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  • 1
    Electronic Resource
    Electronic Resource
    Respiration und mitochondrienverteilung im fettkoerper woehrend der kastendifferenzierung vonFormica polyctena (Foerster) (1990)
    Springer
    Insectes sociaux 37 (1990), S. 294-314 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary The respiration of both castes ofFormica polyctena (Foerster) during the larval development was investigated manometrically. The distribution of mitochondria and their structure in the fat body cells were measured simultaneously by electron-microscopy to ascertain if caste-specific differences of the intensity of respiration were recognizable by the content of mitochondria. The following results were obtained: At 20°C larvae of sexuals weighing 1 to 5 mg per individual consumed 860–910 μl O2/g/h, which was double the oxygen amount used by larvae of workers weighing up to 1.5 mg per individual. At the end of the larval development this difference disappeared, with values stabilizing at 410–420 μl O2/g/h. The volume density of mitochondria in 8 mg-sexual larvae was 12.2%, and in 60 mg-larvae or 1.9 mg — and 12.5 mg — worker larvae only 8.2–8.6% of the cytoplasm (without nucleus). The numeric density of the mitochondria was calculated as 840 per mm3 in larvae of 8 mg-sexuals, and in those of 60 mg or in 1.9 mg — and 12,5 mg — worker larvae only as 570–625 per mm3. No caste-specific and stage-dependent differences could be found in the size and microstructure of the mitochondria. An increased respiration was associated with a higher numeric and volume density of the mitochondria.
    Notes: Zusammenfassung Die Atmung wurde während der Larvalentwicklung beider Kasten vonFormica polyctena (Foerster) manometrisch untersucht. Parallel dazu wurde nach elektronenoptischer Präparation die Mitochondrienverteilung und Mitochondrienstruktur in Fettkörperzellen ermittelt, um festzustellen, ob kastenspezifische Unterschiede in der Atmungsintensität auch im Mitochondriengehalt zu erkennen sind. Folgende Resultate wurden erhalten: Geschlechtstierlarven von 1–5 mg/Tier verbrauchten mit 860–910 μl O2/g/h bei 24°C mehr als doppelt so viel Sauerstoff wie Arbeiterinlarven bis 1,5 mg/Tier. Am Ende der Larvalentwicklung war dieser Unterschied bei 410–420 μl O2/g/h ausgeglichen. Die CO2-Abgabe verhielt sich ähnlich. Die Volumendichte der Mitochondrien betrug bei 8 mg-Geschlechtstierlarven 12,2%, bei solchen von 60 mg sowie Arbeiterinlarven von 1,9 mg und 12,5 mg nur 8-2-8,6% des Cytoplasmas (ohne Kern). Die numerische Dichte der Mitochondrien betrug bei 8 mg-Geschlechtstierlarven 840/mm3, bei solchen von 60 mg sowie Arbeiterinlarven von 1,9 mg und 12,5 mg nur 570–625/mm3. In der Größe und Feinstruktur der Mitochondrien konnten keine kastenspezifischen und stadiumabhängigen Unterschiede festgestellt werden. Eine erhöhte Atmungstätigkeit war verbunden mit höherer numerischer und Volumendichte der Mitochondrien.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225994
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  • 2
    Electronic Resource
    Electronic Resource
    The saluretic effect of the thiazide diuretic bemetizide in relation to the glomerular filtration rate (1994)
    Springer
    European journal of clinical pharmacology 46 (1994), S. 9-13 
    Details
    ISSN: 1432-1041
    Keywords: Bemetizide ; Salt excretion pattern ; Na+ ; K+ ; Cl− ; Mg2+ ; Ca+ ; chronic renal failure ; renal haemodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of the thiazide diuretic, bemetizide, on the excretion of Na+, K+, Cl−, Ca2+, and Mg2+ in relation to the glomerular filtration rate (GFR) was studied in 17 subjects whose creatinine clearances ranged from 133 to 5 ml·min−1. After a 2-day fluid and salt balanced control period, 25 mg bemetizide given orally induced natriuresis and kaliuresis which lasted for 24 h and were proportional to the GFR of the patients. The ratio of bemetizide-induced K+/Na+ excretion was always 0.17 irrespective of individual GFR. In renal failure, bemetizide increased the fractional Na+ excretion from 3% to about 10%. Kaliuresis was associated with magnesiuria, whereas bemetizide-induced calciuresis was insignificant. The thiazide reversibly lowered GFR in all subjects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00195908
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  • 3
    Electronic Resource
    Electronic Resource
    Spatial variability of the aspect sensitivity of VHF radar echoes in the troposphere and lower stratosphere during jet stream passages (1994)
    Springer
    Annales geophysicae 12 (1994), S. 733-745 
    Details
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The aspect sensitivity of SOUSY-VHF-radar oblique-beam echoes from the troposphere and lower stratosphere has been examined for a number of jet stream passages during the years 1990 - 1992. When the core of the jet is overhead or nearly so, vertical profiles of the aspect sensitivity display two notable features. First, the distinction between mainly isotropic and strongly aspect-sensitive echoes in the troposphere and the lower stratosphere, respectively, often reported for measurements made during calm conditions, does not necessarily prevail in the vicinity of the jet stream. Second, echoes obtained at altitudes near the height of the horizontal wind maximum are found to be more aspect sensitive for beams directed parallel to the horizontal flow or nearly so, than for other beam directions. It is demonstrated that time-averaged horizontal wind speeds estimated from the radar data, taking into account the reduced effective oblique-beam zenith angle resulting from aspect sensitivity, may exceed uncorrected wind speeds by as much as 10 m s−1 in these circumstances. Implications for wind profiling and for describing the backscattering process are discussed. Doppler spectral widths examined for one jet stream passage are found to be narrower in a beam aligned with the horizontal wind at heights near the wind speed maximum than corresponding widths measured in a beam projected at right angles to the jet. The narrowest spectra thus coincide with the most aspect-sensitive echoes, consistent with the hypothesis that such returns result from specular backscattering processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-994-0733-9
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  • 4
    Electronic Resource
    Electronic Resource
    Field campaign for the comparison of SOUSY radar wind measurements with rawinsonde and model data (1994)
    Springer
    Annales geophysicae 12 (1994), S. 746-764 
    Details
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A field campaign was carried out from 26 October to 7 November 1992, using the SOUSY-VHF radar and a mobile rawinsonde system installed and operated nearby to produce vertical wind profiles. The purpose of this campaign was to compare the two types of wind measurements with one another and with results from forecast models. Numerical algorithms were developed and applied to the radar data in order to eliminate random errors, correct for velocity aliasing, and calculate the effective zenith angle of the off-vertical beams. Differences between wind profiler data and rawinsonde or model results depend not only upon the errors of the different systems, but also on temporal and spatial variations of the wind field. Therefore, methods for the comparison of radar and rawinsonde data were developed which take into consideration these variations. The practical potential of these methods is demonstrated by comparisons of rawinsonde and radar wind profiles. The comparison of radar data and model output shows excellent agreement in the direction and in the speed of the wind at virtually all altitudes. An evaluation of the quality of wind profiler measurements is possible using the estimation of variance and variability of wind components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-994-0746-4
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  • 5
    Electronic Resource
    Electronic Resource
    Effect of peppermint and eucalyptus oil preparations on neurophysiological and experimental algesimetric headache parameters (1994)
    USA/Oxford, UK : American Association for the Study of Headache/Blackwell Science Ltd
    Cephalalgia 14 (1994), S. 0 
    Details
    ISSN: 1468-2982
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The effects of peppermint oil and eucalyptus oil preparations on neurophysiological, psychological and experimental algesimetric parameters were investigated in 32 healthy subjects in a double-blind, placebo-controlled, randomized cross-over design. Four different test preparations were applied to large areas of the forehead and temples using a small sponge and their effect was evaluated by comparing baseline and treatment measure. The combination of peppermint oil, eucalyptus oil and ethanol increased cognitive performance and had a muscle-relaxing and mentally relaxing effect, but had little influence on pain sensitivity. A significant analgesic effect with a reduction in sensitivity to headache was produced by a combination of peppermint oil and ethanol. The essential plant oil preparations often used in empiric medicine can thus be shown by laboratory tests to exert significant effects on mechanisms associated with the pathophysiology of headache.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1468-2982.1994.014003228.x
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  • 6
    Electronic Resource
    Electronic Resource
    Thermal Destruction of Listeria monocytogenes in a Meat Slurry and in Ground Beef (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 55 (1990), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Thermal destruction of Listeria monocytogenes cells was determined in phosphate buffer, a meat slurry (20% ground beef/80% water) and in ground beef. D-values at 60°C, 65°C and 70°C in phosphate buffer, and in the meat slurry were 0.63, 0.29 and 0.15, and 2.54, 0.75 and 0.23 min, respectively. Heating of ground beef (80% lean) in a 75°C water bath to 50°C, 60°C or 65°C required 6.2, 8.4 and 10.6 min, respectively, and resulted in 0.2-0.9, 1.6-3.4 and 4.4-6.1 log reductions in L. monocytogenes cells, from the initial inoculation level of 8.08 log CFU/g. Viable cells were also detected after cold (21 days) or selective enrichment (24 hr) in eight out of nine samples of ground beef inoculated with 7.84-8.08 log CFU/g and cooked to 70°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1990.tb06754.x
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  • 7
    Electronic Resource
    Electronic Resource
    The genus-specific lipopolysaccharide epitope of Chlamydia is assembled in C. psittaci and C. trachomatis by glycosyltransferases of low homology (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 10 (1993), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Chlamydiae possess a genus-specific epitope that is located on the lipopolysaccharide (LPS) and is composed of a 3-deoxy-d-manno-octulosonic acid (Kdo) trisaccharide of the sequence αKdo-(2→8)–αKdo–(2→4)-αKdo. In Chlamydia trachomatis, this trisaccharide is biosynthetically generated through the action of a multi-functional Kdo-transferase encoded by the gene gseA. gseA of Chlamydia psittaci 6BC was cloned and expressed in a rough mutant (Re chemotype) of Escherichia coli (strain F515) that contains an LPS with only two α2→4-linked Kdo residues. Recombinant strains were able to add the immunodominant Kdo residue in a α2→8-linkage to the parental LPS, as determined by SDS–PAGE and Western blot analysis using a monoclonal antibody against the genus-specific epitope. The DNA sequence of gseA was determined and aligned to that published recently for C. trachomatis serovar L2. Most surprisingly, the two deduced amino acid sequences shared only an overall homology of 67%. Thus, gseA exhibits species specificity at the DNA level, whereas its gene product results in the synthesis of a carbohydrate antigen with genus specificity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2958.1993.tb00965.x
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  • 8
    Electronic Resource
    Electronic Resource
    Chaotic scattering and acceleration of particles by waves (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Chaos 3 (1993), S. 525-528 
    Details
    ISSN: 1089-7682
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Relativistic charged particles in a uniform magnetic field and traveling waves of large amplitude can be accelerated limitlessly. Since much of phase space is chaotic the process can be viewed as chaotic scattering on waves. For multiple waves an explicit map arises with unusual properties. It contains infinite island chains around nonperiodic orbits and it is also an example of transient chaos in a Hamiltonian system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.165957
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  • 9
    Electronic Resource
    Electronic Resource
    Measurement of internal magnetic field pitch using Li pellet injection on TFTR (invited) : Eighth topical conference on high−temperature plasma diagnostics (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 2908-2913 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A diagnostic technique which measures the direction of the internal magnetic field pitch angle has been used successfully on TFTR. The technique requires the injection of high-speed Li pellets. The magnetic field direction is measured by observing the polarization direction of the intense visible line emission from Li+ (λ≈5485 A(ring), 1s2p 3P0,1,2→1s2s 3S0) in the pellet ablation cloud. The presence of the large (primarily toroidal) magnetic field causes the line to be split due to the Zeeman effect, and the unshifted π component is polarized with its polarization direction parallel to the local magnetic field. In devices with sufficiently strong fields (B(approximately-greater-than)4.5 T), the Zeeman splitting of the line is large enough, relative to the linewidth of each Zeeman component, that enough residual polarization remains. Because the pellet moves about 1 cm before the Li+ is ionized (τionization(approximately-less-than)10 μs), the time history of the polarization direction (as the pellet penetrates from the outside toward the plasma center) yields the local magnetic field direction. In the TFTR experiment, spatial resolution of the measurement is typically ∼7 cm, limited by the requirement that a large number of photons must be collected in order to make the measurement of the polarization angle. Typically, the pitch of the field is measured with an accuracy of ±0.01 rad, limited by the photon statistics. The measurements of the internal field pitch angle, combined with external magnetic measurements, have been used in a code which finds the solution of the Grad–Shafranov equation, yielding the equilibrium which is the best fit to the measured inputs. The q profile constructed from this equilibrium is believed to be accurate to ∼±10% over the region where there are internal magnetic measurements. Internal field measurements and equilibrium reconstructions have been performed for a variety of TFTR discharges, including 1.6 MA ohmic plasmas where the internal field is measured at the beginning of the current flat top (before the onset of sawteeth) and 2 s into the flat top (with sawteeth), and in extremely high βp(Ip=0.3 MA, βp≈4.5) discharges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141775
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  • 10
    Electronic Resource
    Electronic Resource
    Magnetic Field Generation in Convective Cells (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 706 (1993), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1993.tb24688.x
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