yeast strain Kluyveromyces lactis and any bacteria. They developed strong fruity olfactory notes related to their high content of ethyl esters and various alcohols. The sample plot on a restricted set of samples evidenced the fruity characteristics of Debaryomyces hansenii and bacteria associations and the cheesy odors of Yarrowia lipolytica and Geotrichum candidum cocultures that produced sulfur compounds.
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• 5
Electronic Resource
Oxford, UK : Blackwell Publishing Ltd
FEMS microbiology ecology 41 (2002), S. 0
ISSN: 1574-6941
Source: Blackwell Publishing Journal Backfiles 1879-2005
Topics: Biology
Notes: A type II methanotrophic bacterium (Methylocystis strain SC2) was isolated from a polluted aquifer and identified based on morphology and on 16S rRNA gene phylogeny. Primers targeting the particulate methane monooxygenase subunit A gene (pmoA) were used to obtain a PCR product from DNA extract of strain SC2. Denaturing gradient gel electrophoresis of this PCR product demonstrated that strain SC2 contained two very different pmoA-like genes. One gene (pmoA1) had very high sequence homology to pmoA genes of other type II methanotrophic bacteria (identical amino acid sequence to pmoA of some other Methylocystis strains). The second gene (pmoA2) possessed only 73% identity with the first gene at the nucleotide level and 68.5% identity (83% similarity) at the amino acid level. The presence of both pmoA-like genes was verified by developing specific oligonucleotide probes for each and using these in Southern hybridisation of genomic DNA. Purity of the culture was exhaustively verified with a variety of methods to ensure that both genes were present in a single genospecies. These included microscopic examination, plating on various media, denaturing gradient gel electrophoresis of PCR products of the 16S rRNA gene (universal to bacteria) and of the methanol dehydrogenase α-subunit gene mxaF (universal to methylotrophic bacteria), and whole-cell hybridisation with fluorescently labelled 16S rRNA-targeted oligonucleotide probes specific for the genera Methylosinus and Methylocystis, or specific for strain SC2. Reverse transcription PCR of extracted RNA suggested that the novel pmoA2 gene was not expressed during growth under standard conditions used for the cultivation of these bacteria. The presence of multiple, diverse pmoA-like genes in a single genospecies of methanotrophic bacteria implies that pmoA must be cautiously applied as a phylogenetic marker in cultivation-independent molecular ecology studies.
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• 6
Electronic Resource
[s.l.] : Nature Publishing Group
Nature 419 (2002), S. 686-686
ISSN: 1476-4687
Source: Nature Archives 1869 - 2009
Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
Notes: [Auszug] Respiratory physiologists traditionally attribute the increased ventilatory response to hypoxia to increased discharge by the carotid-body chemoreceptor, which is transmitted by sensory processes to neurons in the medullary nucleus of the solitary tract. However, Lipton et al. propose a ...
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• 7
Electronic Resource
Oxford, UK : Munksgaard International Publishers
Physiologia plantarum 114 (2002), S. 0
ISSN: 1399-3054
Source: Blackwell Publishing Journal Backfiles 1879-2005
Topics: Biology
Notes: Vegetative storage proteins (VSPs) are thought to fulfil important nutritional roles during plant development and stress adaptation. Plant responses to mechanical wounding and herbivore damage include an activation of VSP expression. It was recently suggested that vsp is part of the systemic response of Arabidopsis to wounding. To test this proposal, we monitored the spatial regulation of vsp mRNAs and VSP proteins. Arabidopsis contains two vsp genes and real-time quantitative PCR allowed us to characterize their differential expression. The ratio of vsp1 to vsp2 mRNA abundance increased when plants were challenged with diamondback moth larvae or Egyptian cotton worms, but not when they were mechanically wounded. We observed a dramatic increase of vsp1 and vsp2 mRNA as well as VSP protein levels in leaves that experienced herbivore damage. By contrast, there was a relatively minor increase of vsp mRNA and VSP protein levels in undamaged leaves of infested plants. These results clearly demonstrate that VSPs are part of the local plant response to herbivore attack. To obtain additional information on vsp regulation, we analysed a fusion of a soybean vspB promoter fragment to the β-glucuronidase gene in transgenic Arabidopsis plants. The vspB promoter responded to both jasmonate and herbivore treatments, suggesting that similar signals regulate its expression in both plant species.
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• 8
Electronic Resource
[S.l.] : American Institute of Physics (AIP)
Journal of Applied Physics 91 (2002), S. 5341-5346
ISSN: 1089-7550
Source: AIP Digital Archive
Topics: Physics
Notes: 180° domain walls in ferromagnetic nanoconstrictions are investigated by classical atomic Monte Carlo simulations. Two types of constrictions are considered; one is a uniform circular cylinder (isthmus), the other is a double-truncated cone (hour glass). The wall width is determined by the effective length of the constriction, which may be as little as a nanometer. The wall can have a Néel-like configuration for constrictions much narrower than the normal wall width, but there is a crossover region with vortex-type walls before reaching a Bloch-type wall at larger diameters. In very narrow constrictions, effects of the atomic-scale structure become evident as the domain-wall structure depends on the number of atoms in the cross section. The simulations confirm the prospect of creating very narrow domain walls in a nanoconstricted soft magnetic material, and they indicate the possibility of spontaneous thermal fluctuations between different magnetic modes in walls smaller than about 10 nm. © 2002 American Institute of Physics.
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• 9
Electronic Resource
[s.l.] : Nature Publishing Group
Nature structural biology 9 (2002), S. 565-566
ISSN: 1072-8368
Source: Nature Archives 1869 - 2009
Topics: Biology , Medicine
Notes: [Auszug] They say there's more than one way to skin a cat, and so it may prove in the case of linked covalent modifications of the N- and C-terminal 'tails' of nucleosomal histones. Spatially, it is not obvious how domains within histones extending from opposite sides of the nucleosome can be ...
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• 10
Electronic Resource
Oxford, UK : Blackwell Science Ltd
Haemophilia 8 (2002), S. 0
ISSN: 1365-2516
Source: Blackwell Publishing Journal Backfiles 1879-2005
Topics: Medicine
Notes: Summary.  Scarce resources in healthcare are a fact of life everywhere. Providing optimal healthcare for haemophilia means delivering the best possible clinical outcomes at an acceptable total cost, however that is defined by individual societies. Health economics helps us to do this. So far, economic evaluation has enhanced our understanding of some of the economic implications of haemophilia and has provided some guidance on the way forward to optimize efficient allocation of resources for this condition. Further advances and consensus on evaluation methods and standards for the economics of haemophilia are required, however. This need will continue in the face of new, more sophisticated and therefore more costly haemophilia therapies.
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