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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 174 (1994), S. 803-811 
    ISSN: 1432-1351
    Keywords: Temporal filters ; Flicker fusion ; Stimulus measurement ; Lobster olfaction ; Crustacean
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract 1. We developed a high resolution, on-line stimulus measurement system for accurate control of chemical stimulus applications for Homarus americanus lateral antennule chemoreceptors. Focal stimulus presentations in an electrophysiological preparation with the receptor sensilla intact were measured at small spatial (30 μm) and time (5 ms) scales. 2. We tested 15 receptor cells with ten 100 ms pulses of 104 M hydroxyproline at 0.5, 1, 2 and 4 Hz and with a single 8 s square pulse. Individual cells showed differences in their capabilities to resolve pulses (“flicker fusion”). At 2 Hz stimulation, some cells could follow stimulus pulses while others could not. At 4 Hz, 3 cells could still encode individual stimulus pulses accurately. The population resolved pulses up to 2 Hz; at 4 Hz, the population response to a pulse series approximated the response to a square pulse. 3. Repetitive stimulation caused a gradual decrease in the number of spikes and a gradual increase in first spike latency (“cumulative adaptation”). Increased stimulation frequency resulted in greater cumulative adaptation. 4. Since individual differences in adaptation and disadaptation rates of the receptor cells could not be attributed to measured stimulus variability in situ, lobster chemoreceptor cell populations have intrinsic temporal diversity which, we hypothesize, could be used to analyze pulsatile stimuli that occur in natural turbulent odor plumes.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 172 (1993), S. 81-90 
    ISSN: 1432-1351
    Keywords: Spontaneous reactions ; Learning behaviour ; Chemosensory stimuli ; Goldfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The present behavioural experimental paradigm made use of the responsiveness of goldfish to natural and non-familiar chemosensory stimuli in the context of feeding. With the exception of Tubifex food extract, which was spontaneously preferred, goldfish exhibited no spontaneously recordable response to low concentrations of the stimuli tested. Training experiments using non-familiar stimuli (amyl acetate, α-ionone, β-phenylethanol, 10-6, 10-7 M) required 2–3 months of daily training prior to the animals reaching a 70% positive response level for discrimination. This discrimination was dependent upon a functioning olfactory system as no responses were recorded after bilateral exclusion of olfaction, e.g. dissection of olfactory nerve or olfactory tracts. Amino acids (Ala, Arg, Gln, Gly, Lys), more natural stimuli than those listed above, were preferred when applied at concentrations 〈 10-5 M. Goldfish were able to discriminate amino acid odours applied at 10-6 or 10-7 M, but these stimuli elicited no spontaneous response below 10-5 M. Ten to twenty reinforcements were sufficient to achieve discrimination between amino acids, which again was eliminated after bilateral exclusion of olfactory pathways. In contrast to the 4-week period for long-term memory to non-familiar odours, long-term memory for amino acids lasted at least 3 months.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 175 (1994), S. 95-105 
    ISSN: 1432-1351
    Keywords: Chemoreceptor ; Response reliability ; Intensity coding ; Hydroxy-L-proline ; Lobster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract 1. To determine reliability of stimulus intensity coding we measured the response variability of 30 hydroxy-L-proline sensitive chemoreceptor cells from antennules of Homarus americanus. First, cells were tested with 5 repeated presentations of 10-5 M and l0-4 M hydroxy-L-proline. Then a stimulus response function was determined in each cell from l0-6to 5 × l0-4 M in half log steps. 2. Population mean responses to repetitive stimulation showed little variability and mean stimulus response functions increased monotonically. In contrast, most individual cells showed a high response variability and no single cell stimulus-response function increased monotonically. The greatest response variability occurred between different cells. 3. Mean response magnitude of a 30 cell population allowed reliable discrimination between 10-5 M and l0-4 M hydroxy-L-proline for each of the 5 repetitions. It also allowed discrimination of all concentrations of hydroxy-L-proline tested. Across-fiber response patterns also differed significantly with concentration while they remained relatively stable with repetition of the same stimulus. 4. We applied different analytical methods to test the reliability of response magnitude and across-fiber pattern as possible codes for intensity discrimination. We demonstrated that a random population of rather unreliable receptor cells could provide remarkably reliable intensity information to the CNS based on response magnitude or across-fiber pattern.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung Anhand urodynamischer, klinischer und sexologischer Auswertung kann festgestellt werden, daß die abdominale operative Streßinkontinenztherapie subjektiv und objektiv bessere Resultate im Vergleich zum vaginalen Vorgehen liefert.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung Die Erfassung der Morphologie des Blasenhals-Urethra-Übergangs kann sowohl durch die Kolpourethrozystographie als auch die Introitussonographie erfolgen, wobei der Vorteil der Sonographie in der beliebigen Wiederholbarkeit zu sehen ist, aber auch eine größere Erfahrung in der Einschätzung erfordert.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1573-5079
    Keywords: net CO2 assimilation ; Pennisetum americanum ; water use efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Single leaf photosynthesis (Pn) and stomatal conductance (Cg) of drought stressed and nonstressed pearl millet [Pennisetum americanum (L.) Leeke] were measured across growth stages to determine if a pattern exists in Pn and Cg during the growing season and to evaluate the influence of air vapor pressure deficit (VPDa) on the seasonal variations of Pn and Cg. Leaf photosynthesis and Cg were measured independently on pearl millet plants grown at the driest (drought stressed) and wettest (nonstressed) ends of a line-source irrigation gradient system. Well defined and predictable variations in both Pn and Cg were found across two growing seasons. Leaf photosynthesis of the nonstressed plants declined from a maximumof 25.8 μmol m−2 s−1 at the flag leaf emergence (48 days after planting, DAP) to a minimum of 14.5 μmol m−2 s−1 at physiological maturity. Stomatal conductance of the nonstressed plants peaked at the flowering and early grain fill stages and declined as plants approached maturity. In contrast, Pn and Cg of the stressed plants declined from a maximum at flag leaf emergence to a minimum at flowering and increased as plants approached maturity. High VPDa during the flowering and grain fill stages induced stomatal closure and decreased Pn in the stressed plants. High mid-season VPDa did not induce stomatal closure and did not reduce leaf photosynthesis in nonstressed plants. The lack of sensitivity of Pn to VPDa in the nonstressed treatment suggests large air VPD such as that prevalent in southern Arizona does not limit the growth of irrigated pearl millet by limiting CO2 assimilation.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    International urogynecology journal 3 (1992), S. 298-301 
    ISSN: 1433-3023
    Keywords: Cervical cancer ; Oncology ; Urodynamic investigation ; Urogynecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two groups of patients treated for cervical cancer stage Ib with radical Wertheim-Meigs hysterectomy, in two periods (1957–1966 and 1981–1986) were compared. To avoid urological complications after the Wertheim-Meigs operation the experience of the surgeon is very important. Only mild disturbances of the lower urinary tract function were found in 36% of patients in the second group. In those patients treated subsequently by irradiation the bladder compliance is significantly lower compared to the control group.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    International urogynecology journal 3 (1992), S. 129-132 
    ISSN: 1433-3023
    Keywords: Bladder instability ; Urethral pressure variations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cause of ‘female urethral instability’ is still controversial. With the help of this retrospective analysis of 1168 continuous long-term recordings of the intraurethral pressure at the maximum point of urethral pressure, the correlation between pressure variations (UPV) and simultaneous bladder instability was investigated. It could be stated that clinically important UPV (more than 15 cmH2O) are found more often in women who suffer from signs of bladder instability (defined as low bladder compliance combined with uninhibited detrusor contractions and/or urinary leakage) than in patients without signs of unstable bladder.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1433-3023
    Keywords: Female stress incontinence ; Introital sonography ; Urethrocystography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphologic investigation of the urethrovesical junction combined with urodynamic findings is necessary to choose the correct surgical procedure for female stress incontinence. This study compares colpourethrocystography and perineal sonography in 41 patients with genuine stress incontinence, 30 patients after Burch colposuspension and 40 healthy control women. The study determined the inclination angle, the pubourethral angle, the posterior vesicourethral angle and as the distance H between the lower pubis and the internal urethral meatus. Introital sonography avoids exposure of the patient to X-irradiation and gives similar findings to urethrocystography. Sonography is a fast, easy to perform, inexpensive and reproducible method which is well accepted to the patient. It may be very important in evaluating the morphologic effect of incontinence surgery instead of urethrocystography.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 340 (1991), S. 781-782 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. Cefotaxime concentration values in serum and urine can be well estimated by means of pulse polarography. 2. In spite of hydrolysis and thin-layer chromatography, pulse polarography offers prompter and more reliable results. 3. It seems to be not necessary to change the dosage and application interval of cefotaxime because there are only a few statistical differences between pregnant and non-pregnant women.
    Type of Medium: Electronic Resource
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