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  • 1
    Electronic Resource
    Electronic Resource
    A Method of dissolving the Protective Spittle Masses of Frog Hopper Nymphs (1961)
    [s.l.] : Nature Publishing Group
    Nature 189 (1961), S. 509-510 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Since Cercopidae are of considerable economic inportance, especially Aeneolamia varia saccharina in the cane sugar industry, and are protected from the action of insecticides by the spittle which they produce, it was realized that the above observation might be utilized in the measures taken for ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/189509a0
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  • 2
    Electronic Resource
    Electronic Resource
    Sub-cellular localization of Ni in the hyperaccumulator, Hybanthus floribundus (Lindley) F. Muell (2004)
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 27 (2004), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The cellular and subcellular distribution of Ni within leaves of Hybanthus floribundus (Lindley) F. Muell, a hyperaccumulator of Ni, was investigated at relatively high spatial resolution using energy-dispersive X-ray microanalysis (EDAX). Elemental distribution maps showed that Ni was predominantly localized in the vacuoles of epidermal cells in the leaves. Quantification of Ni revealed concentrations up to 275 mmol kg−1 (embedded tissue) in some epidermal vacuoles. The accumulation of Ni in these cells was associated with a decrease in the concentration of Na and K. There was no indication that Ni was associated with P, S or Cl in the vacuoles. Ni was also concentrated on the outside of cell walls throughout the leaves, indicating that apoplastic compartmentation is also involved in Ni tolerance and accumulation in this plant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.0016-8025.2003.01170.x
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  • 3
    Electronic Resource
    Electronic Resource
    Coral calcification: autoradiography of a scleractinian coral Galaxeafascicularis after incubation in 45Ca and 14C (1998)
    Springer
    Coral reefs 17 (1998), S. 37-47 
    Details
    ISSN: 1432-0975
    Keywords: Key words Coral ; Calcification ; Biomineralisation ; Autoradiography ; Freeze-substitution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract  The uptake of 45Ca and/or 14C by the skeleton of coral colonies has been commonly used to investigate the processes of calcification. This study reports the differential uptake of these tracers within different regions of the skeleton and tissues of individual corallites and polyps of the hermatypic coral Galaxea fascicularis. Incubation in 45Ca in the light resulted in 80 percent of the 45Ca taken up being deposited in the skeleton. Autoradiography of transverse and longitudinal slices of freeze-substituted polyps and corallites showed that in the light 45Ca was incorporated into the exsert septa, the outside of the thecal walls of the corallite and the inner edges of the septa. Incorporation did not occur in the costae. The radioactivity in the skeleton was considerably greater than in the tissues. In the dark, or in the presence of the photosynthetic inhibitor Diuron, 45Ca was taken up by the exsert septa and was patchily distributed in the corallite walls which suggests that it was not a result of isotopic exchange. The differential incorporation of 45Ca onto the exsert septa was confirmed by scintillation counting. Negligible radioactivity remained in the extrathecal coelenteron after a brief 5 min rinse in non-radioactive seawater. Only 0.1% of 14C taken up in the light was incorporated into the skeleton and this was confirmed by autoradiography. In the presence of Diuron or in the dark, very little 14C was incorporated into tissues or skeleton and in autoradiographs was either not evident in the skeleton or the distribution was similar to that seen in autoradiographs of 45Ca uptake. These results show that the deposition of 45Ca, and therefore calcium carbonate, occurs at specific loci on the skeleton of a corallite. In the dark, deposition occurs specifically at the growing points of the corallite. Differential deposition of calcium carbonate within individual corallites has not been previously reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003380050092
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  • 4
    Electronic Resource
    Electronic Resource
    Batelli Glands of Cercopoid Nymphs (Homoptera) (1965)
    [s.l.] : Nature Publishing Group
    Nature 205 (1965), S. 925-925 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The Batelli glands have, from time to time, been supposed to produce a 'mucilaginous' compound2,5 or a component or components of a 'soap'3,6. Such compounds, it is suggested, behave as surface tension depressants. Batelli glands are swollen hypodermal glands, the precise location of which has ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/205925b0
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  • 5
    Electronic Resource
    Electronic Resource
    Calcium transport across the isolated oral epithelium of scleractinian corals (1991)
    Springer
    Coral reefs 10 (1991), S. 37-40 
    Details
    ISSN: 1432-0975
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Oral epithelia were isolated from Lobophyllia temprichii and Plerogyra sinuosa and placed in Ussing chambers. Calcium flux was measured under open circuit and short circuit conditions using 45Ca. Only a small transepithelial potential of 1.5 mV was recorded under open circuit conditions and no effect on flux rates were observed when the preparation was short circuited. Unidirectional fluxes in single and paired experiments were consistently greater in the ectoderm to gastroderm direction than from gastroderm to ectoderm with net flux of Ca2+ frequently being more than 3x10-4 μEq mm-2 min-1. A small number of paired experiments showed that net flux of Ca2+ was reduced by Sr2+ and sodium azide but not by dinitrophenol. Unidirectional fluxes from ectoderm to gastroderm appeared to have maxima in the early and late parts of the day when recorded between 0900 and 2100 hrs. It is concluded that active transport of Ca2+ occurs across the isolated oral epitheia and that this may be an initial step in the process of keletal Ca2+ deposition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301905
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  • 6
    Electronic Resource
    Electronic Resource
    Ionic balance of Homoptera in relation to feeding site and plant sap composition (1975)
    Springer
    Entomologia experimentalis et applicata 18 (1975), S. 117-120 
    Details
    ISSN: 1570-7458
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00342407
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  • 7
    Electronic Resource
    Electronic Resource
    Secretory capacity of the lachrymal salt gland of hatchling sea turtles,Chelonia mydas (1988)
    Springer
    Journal of comparative physiology 157 (1988), S. 821-827 
    Details
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lachrymal salt glands ofChelonia mydas were functional when hatchlings emerged from the nest. Osmotic concentrations up to 720 mosmol kg−1 were recorded in spontaneously produced tears (salt gland secretions). When injected with a Na+ load (1500–2700 μmol (100 g)−1) newly emerged hatchlings produced tears ranging in osmotic concentration from 1000–1900 mosmol kg−1 with Na+ secretion rates from single glands of 200–475 μmol (100 g·h)−1. In these circumstances the rate of sodium excretion, via the salt glands, was equivalent to the sodium content of 0.2 to 0.5 ml of sea water per hour. Since the apparent drinking rate of hatchlings within the first two days of entering sea water was approximately 0.5 to 1.7 ml per day, the excretion of Na+ imbibed by drinking is well within the secretory capacity of the lachrymal salt glands. In feeding hatchlings extraordinarily high Na+ secretion rates were induced by Na+ loading. Hatchlings which were loaded with Na+ by injection (1500–5400 μmol (100 g)−1) produced tears having osmotic concentrations between 1500 and 〉2000 mosmol kg−1. The Na+ secretion rates from single glands were 750–4185 μmol (100 g·h)−1 with extremely high short term rates of 10700 μmol (100 g·h)−1 (50 μmol min−1 for 28 g hatchlings). In terms of gland mass the highest long term secretion rate translates into 21 mmol of Na+ per gram of salt gland per hour and is the highest secretion rate yet recorded for a reptilian salt gland. This rate is almost three times the highest rate recorded for sea snakes (8 mmol g·h−1) and is similar to rates commonly observed in avian salt glands (25 mmol g·h−1). Secretion by the lachrymal salt glands was initiated by increased blood concentrations of Na+ or K+, K+ being as effective as Na+ but with the composition of the teras being virtually unchanged compared to tears from Na+ stimulated hatchlings. Preliminary experiments indicated that secretion was not initiated by increased Cl− concentration in the blood or by increased volume or osmotic concentration of the blood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691014
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  • 8
    Electronic Resource
    Electronic Resource
    Isosmotic secretion in the avian nasal salt gland: X-ray microanalysis of luminal and intracellular ion distributions (1985)
    Springer
    Journal of comparative physiology 156 (1985), S. 213-227 
    Details
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The secretory tubule epithelium of the avian nasal salt gland has been thought to secrete a hyperosmotic fluid containing high concentrations of Naα and Cl−. It is shown by X-ray micro-analysis that the average composition of the luminal fluid of secretory tubules in duckling salt glands is Na 80 mmol l−1, Cl. 100 mmol l−1, K 40 mmol l−1, Mg 11 mmol l−1, Ca 6 mmol l−1. It is assumed that the anion deficit is accounted for by HCO 3 − . This fluid is approximately isosmotic or slightly hyposmotic to blood. There were no significant differences between the composition in different regions of the tubule nor between active and inactive glands. The fluid becomes increasingly hyperosmotic in the duct system, most concentration apparently occurring in the main ducts running from gland to external nares. Modification of the primary hyposmotic or isosmotic secretion therefore appears to occur in the duct system. There were few differences in intracellular composition between the different cell types in the secretory tubule or between active and inactive glands. The average intracellular composition was Na 47 mmol l−1, Cl 54 mmol l−1, K 113 mmol l−1, Mg 14 mmol kg−1, Ca 8 mmol kg−1 wet weight. The high Cl− concentration is suggestive of active Cl− transport. It is suggested that Kα transport into the cells may be a rate limiting process in secretion. It can be calculated that much of the Kα arriving at the gland in the blood must be extracted at high secretion rates. If modification of the primary secretion rccurs in the main duct by water reabsorption, thereby implying a substantially higher secretion rate of primary fluid, then it can be calculated that virtually all of the Kα arriving in the blood may be extracted by the gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695776
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  • 9
    Electronic Resource
    Electronic Resource
    Confocal laser scanning light microscopy of the extra-thecal epithelia of undecalcified scleractinian corals (1993)
    Springer
    Cell & tissue research 272 (1993), S. 533-543 
    Details
    ISSN: 1432-0878
    Keywords: Mucocytes ; Calcification ; Intercellular spaces ; Zooxanthellae ; Calicoblastic ectoderm ; Confocal laser scanning microscopy ; Freeze-substitution ; Corals: Galaxea fascicularis, Acropora formosa, Tubastrea faulkneri (Cnidaria)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The extra-thecal epithelia of cryofixed undecalcified, freeze-substituted polyps of the scleractinian corals Galaxea fascicularis and Tubastrea faulkneri and axial and basal polyps of Acropora formosa have been examined, in anhydrously prepared thick slices, by confocal laser scanning light microscopy. The avoidance of chemical fixation and decalcification makes it possible to determine whether previously seen structures are real or artefactual products of swelling, shrinkage and distortion. All of the epithelia of all the corals examined are characterised by well defined intercellular spaces. Mucocytes are present in all cell layers in Galaxea and Tubastrea but are not present in any cell layers in the axial polyp of Acropora although they are abundant in the oral ectoderm of the basal polyps in this coral. Zooxanthellae are absent in Tubastrea, the epithelia of the exert septa of Galaxea and the axial polyp of Acropora. The calicoblastic ectoderm is generally composed of thin squamous cells with large intercellular spaces. At rapidly calcifying regions such as the tips of the exert septa of Galaxea, the calicoblastic cells are elongated with extensive arborisation of the basal regions of the cells. They are separated by large intercellular spaces and contain numerous fluorescent granules. The apical regions of these cells appear to be closely applied to the surface of the skeleton. There is no evidence of a space between the apical region of the calicoblastic cells and the skeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318560
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  • 10
    Electronic Resource
    Electronic Resource
    Intracellular and luminal ion concentrations in sea turtle salt glands determined by x-ray microanalysis (1989)
    Springer
    Journal of comparative physiology 159 (1989), S. 609-616 
    Details
    ISSN: 1432-136X
    Keywords: X-ray microanalysis ; Frozen-hydrated ; Salt glands ; Ion transport ; Chelonia mydas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lachrymal salt glands of hatchlings of the green sea turtle (Chelonia mydas) secrete a hyperosmotic (up to 2000 mosmol·kg−1) NaCl solution. X-ray microanalysis of frozen-hydrated glands showed that during secretion intracellular Na+ concentration in the principal cells increased from 13 to 34 mmol·l−1 of cell water, whilst Cl− and K+ concentrations remained unchanged at 81 mmol·l−1 and 160–174 mmol·l−1, respectively. The high Cl− concentration and the change in Na+ concentration are consistent with the prevailing paradigm for secretion by the structurally and functionally similar elasmobranch rectal gland. Concentrations of Na+, Cl− and K+ in the lumina of secretory tubules of secreting (Na+ 122, Cl− 167, K+ 38 mmol·l−1) and non-secreting (Na+ 114, Cl−1 174, K+ 44 mmol·l−1) glands were similar and the fluid was calculated to be approximately isosmotic with blood. In the central canals Na+ and Cl− concentrations were similar but K+ concentration was lower (11–15 mmol·l−1). It is concluded that either a high transepithelial NaCl gradient in secretory tubules and central canals is very rapidly dissipated during the short time between gland excision and freezing, or that ductal modification of an initial isosmotic secretion occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694387
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