ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 1980-1984  (13)
  • 1
    Schriftenreihen ausleihbar
    Schriftenreihen ausleihbar
    Mineral resources of the Strawberry Mountain Wilderness and adjacent areas, Grant County, Oregon (1981)
    Washington, DC : United States Gov. Print. Off.
    Dazugehörige Bände
    Details Verfügbarkeit
    Signatur: SR 90.0001(1498)
    In: U.S. Geological Survey bulletin
    Materialart: Schriftenreihen ausleihbar
    Seiten: XI, 67 S. + 1 pl.
    Serie: U.S. Geological Survey bulletin 1498
    Sprache: Englisch
    Standort: Kompaktmagazin unten
    Zweigbibliothek: GFZ Bibliothek
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    BUCH
    Link zum Bibliothekskatalog
    get availability status
  • 2
    Digitale Medien
    Digitale Medien
    Long-term memory modules (1984)
    Springer
    Bulletin of mathematical biology 46 (1984), S. 295-326 
    Details
    ISSN: 1522-9602
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Mathematik
    Notizen: Abstract One particular kind of structure offers possible explanations, for long-term memory, efficient consolidation of stored information from the environment, clustering of data strings and multimodal functioning. It is a possible model for pieces of neural structure and its use offers a uniform method for both studying and constructing an extensive class of mechanisms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02460076
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Control of flashing in fireflies (1981)
    Springer
    Journal of comparative physiology 144 (1981), S. 287-298 
    Details
    ISSN: 1432-1351
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The restrained male of the fireflyPteroptyx cribellata of Papua New Guinea responds to exogenous light signals with a latency of about one second, which equals the period of the natural spontaneous rhythm of flashing and includes about 800 ms of central nervous delay. The response is cycle-by-cycle and all-or-none and the duration of the response time is independent of the phasing of the driver in relation to the free run rhythm (Figs. 1, 2). The firefly can be entrained to rhythms over a period range of 800 ms to 1,600 ms, during which it leads or lags the concurrent signal by an amount equal to the difference between the driving period and the animal's period (Figs. 3, 4). The phase-response line is nearly straight and is inclined 45 ° (Figs. 2, 5). Normally an exogenous signal dictates interflash timing but occasionally may fail to entrain the firefly (Figs. 7B, E) or may fail to evoke a flash (Figs. 7F, G). Persistence of endogenous control of timing period duration even during driving is occasionally seen as spontaneous drift in response time (Fig. 9). It is proposed that during entrainment each exogenous signal resets the pacemaker immediately to the start of its endogenous cycle, from which point it then begins a new series of free run periods. Thus each flash is timed in relation to the signal of the preceding cycle (Fig. 3). We devised a model of the endogenous timing cycle which fits the empirical data and achieves entrainment by a single mechanism involving phase advance or delay rather than change in actual rate of endogenous timing (Fig. 12). The proposed mechanism by which single males entrain to light signals seems compatible also with the mass synchronous flashing which is the characteristic behavior of field congregations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00612560
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Luminescent microsource activity in bioluminescence of the dinoflagellate,Pyrocystis fusiformis (1982)
    Springer
    Journal of comparative physiology 145 (1982), S. 517-527 
    Details
    ISSN: 1432-1351
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. The basis for the different bioluminescent flash forms previously described inPyrocystis fusiformis was examined using image intensification and microphotometric analysis. 2. The unique kinetics (10 ms rise time and biphasic decay) of the first flash (FF) from a mechanically stimulated night phase cell resembled the kinetics of light emission from the individual microsources (microflashes). 3. Synchronous light emission by microsources during the FF was replaced by their asynchronous flashing during subsequent flashes (SFs). Microsource kinetics changed to a skewed, bell-shaped microflash with a 40 ms rise time. The whole cell flash (macroflash) was of similar form but had slower kinetics than the microflash due to the asynchronous summing of microflashes, resulting in the 150 ms rise time characteristic of SFs. 4. All microsources appeared to flash during the FF. Microsource emission during SFs was temporally unpredictable. A given microsource might or might not flash during an SF and could flash several times per stimulus. The dimness of SFs immediately following the FF resulted from a decrease in the number of active microsources. Potentiation of SFs with stimulus intervals of 1 min or less involved increasing numbers of active microsources. Fatigue occurred as a result of decreasing numbers of active microsources and decreasing microflash emission strength. 5. Submaximal mechanical stimulation produced localized luminescent activity. Microsources responded as with maximal stimuli: initially with FF kinetics and synchrony, followed by SF kinetics and asynchrony. At frequencies of 0.33 pps and faster, the area of local luminescent activity enlarged with each stimulus, causing microsources in the new region of activity to respond as with an FF while the previously stimulated microsources exhibited SF kinetics and asynchrony. 6. The long-term glow produced by acid-stimulated cells resulted from prolonged asynchronous activity of the microsources. Acid-stimulated microflashes displayed SF kinetics even with the first flash of a microsource. 7. Recovery of FF kinetics occurred with a transition from asynchronous to synchronous coordination that was almost complete after 6 min. The transition from SF to FF microflash kinetics required longer recovery and was not abrupt, but exhibited intermediate kinetics. 8. A model is presented as a guide to further study of bioluminescence control in this dinoflagellate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00612817
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Two flash forms in the bioluminescent dinoflagellate,Pyrocystis fusiformis (1981)
    Springer
    Journal of comparative physiology 143 (1981), S. 43-52 
    Details
    ISSN: 1432-1351
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. A method was developed for studying bioluminescent activity in single cells of the dinoflagellate,Pyrocystis fusiformis. Individuals were isolated in holding tubes in day phase and held without stimulation until bioluminescence was maximally excitable, between circadian time (CT) 14 and CT 22, where CT 0 designates daybreak. Mechanical stimulation, via a pulse generator controlled solenoid, was applied to individual cells that had received no prior excitation in the night phase tested. 2. Two different flash forms were recorded. The first flash (FF) in response to a mechanical stimulus was very bright and had a rise time of 10 ms, and a biphasic decay that was 90% complete approximately 200 ms from flash onset. The form of subsequent flashes in response to further stimuli differed radically from the FF. They were dimmer and longer lasting than the FF with approximately 150 ms rise times and a monotonic decay that was 90% complete as long as 500 ms from flash onset. 3. Cells responded with one flash per mechanical stimulus and recordings were made until the response was exhausted. Total mechanically stimulated luminescence (TMSL) was measured with a digital integrator. TMSL and the integral of the FF were functions of cell size. 4. The degree of potentiation and number of flashes per cell were functions of stimulus frequency. At higher stimulus frequencies cells produced fewer flashes and more light per flash. The effects of potentiation were long lasting, persisting for stimulus intervals of up to one minute. 5. At slow stimulus frequencies (one pulse per 48 s) bioluminescent activity was not totally exhausted during the 8 h night phase test period. With prolonged stimulation a fatigued flash form developed that combined elements of the FF and subsequent flashes. 6. Cells that were stimulated to exhaustion recovered some bioluminescent capacity once stimulation ceased. Initial recovery was rapid and cells stimulated after only a 15 min recovery period produced as many flashes in the second stimulus series as in the first even though their TMSL was reduced 82%. Therefore, the number of flashes a cell produced was not simply proportional to the amount of bioluminescent material available. 7. The unique FF kinetics recovered with time, requiring 30–60 min in unfatigued cells and more than 6 h in fatigued cells. With a 24 h recovery period FF kinetics were more dependent on the cell receiving a normal 12 h day phase than was TMSL recovery. 8. Mechanically triggered bioluminescence inPyrocystis fusiformis appeared to be the result of at least two temporally distinct processes, one of which was dependent on a precharging period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00606067
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Control of flashing in fireflies (1981)
    Springer
    Journal of comparative physiology 144 (1981), S. 277-286 
    Details
    ISSN: 1432-1351
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Males of the fireflyPteroptyx cribellata of Papua New Guinea luminesce spontaneously in two principal modes: a regular one-per-second display flash (Fig. 1 A) and an irregular flicker of 3–10 peaks per second (Fig. 1B). In free run rhythmic display flashing by intact, restrained individuals, serial correlation analysis of interflash duration in successive cycles indicates that the variability of the brain-to-lantern excitation delay is negligible in comparison with the variability of the endogenous timing process (Figs. 6, 7). It is therefore possible to use the duration of the flash-to-flash interval of the intact firefly as a measure of endogenous pacemaker timing behavior. It is deduced that the cycling of the pacemaker is continuous, does not require that the animal see his own flash or even that he flash (Fig. 2 A), shows intercycle independence (Fig. 5) and may phase-shift its rhythm spontaneously upon occasion (Fig. 2C). Pacemaker period is normally distributed (Fig. 3), is not correlated with flash intensity, and appears to shorten slightly if a flash is skipped (Table 3). The occurrence of spontaneous flash skipping is taken to indicate that the timing process that measures pacemaker period can cycle independently of its usual triggering of the flash-excitation message to the lantern.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00612559
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Optical parameters of euphausiid eyes as a function of habitat depth (1984)
    Springer
    Journal of comparative physiology 154 (1984), S. 307-318 
    Details
    ISSN: 1432-1351
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The relationships between habitat depth, eye diameter relative to body length, and the dimensions of rhabdoms and crystalline cones have been examined for 13 species of three oceanic euphausiid genera with habitats ranging from near-surface waters to the deep-sea. Rate of eye growth decreases with depth. Longer rhabdoms may increase the visual sensitivity to point and extended light sources by an eye of a particular size with depth. Larger interommatidial angles suggest that visual acuity decreases at depth. Depth-related changes in euphausiid eyes are considered with respect to the probable roles of vision and bioluminescence in the deep-sea. Unusual features of the eyes of several species are described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00605230
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Chemical induction of feeding in California spiny lobster,Panulirus interruptus (Randall): (1984)
    Springer
    Journal of chemical ecology 10 (1984), S. 957-971 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Chemoreception ; feeding ; lobster ; Crustacea ; Panulirus interruptus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Molecular weight fractions of abalone muscle were tested for the ability to induce appetitive feeding and locomotor behavior in the spiny lobster,Panulirus interruptus. Fractions of 〈1000, 1000–10,000 and 〉10,000 daltons were isolated by ultrafiltrations and gel chromatography from a seawater extract of abalone muscle. The two lower-molecular-weight fractions (〈1000, 1000–10,000) were the least stimulatory of the three fractions tested, and both were ineffective as feeding stimulants. Solutions combining any two of the three isolated fractions produced behavioral activity equal to that caused by whole extract; thus, no single fraction was essential to the stimulatory capacity of abalone. The 〉1000-dalton fraction was also highly stimulatory, meaning that large and not small molecules were essential in initiating feeding. Finally, a 75% ethanol-insoluble component of the 〈10,000 fraction was effective, while the ethanol-soluble portion was not. Since the insoluble material consisted predominantly of peptides and polypeptides, it is probable that these molecules act as principal stimulants in abalone muscle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00987976
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Maternal inheritance of mitochondrial DNA polymorphisms in cultured human fibroblasts (1981)
    Springer
    Somatic cell and molecular genetics 7 (1981), S. 103-108 
    Details
    ISSN: 1572-9931
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract We have isolated the total cellular DNA from the cultured diploid fibroblasts of a six-member, three-generation human family. Using a specific radioactive probe for mitochondrial (mt) sequences we have identified new polymorphic variants in this family for the Hhal restriction endonuclease cleavage pattern of the mtDNA. The inheritance of these cleavage patterns verifies the maternal inheritance of mtDNA through all three generations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01544751
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    The influence of three sour gas processing plants on the ecological distribution of epiphytic lichens in the vicinity of fox creek and Whitecourt, Alberta, Canada (1980)
    Springer
    Water, air & soil pollution 14 (1980), S. 45-68 
    Details
    ISSN: 1573-2932
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract The ecological distributions of epiphytic lichens have been reduced by SO2 emissions from three sour gas processing plants located near Fox Creek and Whitecourt, Alberta. Pollutants tend to concentrate in drainage channels leading to the Athabasca River. These channels parallel the prevailing wind. No sites were encountered which totally lacked lichens but at sites within 1 to 2 km downwind of gas plants and associated S storage blocks, the epiphytic lichen flora was reduced in variety, cover and vitality. An Index of Atmospheric Purity (IAP) was calculated from epiphyte data using selected indicator species and air pollution zones determined. Zone maps of relative air purity were generated using the SYMAP mapping package. Improvements to previous IAP methodologies are suggested. Average sulfation rates, S content, and stable S isotope abundance ratios are discussed as they relate to lichen diversity, vitality and IAP values.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00291825
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...