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  • Articles  (75)
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  • 1
    ISSN: 1432-1041
    Keywords: Bronchodilators ; methacholine ; healthy human subjects ; SDZ MKS 492 ; specific airway conductance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary An approximately steady-state reduction of specific airway conductance was induced in healthy human subjects by means of an individualized inhaled methacholine loading dose followed by a maintenance dose regime. Tested against this background bronchoconstriction, the xanthine analogue SDZ MKS 492, when administered as a single oral dose of 40 mg, showed a significant bronchodilator action, which lasted for up to 5.5 h. Bronchodilatation was not seen after administration of 10 or 20 mg doses. SDZ MKS 492 inhaled as a dry powder had a bronchodilator action that was small, most evident with the 12 mg dose and transient. The peak relief of imposed bronchoconstriction was 29% and the apparent half-time of removal of SDZ MKS 492 from its site of action was 5–6 min. Inhaled SDZ 492 had a bitter taste that was not masked by inclusion of menthol and aspartame in the formulation. The bronchodilatation seen in laboratory animals can also be produced by SDZ MKS 492 in man when administered orally or by inhalation. Its magnitude correlates better with the plasma concentration of parent drug than with that of either of the identified metabolites. Dispositional processes in the lung abbreviate its action after administration by inhalation.
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  • 2
    ISSN: 1432-2242
    Keywords: Cell wall ; Ideotype breeding ; Selection ; Smooth bromegrass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A random sample of 80 families of the B8HD smooth bromegrass (Bromus inermis Leyss.) population were tested in three environments for forage yield and cell wall constituents. Expected progress from one cycle of family selection was computed for single-trait selection and multiple-trait restricted selection. Expected gains were compared to desired goals and actual results from one cycle of phenotypic selection. Desired goals were: Model I = reduced lignin and cellulose, with increased hemicellulose, resulting in no change in cell wall content; Model II = reduced lignin and cellulose with no change in hemicellulose; or Model III = reduced lignin, cellulose, and hemicellulose. Single-trait selection for high hemicellulose in first harvest or low cellulose in second harvest had the best expected responses, of any single trait, for Model I. Possible undesirable effects of selection for low cellulose would be a reduction in forage yield potential. Multiple-trait restricted selection was judged to be more effective, with responses all in the desired direction, by specifying increased hemicellulose in index development. Selection in second harvest was expected to have similar responses as first harvest, except for a greater increase in forage yield. Development of Models II or III is expected to be difficult due to a negative correlation estimate between first and second harvest cell wall concentration.
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  • 3
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Varvio-Aho et al. (1984) ont fait une analyse incorrecte de leurs données sur des allozymes de huit espèces de guêpes d'Europe du Nord. Une analyse correcte produit cinquante arbres d'une déviation standard d'un pourcent plus basse que leur arbre de Fitch-Margoliash, et trois arbres de Wagner supplémentaires de même longueur que leur réseau. La construction des arbres de consensus indique que leur données ne sont pas très informatives sur les parentés des espèces de vespines. Leur suggestions queDolichovespula ne forme pas un groupe monophylétique n'est pas soutenable.
    Notes: Summary Varvio-Aho et al. (1984) incorrectly analyzed their data on allozymes for eight species of European yellowjackets. Correct analysss produces 50 trees of lower percent standard deviation than their Fitch-Margoliash tree, and three additional Wagner trees of the same length as their network. Construction of consensus trees shows their data to be relatively uninformative on relationships of these vespine species. Their suggestion thatDolichovespula is not monophyletic cannot be upheld.
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  • 4
    ISSN: 1365-2214
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Background  This paper recounts the difficulties experienced when the authors sought access to children in hospital for social research interviews. These were part of a 2-year study, funded by the Joseph Rowntree Foundation, aiming to explore the numbers, circumstances and experiences of children who spend prolonged periods in health care settings.Methods  As the intention was to carry out ‘guided conversations’ with 24 young people in various different NHS locations, permission to do so was sought from a multi-site research ethics committee (MREC), and from several local research ethics committees (LRECs). Agreement was then necessary from NHS trusts, which were asked to nominate a liaison person to help identify and recruit children to the study. Consent was also required from individual parents and children. A series of unexpected delays encountered during this process are discussed in some detail. Eventually a sample of 15 children was achieved.Discussion  The second part of the paper locates this experience within a wider context, noting that similar difficulties gaining access to children in NHS settings have recently been reported by other social researchers. Several possible reasons for this trend are identified and discussed. These relate to the role of MRECs and LRECs in screening social research proposals, recently implemented legislation about data protection, heightened concerns within the NHS about confidentiality and consent, and increasing awareness of the risk of child abuse in health care settings.Conclusion  Finally, some suggestions for facilitating the access process are discussed. They include the sensitive and appropriate application of research governance frameworks to social research – including studies within health care settings. Ethical considerations and adequate protection of children are vital but, the authors argue, wherever possible children themselves should be encouraged to decide whether or not to participate in research. In addition, unnecessarily complex access procedures may adversely affect research outcomes.
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  • 5
    ISSN: 1420-9098
    Keywords: Polybioides ; Ropalidiini ; Polistinae ; caste differences
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Queens ofPolybioides tabidus differ from workers of the same species in the presence of very much longer bristles on the eyes and head and in the size of some morphological characters. The presence/absence of eye bristles in queens/workers of P. tabidus is the first qualitative morphological caste difference reported in the Polistinae.
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  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 227 (1970), S. 83-84 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] We examined eight populations, three pathotype A (including one from the type locality near Rostock, East Germany), two pathotype B and three pathotype E, and we confirmed Guile's and Webley's findings. We also found that pathotype B or E males raised on the susceptible potato variety Arran Banner ...
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  • 7
    ISSN: 1615-6102
    Keywords: Mycorrhiza ; Pisonia ; Root epidermis ; Transfer cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cells of the root epidermis ofPisonia grandis R. Br. at the interface with the mycorrhizal fungus are modified as transfer cells. The length of wall profile in transverse section is increased 1.7-fold by the wall ingrowths, on average, over the outer tangential wall and the outer third of the radial walls; this corresponds to a 1.3—fold increase in wall profile length over the whole cell. These increases in length of wall profile approximate—slightly underestimating-the amplification of surface area of the epidermal cells that results from the ingrowths. The surface area between the symbionts in thePisonia mycorrhiza is less amplified than in classical ectomycorrhizas with a Hartig net: this may be functionally adequate because of the extremely high nutrient status of theP. grandis habitat.
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  • 8
    ISSN: 1615-6102
    Keywords: Apoplastic permeability ; Cellufluor ; Sheath structure ; Mycorrhiza ; Pisonia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The tracer Cellufluor has been used to test the apoplastic permeability of the fungal sheath inPisonia grandis R. Br. mycorrhizas. In the tip region in the immediate vicinity of the root cap, where the sheath is not yet fully differentiated, Celluflor penetrates as far as the root epidermal cells. Behind this (i.e. just proximal to it) in differentiated regions, where the ultrastructure of both the root and fungal cells indicates that the mycorrhiza is likely to be functionally active, the sheath is impermeable to Cellufluor. During the development and differentiation of the sheath, the interhyphal spaces become filled with extracellular material. In the outer and middle regions this becomes electron opaque after fixation and staining. It is proposed that the dramatic decrease in apoplastic permeability over a short distance back from the root apex as the fungal sheath differentiates results from secretion of extracellular material by the fungus and its modification by deposition of phenolic substances. The symplastic pathway within the fungus may be very important for radial transfer of materials across the sheath. Blockage of the sheath apoplast could provide a sealed apoplastic compartment at the fungus-root interface, with resulting increase in efficiency of transfer between partners. The implications of these observations are discussed in relation to radial transfer across the sheath and transfer between partners in sheathing mycorrhizas in general.
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  • 9
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A time-of-flight small-angle diffractometer employing seven tapered collimator elements and a two-dimensional gas proportional counter was successfully utilized to collect small-angle scattering data from a solution sample of the lipid salt cetylpyridinium chloride, C21H38N+.Cl−, at the Argonne National Laboratory prototype pulsed spallation neutron source, ZING-P′. Comparison of the small-angle scattering observed from the same compound at the University of Missouri Research Reactor corroborated the ZING-P′ results. The results are used to compare the neutron flux available from the ZING-P′ source relative to the well characterized University of Missouri source. Calculations based on experimentally determined parameters indicated the time-averaged rate of detected neutrons at the ZING-P′ pulsed spallation source to have been at least 33% higher than the steady-state count rate from the same sample. Differences between time-of-flight techniques and conventional steady-state techniques are discussed.
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  • 10
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 19 (1986), S. 311-319 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The resolution of a time-of-flight small-angle scattering spectrometer is complicated because many wavelengths contribute to the intensity for a particular scattering vector. The resolution function varies according to the wavelength distribution as well as with collimation. A rigorous calculation of the instrumental resolution requires averaging the resolution function weighted by the wavelength spectrum within the band of wavelengths used in a given measurement. For each scattering vector an effective wavelength is defined which, after substitution into the resolution expression developed for fixed wavelength, gives the resolution of the time-of-flight measurement. Alternatively, the resolution may be established by Monte Carlo methods. In order to check the calculated resolution function and the overall instrument resolution, measurements have been made on biological samples (myelin and collagen) which give sharp Bragg peaks at small values of scattering vector. The analysis of these results provides a direct comparison with calculations and with a similar measurement on a steady-source instrument.
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