ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Reactions of fish to sound generated by divers' open-circuit underwater breathing apparatus (1974)
    Springer
    Marine biology 27 (1974), S. 357-366 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Observations were made on the influence of underwater divers on the behaviour of fish in Loch Torridon, on the west coast of Scotland. An electronically scanned sonar and a television camera were used to record the behaviour of 4 species common in the loch. These were the cod Gadus morhua (L), the saithe Pollachius virens (L), the pollack P. pollachius (L) and the common dab Limanda limanda (L). These fish were attracted to divers and to a sound source when the recorded noise from an aqualung and demand valve was transmitted into the water. By analysis and by testing different components of the noise it was shown that low frequencies between 30 and 110 Hz, generated by the release of exhaled air, were responsible for the attraction. It is suggested that the fish associated this noise with the presence of food organisms disturbed from the sea bed by the diver and that they had become conditioned to the noise over a period of time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00394372
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Computer simulation of an electrostatic spherical analyzer used as an energy spectrograph (1985)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 56 (1985), S. 1320-1328 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Exit positions and velocities of charged particles passing through an electrostatic spherical analyzer were generated by a computer program which utilizes transformations to the trajectory plane of the particle to obtain an exact solution in the central force field of the analyzer. Entrance and exit planes were treated as a potential jump to zero potential, thus simulating grounded wire meshes at the entrance and exit. It was found that particle input energies could be determined as a function of exit position. A wide variety of designs were tried, varying plate radii, plate voltages, and incoming collimation of the particles. A power-law relationship between exit radius and input energy was found for designs in which the mean radial position between the plates corresponded to zero potential. However, the total input energy spread ΔE of the particles passed by an analyzer could never be made to approach twice the mean input energy E of the particles passed. Since a parabolic analyzer can be made to have a ΔE/E=1.92, we conclude that the parabolic analyzer makes a better spectrograph.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1137998
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Space plasma measurements with ion instruments (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 3750-3761 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In this article we examine the factors which affect the determination of the plasma bulk parameters in space, with particular emphasis on the density determination. We make this assessment with reference to a particular instrument, the AMPTE-UKS ion instrument, in order to be specific, but the issues raised here are likely to be encountered in the use of any space plasma instrument containing electrostatic energy analyzers or microchannel plate detectors. We have established a mathematical formalism for determining these parameters by relating the measured counts to the distribution function in terms of the geometric factor. The geometric factor is determined in the calibration of the instrument which is described in some detail. Among the factors we have considered are our calibration techniques, MCP efficiency, detector energy, and angular resolution, as well as the approximations used in our mathematical formalism. To establish confidence in our determination, we used a computer simulation to look for systematic errors in the particular characteristics of the analyzer and to verify the method of extraction of plasma parameters. We can conclude that the detector resolution is adequate for determining density for both solar wind (〈5% error) and magnetosheath conditions (〈6% error). The detector resolution is also adequate for measuring velocity, 〈1% error for the solar wind and 〈3% error in the magnetosheath. The detector resolution is not adequate for determining temperature in the solar wind ∼50%; however, in the magnetosheath where the thermal spread is at least as large as the acceptance angles, the resolution is adequate (〈6%). In addition, we tested the influence of the geometric factor on the output bulk parameters by varying the input velocity direction over the entire polar range. The systematic error in the output parameters was less than 5% in all cases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141075
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A western Scottish population of the leopard-spotted goby, Thorogobius ephippiatus (Lowe) (Teleostei: Gobioidea) (1973)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 5 (1973), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A population of the sublittoral leopard-spotted goby, Thorogobius ephippiatus (Lowe, 1839), is recorded from Upper Loch Torridon, Scotland, and the more northerly occurrence of this Mediterranean-Atlantic species along western Scottish coasts confirmed. Modified methods of capture are described. Distinctive systematic features of this population, which tends to have low sensory papilla and pectoral ray values, are examined with reference to other T. ephippiatus and the related T. macrolepis (Kolombatovic, 1891). The time of onset and reasons for this local differentiation are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1973.tb04452.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A comparison of the movements of two species of gadoid in the vicinity of an underwater reef (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 45 (1994), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Two saithe (35 and 38 cm) and two pollack (43 and 44 cm) were tracked simultaneously for 170 h. During the day, saithe generally patrolled over the whole of an underwater reef as part of a school, making occasional excursions off the reef to another smaller reef 250m distant. At night, saithe movements were largely limited to the reef. Pollack covered less than 50% of the reef during the study period, moving only small distances off the reef. Pollack swam more slowly than saithe during the day, but at the same speed at night.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1994.tb00946.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Diurnal patterns in the spatial relationships between saithe, Pollachius virens, schooling in the wild (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 43 (1993), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Six saithe, length 35 to 43 cm, were tagged with acoustic transmitters and individuals tracked for between 9 and 508 h during May 1989. The tagged fish were members of a schooling group and during the study, pairs of tagged fish were tracked simultaneously for periods ranging from 9 to 139 h. These data have been used to investigate the spatial relationships between individuals schooling in the wild. Distances between individuals showed a distinct diel pattern. Tagged fish were generally closer together during the day, than either at night or the periods of dawn and dusk. Those circumstances under which pairs of tagged fish could be shown to school together were investigated by analysing the differences in their swimming directions. Schooling was generally evident during the hours of daylight, although the degree to which fish schooled varied between pairs. The degree to which the fish schooled was also dependent upon distance between the tagged individuals. Schooling could be demonstrated for saithe within 20 m of each other during the day and within 10 m in two out of three pairs at night.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1993.tb01195.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Retention of intragastric transmitters after voluntary ingestion by captive cod, Gadus morhua L. (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 40 (1992), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Squid-encapsulated acoustic transmitters were ingested by Atlantic cod, Gadus morhua, (3128–10 221 g) held in captivity at 12° C. Retention times ranged from 5 to 〉 21 days. There was no significant change in feeding rate after transmitter ingestion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1992.tb02560.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The detection of dissolved amino acids by the Atlantic cod, Gadus morhua L. (1980)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 17 (1980), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A classical conditioning technique was employed with cod, Gadus morhua L., to determine thresholds for the detection of the L-forms of some α amino acids which are thought to be attractants or feeding stimulants for fish. The amino acids investigated, in order of effectiveness, were tyrosine, cysteine, phenylalanine, glycine and methionine with mean threshold response levels ranging from 2·5 × 10-8M to 7·4 × 10-8M. Histidine and lysine resulted in similar thresholds with a mean value of approximately 3 ± 10-7M while taurine and leucine were least effective with mean threshold levels of 2·1 × 10-6M and 2·1 × 10-5M respectively. Comparison is made with electrophysiological and behavioural response data from other species. The effect of raising the background level of glycine on the threshold to glycine for cod is described. The results are discussed with reference to data on levels of dissolved free amino acids in shallow sea waters which may have a bearing on determining chemosensory threshold levels. To detect a specific amino acid against a background level of the same substance the difference in level for detection is proportionally greater for higher background concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1980.tb02755.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The hearing of the Atlantic Salmon, Salmo salar (1978)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 13 (1978), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The hearing of the salmon, Salmo salar L., was studied by means of a cardiac conditioning technique. Fish were trained to show a slowing of the heart, on hearing a sound, in anticipation of a mild electric shock applied later. The minimum sound level to which the fish would respond was determined for a range of pure tones, both in the sea, and in the laboratory. The fish responded only to low frequency tones (below 380 Hz), and particle motion, rather than sound pressure, proved to be the relevant stimulus. The sensitivity of the fish to sound was not affected by the level of sea noise under natural conditions but hearing is likely to be masked by ambient noise in a turbulent river. Sound measurements made in the River Dee, near Aberdeen, lead to the conclusion that salmon are unlikely to detect sounds originating in air, but that they are sensitive to substrate borne sounds. Compared with the carp and cod the hearing of the salmon is poor, and more like that of the perch and plaice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1978.tb03480.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Measurements of aerobic metabolism of a school of horse mackerel at different swimming speeds (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 49 (1996), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Oxygen consumption rates were measured in a school of 56 horse mackerel Trachurus trachurus while at rest and while swimming at steady sustained speeds. Resting values of 38.76 and 42.10mg O2 kg−1 h−1 were measured in a sealed cylindrical tank (535 l) while observing that the fish school remained neutrally buoyant and inactive with only gentle pectoral fin movements and no swimming motion. The same school was trained to swim with projected light patterns within a 10-m diameter annular doughnut respirometer. The oxygen consumption increased from the resting level through 51 mg O2 kg−1 h−1 at the slowest swimming speeds of 0.29 m s−1 (0.95 L s−1) to around 259 mg O2 kg−1 h−1 at the higher measured swimming speed of 0.87 m s−1 (2.82 L s−1). The data fitted a curve where oxygen consumption rose in proportion to velocity to the power of 2.56 with the intercept at the resting level. The maximum sustained speed (80 min) of 1.12 m s−1 (3.63 Ls−1) was not achieved within the respirometer but corresponded to an estimated oxygen consumption of 458.33 mg O2 kg−1 h−1 giving a scope for aerobic activity of 419.02 mg O2 kg−1 h−1. At a speed of 0.87 m s−1, there was a lower bound on the aerobic efficiency of at least 38% and at 1.12 m s−1, the highest aerobic speed, of 40%. Sustained speeds swum in a curved path as here should be increased by 5% for a straight path giving a maximum sustained 80 min speed of 1.18 m s−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1996.tb00084.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...