ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles  (375)
  • Other Sources
  • Springer  (303)
  • International Union of Crystallography  (47)
  • Hindawi  (25)
Collection
  • Articles  (375)
  • Other Sources
Journal
  • 1
    ISSN: 1573-5044
    Keywords: adventitious organ formation ; in vitro culture ; Lycopersicon esculentum ; mannitol ; sodium chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The possible use of in vitro shoot morphogenesis and shoot apex culture to evaluate salt tolerance in cultivated tomato (Lycopersicon esculentum Mill.) has been analyzed, using two cultivars with similar salt tolerance, Pera and Hellfrucht frühstamm (HF). The effect of salt on shoot regeneration was studied by culturing leaf explants on media supplemented with 0, 43, 86, 129 and 172 mM NaCl. The presence of NaCl in the regeneration media at 86 mM strongly inhibited shoot regeneration in the cultivar HF, but not in Pera. However, the substitution of NaCl by mannitol, maintaining the same water potential in the culture media, decreased the regeneration percentage in Pera but did not affect HF. Shoot apices of both cultivars were also subcultured at 6-week intervals, for 4 subcultures, at the same NaCl concentrations as used in the previous experiment, and the shoot growth, leaf and root number, rooted shoot and shoot necrosis were recorded at the end of each subculture. Root formation was the parameter most affected by salt in both cultivars, Pera being more sensitive than HF. The substitution of NaCl by mannitol significantly increased the percentage of rooted shoots in Pera after four subcultures, and slightly decreased this percentage in HF. Shoot necrosis was only observed in the last subculture at NaCl higher than 86 mM, the percentage of necrotic shoots being higher in Pera than in HF (75% and 45%, respectively). The lack of agreement between the results obtained with the in vitro tests, e.g., adventitious shoot formation and growth of apical stem sections, suggests that this approach may not be a reliable tool to evaluate salt tolerance in cultivated tomato.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1476-5535
    Keywords: Keywords: exopolysaccharides; Halomonas; halophilic bacteria; viscosifier; crude-oil emulsifier
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: We have studied the exopolysaccharides (EPS) from a new group of moderately halophilic bacteria belonging to the genus Halomonas. The quantity of EPS produced, its chemical composition and physical properties depend greatly upon the bacterial strain. The majority of the polymers produced viscous solutions and/or emulsified different hydrocarbon compounds. The most interesting strain, S-30, produced EPS at 2.8 g/l with a maximum viscosity of 23.5 Pa·5 and exhibited pseudoplastic behavior. This EPS emulsified five hydrocarbons more efficiently than did four control surfactants tested. Its monosaccharide composition was glucose:galactose:manose:glucuronic acid in equimolar ratio. Some two-thirds of the strains tested emulsified crude oil better than control surfactants did. There are many potential industrial applications for polysaccharides with these qualities. Journal of Industrial Microbiology & Biotechnology (2000)24, 374–378.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 94 (2000), S. 57-65 
    ISSN: 1570-7458
    Keywords: metamorphosis ; histolysis ; Ceratitis capitata ; acid proteinases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The induction of several biochemical indicators of larval tissue histolysis in the Medfly, Ceratitis capitata (Diptera: Tephritidae) (Wiedemann) was studied. Using synchronized third instar larvae, we have determined the time of occurence of gut evacuation (12 h before puparium formation, bpf), disappearance of digestive enzymes (10 h bpf), and jumping from the food (8 h bpf). We can also correlate these events temporally with other early landmarks of metamorphosis. The decrease in protein content between 0 hours and 144 hours after puparium formation (0–144 h apf) corresponds to a sharp increase of total acid proteolytic activity measured in vitro from 0 to 44 h apf. This activity appears to be lysosomal, judging by the activation of other lysosomal markers, such as acid phosphatase and β-glycosidases. The maximum proteolytic activity occurs during the pre-pupa to pupa transition, i.e. during morphogenesis from the cryptocephalic to the phanerocephalic pupa. The results of endopeptidase inhibitor assays indicate that in dipterans, members of the aspartic and cystein proteinase families are responsible for the degradation of larval tissues.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Catalysis letters 13 (1992), S. 383-387 
    ISSN: 1572-879X
    Keywords: Catalytic cracking ; catalyst deactivation ; vanadium effect in FCC ; sulfate effect in FCC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The existence of acidic species other than those of vanadic acid is suggested to be responsible for the FCC catalyst deactivation. These species would come from SO s adsorption on the catalytic surface which would react with the most acid sites of the zeolite, ultimately leading to loss of crystallinity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 60 (1991), S. 135-141 
    ISSN: 1570-7458
    Keywords: Cuticle ; metamorphosis ; puparium ; medfly ; Ceratitis capitata ; pupal proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Changes in morphology during early metamorphosis of the medfly, Ceratitis capitata (Wied.) (Tephritidae) were correlated with biochemical differentiation events. Protein profiles were studied both in the 3rd instar larval cuticle further transformed into puparium and the newly synthesized pupal cuticle. Beta-alanine incorporation into the puparium (0–20 h) correlates with concomitant pigmentation (completed by 16 h) and sclerotization phenomena. This early ‘tannification program seems to be followed by deposition of a layer of substances, probably ecdysial fluid remnants, into the puparium. Their deposition ends approximately at +46 h. Simultaneously, pupal cuticle material starts to be deposited. Synthesis and deposition of the main pupal cuticle protein was detected 48 h after pupariation. At that time, eversion of the pupal head occurs. The definitive profile of pupal cuticle proteins was attained at around +72 h together with the establishment of adult body proportions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Astrophysics and space science 105 (1984), S. 151-160 
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In this paper, 704 photoelectric observations in the Johnson B-band of the eclipsing binary recently discovered in the multiple system HR 4560, are presented. All measurements were made at the Observatory of Mojón del Trigo in Granada (Spain) during the years 1979, 1980, and 1981. The light curve derived from these observations is also given. A detailed analysis of the photometric elements will be published in a separate paper.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 45 (1989), S. 92-94 
    ISSN: 1420-9071
    Keywords: Retina ; ganglion cells ; axon ; chick
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using Golgi's staining technique, we investigated some ganglion cells whose axons do not project out of the retina area. These axons, after following a short trajectory through the optic nerve fiber layer or through the 5th stratum of the inner plexiform layer (IPL), change their direction and end in the inner stratum of the IPL.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Grammars 1 (1998), S. 57-84 
    ISSN: 1572-848X
    Keywords: computational representation and inference ; lexical object theory ; lexical object specification formalism ; unification-based grammar formalisms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Linguistics and Literary Studies , Computer Science
    Notes: Abstract Unification has become a major paradigm in Mathematical and Computational Linguistics. The research done in this area may be classified in four main streams: feature structures as an adequate model for the description of linguistic phenomena, typed unification, representation of feature structures, and unification algorithms. This work proposes a new approach to unification-based Mathematical and Computational Linguistics: the Lexical Object Theory. The main design criteria are based on linguistic motivation, computational efficiency and formal soundness. The first part of the work outlines the main characteristics of the Lexical Object Theory, its comprehensive orientation, and its layered structure based on the separation of the following levels: specification, transformation, typification, representation and unification. The second part concentrates on the specification level of the Lexical Object Theory. The linguistic motivation of this model is presented, as well as a detailed description of the specification formalism, the computational model it is based on, and finally, the inference rules on lexical objects at the specification level.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-0673
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract The irreducible representations of the scale-Euclidean group in three dimensions are introduced, and the general tensor is expanded in terms of these representations. The cases of zero-rank tensor (scalar), rank-1 tensor (vector), and rank-2 tensor are studied in detail. The expansion is shown to be a generalization of the Helmholtz expansion of a vector into rotational and irrotational parts. As in Part I of this work (Concepts: One-Dimensional Problems), the correlations that are introduced are invariant under changes of frames of reference. Correlations are set up between tensors of different ranks and dimensions. A correlation that measures a degree of isotropy is defined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0673
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract The group of transformations is introduced which consists of translation, rotation, and dilation of a Euclidean coordinate system. It is shown how physical quantities can be expanded in the irreducible representations of the group. It is then possible to introduce correlations which are invariant under the transformations of the group. The most novel feature is the introduction of a scale autocorrelation which compares a quantity with itself when “stretched”. This autocorrelation is expected to find use in problems involving noise and turbulence. It is shown in the present paper how this new autocorrelation enables one to find relationships between periodicities. This paper is concerned with concepts and the one-dimensional problem. Part II will deal with three-dimensional problems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...